Neem based products come from the neem tree. The neem trees scientific name is Azadirachta indica, and it is related to trees in the mahogany family. The neem tree is native to India, Bangladesh, Nepal, Sri Lanka, The Maldives, and parts of Iran.
The neem seeds harvested from neem trees is the source of all of the neem oil based products you see on the market. In India these can range from neem soap, neem shampoo, neem lotion, and even medicinal neem supplement products. In the west, organic gardeners know of neem as the oil is used as a natural insecticide for many pest issues. In India neem seed meal is a byproduct of the neem oil industry. When neem seeds are pressed into cakes for their oil content, the left over product is neem seed meal.
Neem seed meal has been a widely used organic soil amendment for many years in the US. It caught on in the early years of living organic soil in the cannabis industry. It became popular via forums from “coot” touting it's benefits. From there it has spread into different applications in the cannabis industry such as a direct input used in soil recipes.
How To Use Neem Seed Meal As a Soil Amendment
Neem seed meal is most widely used as a soil amendment in the US. It contains high amounts of nitrogen, and lesser amounts of phosphorous and potassium. Neem seed meal can also help replenish micro-nutrients in unbalanced soils, and help to build up organic matter. When the meal is used as a soil amendment it will work as a longer term amendment releasing nutrients slowly over time.
In the US, neem seed meal Is typically used for it's ability to protect against parasitic nematodes and soil borne pest insects like fungus gnats and roots aphids. This is why you see a lot of DIY soil mixes including neem in their recipes. The application of neem meal will also help to feed the micro-organisms in the soil.
Neem Seed Meal Application Rates:
DIY Soil Mix Use Rate:
¼ to ½ cup per cubic foot of soil
Indoor Cannabis Plants: 1/2 to 1 Tablespoons Per Gallon Of soil
(Add Once Per Cycle)
Outdoor Cannabis Plants: 1/2 To 1 Tablespoons Per gallon Of Soil
(Can Be Applied Multiple Times During a Full Outdoor Season)
House Plants: 2-4 Tablespoon Per Gallon Of Soil
(Apply Once Per year)
Outdoor Vegetable Garden Beds: 2 To 5 Pounds Per 100 square feet
(Apply Once During Growing Season)
How To make Neem Seed Meal Tea
One of the best ways to use neem meal is to make a tea out of it. It's a simple process, not unlike brewing compost tea. It will create a strong odor, so be prepared when brewing your next batch.
Neem Meal Tea Recipe:
1-2 Cups Neem Seed Meal
5- Gallons Of Water
Place the neem seed meal in a mesh bag, and hang the mesh bag in a 5 gallon bucket full of water. Using your air pump, and air stones, bubble the tea for 36 to 48 hours. As the tea brews you will notice a strong odor beginning to develop. This is perfectly normal. Once the tea is finished brewing, you can either foliar spray or soil drench as needed. Always start with a lesser amount, and test on a single plant to make sure there are no issues from the application of any new product in your garden.
My Thoughts On Neem Seed Meal
There is just no need to ship heavy neem seed meal half way around the world to use in our gardens. There are better alternatives that can be locally sourced. I have seen some companies begin to plant neem trees in the US though. Moving forward I can see this as a good option if you are wanting to use neem seed meal in your garden. That being said, beneficial insects, and beneficial nematodes can help protect your garden way better than neem seed meal ever would. Also there are limitless soil amendments that are available that can be used as an alternative to get n-p-k and micro-nutrients into depleted soils.
My opinion only applies to my gardens, and my plants, whether they be cannabis, ornamentals, or vegetables. There may indeed be situations where using neem seed meal in your soil is the best alternative for your issues. However I do feel the cost is a hard sell for any larger industry, like say the greenhouse industry, where margins are razor thin. This is why you see neem seed meal so popular in the cannabis industry. More money is spent growing cannabis per pound than almost any other crop. So spending an obscene amount of money a single soil amendment is possible if you are selling a crop that goes for between 1k and 2k per pound. Whereas tomatoes are selling wholesale for around $1 per pound. Hard to justify such an expense when an entire acre of crops only nets you as much as 1 pound of cannabis.
It is always a good idea to re-purpose waste products like neem seed meal, and this one in particular does have some good qualities about it, but until there is larger scale domestic production of neem oil(which creates neem seed meal as a by-product) via domestically grown neem trees, I would use alternatives that will perform better at an over all lower cost.
Again, You need to do what is right for your garden and your situation, and if that means including neem seed meal in your soil, then that's the choice you need to make. I would however do plenty of your own research that doesn't include cannabis based guru's information so that you can make an informed decision on every product you use in your garden. I will now step off of my soap box. :)