Judging by the calls, emails and FB posts we’re getting, pests are having a banner year in our gardens and houseplants.
Of course, we recommend NimBioSys neem oil to control them. Most people automatically spray neem on their plants to control pests, but sometimes soil drenching is more effective.
Soil drenching doesn’t work as quickly as spraying neem oil, but it lasts for weeks. There’s no possibility of harming beneficial insects or bees because it only affects critters that are sucking or chewing your plants. Worms actually benefit from being fed neem leaf, growing bigger and fatter in vermicomposting research. And in hot climates, you’re not spraying an oil on your plants that could potentially burn them.
When you use neem as a soil drench, it becomes a systemic pesticide — the roots absorb the active ingredients and spread them throughout your plant. That makes an enormous difference for pest like aphid, spider mites and mealybugs. Yes, spraying neem will knock them out but when an aphid goes from egg to reproducing adult in just eight days, you’ll have to spray often to keep them under control.
And because neem (and most insecticides) contact the insect to control it, a spray won’t affect critters like leafminers and pickleworms that destroy plants from the inside out.
The same is even more true for insects that live in the soil. While nematodes are so small they’re invisible to the naked eye, they cause an estimated $157 billion (yes, that’s a b) in damage to crops around the world with no easy way to control. And of course that doesn’t count the damage they cause to popular crops like tomatoes, peppers and peas in home gardens.
We’re attributing the increased number of calls about fungus gnats in houseplants to the explosive growth in sales of potting soil with “water-managing” polymers that hold far more water than normal soil. They’re hard to control without harming delicate plants but a NimBioSys soil drench knocks them right out.
Mixing a neem soil drench is even easier than mixing a spray because you’re dumping water on the soil quickly so emulsifying it is not critical. Just put one tablespoon neem oil in a gallon of very warm but not hot water (or one teaspoon per quart) and pour over the soil. There’s no clear documentation on how much neem or how often it needs to be applied, but I’d recommend a quart per plant in vegetable gardens applied monthly.
Please let us know if you’ve tried the soil drench and what you think.
(The cover photo compares peanuts treated with neem vs. a control crop. Photo courtesy Georgia Organic Solutions.)
Hello. I Need Help!!!
I pulled plants out of my containers for the winter and found either grubs or maggots in the soil. I want to save and reuse the soil next year. Can I use Neem oil as a soil drench to kill existing
and very much alive unwanted insects? I want to soak the soil and leave it alone in a separate container with a lid until
this upcoming Spring. Will this method kill the grubs during the winter? I live in Hot Springs Arkansas.
It should, particularly if you pull the plants out and the grubs don’t have anything to eat all winter. Let us know!