Is Fish oil a good fertilizer for tomato plants?
Yes indeed it is! This is due to the fact that commercial fish fertilizer isn't fish oil at all; it's actually called fish emulsion and is a mild, liquid fertilizer made from fish byproducts and waste that provide nitrogen, enzymes and other essential nutrients for plant growth. The chocolate-brown liquid gives off a strong odor, but it strongly benefits both tomato (Solanum lycopersicum) seedlings and the transplants. When the fertilizer is applied to a tomato plant at the right time with the correct ratio of liquid concentrate to water, you can achieve greater yields and better-tasting tomatoes!
How to apply the fish oil fertilizer!
Fish emulsion should be applied in cool weather, preferably in the early morning or evening. Avoid applying it in the midday heat or to any heat-stressed plants. If fertilizer is applied at the wrong time or if too much of it is applied at once, it may prevent your tomato plants from forming fruit.