Planting trees in the fall is one of my favorite things to do, so today I’m giving you 9 videos from my online gardening course on how to plant a tree (these videos are from 1 of the 4 ‘modules’ from month 8 of the Academy).
Yes, there are a lot of videos on this page.
Here are the most important organic fertilizers and inoculants I mention at some point in these videos because I always use them when planting trees:
Okay, now onto planting trees in the fall.
Where To Plant A Tree
If you want your trees to be healthy and achieve their proper size, they need enough space above and below ground.
Most trees want soil that is 3 feet deep. That doesn’t mean you have to dig 3 feet down, just that it’s best not to plant a tree on soil that is solid rock a foot down, or water-logged a foot down, and so on.
And they need a wide space, too. If the trunk will mature at 1 foot wide, it needs 200-300 square feet of soil space. If 2 feet wide, it needs 500-600 square feet.
Of course, they need space above ground, too. I’ve seen thousands of trees planted too close to buildings and other obstacles.
So what this means is you want to place your trees as far away from hardscaping and buildings as you can, including the swimming pool, septic system, retaining walls and hydro wires.
It also includes the sidewalk and driveway. I go with a minimum of 10 feet when possible. Roots can grow under a sidewalk and driveway, but it’s not ideal – for them or the hardscaping, which will inevitably get cracked. Plus, the trunk flare needs plenty of room to develop properly.
Trees can be spaced quite close together, though. If you plant trees close at 10 to 20 feet apart, it will encourage them to go more upright, which is actually more natural for them – trees are happy to be planted in clusters.
It will provide a better canopy and decrease the need to prune branches that would otherwise branch out too low if the trees were planted further apart.
Trees for a hedge can go even closer. Coniferous trees are often used for this.
I’ve planted trees as close as 3 feet apart, trunk to trunk, but I prefer to give the trees 5 feet to allow them a little more room.
Planting Trees In Pots
Hopefully it’s obvious that plastic and fabric pots need to removed before planting your trees, but the garden center will probably tell you to leave fiber pots and balled & burlapped (b&b) root balls on when you plant.
They may tell you to take off the lip and the bottom of fiber pots, but that’s generally all.
In fact, they might remove the guarantee if you take these things off. It’s a good idea to find out before you buy if they will guarantee them when you remove the pot and burlap. If so, you may want to shop elsewhere.
The truth is, most tree experts who have spent a lot of time observing what happens over time when the pots or burlap are left on agree you should take them right off, or at least remove the majority of them.
Fiber pots and burlap are supposed to quickly break down in the soil, and they do if they’re kept at the right moisture level and if you have the right microorganisms to break them down.
But if they dry out, or if the microbes aren’t there, they can take many years to disintegrate.
During the years they remain in the soil, they create a soil texture interface that may not let water pass easily, as does anything that is buried in the soil if it’s a different texture than the soil.
Sometimes this can lead to flooding in the pot and sometimes it can lead to insufficient water.
Also, roots might not make their way through the pot. Sometimes they just circle around inside the pot, making an unstable, unhealthy tree that eventually dies.
Trees have died and been dug up decades after they were planted with the pot or burlap still intact. Or sometimes the burlap will decay, but the string will strangle the trunk.
Burlap is often treated with copper sulfate or other synthetics because it stays intact longer and keeps a tight root ball. It can last a long time in the soil. The string that ties it together is often synthetic, too.
Treated burlap is often hard to recognize. It can have a green color early in its life, but that fades. The way to tell is to burn a piece of it. If it melts and/or smokes, but doesn’t really catch fire, it’s synthetic.
Natural burlap and string is sometimes used instead, which is better. Traditionally, it has decayed within a few months under the right conditions, but it can last a long time if it’s dry, and they’re also finding ways to make it last longer – good for the grower and the garden center, but not good once in the soil.
I don’t bother trying to figure out if it’s synthetic or not. I just take it off.
For b&b trees, when you take the burlap off, the rootball won’t fall apart unless it has a poor root system, which may be the case if it wasn’t root pruned in the nursery or is freshly dug. You don’t want that tree anyway.
At the very least, take the string off and the top part of the burlap. If you fold it over, it takes longer to break down, so cut it off instead.
Wire baskets are used with big b&b plants to make them easier to move. I often leave this on, especially if it voids the warranty to remove it, but mainly because it’s a pain to get off of big root balls and it does help to hold them together if they’re made of sandy soil.
