Pender Gardener

Pender Gardener

By Charlotte Glen

Special to Topsail Advertiser

Get Ready for Spring Planting by Soil Testing Now!

Now is the time to begin preparing for spring planting by bringing soil samples to your local Cooperative Extension Office for testing! Soil testing can help you save money in your lawn, garden and landscape and grow healthier plants by telling you which nutrients are already in your soil and which ones you need to add with fertilizers. In addition, soil testing is a free service for North Carolina residents, provided by the NC Department of Agriculture. If you haven’t submitted soil samples for your yard or garden in the past couple of years, take the time to do it now! Samples submitted at this time of the year, the lab’s busiest season, may take several weeks to be analyzed, so get your samples in ASAP to make sure your results are back in time for spring planting!

What Soil Testing Can Tell You

Soil test results can tell you some very important things about the soil your plants are growing in. One of these is the soil’s pH. Soil pH, measured on a scale of zero to 14, is an indication of how acidic or basic your soil is. Soil pH’s in eastern NC and Pender County vary anywhere from 3.5 (very acidic) to 8.0 (basic) or higher. Most plants prefer to grow in soils with a pH of 5.5 to 6.5, though there are some notable exceptions like blueberries, which prefer a soil pH around 4.5. It is very important to know your soil’s pH because pH affects your plants’ ability to absorb nutrients. If your pH is too high or too low, your plants will not be able to take up certain nutrients, even if they are plentiful in the soil. This results in nutrient deficiency symptoms like yellow leaves or stunted growth. Having your soil pH in the correct range for the plants you are growing will also help reduce disease problems and produce naturally stronger, healthier, more productive plants. The recommendations you receive back from your soil test will tell you what your pH is and if you need to add lime to raise pH (if your soil is too acidic), and how much if necessary. Many people apply lime unnecessarily, which wastes money because the lime isn’t needed, and also can raise your soil pH too high, resulting in poor plant growth.

Soil test results will also tell you which nutrients you need to apply to your soil for the type of plants you are growing. Recommendations are included for common nutrients like nitrogen, phosphorous and potash, as well as for micronutrients like magnesium, sulfur, boron and others. These recommendations are good for both synthetic and organic fertilizers. Soil test results can help you save money by letting you know the correct amount of fertilizers to apply and by showing you which nutrients are not needed. Applying the correct amount of fertilizer results in healthier plants and helps prevent water pollution, since over application can damage plants and leach into groundwater.

While soil test results are very helpful in telling you about the nutrient status of your soil, they will not tell you about any insect or disease problems that may exist in your soil, or if your soil is contaminated with chemicals or herbicides. Testing soil for chemical or herbicide contamination is very expensive and can only be done through private labs.

How to Test Your Soil

Soil testing can be done any time of the year and boxes and forms are available from any Cooperative Extension Office (There is one in every county). To have your soil tested, collect samples from different areas of your yard. You will need to collect three to five random samples from each area in your yard where you are growing something different, for example, 3 to 5 samples from your lawn, 3 to 5 samples from your vegetable garden, etc. Samples can be collected with a stainless steel trowel and usually need to be taken around 6” deep into the soil. For each sample you are going to submit (example – lawn, garden, flower bed), aim to collect a total of about a cup and a half of soil when the 3 to 5 random samples are mixed together. If there are areas in your yard where plants are not growing well be sure to sample them separately to find out if the problem is nutrient or pH related. Submitting soil samples to the NC Department of Agriculture’s soil testing lab through your local Extension office is the only accurate way to know the amount of nutrients your soil needs, plus it is free. Home soil test kits sold at garden centers and big box stores are often very inaccurate and do not tell you how much fertilizer to apply.

Once your samples are ready, drop them off at any Extension office to be shipped free to the soil testing lab in Raleigh. When complete, your results will be posted online at http://www.ncagr.gov/agronomi/ (click on the link on the left hand side titled ‘Find Your Report’), and you should begin checking this site for your results three to four weeks after you submit them. If you do not have internet access, contact your local Extension office and provide the name the samples were submitted under to get your results.

Learn More!

If you have questions about soil testing, want soil testing supplies, or need help understanding your soil test results, contact your local Cooperative Extension Center. In Pender County call 259-1235 or visit our office located at 801 South Walker St., in Burgaw (office hours: Monday through Friday, 8 a.m. to 5 p.m.). Soil test supplies can also be picked up from and samples dropped off at Pender Pines Garden Center, located between Hampstead and Surf City, on Hwy 17.

More information about soil testing is available online from the Department of Agriculture’s website at http://www.ncagr.gov/agronomi/sthome.htm. ‘A Gardener’s Guide to Soil Testing’, a very informative publication about soil testing and soil test results, is available from your local Extension office or can be downloaded online at http://www.ces.ncsu.edu/depts/hort/consumer/ag_publications.html.

Charlotte Glen is a Horticulture Agent with Pender County Cooperative Extension of

NC State University, College of Agriculture & Life Sciences. She can be reached via e-mail at Charlotte_Glen@ncsu.edu