Q. You mentioned that you added preplant fertilizer to your soil before planting seeds. I would think that seeds and fertilizer are a bad idea. Shouldn’t you place the fertilizer in the beds you are transplanting established seedlings into, not in with the seeds you are starting? It seems to me that adding fertilizer before planting seeds would be like trying to start the seeds with ocean water… Toooo salty….
A. Has anyone else had the feelings expressed here – that because nitrogen might burn your emerging seedlings you shouldn’t fertilize the ground before planting? It is a valid concern and needs to be addressed.
First, let’s talk about the common practice of amending your garden soil by applying manure. Many people who strongly advocate this, while at the same time accuse others of polluting the soil by adding “chemicals,” haven’t done their math.
I recommend you look at my article on this subject at https://sustainable-gardening.subto.us/tip/soil-amendments.html (and while you’re at it, subscribe to the Foundation’s Sustainable Gardening Ezine), where I review this subject.
If you were to put 2″ of cow or horse manure on your 18″ X 30′ soil bed and till it into the top 8″ of soil, you would have added about 250# of manure containing 1% nitrogen to 30 cubic feet of soil. That’s 2 1/2 pounds of actual nitrogen in 30 cubic feet of soil, or 2 1/2# nitrogen in about 3,000# of dirt. This is 20 times as much as we recommend, and often a high enough concentration of nitrogen to burn newly germinating and emerging seedlings, and people can have very disappointing results after amending their soil in this way.
What does the Mittleider Method recommend? We recommend you add 32 ounces of Pre-Plant Mix and 16 ounces of Weekly Feed Mix to that size soil-bed. Pre-Plant Mix is mostly lime or gypsum. These are base elements, rather than salts, and won’t burn your plants, so there’s no worry about the Pre-Plant Mix burning your new seedlings. The element most responsible for burning tiny plants is nitrogen, which is in the Weekly Feed Mix. Sixteen ounces – or 1# of Weekly Feed contains 13% nitrogen, so you will be applying just 2 ounces, or 1/8th of a pound of nitrogen in that same 30 cubic feet of soil.
Therefore, applying 32 ounces of Pre-Plant and 16 ounces of Weekly Feed to a single 18″ X 30′ Soil-Bed adds 1 part nitrogen to 24,000 parts soil, or 42 parts per million. This concentration is not a problem for new seedlings, and is about 1/500th the concentration of ocean water, so the analogy used in the question is not accurate.
You will find Dr. Mittleider has addressed and resolved your concerns in every aspect of vegetable production. I invite you to relax, follow the procedures accurately, and enjoy the ride to a great garden – no matter what kind of soil you have!