How To Improve Clay Soil And Improving Sandy Soil

Gardeners ask how to improve clay soil more often than about improving sandy soil, but the reasons are generally the same, and the main reason has to do with water.

In many gardens, clay doesn’t infiltrate and drain fast enough and sand drains too fast.

One of the most commonly given pieces of advice on how to improve clay soil is to add sand. When it comes to improving sandy soil, the advice is often to add clay.

Both of these are poor organic gardening practices. Before we go into why, we need to take a quick look at how water moves through the soil.

Trust me, this is really good to know and quite interesting.

How Water Moves Through Clay And Sandy Soil

Water moves downward after rain or irrigation and upward to eventually evaporate from the soil surface.

This water flows through the open “pores” between soil particles. In any soil that is not dominated too much by sand, silt or clay, approximately half the soil volume is pore space. Water and air share this pore space.

When soil is entirely saturated with water, gravity forces the water to move very quickly through the big pores, but the rest of the time, gravity doesn’t play as big a role in how water moves through the soil.

The rest of the time, adhesion (how water molecules tend to stick to other surfaces) and cohesion (how water molecules tend to stick together) govern the movement of water in the soil. Interestingly it moves out in all directions fairly equally – up, down and horizontally. It moves downward only slightly more due to gravity.

How To Improve Clay Soil And Improving Sandy Soil
Adhesion and cohesion in action

So let’s say it’s a beautiful Saturday morning and you are doing some organic gardening.

Let’s look at what happens when you have layers in your soil.

How To Improve Clay Soil

Let’s say you have a clay or silt loam soil that doesn’t infiltrate or drain well.

What happens if you add 6 inches of a coarser soil such as a sandy loam on top of the soil?

When it rains, the water slows down when it hits that fine soil layer as you might imagine, although it does continue to move through.

Still, it slows down, which is the opposite of what you were going for. If you instead rototill the sand into the clay, it doesn’t create a nice soil texture like you would think.

The sand just gets embedded in the clay and often forms a soil environment that is like concrete.

When deciding how to improve clay soil, adding sand is not the answer.

How To Improve Sandy Soil

This part is really interesting. Let’s reverse it and say you have a sandy soil that doesn’t hold water.

What happens if you add 6 inches of a finer soil on top of a coarser soil below? This also may happen if the builder brought in some topsoil that was clay based and put it on top of your sandy subsoil.

When it rains, you might think the water would speed up when it hits the coarse sandy layer, but in fact, water movement stops until the soil becomes nearly saturated above.

Even more interesting, if the finer soil is on extremely coarse sand or even gravel, the finer soil must become very wet before water will move down through the coarse layer.

In this case, the overlying soil can hold two or three times as much as it normally would.

These same principles are often used when making golf greens. A layer of gravel is used underneath the sandy soil for the green in order to create a situation where water will stay in the upper layer of sandy soil and be available to the short roots of the grass on the green, rather than draining away.

But doing this in a home organic garden is dangerous because you may create the opposite problem, which is a very waterlogged soil, or you may make a soil that is like concrete if you rototill the coarse and fine soils together.

Improving Clay Soil And Improving Sandy Soil

The answer is the same for both: organic matter.

Compost is what I’m generally referring to. Amend soil with 6 inches of good compost. Work it right into the top of clay soil and it will improve infiltration and will probably improve the amount of air and water available to your plants.

(I should mention that no amount of organic matter, rototilling and aeration will fix a serious drainage issue such as flooding. That needs to be addressed by installing drainage, or even better, work with nature and put in a pond.)

Back to compost. Improving sandy soil with 6 inches of good compost will drastically improve the water-holding capacity of the soil.

Amending Soil With Compost
Improving clay soil with sand won’t help, but compost will

Other Organic Gardening Implications

Since we’ve been learning about how to improve clay soil and improving sandy soil and specifically about water moves through the soil, I’d like to mention a couple of other important organic gardening implications of what we’ve learned about amending soil.

Take patio pots for example. Gardeners will often put a layer of gravel in the bottom of a container to improve drainage, but as we have seen it actually does the opposite.

The soil on top has to be very saturated before the water will drain through. This is not necessarily a bad thing with the right plants, but it is important to know how this works.

The other main implication is with regard to organic matter. If you amend soil by turning in (burying) coarse organic matter such as leaves or straw and they end up buried in a layer, or if you drop 6 inches of soil on top of a big layer of coarse material such as sticks or straw, you could be creating a coarse layer underneath a fine layer.

This is the same situation where that soil will get very wet before water will drain out. If straw is incorporated very well, this will not occur, but if it is just turned under, it will.

If you need to bring soil into your yard in order to build your garden, you must make sure to rototill it into the existing soil extremely well. If you just drop it on top, you are inevitably creating an interface that will slow drainage.

And try to find a soil that has a similar texture to your exiting soil (i.e. if your soil is clay, bring in more of a clay topsoil than a sandy topsoil). Also, use compost for perhaps 25% of the mix.

Is there anything organic matter can’t do?

