Archive for Thursday, April 10, 2008

Moderation in fertilizer applications important

April 10, 2008


I try to base this column on the questions that come in to the Extension Office each week, and right now, fertilizing lawns is a hot topic. I have talked about some of the basic principles of lawn care before, but today I have a new spin on fertilization based on the concepts of a new program called Green Yards and Communities. You will hear more about this program in the weeks to come.

Applying fertilizer when it is most useful to the plant is the most important thing to remember. The Environmental Protection Agency reports that more than 70 million tons of fertilizers are applied to residential lawns and gardens annually - and much of it is unnecessary, so get the facts on what you need before you apply.

Lawns are purposeful in the landscape. Turfgrass filters stormwater runoff and prevents erosion by holding soil with plant roots. My lawn holds the soil on a steep bank in my yard better than most ornamental plants could - and requires less weeding.

Fescue is the most common grass species used in this area and the best choice of cool-season grasses, and the following management recommendations will refer to it.

Q: When should you fertilize?

A: Apply fertilizer to fescue only in September and November for best results. You may make a third application in May only if your lawn is irrigated. Research proves that fescue lawns require a maximum of three fertilizer applications to stay green and healthy.

Fertilizing now (in the spring) encourages lush growth that the roots will not be able to support later this summer, so you will end up watering more. Improperly fertilized lawns also develop more thatch (compressed surface roots, stems and runners between grass blades and soil) which can keep water and nutrients from reaching plant roots.

If you want to fertilize less than three times a year, September is the prime time for application.

Q: What kind and how much fertilizer does your grass need?

A: The three numbers on the bag represent nitrogen (N), phosphorus (P) and potassium (K), respectively. All plants require these nutrients (and several others) to survive, but many of them are available in the soil, air and water. Nitrogen is the most common nutrient that needs replacement because plants use more of it than any of the others.

All fertilization programs should be built around nitrogen requirements. Fescue only needs 1 to 1 1/2 pounds of nitrogen per 1,000 square feet to be healthy. Add phosphorus and potassium only if needed. Excess nutrients make it harder for the plant to use other nutrients and can also run off of the lawn into stormwater and eventually into our water supply.

The only way to know for sure how much phosphorus and potassium your lawn needs is to have a soil test. Kansas State University has a laboratory that performs the analyses, and samples can be submitted through the Douglas County K-State Research and Extension Office (or your local county's office). Douglas County residents can test up to 10 samples free of charge because of a temporary grant partnership with the Douglas County Conservation District.

Soil from vegetable and flower gardens and landscaped areas can also be submitted for nutrient analysis.

Make some changes in the way you fertilize your lawn this year for the good of your yard and your community. To me, saving money on unnecessary fertilizer means I have more to spend on flowers and shrubs for my landscape.

Stay tuned for more information about Green Yards and Communities. If you have gardening questions, call a Douglas County Extension Master Gardener at 843-7058, 1 p.m.-4 p.m. Monday-Friday, or e-mail anytime.

Jennifer Smith is the Douglas County Extension AgentHorticulture for K-State Research & Extension. She can be reached at 843-7058 or <a href=""></a>.


Richard Heckler 10 years, 1 month ago

Applying MulchesApply mulch around established plants in the garden in mid-spring, when the soil has warmed up sufficiently for active root growth. If a mulch is applied before this time, it will keep the ground cool and root development will be delayed. With newly planted material, apply a mulch after the plants are set in place and watered in well. If you are planting in the late summer or early fall, apply the mulch immediately after watering the plants so that the soil temperature will be kept warm during the cool nights. It is important for fall-planted stock to have sufficient root growth so that the plants don't heave out of the ground during the winter months because of alternate freezing and thawing. Organic mulches such as leaves, sawdust, or shredded bark should be moist when applied to the soil. Extremely dry mulches act as a blotter and remove moisture from the soil.Bark (Softwood): Chunk pine, fir, and redwood barks are the most popular types. This material is acidic in its reaction and does not require any additives to modify the pH. Compost: An excellent mulch and soil conditioner that you can make at home by composting various types of yard wastes such as grass clippings, leaves, and plant tops from vegetables and flowers. This partially decomposed material rates as one of the best organic mulchesHops (spent): These may be available from local breweries. They have excellent color and are nonflammable. The odor of fresh material may be offensive but it subsides in a few weeks. Lawn clippings: Grass clippings are best used when dry. If applied fresh, it should be spread loosely; otherwise, it mats down, produces heat during decomposition, and gives off an offensive odor. Do not use grass clippings from the first mowing after the lawn has been treated with pesticides.Leafmold: This mulch can be obtained by home composting of leaves or from a municipal composting facility. Leaves composted in the fall of the year will be ready for use by spring. This is a good mulch that provides some nutritional value to landscape plantings. Mushroom compost (spent): This material is available in garden centers and in areas where commercial mushrooms are grown. It is inexpensive and has good color for use in the landscape. Pecan shells: A good long-lasting mulch with pleasing color and texture. Pine needles: This material makes a light, airy, attractive mulch. It is recommended to leave pine needles beneath pine trees rather than remove them. Pine needles are recommended for use around acid-loving plants. Wood chips: This material is available from garden centers, arborists, power companies, and municipal yard waste facilities. It is very durable and makes an excellent material for covering paths and walkways. If used on landscape beds, nitrogen deficiencies will develop.

Richard Heckler 10 years, 1 month ago

Ahhhhh yes, the beauty of mother nature coming to life in the fall color of our forest and landscape plants. For some, this marvel is overshadowed by the chores of raking and disposing of fall leaves.What's needed here is an attitude adjustment! Yes! Autumn leaves don't have to become trash. On the contrary, they easily can be turned into valuable soil-enhancing organic matter. Tree leaves can be recycled directly on the lawn. Use your power mower or shredder/vacuum to break dry leaves up into smaller pieces. A mulching blade on the mower will speed this process, but even a standard blade will do an adequate job. For large leaves like maple and sycamore, it may take several passes to get a finely shredded product. Once the leaves are pulverized, they will break down quickly and also will benefit the grass plants.

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