Tree roots can often grow around the wire without being hurt, so it’s not as big of an issue, although wire is occasionally found to be the cause of poor health in trees when it damages the root from the inside out.
In that case, the tree may just never reach a healthy state and hence always be covered in plant-feeding insects and diseases. It’s impossible to figure out unless the tree is dug up and examined.
At the very least, I cut back the top 12”-18” of the basket. If you want to take off the whole thing, first cut off the bottom half, then lift the tree into the hole via the top half, and then take off that top half.
Planting Trees In The Fall – Part 1
When I was a young landscaper, I planted a lot of trees. If the root ball was 36 inches wide, I probably chose a planting width of about 40 inches.
That’s the way most landscapers do it, because it just saves so much time. The thing is, you’re really preparing an entire area for your shrubs and trees. If you just go for a planting width of 40 inches with straight sides for a 36 inch root ball, the roots aren’t going to be very excited about leaving that hole.
In compacted soil, they may just turn around when they hit the edge of your hole and grow in a circle within the soil, resulting in an unstable, unhealthy, unsafe tree.
If you’re trying to do the best job possible when planting trees and shrubs, go wider with your planting width and make sides that have a more gradual slope. I now dig my holes at least 1.5 times wider than the root ball.
I suggest going 2-3 times wider in compacted soil, although if I’m digging with just a shovel in compacted soil, for a big root ball, I may not want to spend that many hours digging one hole, so I can’t really tell you to, can I?
But I will always go at least 1.5 times wider.
Planting Trees In Fall – Part 2
I started planting fruit trees in the fall of 2012 for this garden. I created a little bed for each of them just like I did in the video above.
You basically want to prepare a little garden bed for a tree, creating a tree ring around the tree as wide as you’re willing to go.
Improve the soil with compost and other amendments, either double digging or rototilling.
For depth, you need to look for the trunk flare at the base of the tree.
As mentioned earlier, it may not have a discernible flare, in which case you need to find the top most major root and make sure it’s within 2 inches of the top of the root ball. If it’s not, remove some of the top of the root ball.
You may kill some surface roots, but it’s more crucial for the trunk flare to be exposed. It can’t be buried or the tree may die a slow death that can take many years. Same goes for the graft – make sure it’s above ground.
The depth of the hole should be slightly less than the distance from that top root to the base of the root ball. That would mean about 5% of the root ball is above ground.
If your soil is going to be very wet or compacted, you might plant the tree so it’s 10% or even as high as 20% is above ground.
Planting a tree too high is much better than planting too low. I don’t want to plant even an inch too low.
Planting high ensures the roots will get enough air and lessens the chance of too much water ending up in the planting hole. It also makes it almost impossible to develop roots that circle and strangle the trunk, which happens when planting trees too deep.
If you’re planting your tree in a loose, sandier soil, you may only need 1 or 2 inches above ground for your trees. In a compacted soil with a big root ball, you may have 6 inches above the ground.
Don’t loosen up the soil underneath the root ball. You want it solid so the tree doesn’t sink.
If it’s very compacted or rocky, you may drill some holes down in there to encourage some roots to go deep to anchor the tree.
If you’re on a slope, the top root should be even with the ground at the top end of the ball. The bottom end will be high above the soil and will need a berm under it.
If you have lots of roots circling on the outside of the root ball, the traditional thing to do is to slice them vertically with a spade or saw, as much as 8 times around the ball. The idea is that it encourages the roots to move out into the soil instead of continuing to circle.
Interestingly, new research is suggesting that doesn’t really help much for trees. They now suggest we saw off the outer 1 inch of root ball on all sides and the bottom. I don’t do that because it just seems like a lot of work, and I’m not yet convinced.
Plus, I try not to plant trees that are that root bound in the first place. But the research is apparently showing that it gets rid of those circling roots and better encourages the roots to move into the soil.
Planting Trees – Part 3
Some research shows that you don’t really have to do anything to amend or improve your soil before planting trees, because it doesn’t make much difference, so that’s what some experts recommend – doing nothing to the soil.
But it seems to be that they’re just looking at survival rates for trees with all of this research, not how healthy the tree is, how long it lives, how free it is of pest and diseases, and so on. Frankly, I’m actually surprised that survival rate isn’t impacted.
I would say that proper watering is more important than amending the soil for trees. I’m sure you’ve heard me say that before – watering is crucial.
And there is one point I agree with and that is that you should generally use whatever your existing soil is, rather than carting it away and using topsoil.
