If there is one time of year that gardeners should earn a rest, you might think winter would be it. Gardening does slow down in the winter, but a gardener’s task list is never completed. Pruning is a great winter task that I look forward to because it means spring growth is just around the corner!

Pruning is used to train plants, maintain plant health, improve quality of flowers, fruit or foliage, and to restrict growth. Advances in plant breeding and selection have provided a wide range of plants that require very little, if any, pruning, but there are some plants that need a good trim.

The best time to prune many plants is late winter and early spring. We want to prune at a time when there will be the least amount of damage to the plant. Plan to prune before plants put on new growth in the spring. In the spring, plants put considerable energy into developing new growth. If you wait too long and prune off that new growth, the plant has used up a lot of its resources and doesn’t have the new growth available for photosynthesis.

Plan your cuts by following a plan. First, remove all dead, broken, diseased, or problem limbs. Cut them at the point of origin or back to a strong lateral branch or shoot. Second, you can make any training cuts that are necessary. Lateral branches are branches that originate from the main trunk. You can prune lateral branches to help train your plant to a desired shape. Be sure to know the natural growth habit of your plant so you can prune for a natural look (i.e. shrubs are not naturally square). Finally, make any corrective pruning cuts to eliminate narrow crotches, double leaders, or water sprouts. It’s helpful to take a step back and check your work.

Many people call me to ask about pruning paint or wound dressing. Research has found that wound dressing is not necessary and might slow down the healing process. The only exception to this rule is for oak trees. We have oak wilt in Williamson County, so you need to take care to paint all pruning cuts with a latex paint within 15 minutes of the cut to prevent the spread of the disease.

Texas A&M AgriLife Extension has great instructions for pruning specific types of plants at https://aggie-horticulture.tamu.edu/earthkind/landscape/proper-pruning-techniques/.

A Benefit to the Winter Blues: Chill Hours

Cold temperatures arrived in Williamson County in a hurry this year! I hope were able to cover your plants to protect them from the freezing temperatures.  I have to admit that I am a summer lover and I really do not like the short daylight hours and cold temperatures of winter.  There is one bright side to the cold: a winter with enough cold hours makes for a good summer crop of peaches!

Many of our favorite summer fruits like peaches, plums, and nectarines require a certain number of hours of cold weather, called chill hours. Chill hours are temperatures between 32◦ and 45◦F. In the late fall and early winter, fruit trees go into dormancy and hormones within the plant suppress the bud until temperatures warm up and the days lengthen in the spring.  The hormone that causes the plant to go into dormancy breaks down in the temperature range of chill hours.  In an ideal winter, the hormone has enough child hours to completely break down by the time spring comes around and the tree needs to begin blooming.  What a cool process!

In Texas, you might have noticed that the weather is unpredictable. In some winters we do not get enough chill hours for our fruit trees.  This can cause delayed foliation and the tree does not set much fruit.  Some winters we get a late freeze after the trees have bloomed and the blooms do not set fruit.  It’s a challenge, but well worth it when we get a good crop!

Williamson County usually receives between 450-750 chill hours each year. You can do a few things at your home to help ensure that you get some fruit every year.  Purchase varieties of fruit trees that need the recommended number of chill hours for our area.  In peaches, you can get Flordaking, Rio Grande, and Texstar varieties which need 450 hours.  La Feliciana, Junegold and Texroyal need 550-600 chill hours.  Another trick is to purchase several varieties with varying chill hours so you have a better chance that one variety will get the right number.

If you are mourning the loss of your tomato and basil plants after the recent freeze, take heart, the peaches are coming! For more information about growing fruit trees and chill hours, visit the Aggie Horticulture website at https://aggie-horticulture.tamu.edu/ or contact Kate Whitney, Williamson County Horticulture Extension Agent, at klwhitney@ag.tamu.edu.

Mistletoe is a fun holiday tradition, especially for those looking for some extra Christmas kisses. The mistletoe plant is not quite as romantic as our holiday tradition would have you believe.

Mistletoe (Phoradendron tomentosum) is a parasitic plant that lives on hardwood trees like oaks, pecans, elms, and hackberries.  It is an evergreen plant, but we probably notice it more this time of year because the bright green shows up more after the trees drop their leaves.

The female mistletoe plants produce a small, white flower and a seed that is encased in a sticky pulp. The seeds are commonly distributed by birds when they stick to their feet or beaks or pass through their digestive system.  If a seed manages to land on small branches and gets enough moisture, it will germinate and form a root-like structure that penetrates the bark of the tree.  Mistletoe steals water and nutrients from the tree, but it uses its own chlorophyll from the leaves to make food through photosynthesis.

Mistletoe grows only about one-half inch the first year, but it can grow up to three feet in six to eight years! Mistletoe can to live as long as the tree does.  The leaves and stems that you see in the tree might only survive eight years, and it’s easily broken off in storms.  Breaking the mistletoe stimulates regrowth of dormant buds, and it just multiplies on its host.

The thought of hosting a parasitic plant sounds terrible, but mistletoe does not do much damage to a tree unless the tree is severely stressed by other conditions like drought. Mistletoe can get out of control in a tree and become unsightly.

Controlling mistletoe in your trees can be difficult! The most effective control method is to prune out the branch where the mistletoe is growing.  Be sure to cut at least 12 inches from the growth point to be sure the mistletoe root structure is removed.  Before you start pruning multiple branches, consider the aesthetics of your pruning cuts.  If you need cut out a lot, it might be better to remove the tree. Chemical control is not recommended because it can easily damage the host tree.  One final option is to harvest your mistletoe and share with your sweetheart.  The reward might be worth it!

For more information about mistletoe or other horticulture questions, contact Kate Whitney, Horticulture Extension Agent, at 512-943-3300 or klwhitney@ag.tamu.edu.

Twig Girdler

One interesting aspect of my job as a horticultural extension agent is the bug questions and samples I get to see. Just last week, a client brought in a photo of a Tramea onusta, a red saddlebags dragonfly.  Another client sent a photo of a tomato hornworm.  Some of the photos have beautiful and interesting bugs, but usually the questions focus on insects that are causing problems.

Over the last few weeks, I have received several phone calls from homeowners who have small tree limbs that look like they’ve been cut off. The clients describe a blunt cut that might be made with pruning shears or a small saw on limbs the size of pencils or a finger.  This is not the work of pranksters!  The trees have been visited by the twig girdler beetle!

Twig girdler beetles in our area are the pecan twig girdler, Oncideres pustulatas LeConte, which attack citrus, elm, hackberry, hickory, huisache, mimosa, pecan, persimmon, red oak, retama, Texas ebony, walnut, and various fruit trees.  They are ½ to ¾ inch long, light to dark brown with a wide gray band across the wing covers, pink, orange, or yellow spots, and long antennae.

During the fall, usually September through November, the twig girdler reaches adulthood and mates. The female twig girdler will lay her eggs on a small branch, then she chews around the branch forming a notch, much like a beaver would.  The twig usually breaks free and falls to the ground or it might hang loosely.  The eggs hatch in about three weeks and feed on the cut branch.  Twig girdlers have one generation per year and the adults usually live six to ten weeks.

The twig girdler beetle does not do serious harm to the tree; they are mostly a nuisance. Chemical control is not recommended in a home lawn.  The branches that fall from a twig girdler’s work should be collected and destroyed because the eggs are living inside the branch.  The beetles are not commonly found on trees.

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