The main difference between conventional synthetic fertilizers and organic slow-release fertilizers is solubility, or how quickly they dissolve in water.
Synthetic fertilizers dissolve rapidly, releasing nitrogen quickly into the soil. They promote quick "green up" and shallow root systems. They quickly leach into ground or surface waters when it rains, preventing most of the nitrogen from actually being absorbed by your plants. This causes pollution that can lead to algal blooms. Over time, synthetic fertilizers can build up in your soil and kill the microbes that keep your soil and plants healthy.
Slow-release organic fertilizers, along with compost and compost tea, work by providing beneficial microbes and food for microbes already living in your soil. These microbes, in turn, produce nutrients for your plants. These fertilizers are less soluble than synthetics, leading to less leaching of nutrients, and lessening the need for frequent fertilizer applications.
Many landscapers now provide compost tea applications, or you can check out our how-to for brewing your own.
You can buy a compost tea brewing system or make your own at home. Whichever system you use, you will need a heavy-duty pump to aerate the water sufficiently. Proper aeration encourages beneficial microbes to multiply and discourages harmful microbes from growing in your tea. A fish aquarium bubbler will not be strong enough.
1. Start with great compost. Blending two or three composts together will give you a great variety of beneficial microbes. Put your compost in a mesh strainer bag (you can find them at the local hardware store in the paint section).
2. Fill your brewer with water and run the pump for 20 minutes to de-gas any chlorine.
3. Put your compost bag in the water while the brewer is running. Hang the bag from the edge of the bucket to expose as much of the compost as possible to the bubbling water.
4. Check the color of the water to make sure it is getting significantly darker, which indicates that microbes are being extracted from the compost.
5. Add food to feed the microbes. Suggested foods include molasses, kelp, humic acid, and fish emulsion.
6. Brew for 24 hours.
7. Decant your tea and use within six hours. Mix two parts water with one part compost tea and apply using a watering can or sprayer.
8. Clean your brewer immediately.
9. Brew more tea!
Got new trees and shrubs? Drip irrigation can be an effective way to keep them well-hydrated this summer, but keep in mind the following before you put down those hoses:
- Place drip tubes beyond the root ball, as well as on it, to encourage roots to grow into the surrounding soil.
- Water newly planted trees and shrubs seldom (less often than your lawn) and deep (12-18"). Too much watering encourages excess growth, a magnet for fungus diseases and sucking insects.
- Remove tubes after two years. Your plants will be well-established and just won't need the irrigation anymore.
Photo credit: U.S. Department of Agriculture
So, you are leaving your clippings for 80% of your lawn’s nutrient needs. What is free and easy to add to that? If you’re lucky, the PRFCT ingredient is already growing right beneath your toes.
Clover is a nitrogen fixer—it pulls nitrogen from the air and releases it back into the soil when mowed. Those nitrogen-fixing roots run deep, keeping clover green even in hot, dry months. Your grass will love the nitrogen boost every time you mow, and the environment will love you for not adding more fertilizer.
Worried about bees? It's true that bees (and butterflies!) love clover flowers, but they are not aggressive away from their hives. Bees feasting on clover flowers should not sting unless stepped on directly. You can prevent stings by avoiding large clover patches, wearing shoes when on a flowering clover lawn, and mowing as soon as the flowers open. The cut flowers are also nitrogen-packed, so be sure to leave them along with the rest of your clippings.
Worried about thatch? If you're fertilizing PRFCTly, you don't have to be.
Thatch is a naturally occurring layer of decaying material that accumulates in soil. A ½" layer of thatch is healthy. It acts as insulation for soil and roots and a cushion for your kids' knees when they fall on the grass.
Thatch build-up is not caused by the presence of grass clippings. In fact, having organic material like grass clippings on your lawn feeds the same microbes that remove excess thatch from your soil.
Problems occur when soil is pickled by the salts and acids in chemical fertilizers and pesticides, preventing the natural composting process from taking place. Material builds up, resulting in a thick layer of thatch that attracts pests and creates conditions for fungus to spread.
Instead, prevent thatch build-up by fertilizing your lawn with natural fertilizers like compost tea and, of course, grass clippings.