Weatherford Democrat

May 4, 2013

ASK A MASTER GARDENER: The grass is always greener – unless it’s turned yellow


Weatherford Democrat

Here are this week’s gardening questions and answers, provided by Parker County Master Gardeners. To submit a question, send it to pcmgaquestions@gmail.com. For more information about Parker County Master Gardeners, or to become a member, call 817-598-6096 or visit www.pcmg-texas.org.

Why is my grass not green? I fertilized according to directions, but it is a yellow-green.

You may have an iron deficiency. Parker County soils are notoriously high in phosphorous. Combined with our alkaline pH, phosphorus ties up the iron and does not let plants take in this nutrient. This symptom is known as iron chlorosis and it also affects some shrubs. You can apply iron sulfate (e.g., copperas) according to directions to help alleviate this problem. You should also choose fertilizers with little or no phosphorus.

My St. Augustine grass is coming out, but some of the leaves have a yellow appearance while others look fine. What should I do?

You may have St. Augustine Decline (SAD), which is a virus that weakens the plant and makes it more vulnerable to other diseases and insect damage. Early stages of SAD are often confused with iron chlorosis, but you can distinguish between the two. Leaves showing iron chlorosis are either uniformly yellow or have yellow stripes parallel to the main vein of the leaf. Leaves infected with SAD have more of a smudged or mottled appearance. The picture demonstrates this difference. The leaf on the left is affected by SAD and the leaf on the right by iron chlorosis.

While iron chlorosis can be corrected with applications of iron sulfate, there are no chemical controls for SAD. If your grass continues to lose vigor despite applications of fertilizer and iron sulfate, the best solution is to replace the diseased areas with a resistant variety such as Floratam, Floralawn, Raleigh or Seville. All are SAD-resistant varieties which will choke out the diseased grass over a period of years.

My garden vegetables aren’t growing as they usually do. Can you tell me why?

Our spring weather has been much cooler than usual this year. Vegetables need sunshine, warm air and a warm soil temperature for optimum growth; not the cloudy days and cold nights we have had in the past month. You should see a significant improvement when the weather warms up. If not, then you may have other problems that need to be addressed.

Rainwater seminar

Plan to attend a seminar on Rainwater Harvesting and Drip Irrigation to be held at the Texas A&M AgriLife Extension Office at 604 N. Main St. in Weatherford on May 11.

The seminar will be from 9 a.m. to 3 p.m. A fee of $20 will be charged and will include lunch, refreshments and handouts.

Don’t miss this great opportunity to get more information on these two important subjects.