Fall Gardening

AgriLife Logo

We are right in the middle of the hottest days of summer, and now is the time to start thinking about your fall garden.  Texas is a great place for vegetable gardeners because we can grow crops all year long!

Not many people want to be working in the garden in August, but now is the time to be planting pumpkins, winter squash, peas, sweet corn, and lima beans.  Just around the corner in September we can start planting cole crops like broccoli, Brussels sprouts, cabbage, and cauliflower.  The list goes on with something new to plant all through the fall and winter!

Gardening in the fall is a lot of fun, but there are a few tips that can help you be more successful.  Fall crops generally do better when you start with transplants, rather than planting by seed.  Many of our local nurseries will have vegetable transplants you can purchase.

The trick to fall gardening is making sure your transplants have plenty of water to get established in our late summer heat.  The small transplants need at least two weeks to get a root system established in the ground, and you might need to water every day to support the plant until it’s established.  Use a moisture meter or just stick your finger in the ground to see if the soil is moist at the root zone.

Vegetables are quick growing plants that need a lot of nutrients so they can produce fruit for us to eat.  The soil in Williamson County does not have enough nutrients to support vegetables without some additional help from us.  You can provide a good boost to the soil by working in compost when you prepare the garden bed.  Vegetables usually need extra nitrogen every three weeks after they are established.  Plants need nitrogen more than any other element, and it’s used by the plant for photosynthesis and building proteins.   For an abundant harvest, add 1 tablespoon of ammonium sulfate (21-0-0) around each plant every three weeks and water it in well.

Be sure to stop by the Demonstration Garden on 3151 SE Inner Loop in Georgetown to see our fall vegetable garden.  We planted fall tomato and pea variety trials in July, and we plan to plant strawberries and winter squash in the coming months.  The Master Gardeners work in the Demonstration Garden on Tuesday and Friday mornings, and they are a wealth of garden knowledge if you have questions.

For more information about fall gardening, contact Kate Whitney, Williamson County Horticulture Extension Agent, at 512-943-3300.

Summer Lawn Watering Tips

AgriLife Logo

We have enjoyed a nice summer so far with cooler temperatures (for Texas) and good rains in June.  This is great news for our lawns and plants, and especially for our water bills.  Over the last few weeks, we’ve had hotter temperatures and less rain, so you need to start thinking about supplying extra water to your lawn.

If you plan to water your lawn, be sure to follow these tips to conserve water.  Turfgrass in our area needs about one inch of water per week, and you can split that into two different watering periods of ½ inch each.  Be sure to check your city’s watering guidelines and water on the appropriate days.

  • Water deeply and infrequently. Try to water to a depth of approximately six inches each time you water.  This means the water should penetrate six inches in the soil.  Watering deeply encourages deeper, denser root growth.
  • Wait to water until visual wilt occurs, and water late at night or early in the morning. Watering during the cool hours of early morning or late evening will reduce losses from evaporation and improve water-use efficiency.
  • Monitor your irrigation equipment. Broken heads or pipes can waste water and create dry spots in your lawn.  Replace broken heads and consider an irrigation audit by a licensed irrigator.
  • Take advantage of rain. Remember that a lawn irrigation system is put in place to supplement water during dry times, so save water by turning off your irrigation system when it rains and wait until the lawn needs to be watered again.
  • Mow at the upper end of the appropriate mowing height for your grass species. Taller grass means your grass will develop a deeper root system that allows the grass to access water deeper in the soil.  You can find the mowing height for your grass species at http://aggieturf.tamu.edu/.
  • Follow the 1/3 rule. Mow frequently enough that you never remove more than 1/3 of the total grass.  Cutting off too much of the grass will stress your grass.  Stressed grass is less tolerant to heat and drought and more vulnerable to pests and diseases.

For more information about lawncare or water use, contact Kate Whitney, Williamson County Extension Agent for Horticulture, at 512-943-3300.

Rose Rosette

AgriLife Logo

Rose Rosette Disease

Rose Rosette Disease (RRD) is a terrible rose disease that we’ve been hearing about for years, especially from the Dallas area. Unfortunately, we are starting to see more cases in Williamson County.  Rose Rosette has been around since the early 1940’s, but the problem seems to be growing in recent years as cultivated roses are used in more and more landscapes.  In 2011, Rose Rosette was diagnosed as a virus and researchers have recently confirmed it is spread by the eriophid mite Phyllocoptes fructiphilus.

Eriophyid mites are microscopic mites (3 to 4 times smaller than a spider mite) that can be transmitted by wind or landscape tools from infected plants to healthy plants where the mites feed and introduce the virus. The mites tend to hide in rose buds, on open flowers or sepals, or at the base of shoots, leaf axils, and leaf scars during the winter.  The virus appears on new foliage in the spring.

