NEIGHBORHOOD GARDEN FOR OCTOBER 20, 2007

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GET YOUR SOIL TESTED NOW!!!

BY GEORGE EDGAR

          Did you have trouble with a particular area of your lawn and/or garden last year? Did some of your plants just not grow the way they should? Are you planning to plant a new flower garden or vegetable garden? Are you going to put in a new lawn next spring, or plant a new tree and/or shrub this fall? Are you wondering if your soil needs to be amended so your plants will grow to their full potential? If you answered yes to any of the above questions, now is a good time to get your soil tested so you know what needs to be added or done to the soil this fall. Fall is the best time to add organic material and can be done anytime before the ground freezes.

          The easiest way to do this is to get a small, postage paid, cardboard box from your County Extension Office or from many full service garden centers.  This container is very easy to use.  It comes with a little plastic bag, instructions, and a form to complete.  Just fill in the form and inform the soil lab at UNL what you are going to plant.  On the form where it says “crop”, put what you will be planting in that particular area.  That is, are you trying to grow flowers, vegetables, a tree/shrub, or grass? This will allow the lab to send specific recommendations for that area.  If you don’t indicate what you will be planting, you will still get an analysis of your soil but no specific recommendations. For specific help you can contact your Extension Educator after you get your analysis.  

          If you want separate tests done for your lawn, your vegetable garden, and or your flower garden, take separate samples from each area and put in separate boxes. The form tells you how much the cost is depending upon the kind of test desired.  Then just mail the postage paid soil sample and it will be tested by the Soil Lab at the University of Nebraska-Lincoln and they will send you the results.  The simplest test will be for the pH level, phosphorus, potassium, and organic matter. There is a minimal cost for each test sent in. 

          One lawn company told a customer twice last fall that it was time for her “fall lime application”. Her daughter-in-law, a Master Gardener, had taught her that lime raises the pH in the soil and is usually not needed in Eastern and Central Nebraska. Without this knowledge she would have had an unnecessary expense. The pH in Eastern and Central Nebraska already runs neutral, 6.5 to 7.3. Thus, we should not add lime unless a soil test indicates a need. The same is true for other soil amendments such as gypsum which also raises the pH and does nothing to break up clay soil. DO NOT ADD AMENDMENTS WITHOUT A SOIL TEST.

          Our youngest son lives in Albany, New York, and the soil there is more acidic, pH 5.5 to 6.5. Acid loving plants like blueberries, azalea, and rhodendrons grow great. But to grow some other plants and vegetables, he needs to add lime. Many books and TV garden shows such as Victory Garden come from New England and the East Coast and they are always adding lime. We do not need it.  Farmers may add lime to their soil because heavy irrigation leaches it out of the soil. But they do this only after they have conducted a soil test.  The water in Lincoln has a pH of about 7.3 so this adds to our problem of high pH.

          Iron chlorosis may occur in some soils that have a pH higher than 7.0 and are compacted and poorly drained. (Sounds like Eastern and Central Nebraska soils doesn’t it?) Pin Oak trees especially get iron chlorosis most every year because the iron in the soil can not be utilized by the plant when the pH gets above 7.0.  Adding iron to the soil probably will not help until the pH is lowered. Problems with chlorosis can be reduced by lowering the pH in the soil by working horticultural sulfur granules into the soil at least every fall and most years also in the spring. I add sulfur to my acid loving plants such as Azalea, Rhododendron, and Blueberries in the fall and fertilize with a fertilizer that is high in sulfur and high in iron (Holly Tone) in the spring.

          The results of the soil test can also tell you about the organic matter of the soil and if you need to add more. Our hard compacted clay soil can be greatly improved with organic matter. If you are going to start a new lawn, a new flower bed or vegetable garden for next spring, don’t just added topsoil. Most top soil you get in a bag or by the truck load has very little organic material. Compost, grass clippings, leaves, straw, Canadian peat moss, humus and manure, or composted manure are the best amendments. Many cities have compost available from their recycling and that is a good amendment any time. Any composted manure should be at least one or two years old, not fresh. Bags of compost or composted manure do not cost much more than top soil and is certainly more beneficial.

          According to the UNL Extension Publication G90-945-A “A Gardener’s Guide for Soil and Nutrient Management in Growing Vegetables”, a soil test is usually needed only every 5 years. This publication also lists the desired pH range for vegetable crops. According to this publication, “Problems with insects, diseases, herbicide injury, and weather conditions may be difficult to distinguish from soil fertility problems, and can occur at the same time.  Although 16 elements are needed for plant growth, only nitrogen (N), phosphorus (P), potassium (K), sulfur (S), iron (Fe), and zinc (Zn) may need to be added to Nebraska soils.”

          More information about getting a soil test and the nutrient needs of plants is available on the internet at http://ianrhome.unl.edu/search. In the top box scroll down to “Extension Publications”. In the bottom box you can type in the name of any plant, shrub, tree, insect, disease, or other subject you want information about. Many extension publications dealing with that subject will be displayed. Click on the one you want to read.  They may be saved on your computer or printed off if desired.

          Remember, the soil test box has a pre-printed, postage paid label so it is easy to use. Get a University of Nebraska –Lincoln soil test kit and have your soil tested now so you can add what you need this fall!!! Remember, fall is the best time to add organic material and can be done anytime before the ground freezes.

Copyright 2007