Vegetable gardens prosper with organic matter

Monday, June 1, 2015

There is nothing better in the summer and fall than to walk out to your garden and harvest some ripe vegetables. But before that happens, healthy soil is a must for a productive garden.

One of the best ways to improve the health of your plants is by adding organic matter in the form of compost or composted manure to your soil. This can help reduce the amount of fertilizer treatments your plants need, said David Hillock, Oklahoma State University Cooperative Extension consumer horticulture specialist.

“The addition of compost or manure to your garden soil will add nutrients, improve drainage and help your plants’ immune systems. In addition, organic matter also improves soil structure and texture, allowing the ground to better retain water and allow pockets of oxygen to exist,” Hillock said.

Organic matter is the main source of soil fertility in an organic garden. Gardeners also can use organic mulches like compost or cottonseed, which decompose slowly and release nutrients into the soil.

When looking for organic fertilizers, gardeners must first know what kind of fertilizer their plants may need. Hillock suggests conducting a soil test to identify the nutrient needs of your garden.

Like traditional fertilizers, organic fertilizers are labeled with three bold numbers showing the percentage of nitrogen, phosphorous and potassium, or N-P-K found in the fertilizer. It is important to understand how these nutrients are used by plants.

“Nitrogen promotes lush, green vegetative growth. Phosphorous encourages fruit growth and strong roots, and potassium (or potash) creates larger, more colorful flowers and helps in overall plant strength,” he said.

Organic fertilizers come in many forms and vary significantly in nutrient content. Most organic fertilizers contain animal waste and decomposed plants. In addition to the macronutrients, nitrogen, phosphorous and potassium, organic fertilizers also contain many micronutrients and trace minerals. Organic fertilizers also have helpful microorganisms that replenish your soil. These are some of the great benefits of using organic fertilizers over conventional ones.

“Gardeners have a choice of solid or liquid organic products,” Hillock said. “Some organic fertilizers include cottonseed meal, blood meal, bat guano, fish meal, fish powder, seaweed, compost tea, worm castings, fish emulsion and mycorrhizal fungi. Keep in mind most organic fertilizers require the activity of soil microorganisms before nutrients are available for plant uptake. Microorganism activity is generally dependent on soil temperatures greater than 50 degrees Fahrenheit and sufficient soil moisture. Dry and/or cold soil conditions will delay the release of nutrients from these organic sources and affect how long they are available in the soil.”

It is always best to use balanced, slow-release, low-concentration fertilizers for vegetables. Well-rotted and composted manure or liquid fish emulsion fertilizers are good choices for a strong, healthy garden.

Once you have selected a fertilizer, follow these steps for a successful application:

• First, remove any weeds around your vegetables that may compete with your crop.
• For solid products, spread the fertilizer in a circle around your plant, leaving about 4 inches to 6 inches of bare soil around the stem of the plant.
• Use a hoe to gently mix the fertilizer into the upper soil layer.
• Water the garden thoroughly to dilute the fertilizer and mix it into the soil.

If you are using a liquid fertilizer, carefully mix the fertilizer according to label directions. Apply the liquid to the soil around each plant, but avoid wetting the foliage. Irrigate after each application to dilute the fertilizer and carry it into the soil.