This is my general recipe for pest management top-dress that I use on my vegging soil plants. I mix these ingredients with my soil during transplants, but overtime needs recharging. This top-dress is applied about every 4-6 weeks on long-term soil mother plants. There is much more information about the benefits of each ingredient than provided, so if curiosity strikes, research further.
This is the rough base I use and can have many other amendments added for plant nutrition, but the purpose of this recipe is pest management.
Ingredients:
- Neem Meal/Cake [pic 1] – left over tree material after the neem oil has been pressed/extracted. It is a great soil amendment with a 6-1-2 NPK and pest mitigating compounds such as Azadirachtin. Neem meal can feed the plants, reduce nitrogen loss in the soil, help your plants assimilate the pest repelling natural compounds into the plant, and provide a slow release pest repelling soil environment.
Neem meal can acidify the soil, so be aware that your pH may drift downward if used in excess or without any balancing effort.
- Diatomaceous Earth (food grade) [pic 2] – microscopic sharp crushed minerals that slice up pests. Food grade is better than the DE used for swimming pools as the food grade quality is processed to retain many of the elements naturally found in the diatomite (magnesium, calcium, iron, and trace elements)
DE easily kicks up into a dust while being handled; wear a mask while handling, as the microscopic slicing doesn’t discriminate against your lungs.
- Mosquito Dunks [pic 3] – These are found in many hardware and big box stores to be used in standing water to kill of mosquito larvae. The active ingredient is a strain of bacteria that eats the larvae of a group of insects that includes fungus gnats.
This can also be mixed in water to more easily inoculate potted plants. A singular dunk can also be used in your hydroponic reservoir as a fungus gnat mitigator.
- Cinnamon Powder – repels pests, provides rooting hormones, and acts as a fungicide.
The fungicide property can affect soil biota, so be careful if you are purely organic.
MIXING THE TOP-DRESS
Mix the ingredients at a
1part Neem: 1part DE: ¼part Mosquito Dunk: ¼part Cinnamon [
pic 4]. I use a grater to get the Mosquito dunks into a powder, but you can also pick/crush it by hand. This mix is not set in stone, so feel free to play around with the ratio.
When mixed, it will appear that the DE has taken over the batch [
pic 5].
Spread the dressing around your target plant [
pic 6]. The amount can vary based on the age of the soil, pot size, and any existing pest problem. Since this is just maintenance and there is no pest outbreak, a light application is all that is necessary.
I use a spray bottle to moisten the dressing [
pic 7]. This is a practice I use with any freshly potted plants to make sure the top layer of the soil is damp enough not to lift and displace if I were to instead just pour large amounts of water. This allows the mix to settle into the soil evenly.
The DE will “wash off” the neem and leave behind a taco-seasoning look to your soil [
pic 8]. As you water, you’ll be slowly working this top-dress into the soil feeding and keeping pests away.
I use this along with regular foliar applications of various pest repelling, and plant strengthening sprays that are not harsh chemicals as apart of my IPM regimen.