I have hundreds of big plants in my yard and groundcovers all over and I use...

Asked October 8, 2014, 10:04 AM EDT

I have hundreds of big plants in my yard and groundcovers all over and I use a lot of compost and try to be organic. I have a lot of earthworms. Is it allright to use an organic liquid fertilizer as a root drench in the spring and fall for my fertilization program rather than a powdered organic fertilizer that needs to be scratched in the soil around each perennial plant, shrub, or tree?

Pennington County South Dakota

1 Response

If you are using a lot of compost and your soil is good you should not need to fertilize nearly this much or not at all, in Maryland any way. We do not recommend the need for fertilizing mature trees and shrubs at all, and other plants on an as-needed basis. (For instance roses are heavy feeders, while many plants are happy with just good soil)
We are very sensitive here to over-fertilization, because run-off is a prime polluter of the Chesapeake Bay.
Your use of organics is good. Read the label on your products for N, P and K. That is what you really want to be comparing. If the N,P and K nutrients are the same ratios/numbers, it doesn't really matter whether you are applying liquid or granular.
The other difference to be aware of is soluable (fast releasing Nitrogen) versus non-soluable (slow release over a longer time).
At any rate, we recommend you contact your local Extension or Master Gardeners to understand your situation, because climate, soils etc. can vary greatly around the U.S. Here is that link: http://www.sdstate.edu/sdsuextension/anr/horticulture/master-gardeners/
cm