Time to put plants on a summer diet

Plants need 16 nutrients, such as nitrogen, phosphorus, potassium, sulfur, iron, magnesium, calcium and copper, to produce their own "food" via photosynthesis, using light. A good soil is the warehouse for plant nutrients, supplying plants with what they need to thrive. Plants absorb nutrients in solution through their roots. Often soils lack the required building blocks for growth, and we, as gardeners, supply them through fertilization.

Proper fertilizing in summer is important. It can increase vegetable yield and flower production. However, improper fertilization encourages lawn diseases and burns plants. It may also cause rampant green growth of vegetable plants, with little fruit set.

Fertilizers can be organic or inorganic. Organic fertilizers are generally less likely to burn plants than inorganic products. Inorganic fertilizers are readily available and can be quite affordable. Inorganic fertilizers come in a wide range of nutrient ratios, such as 16-16-16, 5-10-10 and 21-0-0. Whether the source of plant nutrients is organic or inorganic is not important to how the chemistry of a plant functions. However, organic fertilizers usually contain ingredients that build up the soil microorganisms, and inorganic fertilizers do not. Soil microbes are critical to a soil's ability to break down nutrients into a usable form for plants.

Roses are regular feeders and need light fertilization every three weeks. Apply an inorganic rose fertilizer in one application. Then, for the next feeding, use an organic fertilizer, such as compost tea. Alternate between using the two types of fertilizers. Vegetables do well with an application of one tablespoon of a 5-10-10 per plant every three to four weeks. Adding a generous helping of compost around each plant is also an excellent practice.

Now that it is hot, the only fertilizer that should be applied to a lawn is a slow-release fertilizer or an organic product. A typical lawn fertilizer is too high in nitrogen to use during the heat of summer and is likely to burn the grass. High-nitrogen fertilizers also encourage excessive growth of young tender tissue that is easily stressed by the heat and sun. Stressed plants attract disease organisms that may damage or kill a lawn.

No matter what fertilizer you use, or what plant you are fertilizing, make sure the plant is well hydrated prior to application. Immediately after fertilizing, water thoroughly to wash any excess product off the plants and into the ground. However, do not overwater, causing water (and the fertilizer) to run off the area fertilized. Fertilize and irrigate when the sun goes down to avoid burning plants. Always read and follow all label instructions.

In case your garden isn't producing yet, go to the Farmers' Market at Third and Curry Streets. Open 9 a.m.-1 p.m. on Saturdays, now through October, this local growers' market also offers a variety of fresh baked breads, pastries, jams, honeys and plants. For more information, see www.downtowncarsoncity.com.

For more information on gardening, contact me, 887-2252 or skellyj@unce.unr.edu, or your local University of Nevada Cooperative Extension office. Check out many useful horticulture publications at www.unce.unr.edu. "Ask a Master Gardener" by e-mailing mastergardeners@unce.unr.edu.

• JoAnne Skelly is the Carson City / Storey County Extension educator for University of Nevada Cooperative Extension.