If you want to learn more about amending soil, here’s my post on double digging.


  1. You’re right about the patio pots. I’ve always found that especially if I use small stones, the soil stays really wet. Now I know why.

    1. I too was surprised to learn about this. I’ve some experts call this a platform water table and all potted plant have this. A layer of gravel only makes it higher in the pot. One person I know described the mini-water table in a plant pot to a kitchen sink sponge. If you soak the sponge with water and set it on edge to drain naturally, it will drain down only to a point and the bottom layer remains saturated. This is the point where capillary action overcomes gravity. So it’s important to use pots that are deep enough that the saturated bottom is below the depth of the roots. I use broken pot shards to cover the hole (not sealed) and fill with potting soil that uniformly mixed. Afterward, as with my potted pelargoniums, I may top dress or use nutrients to aid the plant over the summer. These will water through nicely.

  2. Timely info for me. Thanks, Phil. I’ve been planning to add 25-30% sand to my veggie grow beds which are 12″-18″ deep. Now I’m wondering what to do. The beds have fairly good drainage, good production depending on the crop but are prone to extreme compaction. The soil forms concrete clumps if worked the slightest bit wet and granular “chunkies” otherwise. I’ve not tilled in 3 years, using a broadfork when compaction gets real bad or to pull infiltrating roots from a neighbor’s tree. Soil texture test last year showed 75% clay, 15% silt and 10% sand. Lots of organic matter – more than half the test jar was organic fluff on top of the clay. For the first 6 years of the beds I added peat moss yearly, but for past six it’s 2″ – 6″ organic matter (compost, leaf mold, chopped rotted straw or hay and/or manure), using a fork to incorporate. Good news is I’m moving in spring 2012 but I would like to leave a legacy of excellent soil. Should I just keep piling on the organic matter?

    1. Hi Janet,Wow, that’s a lot of clay. Still, normally I would expect organic matter tovastly improve things. You could try to find a bag of rock dust at yourlocal garden centre or farm supply store and that can be helpful in slightlyimproving soil texture. Otherwise, it may be an imbalance ofcalcium:magnesium and/or phosphate:potash, which is too complicated for meto describe here. But you could add calcitic lime, aka calcium carbonate(not dolomite) at 10lbs/1000 sq ft and that may help over time. I wouldn’tadd any more fresh manure as that can supply too much potassium – compost itwell first.Other than that, just make sure you wait until it’s dry to work it. I hopethis has been helpful.

  3. Connie Kuramoto says:

    Isn’t it amazing that things truly can be this simple? Add organic matter. It is like a sponge, holds water and air in just the right proportions. Love your articles Phil!

  4. Heidi Marion says:

    Really? Zeolites are affordable in a soccer pitch context? Huh!

    1. I consulted for one soccer field where they were spending $3000 per year on sand, just to topdress the field. Here I was trying to make an affordable fertilization program, and they were spending $3000 on just sand!On high value landscapes, it’s often worthwhile to spend the money on things like zeolites before the grass is seeded. It can save a lot of money in fertilizers over the long haul.

      1. When consulting on soccer fields, keep something in mind. They play soccer in the rain. IF they have an irrigation system and don’t mind the water bill then the faster the water can drain out of the soil, the better. You have much less damage to the field during wet weather play. When I was managing our soccer field program I used a lot of sand for that reason. Professional fields actually install very expensive fan (suction) systems under the top layer of fine gravel and sand to keep the playing surface from getting boggy during rain games.The engineer who designed the surface for Legion Field in Birmingham, for the 1996 Olympic games, told me it would take up to 4″ of rain per hour and still remain playable. When installing the sod, they actually pressure wash the soil from the sod before laying it down. Like I said , it is very expensive to maintain, but if your goal is to keep the surface playable in all weather, I have found that sand works best.

        1. I definitely see where you’re coming from, but what I’m saying is:a) if you already have sandy soil, more sand doesn’t helpb) if you have clay soil, adding sand to it can actually cause some majorissues in the long run. It doesn’t always happen, but it can. I suppose itdepends on the kind of sand and kind of clay and many environmental factors.

  5. Heidi Marion says:

    Zeolites… How do they work? How do the nutrients that are in the soil get stuck to the zeolites? or to clay for that matter? Is it the ion particle charge? Can zeolites have an effect in a soil with low soil life?

    1. Positively-charged nutrients stick to zeolites the same way they stick to clay. They stick to the cation exchange sites. Zeolites just happen to have a whole lot more of them than clay. My understanding is it’s because they have a much bigger surface area. And yes, they have this effect in a soil with low soil life, although that should be improved, too.Like I said, I generally prefer compost, but zeolites can more permanently improve a very low CEC soil, and would be especially useful in a place where you know organic matter will not be continually recycled and increased.

