What you use instead of bone meal for plants depends on how much effort you want to put into this, but the cost isn’t much and neither is the time.
There are the 3 products I generally use when planting in my organic garden.
I've already discussed the risks of using bone meal for plants.
These alternatives are in order of importance, in my opinion, so if you just want to keep it simple, use the first:
1. Mycorrhizal fungi are a very specific class of fungi that wrap around and penetrate plant roots and form a relationship whereby both the fungi and the plants benefit.
They're incredibly important for plant health and are believed to have been critical in the evolution of trees. They are a big deal in the organic gardening world.
They do a lot of things, but are often specifically credited with bringing phosphorus to plant roots, which is a good thing because plants have a difficult time getting phosphorus out of the soil, since it is held very tightly.
These fungi can actually supply more phosphorus than using bone meal for plants because the plant can actually obtain and use the phosphorus.
Mycorrhizal fungi also bring water and other trace minerals to the plant, in addition to helping to protect the plant from root-feeding microbes. The fungi does all of this work for the plant in exchange for food from the plant.
Mycorrhizal fungi are found everywhere in nature, but are often lacking in our residential gardens. Fortunately, they can be purchased as a powder and should be applied directly to the roots or seed or in the planting hole whenever you are planting. They can also be watered into porous soils, and is often used after aeration of turf.
Instead of using bone meal for plants, I always use mycorrhizal fungi in my organic garden.
2. Sea minerals is very concentrated, mineral-rich ocean water from the Pacific Ocean. It is so full of nutrients and life that it is the most incredible broad-spectrum product to spray directly on your plants and soil.
There has been a lot of research and the benefits are unbelievable. This is often my first choice for an organic biostimulant.
3. Liquid kelp is different. It has many of the same nutrients as sea minerals, but you want to use it for its natural plant growth hormones that stimulate many processes in plants.
With the product I use, you only apply 20mL per 1000 square feet, so although the nutrients are beneficial, it's really all about the hormones. Regular applications improve many aspects of plant growth.
When planting anything from annuals to trees, I am no longer using bone meal for plants.
Instead, I like to make a recipe in a pail and then briefly dip the roots of each plant into it, or spray it onto the rootball.
Here's a recipe per 4 litres of water, and it can be adjusted according to the size of the pail. Mix the first 3 ingredients in one pail and after dipping the plant, rub the fungi onto the roots separately.
Amounts will change depending on the product you buy. Make sure you get products allowed in organic gardening and follow the instructions on the label:
Feel free to post any questions below about these ingredients. I used to sell them, so I know a fair bit about them.