The roots are fairly quickly going to go much wider than the planting hole – averaging about 2-3 times further than the drip line – so they’re going to have to get used to your soil anyway.
Besides, using soil of a different texture will often cause some problems.
But what I definitely do is incorporate some compost in the backfill and over the whole bed, often as much as 2 inches.
I also incorporate rock dust and other mineral fertilizers based on a soil test.
Before I plant trees in the fall, I also spray the same solution that I use for seeding onto the root ball, using enough water for coverage and then 5ml each of sea minerals and liquid kelp per litre of water.
And then I definitely rub some mycorrhizal fungi onto the root ball, about 1 Tbsp per inch of trunk diameter with the brand of fungi I use.
When your tree is in the hole, make sure it’s straight by viewing it from at least 2 angles. Fill the hole halfway with your backfill. Use a shovel to lightly tamp down the soil to remove air pockets.
First I slice down with the shovel and then I may use the other end. Very gently.
Watering helps to get rid of air, too, and this is about the time I want to add 10-20 gallons of water anyway, which takes about 3 minutes from a hose.
Planting A Tree – Part 4
Fill the rest of the hole with backfill and tamp and water to settle it, but don’t cover the top of the rootball with soil.
You can put a very thin layer of mulch for aesthetics, but especially for the first year, it’s best to leave it fairly bare to allow moisture and air exchange.
Mulch can cause problems with the trunk and bark, which needs to be exposed to the air, not a moist environment.
Mulch too close to the trunk can also promote rodent damage and encourage formation of stem girdling roots. The rest of the area outside the root ball should be mulched with leaves or straw 2 to 4 inches deep.
Even wood chips could be used here, preferably deciduous chips for deciduous trees and coniferous chips for coniferous trees, but I prefer leaves or straw.
No berm is necessary unless it’s on a slope and needs something to hold water.
How To Stake A Tree
The preference is not to stake trees, because it turns out that unstaked trees will develop stronger trunks due to the fact that they have to fend for themselves in the wind.
Trees with trunks bigger than 1.5 inches should hardly ever need staking, unless the root ball is loose.
Smaller trunks may need it. So do bare root trees, many fabric-potted trees, and trees that were very recently dug and potted.
The stakes should be removed after about 6 months in warm climates and 12 months in cooler climates, in order to allow the tree to learn to grow on its own.
It takes longer for the root system to establish in cooler climates, which is why it needs support for longer.
I won’t described the staking methods here because it’s much easier to video them than write about them.
Here’s a poorly staked tree:
How To Care For Trees
The most important maintenance task is watering. If you aren’t going to be able to water much, choose drought-tolerant trees, and opt for smaller trees that will more quickly establish so that you only need to water them well for perhaps a couple of months after planting your trees.
Also, if water will be lacking, don’t plant anything under the tree for the first year, because it may compete with water. That means the weeds should be also pulled.
Interestingly, you have to be prepared to water properly for more months in colder climates, because it takes tree root systems longer to establish in cooler weather.
There’s no need to prune a tree when planting it in order to “balance out the canopy with the root ball” or anything like that.
It’s a good idea to remove dead wood and probably damaged wood, and it’s really important to remove potentially problematic branches, such as codominant branches that are both competing to be the leader.
That causes major problems down the road, so it should be dealt with when the tree is young.
There’s no benefit in wrapping the trunk with burlap or paper, as it doesn’t really protect from climate extremes. Sun scald on the south side of the trunk is usually due to lack of soil moisture, not so much due to exposure to the sun.
If you have rodents, plastic corrugated pipe can be put around the tree in the first year to keep them away. Just cut a slit all the way down the pipe to get it around the tree.
How To Plant A Tree – Summary
Trees need enough space above and below ground. Place them as far away from hardscaping and buildings as you can.
Remove pots, burlap and string. Wire mesh may or may not be removed.
Make the tree planting hole at least 1.5 wider than the root ball and no deeper than the distance from the top major root to the bottom. Take grass out of the root zone.
Consider amending your existing soil with compost and mineral fertilizers based on a soil test. Consider using organic fertilizers and mycorrhizal fungi when planting your trees.
Add half the backfill, gently tamp and water in, then add the rest. Mulch the whole area, except on top of the root ball.
Stake the tree if necessary.
Watering is crucial. Pruning the tree may be necessary for dead/damaged wood and co-dominant stems, but otherwise isn’t usually needed.
Feel free to ask any questions about how to plant a tree this fall down below.