  6. Hi Phil, Another great article. How to zeolites compare to Bentonite? Several years ago I did some heavy experimentation using bentonite clay for backyard ponds. There were several unforseens, but all in all the technique was viable.thanks, Bob

    1. Great question. I would love it if someone could tell us the differencebetween zeolite and bentonite. Personally, I’m not as interested in thechemistry side of things as the implications for us gardeners.All I know is that they’re both good at holding onto cations, but myunderstanding is that the honeycomb structure of (the right kind of)zeolites allows them to be added to a sandy soil without compacting. Abentonite would compact more, but is still useful added to a compost pile atas much as 10% of the volume of the pile, for the cation exchange capacity.Bentonite would be better for ponds, since you want that compaction.

      1. Zeolite and Bentonite are normally both derived from weathered volcanic minerals and both have excellent Cation Exchange capacity (ability to store Ammonium nitrogen, calcium, magnesium and potassium). However Zeolite is the best choice for gardeners because it is naturally granulated and light. Bentonite is normally a fine powder which would translocate to lower soil horizons in rainy well drained enviroments or for less well drained soils it would add to the heaviness of the soil reducing porosity further. If you want to buy Bentonite try asking for Fullers Earth as that is a Bentonite Clay.

        1. Thanks for the explanation!

        2. Mark Ludwig says:

          Bentonite is typically sold totally dominated by sodium (Na), as Na bonds tremendous amounts of water to the clay. This causes the clay to swell and seals the soil profile which is why it can seal a pond or well casing. If you can find calcium bentonite it should work better. Any clay will add CEC to soils, but it may import a cation load which is disadvantageous for soil structure or plant growth. If I was looking for clay I’d look for a local gravel company which sells so called washed gravel for septic systems etc. often they have lots of extra clay and will sell it cheep. I can buy it in MI for $3/yard plus trucking. Ideally add that clay to your compost in order to form clay/organic complexes, add a little gypsum to add Ca to the clay.

          1. A great source for bentonite with specific profiles is potters/ ceramic supply. Chemicals and clay can be purchased in 50 pound bags or in larger quantity .Since potters need very specific chemical profiles this data is available . Benonite is used to suspend other particulates in glazes and clay bodies.

  7. So if I want to grow Water Cress maybe I should make a box, put a layer of sand on the bottom, fill it with good compost and put on a low continual mist?

    1. Ya, that would be something to try. You’ll probably want more than justcompost for the top layer – a mixture of compost and soil.

  8. Do you know where I can buy Bentonite clay in BC?

    1. Sorry, Bill, I’m not sure where you can pick it up in BC. Wish I could help.Let us know if you find it.

      1. Mark Ludwig says:

        Check your local well driller. Also often sold as oil dry or cat litter.

    2. Kim Overall says:

       I buy bentonite from our local ceramics supplier as potters (like me) use a small percentage when making glazes.  I think it helps keep the other ingredients in suspension so it doesn’t ‘settle’ like concrete.  Bentonite is used in the cosmetics industry; it absorbs oil wonderful from facial masks to oil spills.  You have phenomenal potters in BC so ask them where they buy their supplies locally or google search for your area.

      1.  Cat Litter is clay and sometimes called bentonite clay if it came from fort benton.  It’s cheap but you would want the unscented.  It is used at a few pounds per square foot for ponds to seal the bottoms to hold water.

  9. Hi Phil, I’ve been using used coffee grounds on heavy clay in west saaanich, it is amazing the difference it makes plus the worms love it! Anne

    1. Sailtraveler says:

      I would Love to hear application stratagies and the benefits of coffee ground are, especially in clay, alkaline soils.

      1. I use coffee grounds as an organic mulch. It’s got good colour and eventually feeds the soil. In compost coffee grounds are a source of nitrogen. For that reason, I don’t mix it directly into the beds.

    2. Marcia Hall says:

      In addition to coffee grounds a gardening book suggested I read using alfalfa pellets.  Same alfalfa as fed to horses.  We have had very good luck with 20 lb bags of alfalfa pellets obtained from the feed store and incorporated to the soil around individual plants and broadcast over the soil so they can dissolve over time.  Natural, efficient and easy!  Lots of lovely worms too.   Marcia

      1. Yes, alfalfa pellets are great. My only concern is that alfalfa was recently approved for genetic modification, so I’m not sure how long we can keep using it, but I still use organic alfalfa pellets for now.

  10. Michelle Spencer says:

    A rain garden might be better than a pond.

    1. Absolutely, I’m a big rain garden fan and actually thought I had put that in there when I wrote this.

  11. dontknowmuch says:

    Loved the info as I have heavy clay soil!  Can you tell me how to age coffee grounds before they are added to the soil? In the comment above it was stated that they would be better aged before adding, due to the high nitrogen produced. I rely on purchasing organic compost for my organic garden because, besides not having any extra room in my yard, I do not cook, therefore I have no way of producing a compost pile of my own and supplementing with veggies and fruit peels and all that good stuff that comes from the kitchen. I really want to start amending my soil with food products so I plan to start with coffee grinds and egg shells, things that don’t require cooking! (baby steps)

    1. I wouldn’t worry about aging it. Just put it right on the soil and you’ll be fine.

  12. Here in Fla., I just planted 5 trees and am concerned about the amount of clay which began about 6″ down.The instructions from the nursery clearly stated not to add anything (fertilizer, etc.) when planting, so I didn’t do anything other than staking, watering daily the first week, now am at every other day watering for another week.My compost pile is almost “cooked” so will be available, but not sure exactly what to do at this point if anything.Trees:  Plum, nectarine and mangoes.

