Fertilizer doesn’t have to come in a box or jug with chemical warning labels on it. There are many ways to naturally fertilize your garden for added nutrients in your soil. In fact, by choosing a few choice ingredients, you can really fine-tune the nutrient levels to suit your plants better than you would with some broad-spectrum chemical treatment.
To keep things simple, a good dose of aged manure or compost is always an excellent choice for any garden. Stick with that unless you have some specific deficiencies you have to fix up. Mix in a load of it in the spring, and add additional compost about halfway through the growing season around the bases of your plants.
Now for more ingredient-specific fertilizing, do a soil test to see what you need and then get some of the following:
Extra nitrogen: coffee grounds, fish emulsion, bone or blood meal
Extra potassium: potash, wood ash, banana peels
Extra phosphorus: fish emulsion
Extra calcium: lime, dolomite or crushed egg shells
Extra magnesium: Epsom salts (the gardening kind, not bath salts)
Don’t forget to take into consideration what you’re planting. Not all plants need the same things, so don’t treat your entire garden area as one big plot of soil. Low on potassium? Well, some plants may prefer that, so don’t add any fertilizer to their beds and boost it just where it’s needed.
As mentioned just above, if you are using manure for fertilizer, you need to make sure it is at least 3 months old. It needs to be aged or the very high levels of nitrogen still in the material will kill your plants.