Typical symptoms of RRD include elongation and thickening of the shoots/stems; red leaf mottling; leaf distortion; excess thorns that are flexible; yellowing and stunting of plants; witches’ brooms; flower distortion; branch/shoot dieback; and reduced winter hardiness. The “witches’ broom” is a very common symptom of RRD, and it’s a brush-like cluster of shoots and branches that originates from the same point.  This growth is also called a “rosette,” which is where the disease gets its name.  Witches’ brooms spread randomly across the plant, and the flowers fail to open or look distorted.

Researchers all over the United States are working to identify treatments and rose varieties that are resistant to RRD. Right now, early detection and removal of infected plants is the best way to reduce the impact and spread of the disease.  Infected plants should be removed and disposed of immediately, including its roots.  Place in a sealed bag and dispose of the plant off-site to keep the mites from dispersing to another plant.  Wait one to two months after removing an infected plant before planting a new, healthy plant.  Miticides like bifenthrin, carbaryl, or endosulfan can be used to control the spread of the mites.

Fall Webworm

AgriLife Logo

Over the last few weeks, I have received a high number of calls about webs that are taking over trees in Williamson County.  I can certainly understand the concern because they are ugly webs and they seem to spread from limb to limb.

The webs are created by fall webworm (Hyphantria cunea), a common caterpillar pest of trees.  Fall webworm larvae are about an inch long, pale green or yellow, and covered in white and black hairs.  They can cover entire branches with their webs, and the larvae feed within the webs on the tender parts of leaves.  A heavy infestation of fall webworm will rarely kill a tree, but an infestation over several years can make a tree more susceptible to drought, disease, or insect pests.

Fall webworms live during winter as pupae on the ground or in sheltered spots around homes or in tree bark.  The moths are 1 to 1 ½ inches with white wings, and they emerge in the spring to mate.  Female moths can lay up to 600 eggs in a mass on the underside of leaves.  The larvae hatch and immediately begin to build a web and eat the leaves inside the web, expanding the web as they consume the foliage.  The larvae molt six or seven times before they leave the web to pupate.  The life cycle from egg to adult is approximately 50 days.  Fall webworms have two to four generations, depending on where they are in the state.

We have several options to control fall webworm, but it’s not always easy because the webs might be out of reach in the trees.  If you can reach them, you can remove the webs, caterpillars, or egg masses by knocking them out of the tree with a stick or broom or pruning out the webs.  Beneficial insects can help keep the population under control.  You can help the beneficial insects by opening the web.

If the webs are too high to reach, try a hose-end or high-pressure sprayer.  We have a few options for insecticides to help if you have a large infestation.  The sprays must reach inside the web to be most effective because the webworm larvae stay inside the web.  Insecticides containing Bt (Bacillus thuringiensis) or Spinosad are effective against fall webworm, and they will not harm beneficial insects.  Carbaryl and pyrethroid insecticides are highly effective against fall webworm, but they should only be used for severe infestations because they are toxic to beneficial insects.  Be sure to read the pesticide label carefully and spray carefully to avoid drift to other properties.

If you have any questions about controlling fall webworm, contact Kate Whitney, Williamson County Extension Horticulturalist, at 512-943-3300.

Finding an Arborist

AgriLife Logo

Trees are treasured part of our landscape.  They provide great shade and add texture and dimension to the landscape.  I frequently receive phone calls from homeowners who are worried about their trees for potential disease issues or need help with proper pruning.  Texas A&M AgriLife Extension has great information about a variety of tree issues, but sometimes we still need to call in a professional arborist for help.

An arborist is a specialist in the care and cultivation of trees.  They can help with selection, planting, and pruning of trees; deliver proactive plant care for the health of your trees; provide emergency care for trees that are damaged in storms or might be a risk to structures and people on the property; and they can remove weakened or dying trees.

Homeowners often call me for a recommendation of a good arborist.  While I cannot recommend a specific arborist or company, AgriLife Extension does have some really good tips for selecting an arborist.  First, check for membership in a professional organization such as the International Society of Arboriculture (ISA), the Tree Care Industry Association (TCIA), or the American Society of Consulting Arborists (ASCA).  You can also check for an ISA arborist certification.  The websites for these organizations have an arborist locator that will help you find one in your area.

Ask for proof of insurance for personal and property damage, as well as workers compensation.  You can also ask to see any necessary permits and licenses that might be required by the local government.  Many arborists obtain extra certifications in specialty areas like tree risk assessment or oak wilt.  If you have a specific issue, you might search for an arborist with those specialized qualifications.