    1. Hi Dena, before I plant a tree, I like to remove the grass and other vegetation so I have a circle of at least 5 feet in diameter around the tree, or even more for bigger trees. Then I incorporate compost over that whole area. In your case, you can still incorporate compost outside the rootball to the edges of the bed. I would mulch the whole area, too. It’s best to leave the rootball uncovered though.

  13. Thanks Phil,Glad I don’t have to dig them up to put the compost in the hole as I wouldn’t want to disturb them once they are planted.   Luckily I did everythig else you suggested except only did about a 3 to 4′ circle around the trees.   I want to put the compost around now, but since this is my first experience doing homemade compost, it doesn’t seem quite ‘cooked yet’.  It’s all brown but it hasn’t decomposed all the way I don’t think.  Shall I still add it or wait until it’s cooked?  Wouldn’t it attract animals?Shall I add compost to the inside of the holes when I plant more trees, blueberries, grapes in the next week or just add it to the top after it’s planted.  The soil has a lot of clay.  Hope these trees and bushes will be able to survive.

    1. Yes, wait until the compost is done too add it. You shouldn’t be able to see food scraps any more. But it would be nice if you could get some mulch (straw or leaves) on the beds now.As for new plantings, it would be ideal to add some compost to the backfill along with the original soil. Perhaps you need to buy 1 yard of compost if yours won’t be ready in time.

  14. Yes, I did mulch the trees except not around the root ball area.  I appreciate your advise and I will definitely be adding some compost to the backfill along with the original soil on the new trees I plant.Thanks!

  15. Kim Overall says:

    Phil,  like the other posters, I was going to buy coarse sand today to mix in our gumbo soil before planting our new grapefruit tree and some hibiscus plants (making tea).  I’ll buy compost instead.  Thank you for your e-education on gardening.

  16. coarse*

    1. Thanks Ron, thought I had fixed that a year ago.

  17. Scott Gensemer says:

    I have these large wine casks that were cut in half to make large flower pots.  They have always worked extremely well.  this year I decided to add some delphiniums to the mix and I looked up what additives I should use to make the soil the right mix for the delphiniums.  I was told to add sand to the soil which I did.  But the water with all of its nutrients seems to drain down so quickly that I can’t see it is doing any good.  Delphiniums are generally very fast growing plants but mine are growing at a very slow rate.  Admittedly they arrived in very poor condition and at first I was just pleased that they’d survived and were growing at all, but, now I think there must be some problem with the soil mix.  Can you advise?Scott

    1. Hi Scott, while I wouldn’t advise adding sand to your mix, I’m surprised it would cause that drastic of a problem. Perhaps it was just the poor condition of the plants? Very difficult for me to diagnose from here at any rate. Wish I could help.

  18. Lene Ring says:

    What do you thing about  expandable shale? It can improve the soil?

    1. Hi Lene, I’ve never used it, but from the little I know about it, it seems it could be worthwhile. I don’t know anything about the sustainability of the mining and subsequent manufacturing process.

  19. Trish Eilers says:

    Ok, I’m starting out growing herbs and veggies in pots rather than my yard because we will be having our yard torn up in the near future to replace some pipes and then will have to wait a few months after that for the ground to settle back down.What do I use in pots? Is Miracle Grow something I need to use or a combo of that and maybe compost. I’m a very new gardener, much less an organic gardener and would like to spend as little as possible of my time doing the wrong things. PLEASE HELP!I’ve already got some chives that are growing pretty well. I would love to have some basil, garlic and tomatoes growing as well :0) Also, maybe some other herbs as well.

    1. Hi Trish, I don’t support Scotts, so I personally wouldn’t buy Miracle grow, but another organic potting mix would be good. Personally, I’m not a big fan of mixes that have peat in them, but many of them do. It depends on what you get, but I like to mix 1/3 compost with 2/3 potting mix. Then you could bring in some sea minerals fertilizer for nutrients, and effective microorganisms to bring in some biology. Mycorrhizal fungi is helpful, too. A mulch layer of leaves or straw is nice. Lots to learn, but it’s all fun!

      1. Maddie Miller Wichman says:

        I just bought a home (San Diego) and the entireyard is covered in rock, I plan on scrapping the rock (and re purposing it tobuild up terrace on the canyon in the backyard) but the poor soil is clay andhas been suffocated, I started a compost bin. I guess the question is once therock has been removed, what is the best plan of attack to improve the soil? Thanks for your advice!Thanks for your advice!

        1. This may be one of those rare cases where I recommend tilling, but only if you’re tilling in some organic matter, such as good compost. Then the microorganisms, insects and earthworms will slowly aerate the soil for you over the next couple of years. Planting a cover crop over winter should help, too.

