I am often asked if seedlings need fertilizer and if so, when? Good question.
See those long skinny leaves on the seedling in the photo? Those aren't really leaves. They are called cotyledons and they help provide nutrients to the seedling until the true leaves form and the plant can start to photosynthesize. Cotyledons look pretty much the same on most plants.
The two tiny leaves at the top of the seedling are the first true leaves of this tomato plant. When true leaves appear on your seedling, it's time to start feeding them. Here are some tips, along with comments that have come up around this topic before.
- Feeding Seedlings: How Much (and what) to Feed Them?