The bag of lawn fertilizer tore and rain water entered the bag. The fertilizer is now wet. Can I use it for anything now that it is wet? Could I mix it into my vegetable garden before I plant? Can I mix it into water and use it on my flower garden?
Instead of using the fertilizer while it’s wet, I suggest that you spread it out to dry and then break up any chunks that are formed. If you wish, sift it through hardware cloth so it is back to its usual consistency so it is spreadable. If it remains in clumps, it won’t be useful on the lawn, although you could toss the clumps in your perennial garden or around trees and shrubs. My concern about the use of the wet fertilizer is that it is not clear how it should be diluted with water before being applied to the garden — if it were too concentrated, it could harm the plants you are trying to feed.
It is best to use fertilizers for their stated purpose. Your lawn needs different nutrients as well as different quantities of nutrients than other plants in your garden. For example, lawn fertilizers are nitrogen-rich, with low concentrations of potassium and phosphorus (which other plants need in higher concentrations). Nor do lawn fertilizers contain other nutrients like soil acidifiers or iron that some plants (e.g., shrubs) require. Nitrogen is great for lawns and helps plants grow stems and leaves, but may not be ideal for your vegetables or other plants — too much nitrogen can result in the growth of lush leaves at the expense of fruit and roots!
I’d suggest that you not use the lawn fertilizer for your vegetables. Adding nutrients that the veggies don’t need could lead to a deficiency in other nutrients and nutrient imbalance. For example, too much nitrogen can reduce the vegetable yield and quality, and may increase risk of insects or disease.