  20. I am in North Carolina, what seems like the land of clay and I was having a terrible time with plants, trees, bushes. Then I started reading about soil and micro-organisms and composting and it changed my whole outlook. I have cut my home trash in half because most papers, veggie scraps and coffee grounds go in my compost pile.That along with most cuttings and grass from the yard make a wonderful compost blend. I started off with a small tumbler and added a cold compost bin that I hold for 6 months. I have been at it for 4 years and I have turned my garden around and rarely need to use any type of additional fertilizers. It really is that simple! Now I am working on incorporating beneficial bugs to take care of the bad ones. I hope you do a lecture on those. Love your articles Phil!

    1. Hi Lovay, thanks for the great story! I do like to talk about beneficials regularly around here, so be sure to stay tuned.

  21. Phil:I live in San Diego, California. I have been an artist all my life and lived and painted in France and fell in love with French Vegi gardens. They are beautiful to paint but making one is equally challenging! will show what I mean. I have read your book and really appreciate what you have gone through in order to provide a very comprehensive understanding of what is needed to build the soil to the way it should be. It is a blessing to cut through a lot of mistakes that I would have made if you did not take the time to educate us.Just a big THANK YOU!

    1. Thanks so much John!

  22. This is a very interesting article and I’ve learned some new facts – thank you. I’m staying with some friends and they have a layer of hungry sand over a solid 50cm layer of clay that sets like concrete, so I’m looking for ways to help them. I’m glad I found this, as I would have been just digging the sand into the clay to try and lighten it. One thing you don’t mention is gypsum. Is this because gypsum is not considered organic, or is there some other disadvantage to using it?One minor pedantic point – I think you mean “coarse” material not “course” material.

  23. Karen Fazekas says:

    Thanks so much for the informative article. I have a smallish front area that becomes flooded during a heavy Florida down poor. The soil 3 feet down is clayish and hard fine silt/sand. You can actually see the layers! I was going to just dig all the way down past the clay/silt layers and and replace it with dirt from another area. Instead, I collected a ton of leaves and am tilling them into the area along with the better soil. I may still occasionally have some brief flooding but hopefully not as long lasting.

  24. Hey Phil,Looks like I did everything wrong. I built two raised beds, fearing they would hold watert rather draining, I added rock on the bottom. It appears that one side of the bed is wetter than we would like. What do we do now?

    1. That’s very interesting. Perhaps the beds aren’t level and so the water is sliding down to one side? Otherwise, perhaps the soil is a little different on one side of the bed? I can only guess from here.

  25. I know we’re discussing garden, not yard, and I agree with compost/organic especially for garden, yet: About 20 years ago, I decided to fill in a narrow strip along the side of my house where St Augustine and Bermuda were barely surviving. My bro-in-law was working home finalization and warrantee for a construction company and turned me loose on piles of excess sand at nearby home sites. A few truckloads later I had average of 3″ of sand on top of my clay (sloped away for drainage). Within 2 years the St Augustine had spread thickly throughout and did very well until this year when my grape plants resulted in too much shade on that west side.

  26. Pete Singh says:

    Great article Phil, I live in Nothern California (Stockton) and my house built in farm land (clay) very hard to grow except grapes. After reading your article I am doing raised bed gardening and am burying kitchen waste , grass clippings and dry leaves in the bed . What Else should I add to speed up the compost for next years planting season? Pete Singh.

  27. Hi Phil, I’m on the South Peninsula, Cape, South Africa. My soil is 2 million year old seasand- naturally white, and the only thing that grows in it naturally is the Fynbos which has evolved over centuries to absorb enough water to survive on from the morning dew. Summer is hot and dry, winter cold and wet. I’ve added enough compost and bought compost to make the sand light brown, and have basically given up and built raised wooden beds.I plan to fill them with compost augmented with bought compost, vermiculite and the ever-present fine white sand. Will that work for veggies? I don’t know the acidity of the soil, but plants are grateful for ANY nutrients they get.I compost all my kitchen peelings and add some crushed eggshell. I never throw eggshells away now as I have an ongoing war with snails, which I now kill on sight.I also have to spray regularly for white aphids, fungus and red spider mite. I do try not to wet the leaves! It helps to a certain extent.I battle to get peas to sprout but beans come up quickly. I also battle to get blackberries, Cape gooseberry (?!) and raspberry seeds to sprout. Maybe I keep the seeds TOO wet when I plant them in flats or paper pots?

    1. I’ve never grown fruit from seed – mostly always start with canes or tiny shrubs. Your raised bed plan sounds good – I wouldn’t even use vermiculite – just go with compost and sand.

  28. PS- if anyone has a real snail problem, collect by hand and put in a bucket of very salty water. They will die. I have slaughtered over 2000 of them in the past 2 months that way. Pour the salty water and dead snails somewhere you don’t mind the sand getting salty, and leave it open to the sun. If you bury them they stink to high heaven!