Be sure to ask for more than one estimate unless you are familiar and comfortable with the arborist.  Compare the bids and look at the price, work to be done, skill and professionalism of each estimate.  A good arborist will only perform accepted practices, and they will be up front about what is best for your trees.  Be wary of door-to-door salesmen who offer bargains or a cheap solution for serious tree issues.

Trees are a valuable investment, so take time and care to find a good arborist who will deliver quality work.  If you have questions about tree care, contact Kate Whitney, Williamson County Extension Horticulture Agent, at 512-943-3300 or klwhitney@ag.tamu.edu.

Tomato Fruitworm

AgriLife Logo

Tomato season is here! I harvested my first tomatoes last week from the Super Sweet 100 variety.  I would like to say that I was generous with my harvest, but those first few tomatoes did not make it out of the garden.  There’s nothing better than snacking on vine-ripened tomatoes as you work in the garden!

The Master Gardeners work diligently every week in our Demonstration Garden. Part of that work includes scouting for pests in our Integrated Pest Management program.  This week, Master Gardener Jim Williams found evidence of tomato fruitworm.

The tomato fruitworm adults are medium-sized, tan or brown moths that lay eggs on the upper and lower surfaces of tomato plant leaves. The tomato fruitworm larvae are brown, green, pink, or sometimes yellow with a dark lateral line.  They are 1.5mm long at hatching and can be up to 25mm long at maturity.

The larvae feed on the tender leaves of the plant and tunnel into the tomato fruit. A single tomato fruitworm can move from one tomato to another to feed, damaging several tomatoes.  Tomato fruitworm also feed on corn, cotton, and peppers.

Tomato fruitworm can be controlled organically with sprays of Bacillus thuringiensis (Bt) or Spinosad. Monitor your plants closely for signs of eggs on the leaves or damage to the green fruit.

Summer Weed Control

AgriLife Logo

Weeds can be an ongoing battle, especially in a year like this with lots of rain.  I wrote about pre-emergent weed control a few months ago to help get a head start on weeds.  Unfortunately, sometimes we miss the window on timing of our application, or miss spots in the yard, or we just have some stubborn weeds.  If you have weeds popping up in your grass, don’t lose heart!  This is a good time to start to treat your weeds, when they are young and tender.

We have several really good options for good weed control if you have weeds coming up.  One of the best ways you can control weeds is to have a good mowing plan.  Mowing frequently helps to force your grass to grow horizontally and become denser.  Mowing also helps to cut weeds off before they flower and go to seed, preventing future weed problems.  The rule of thumb for mowing is to mow often enough that you never cut off more than 1/3 of the height of the grass.

Another method to control weeds and get some good exercise is to pull the weeds by hand.  If you can regularly check your lawn and pull weeds, you can keep weed populations from getting out of hand.  This is not practical if you have a major weed problem, but it can be good stress relief to spend time outside on a nice spring evening pulling weeds.  There are some great weeding tools available to make the job easier like a Korean Hoe, Diamond Hoe, Stirrup Hoe, or Swan Neck.

If you have a bad weed problem, you might need to use herbicides.  During this time of year, look for a post-emergent herbicide.  You can find herbicides that are non-selective and will kill almost any plant they come in contact with.  A selective herbicide is specifically formulated to kill certain types of weeds like grassy weeds, broadleaf weeds, or sedges.  Identify the types of weeds you have and read product labels to find the appropriate herbicide.  Many weed killers come in a spray bottle that you can use directly on the plant.  Some come in concentrate form that you mix in a sprayer.  When you spray weed killer, use low pressure and large droplet size.  Apply when it is not windy.

A dense, healthy lawn is the best defense against weeds!  For more information about weed control, check out the Aggie Turf website at https://aggieturf.tamu.edu/ or contact Kate Whitney at the Williamson County Extension Office at 512-943-3300.  Did you know we have a Master Gardener Help Desk?  Call us on Tuesdays or Fridays from 10:00am to 2:00pm to talk with a Master Gardener about your garden questions.

Crape Myrtle Bark Scale

AgriLife Logo

Spring has officially sprung, and the wildflowers are outstanding this year! I have really enjoyed watching the wildflowers change from Bluebonnets to Primrose to Indian Blanket, and I cannot wait to see what comes next.

Springtime also brings a lot of insects. One insect that I have written about before, Crape Myrtle Bark Scale (CMBS), is showing up this spring on Crape Myrtles and some new plant hosts.  CMBS is a small, white, sap-feeding insect that lives on the bark of crape myrtle trees.  The adult females look like tiny pieces of popcorn attached near pruning wounds or in the branch crotches.  They are usually 2mm in length.  If you squish the scale, it has bright pink insides.  CMBS does not kill the tree, but it can cause reduced flowering and the scale secretes a honeydew that causes sooty mold.

