Series: Free Organic Gardening Course
- What Is Soil Made Of And How Does Soil Form?
- Home Soil Testing – No Need For A Soil Test Kit
- How To Prepare Soil For A Garden – 2 Different Ways
- Soil Sample Testing – How To Take A Soil Sample
- Natural Organic Fertilizers – How To Choose For Your Garden
- Organic Garden Pest Control – Without Toxins
- Organic Weed Control – Kill Weeds Naturally And Forever
- Organic Composting 101 – Making Compost Better
- Worm Bin Composting – How To Build A Worm Compost Bin
- Homemade Fertilizer – 2 Great Easy-To-Make Fertilizers
- Cover Crops For Gardens – Build Soil And Control Pests
- Soil Inoculant For Plant Nutrition (And Fewer Pests)
- Permaculture Principles – A Few Tips For Your Garden
- How To Make Your Own Garden Inoculant For Less Than $1
- How To Plan A Landscape Design – 6 Steps To A Good Garden
- Seedbed Preparation, Sowing Seed And Planting Vegetables
- Want To Grow Organic Food? Here Are Some Tips
- Forest Gardening – How To Grow A Food Forest
- When Gardening Organically, You Need To Think Differently
Update: I now recommend neem oil instead of horticultural oil.
As I’ve discussed in other posts, the best organic garden pest control method is a healthy ecosystem.
This means creating the right conditions for thriving, healthy plants by doing things like caring for the soil, watering properly, and having the right plant in the right place.
Then our plants won’t attract diseases or plant-feeding insects.
But it’s a tricky balancing act to keep garden ecosystems in perfect balance while shaping them to meet our own needs.
Even the most meticulous organic gardeners don’t manage to keep all their plants perfectly healthy all the time.
Sooner or later, we all end up running into the occasional plant predator – insects and diseases that want to make lunch out of our precious flowers or organic vegetable garden before we get a chance to enjoy them.
Fortunately, there are a few things we can do to avoid this.
There are also some options for how to deal with plant predators when diplomacy fails and we’re faced with a choice between fighting back and losing our crop…
Preventive Organic Pest Control
Organic gardening pest control starts with prevention.
One way to keep predators away from your plants is by using intelligent planting practices.
This means being careful not to bring pests and diseases into the garden from nurseries or on your tools or clothes.
Only choose pest-free plants, and disinfect your tools.
You can also use particularly smelly plants to mislead and confuse plant predators. These odorous plants bear the majestic title of “aromatic pest confusers.”
Many herbs fit into this category, as well as alliums like garlic and onions, and even some flowering plants such as marigolds.
By interspersing them throughout your organic garden, or deliberately planting them around other plants that you know are vulnerable to insect attack, you can do a lot to keep the would-be predators chasing their own tails instead of munching your lettuce.
You can also discourage diseases simply by rotating your crops. Use different plants, and if possible different families of plants, in each bed each year.
It’s harder for soil-based diseases such as clubroot in brassicas, or insects like wireworms whose larval phase lives in the soil, to get established if their favorite food source keeps moving around.
As for soil fertility, it’s important to balance out your soil based on a soil test. Pest problems are often partially caused by a deficiency in calcium and phosphorus, as well as different micronutrients depending on the pest.
Short Term Organic Garden Pest Control
Even if you follow these practices, you may still end up with some pest and disease outbreaks.
When that happens, unless you’re willing to let nature re-establish its own balance by sacrificing the affected plants, you may choose to attack the problem directly with these organic garden pest control methods.
There are a lot of different ways to do this, so I’ll just mention a few of my favorites here.
First, it’s essential to know which plant predator you’re dealing with.
Fortunately, most plants are only vulnerable to a few specific predators and diseases, so once you’ve identified the plant, it’s usually not too hard to find a list of its common predators on the internet or in an organic gardening book.
Once you’ve identified the predator, you can look into some possible ways to deter, remove, or kill it.
Keep in mind that even products that are allowed under organic standards may still kill beneficial insects or have detrimental effects on plants, so always choose the least toxic option.
With some insect predators, a simple solution is to hose them off, or even pick them off by hand.
This can be time-consuming, so you may want to use a natural insecticide like isopropyl alcohol, horticultural oil, or insecticidal soap instead.
Update: I now recommend neem oil instead of horticultural oil.
In that case, I like to come back through the next day with a microbial inoculant like compost tea to repopulate my plants with the good guys.
Biological Garden Pest Control
One of my favorite natural garden pest control methods is to keep my own standing army of other critters to gobble them up.
This approach isn’t actually that out there.
You may have heard, for example, of people buying ladybugs to control aphids.
Now that doesn’t actually work very well, because unless you’ve created pretty great ladybug habitat, they’ll just fly away to find somewhere they’d rather be.
(You need them to stick around and lay eggs, since it’s the juvenile ladybugs who are the really voracious aphid-eaters).
But what does work is making your organic garden a place a ladybug wants to hang out.
This means having a variety of different flowers blooming throughout the season, as well as water sources, complete with pieces of debris for them to sit on while taking a drink – nothing worse than an overly clean bird bath that ends up drowning your parasitic wasps as they try to get a sip.
You can also encourage snakes (yes, snakes!) by having places for them to hide, like grassy slopes or sunny rock piles. You may think snakes are a bit creepy, but they’re a slug’s worst nightmare.
Some people will tell you to clear away the duff layer at the end of the season, to remove habitat for plant predators. The trouble is, this also takes away the habitat their predators need to make it through the winter.
By now, we’re totally over the idea that we can create sterile, perfectly controlled ecosystems.
But we can get amazing results by growing diverse gardens that invite the organisms we want to join our living community, and control plant predators for us!
Let me know about your most important pest problem below, and I will try to give you some good short-term organic garden pest control tips along with my longer-term advice.