    1. If you can get a duck, they are also good at eating snails 🙂

  29. 2011- snails ate my veggies, I got a crop of oxalis. 2012, I had pulled up most of the oxalis bulbs and got a crop of marigolds. 2013, got a crop of nasturtiums. Laid black plastic for 4 months and killed off everything! Now just have sand and the raised beds with enough space to get around, and will divide them up into square-foot squares. Wish me luck! I will also put two rows of uncovered wire close together attached to a battery to dissuade snails and slugs. Then I just have caterpillars, beetles and mites to deal with.

  30. Yup! I’ve been working on my landlady to let me get an Indian runner- that should confuse my mutt : ) They can’t fly, so as the yard is fenced it would be safe from cars- but first I need to work on my landlady some more…

    1. Cool!

  31. FYI, Indian runner ducks are put to work in the vineyards in the Cape to eat insects- they are brought in, left for a time, then taken out again. Natural pest control. SA vines aren’t sprayed, and our wines are among the best in the world : )

    1. Very interesting. So no SA vines are sprayed at all?

  32. I’m trying raised beds this year so that I can actually figure out what grows best here. My son and I will be emigrating to th e US in the next 2-3 years, so will then have SOME idea of what’s what veggie garden-wise. Am VERY sad to know we’ll be leaving, but it’s time. I will be looking for cheap arable land, somewhere not too far from the sea (my first love) and I’d be quite happy with a tumbledown house on the land because I plan to build anyway, and at least that way there would be pipes in place. A borehole or aquifer on CLEAN underground water would be first prize. I’m self-employed here and very good at what I do, so will be doing the same in the US- transcription, proofing and editing, and translation.

  33. Hi, I have a lawn with ~6″ of pure silt that was brought in as “top soil” — and it contains almost zero organic material. Consequently, only crabgrass seems to grow in it. My proposed solution is to 2″ of topsoil and 2″ of mulch an power-rake that into the top 2″-3″ of silt — sort of create a more suitable “top soil blend.” Any thoughts from the experts on this idea would be greatly appreciated. Thanks, Dale

    1. I would just do 2″ of compost. Bringing in topsoil may cause some drainage problems unless you can really blend it well with the silt. Bringing in mulch isn’t great because a lawn doesn’t really want to grow in mulch. But 2″ of good quality compost would be great. While you’re add it – I know it’s a lot more work, but I have to suggest it – I would send a soil sample to a good organic soil lab and follow their fertilizer recommendations. Getting the proper nutrients in there will make a lot of things work better. Good luck!

  34. My garden has turned into sandy soil and nothing wants to go how can I fix it. Please

  35. WE are in sandy-loam soil in Kerala ,India @ AMMA’s Ashram Amritapuri.WE are next to the backwater that comes from the Arabian Sea.Very salty.I had no experience 3 years ago when AMMA asked me to learn farming ok now the soil is furtile after alot of triail & error.WE grow Tulasi & Moringa trees & alot of Ayurveda herbs for medicine.Its a jungle.LOVE the jungle.Thanks for all your tips. We are a zero budget farm so i wont be joining your class but will take -in the free info.WE just built a rain-harvest pond using a tarp to catch the water from the sky via the coconut trees 10 x20 feet.Dug the hole by shovel !8X18 3 feet deep as the salty water is just below that level & sloped the sides at a60 degree angle to collect 4,000literes. We learned this method from AMMA SERVE project where AMMA has adopted 100 villages in 27 states of India where Farmers are being exploded by the big animals so to speak.Its such a joy to use this water now every day for the trees & Plants.We also jump in & cool our bodies as its about 100 degrees here on a average day with 85% humity.Thanks again for all the helpful info.Maybe the rain water is reducing the salt in the soil too.Natures helping waHanuman

    1. Thanks for sharing Hanuman!

  36. I let a pile of dark sandy loam sit for 5 months waiting to complete constuction. Now it had hardened and clodded up. Do you know any solutions?

    1. Hmmm, that’s a really good question. I’m surprised it’s sandy loam if it’s clodded up. Maybe more clay? There are plenty of implements to do this with a tractor when the soil is in a field, but when it’s in a pile, I don’t know.

  37. i have very clay soil, whats the additives to make the soil less clay like ??? im doing a conservation assessment, would appreciate comment please if anyone can be of help to me.

  38. I tried a little experiment last autumn where I simply put 2 inches of fallen leaves on 1.5sqm of one of my raised beds at a point where most shading occurred. We had plenty of rain in the late autumn and winter, so the leaves became well embedded into the soil and the worms got to work (and we saw plenty of vermicompost on the soil surface by March). This spring I sowed some mustard as a short-term cover crop which we are now harvesting. The soil created on top is the best in the garden. The lesson I’ve learned is that fine soil in shaded but somewhat sunny areas may be the perfect place for mini-seed beds in spring followed by shade-tolerant vegetables in summer/autumn, so I’m going to convert another 2.25sqm of the most shaded areas of my no-dig beds for that purpose in the autumn of 2015.I’m wondering whether to do similar where carrots and parsnips are to be sown in the spring??