The AgriLife Extension Specialists in College Station are doing good research on CMBS, and they recently presented information about other plants that have become hosts to this scale insect. Boxwood, pomegranate, cleyera, hackberry, persimmon, soybean, figs, Ligustrum, apple, and beautyberry have all been confirmed as hosts for Crape Myrtle Bark Scale.  This week, I had two Williamson County Master Gardener Volunteers bring a sample of their beautyberry with CMBS.

The good news about CMBS is that we have several treatment options, and now is the time to do it! If you just spot a few, you can squish them.  You can also use soapy water and a brush to remove infestations from your plants.  Scrubbing your tree can also help remove sooty mold.  Ladybeetles are a natural enemy of CMBS, if you prefer to use a biological control option.  If you have a heavy infestation, AgriLife Specialists recommend a systemic insecticide application to be made in March – May.  Imidacloprid and dinotefuran are two systemic insecticides that you can apply as a soil drench.  Both chemicals have been shown to be highly effective at managing scale populations when they are applied in early spring.

Irrigation Audit

AgriLife Logo

As the weather warms up this spring, it’s time to start thinking about lawn care again. Right now is a great time to check your lawn irrigation system to make sure everything is ready to go for the summer watering season. An irrigation audit is a great way to make sure your system is operating efficiently so you can conserve water in your landscape.
An irrigation audit consists of three parts: site inspection, performance testing, and irrigation scheduling. A site inspection is an easy step. Turn on your irrigation system to make sure all sprinkler heads pop up; check the spray pattern to ensure water is not spraying onto streets, sidewalks, and hardscapes; and check for any broken or missing sprinkler heads from mower damage. All of these problems are great DIY projects.

Performance testing is a way to check how much water your irrigation system is putting out in your lawn. The best way to check this is by setting out some mini rain gauges. I often use tuna cans or small plastic food storage containers. Put the cans out in several spots throughout the lawn, run your irrigation system for ten minutes, then measure how much water was fallen in each can. This helps you know the average amount of water your system puts out in ten minutes, and you can adjust your schedule to get the appropriate amount of water on your lawn each time you water.

Irrigation scheduling is the final, and possibly most important step in an irrigation audit. There are a lot of factors that go into the formula for figuring out how much water a lawn needs (temperature, relative humidity, plant requirements, soil type, etc), but the rule of thumb for turfgrass is one-inch per week in the summer and less in the spring and fall. You can divide your watering schedule into two times per week at half an inch per irrigation time. The most important thing to remember is to only water if your lawn needs to be watered. Look for visible wilt in your turfgrass. Do not irrigate after a good rain.

Texas A&M AgriLife Extension has a program called “Water University” with great video tutorials and fact sheets about fixing irrigation systems, cycle soak irrigation, and water conservation. Check it out at https://wateruniversity.tamu.edu/. Contact your city’s water department to find out when you are allowed to water your lawn and if they offer a rebate program for conducting an irrigation audit.

Large Patch in Turfgrass

AgriLife Logo

Spring is in the air! I love seeing the trees bud out and the lawns green up, and I’m enjoying the nice weather.  Unfortunately, this beautiful spring weather has created perfect conditions for large patch in our St. Augustine grass and zoysia grass.

Rhizoctonia solani is a fungus that is present in the soil year-round, but it takes advantage of cool temperatures and wet soil to cause a turfgrass disease known as large patch (sometimes referred to as brown patch in cool-season grasses.  The first symptom of large patch is circular, discolored patches in the turf.  An easy way to diagnose large patch is to pull on the grass blade or shoot.  A diseased shoot will pull out very easily and will have a dark brown lesion that looks a little rotten.

I have good news and bad news about large patch in the spring. The good news is that grass will recover from light disease symptoms as the temperatures rise in the late spring, and new growth should fill in during the summer.  In fact, Texas A&M AgriLife turf specialists say that treatment is not cost-effective in the spring because the warm temperatures will take care of the disease for now.  If there was extensive crown and root damage, however, you might need to put down new sod in the damaged areas.  The bad news is that large patch is hard to get rid of and will probably come back in the fall.  You need to be prepared to treat with a fungicide in the early fall to control large patch.

Large patch thrives in lawns that have poor drainage and are over-fertilized. Good lawn management can help avoid outbreaks of large patch.  A few tips for lawn management:

  1. Improve drainage in your lawn, and only water when necessary.
  2. Mow regularly at appropriate heights. St. Augustine should be mowed at 2-3 inches, and zoysia should be mowed at 1-2 inches.
  3. Do not over-fertilize. Fertilize three weeks after spring green-up. Our grass is just starting to really green-up, so wait until the end of April to fertilize.