QuickTake:

You might be tempted to use chemical fertilizers. If so, follow the directions. I prefer natural fertilizers, which break down slowly as the soil warms and provide your plants with a long duration food source.

Your garden fruits and vegetables take sun, water and soil, and turn it into food for you — and your neighbors, friends and relatives. Providing the plants with a little nutrition is the least you can do, and it is absolutely necessary if you want a continued bountiful harvest. 

Chemical fertilizers are highly water-soluble, and they can easily pass right past the root zone and into the water table if applied incorrectly or at the wrong time. Plants are not growing during cold, wet weather. Adding water-soluble fertilizer is a waste of time and money and harms our groundwater. As a rule of thumb, plant food is not blue. 

I know many people do, and will, use synthetic fertilizers, so if you do, follow the directions and only use them during the active growing season. The idea that “if some is good, more is better” applies to chocolate, but not to synthetic chemical fertilizers. I often see fertilizer (and worse,  herbicide) pellets thrown out of a spreader onto the sidewalk. Next stop, the storm drain and the river. 

Homeowners often apply more “triple 16” fertilizer than their plants or lawn can use. To reduce — or better yet — end lawn fertilization, use a mulching mower (electric or hand, ideally), and leave the clippings to decompose into nutrients for your grass.

Natural fertilizers like soybean meal, cottonseed meal (organic) and feather meal break down slowly as the soil warms and provide your plants with a long-duration food source. Seed meals, alfalfa pellets and composted manure can be added to your soil and scratch-tilled (just work it into the first inch or two of soil; don’t rototill it all in deeply) in to increase tilth and provide nitrogen, phosphorus and potassium to your soil.

If my garden needs a fast fertilizer fix, I go with fish emulsion. It is easy to apply after mixing with water. After a fishing trip, I make my own fish emulsion by grinding up the leftover parts from cleaning the fish and the bones left after eating the fish. I keep it in the freezer. (Label it, so you don’t mistake it for a smoothie! It’s a smoothie for plants.) That quick nitrogen fix can be just the thing for a slow-growing corn patch.

Peruvian bird guano, Indonesian bat droppings and other distant fertilizer sources are effective, and mining them once influenced world politics, but bringing nutrition halfway around the world to get better tomatoes is unnecessary and unsustainable. Keeping what you have in your yard already, by composting your kitchen scraps, grass clippings, and leftover garden plants keeps plant nutrition closer to home.

For those of you with an eewww factor, read this next part while holding your phone far away — if at all. 

Human urine is a great fertilizer. Urine is sterile, and when diluted 10-to-1 with water, it can be applied to the ground around your plants to great effect. Many gardeners (wink wink) have been using this free fertilizer for 60-plus years (wink wink). Keep a jar handy when you’re working outside and don’t forget to dilute.