    1. Seems to me this is worthwhile doing everywhere in your garden, yes? If the leaves get broken down well enough, you can sow root vegetables there. If not, you can remove them and then sow.

  39. Here’s something that’s been puzzling me. I recently tore out a patch of grass from our front yard, about 5′ wide by 2.5′ across, with the notion of using the space for a few bell pepper plants. Water doesn’t seem to soak in at all. It runs downhill and pools, and after it sits for a little while sort of soaks in, but only about 1/2″ into the soil. If I poke through that layer, underneath it’s still dry and dusty. Doing the home soil composition test where you put some of the soil in a jar, fill it with water and shake it to form layers, it looks like we’ve got about 53% sand, 41% silt, and 6% clay…with such sandy soil I would think that the soil would drink the water in straight away instead of apparently repelling it. This is after I’ve already mixed a bag of OMRI-certified manure/compost mix into the soil. I’m not opposed to adding more organic matter, but before I do I want to make sure I’m acting from an accurate understanding of the problem. Any thoughts?

  40. Cassandra Saulman says:

    Understanding how water moves through clay and soil is crucial to landscaping. It will help you avoid future problems of water pooling in the wrong places. Soil and sand are also usually necessary in order to make the perfect landscape.

  41. Doug Powell says:

    Wow! I know this post has been online for a long time but the information is still very timely for me. Living in Colorado we have heavy clay soils. I calculate 55% clay, 18% silt, 27% sand. And just about 0% organic matter. To top it off my clay is hard pan. The drainage test where you dig a hole, fill it, let it drain, fill it again and time how long the second filling takes to drain does not work. It took more than a day to drain the first filling.This summer I spent breaking hard pan and building a finished compost pile. I needed your article again to assure myself I am on the right path. My compost consists of clipped grass and most importantly, chipped wood from tree branches. I am not able to get a perfect green/brown ratio but the microbes and insects seem to love it. So far I have almost 3 cubic yards of finished compost. I just built a raised herb garden about 4′ x 20′ and 4 inches above grade. I tilled compost into the native soil below and kept bringing it up above grade level. A good portion of my compost is now in the bed and I am very hopeful for how it all turns out next summer.I did a pH test and found it to be about 7.3 so I think I should add a little sulfur this fall and let it settle in over winter. I have calculated the needed amount. Does this sound okay to you?Thanks again for the article. Doug

    1. All sounds good Doug, but don’t fertilize based on pH – that’s one of the most common mistakes made in gardening ( ). Instead, send a soil sample to a good organic soil lab and then fertilizer based on which minerals your soil actually needs. Balancing soil nutrient ratios is the other big factor in improving clay soils next to organic matter.

  42. Alex Lane says:

    Thanks for the tips. My wife and I have had a very hard time gardening because of how much clay there is where we live. I hadn’t thought about using compost to help the conditions. Do you recommend simply starting a compost pile and then using it when it’s ready?

  43. Mark Ludwig says:

    Check your soil test for the base saturation % and ratio of Ca to Mg. If the Ca is less than 70% it can be very valuable to add gypsum to boost the Ca, particularly if Mg is over 20%. Mg bonds water to soils (as does Na which is even worse). Ca will also improve micro porosity and improve fruit quality. Lime is not the same, and should only be applied if needed to raise pH. I also suggest avoiding excessive tillage. Till only as deep as needed, 2″ or less in most cases and never when the soil is wet.

  44. Please help! My head is spinning and every article I read online is only confusing me more. We live in Vancouver (AKA the Wet Coast) and bought a house a year ago. Our yard has a lot of clay in the soil. Prior to renovating our house, during the rain season the yard was a wet mess. Now in the summer the soil is hard and compact (no help from the heavy machinery that pounded our yard during the reno). We installed drainage around the perimeter of the house. We are also biting the bullet and forking out the money to have an excavator dig up and remove at least 6 inches of the hard clay/dirt mess surrounding our house and to-be garden areas (or would you recommend more?). We ideally would like to lay sod and plants in the sunny areas, some pavers on pathways and grow hostas, ferns etc in the shaded portions. What organic materials do you recommend we replace the clay/dirt we plan to dig out and haul away in relation to the different areas I have mentioned? Do we just do straight composted soil, top to bottom? Or will the sod and paver areas need a mixture of topsoil and sand on the surface? As the composted soil breaks down will it make the areas we plan to sod lumpy over time? Some have said to lay course gravel between the clay base and top soil, but as I read your article, this is a no-no, correct? Any help would be so greatly appreciated. 🙂

    1. Unfortunately, I can’t tell from here what you should do, other than I would suggest finding a landscaper/gardener (organically-minded) who has experience with a situation such as yours to advise you on what to do. It may be that removing some soil is the right move, but maybe not. Someone with experience will be able to help you.

