Common and strong chemical fertilizers are readily available at any nursery or garden supply store, but they are not the best choice for fertilizing your garden. Non-organic chemical fertilizers can have an adverse effect on the soil and can run off into the water supply. Chemical fertilizers may also harm the plants they are supposed to feed by releasing nutrients too quickly, causing plants to shoot up and become leggy and overgrown with an immature, shallow root system. Natural choices offer the benefits of fertilizer without the harmful side effects, making them the best choice for your garden.
One of the most basic garden substances, a good pile of compost is nothing but well-rotted natural refuse: vegetable scraps, grass clippings, dead leaves and dirt turned into a rich fertilizer with no harmful side effects. You can easily create your own compost at home, or you can purchase organic compost. Compost has many benefits: it helps improve soil structure, creates aeration, releases nutrients slowly and it won't lose nutrients to watering; chemical fertilizers are often washed away by rain or the garden hose before plants receive the benefits.
Fish & Seaweed
A combination of fish and seaweed products is better than standard chemical fertilizer, especially for newly transplanted vegetables. Add 1 tbsp. of fish emulsion and 1 tbsp. of liquid seaweed to 1 gallon of water, then apply generously, recommends Jeff Bredenberg, author of "How to Cheat at Gardening and Yard Work." Both fish emulsion and liquid seaweed are rich in nutrients that plants need, are gentle on the soil and will promote healthy growth and a deep root system. Both are usually available at nurseries or landscaping centers.
Manure & Manure Tea
Well-dried manure works in much the same ways as compost, releasing nutrients at a steady rate and improving the soil at the same time. In the vegetable garden, manure can be applied by side-dressing or top-dressing plants. For heavy-feeding plants, a manure tea is a way to supply nutrients at a faster rate, says Barbara Damrosch, author of "The Gardening Primer." Make manure tea by putting three to four shovel scoops of manure in a 5-gallon bucket, filling with water, covering and letting the "tea" steep for a few days to three weeks; apply the tea as a liquid fertilizer. Damrosch recommends manure tea for vegetable garden plants such as asparagus, cabbage, celery, corn, eggplant, squash and tomatoes.