  45. Hello,
    I live in central Florida. Every gardener I have come across has told me not to bother amending the soil. Amendments in Florida soil disappear faster than free donuts at a Star Trek convention. Because the soil is so sandy it just washes through. But I have an idea and I’d like your opinion. It all starts with a tractor, with a front loader and back hoe. First I dig out the top 18 to 24 inches of soil and make a big pile Then I dig out what is at that depth pure sand. How deep will depend on how much money I think is wise to spend. But at least 12 inches. Truck that sand away. Then, spread out a clay soil mixture in the dug out area. After that put back the native top soil. Then put another layer purchase top soil to bring the ground back up to the original level.

    My thought is that this could solve a lot of my problems. I have very poor sandy soil and I want to plant fruit trees. The clay would slow down the water drainage and prevent future soil amendments from being lost quickly. Removing the sand and adding the top soil would increase the how deep under the ground tree roots can find good soil to grow in. Of course it’s genius, unless it isn’t.

    I have thought about how to do this in greater detail. But before I give you all the information, what do you think of the basic idea?

    Thanks so much for your advice.

    All the best,

    1. If you decide to do this, you’ll want to do some deep research into soil replacement because it’s a huge disruption to the soil. My preference is to work with the existing soil, incorporating compost into the top few inches and then mulching on top. That saves thousands of dollars and is a lot less disruptive to the soil and soil food web. Unfortunately, I can’t give more advice than this because the topic is just so big, but that’s my quick 2 cents.

  46. Charla Emery says:

    In a 4’ round bed on my front patio, there is no drainage because it is solid clay. The clay is fertile and plants will grow. I can control my watering but the bed floods over and pools with water when it rains.
    I initially spaded a hole about a foot deep and a foot wide. Then with my post hole digger, I dug down about five feet and it was still clay. I pressure dug down an additional 3’ with water from my hose attached to a 4’ pipe with a 1/4″ pressure nozzle end before getting any drainage. Then we had a hard rain. Clay settled in the hole I dug, filled the whole bed. The water did not drain… After two days, I manually removed the water.
    How do I amend clay that deep to have drainage?

    1. Wow, kudos to you for going so deep – 8 feet! The only answer I know is to install a drainage system of some kind (which I understand may not be possible or practical in this small bed). Other than that, I might build a raised bed.

      1. I have a 12×12 in city garden. I have piled close to 12” of compost and used coffee grinds with filters on top. If I leave it over winter how much will it settle by the time it melts in the spring? I plan on rototilling in the spring time to fluff up the soil and mix in the settled multch. Past years I have rototilled fall and spring but this year I’m trying less tilling.

        1. Yesterday the smell of the compost was getting bad with a few warm days. To keep the neighbours happy I tore it up with the broadfork and it helped a lot with the smell. Was thinking, would putting the sprinkler on it for a few hours help reduce the stink?

          1. The sprinkler won’t help much with the smell. What you need is more “carbon” materials, like leaves or wood chips.

        2. How much it settles depends on how “finished” the compost is and how many coffee grinds are in there. The more finished the compost and the fewer coffee grinds there are means less settling. My guess is it will settle to 6-9″ in height.

          1. I’ll be adding coffee grinds till there is too much snow to walk back there. Compost is at various stages because I’ve been adding to it from autumn last year to the time that I spread it on the garden. It will have until next spring to be on the garden until we plant the garden. At that time I’ll broadfork it again and maybe rototill. Depends on how it looks after broadfork

      2. Charla Emery says:

        Phil, Because there is a sago palm in the middle of the bed, I could not put in a raised garden. I did solve the drainage…I pressure dug down to about 10 1/2 feet when I hit sand and drainage. I filled the four inch hole with good draining compost and forced a pipe into the top about 5 ft.
        Filled this and the top bigger hole with more compost and topped the pipe with a drain cap. I have not had a flood since then and my plants are blooming beautifully.
        I really like your ideas and suggestions.
        Thank you, Char

  47. The advice to add organic matter is best advice when you have enough of it.
    but on large fields you usually don’t, that’s why farmers in australia for example spread clay on sand bc they have too much of wind blown sand and wind erosion, clay helps to make sand stick to the surface and not get lost.
    the problem is when people use what works for desert farming and apply it to a garden that don’t have wind erosion.
    a garden can also source biomass at a cheaper price than clay, while for a desert farm it’s the other way around.
    About concrete level compaction, the hardest and denser adobe you can make have an idea ration of 30% clay and 70% sand, this ratio comes from that sand fills all the volume and leave 30% air gaps, when you fill the rest with clay, there is no airgaps and it becomes like a solid rock after clay dries out, usually the higher compaction comes at lower moisture level with a stronger pressure, (road geoengineering)
    high moisture and high clay get compacted easily at lower pressure but don’t reach a high density (till it lose most of moisture)
    so it’s easier to get concret level compaction by adding clay to sandy soil than by adding sand to a clay soil,
    if someone can’t source enough biomass to amend clay soil, they can apply silt patchs or bore holes in the clay soil and fill them with sand, they will help with drainage and allow plant roots to go deeper faster or just make a raised bed with soil sourced from elsehwere.

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