Beautiful gardens by William Johnson

A READER recently told one of the county’s master gardeners that one of her pine trees had been struck by lightning during a severe thunderstorm a few weeks ago. She asked if there was anything she could do to save the tree or whether it was likely to die.
Lightning striking a tree in one’s landscape is a traumatic experience for both the tree and its caretaker. After checking to see if one’s own limbs are intact, attention quickly shifts to the tree’s welfare.
In the week after an electrical storm, AgriLife Extension Service offices often field questions from concerned homeowners regarding the prognosis for beloved trees and what care might be given to help them survive or recover.
The question was asked by a neighbor of master gardener Joanne Hardgrove, who was asked about the prognosis for a pine tree that had been struck by lightning in the lady’s home landscape.
Unfortunately, and quite accurately for the concerned tree steward, the best answer to these urgent questions is often that only time will tell but the owner should not give up on the tree just yet.
A lightning strike can affect a tree in many ways. Some are immediately obvious and some are not. Sometimes, the trunk or large branches are splintered. A strike might make continuous grooves in the trunk or main branches.
In many cases, the apparent damage might appear minimal while internal injury to the vascular tissues of the trunk and roots is extensive and gradually manifests itself over a period of months or even years.
In some cases, the majority of the damage occurs to a tree’s main roots as the electrical discharge – up to 100 million volts at thousands of amperes – vaporizes the water inside the roots, creating superheated steam. People standing above such roots during a storm could be electrocuted even though they are standing a good distance from the tree’s trunk.
It is difficult to predict which trees will be struck by lightning and which are most likely to be seriously injured. In general, though, lone trees, those tallest in a group or those growing in moist soil have the highest probability of being struck.
In the considerable body of lightning lore, certain tree species are commonly listed as more lightning-attractive than others. They include maple, ash, tulip tree, sycamore, poplar, oak, elm, pine, spruce and hemlock. Some of these, like sycamores, are likely targets because they tend to tower over other species, while pines and hemlocks can be lightning-prone because of the water that collects on their needles during thunderstorms.
Homeowners typically want to take immediate action to help a damaged tree survive the aftermath of a lightning strike. In most cases, however, there is little that can be done to help a tree recover.
Should one apply any of the various wound-dressing concoctions commonly used? While most do no harm to the tree, over time many dressings develop cracks that can harbor insects or hold water, leading to decay. Applying a wound dressing may make the caretaker performing the operation feel better but it is not recommended.
If the lightning damage creates hazardous broken branches, they should be taken care of quickly. However, in most cases, it is best to wait six months before doing major – expensive – corrective work.
If, during this waiting period, the tree shows no obvious signs of decline, then it might be worth the expense of major corrective pruning. In many cases, it will become obvious at some point during the waiting period that the tree will not recover and that its removal is the best option.
My experience has been that a lightning strike does not automatically spell doom to a tree as many struck trees are able to make a remarkable recovery given adequate care and time.
Another question received recently was from a reader whose back yard has three peach trees of different varieties. All three trees have produced a good crop of leaves this spring but a sparse number of flowers and an even sparser number of fruit. What would cause this to happen?
Despite the cold front that occurred in early January, this past winter was relatively mild. Along with other non-citrus fruit and nut trees, peach trees need a specific number of chill hours each winter to regulate their growth and flowering in order to set their flowers and fruit in the spring.
If a tree doesn’t experience enough chill hours in the winter, the flower buds might open unevenly or not at all in spring.
Chill hours are usually defined as those in a range of temperatures below 45°F and above 32°F; however, some models for calculating chill hours rely on slightly different ranges. Nearly all models take into account temperatures above 60°F during the winter as they will reduce the chill-hour total.
This past winter, we exceeded the 60°F temperature mark on many, many days so air conditioners were running a lot over the season. So it’s really not surprising that peach flowering has been so sparse this year.
William Johnson is a horticulturist with the Galveston County office of Texas A&M AgriLife Extension Service. Visit his website at

Lightning can inflict significant damage to a tree as it did in March to the pine tree pictured above growing in a home landscape in Clear Lake. Being struck by lightning does not automatically spell doom to a tree as many such trees are able to make a remarkable recovery over time if provided good care. Joanne Hardgrove

Beautiful gardens by William Johnson

APRIL IS a wonderful time to enjoy the outdoor garden. Many citrus trees are in full bloom and azaleas are nearing the end of their spring bloom season. Trees are putting out new foliage that is such a delicate green.
I hope you have already planted the trees and shrubs that you want to plant for the year and are ready to concentrate on annuals, perennials, vegetables and lawns. Here’s a checklist for keeping up with the chores while enjoying the pleasures of the first full month of spring.
Azaleas: As flowering finishes, evaluate your azaleas for their pruning needs. April and May are good months in which to trim your bushes but only do it if it is necessary. Generally, a little shaping is all that is required.
Controlling size is a common reason for pruning, especially if large-growing cultivars were planted where smaller ones should have been used.
You should begin to manage the size of your azaleas when they reach the maximum desirable size. Unless you are trying to create a formal clipped hedge, avoid shearing them with hedge clippers because it destroys their attractive natural shape.
It is better to use hand pruners to remove or shorten selected branches to achieve the desired shape and size.
First, identify the tallest or widest shoots or branches on a bush that are too large, then prune the branch back a few inches inside the interior of shrub growth. When the shortened branch sprouts, the new growth will be inside the shrub, creating a thicker, fuller plant.
The new growth will not immediately stick out above the rest of the bush – something that commonly happens if pruning cuts are made just back to the edge of the bush or when azaleas are sheared.
Keep pruning back the tallest and widest shoots until the shrub is the proper size. You may continue to prune occasionally as needed using this technique until late June, or early July at the very latest.
After that, the chances increase that you will remove flower buds when you prune. Alternate-season-blooming azaleas, such as the Encores, have a shorter window of opportunity and pruning them should be done as soon as the major spring blooming period has ended.
Lawns: Mid March to mid April is the recommended time for fertilizing lawns. A good way to determine when to fertilize is to wait until you have mowed the predominant lawn grass twice.
If you fertilize too early, you will be fertilizing the winter weeds! This allows time for the grass to green up naturally without pushing it into growth. Use a fertilizer with a 3-1-2 ratio such as 15-5-10 and distribute it with a broadcast – cyclone – spreader. Uniform distribution is essential to prevent light and dark streaks in the lawn.
Leftover seed: Many flower and vegetable seeds left over after planting the garden can be saved for the next season by closing their packets with tape or paper clips and storing them in a tightly sealed glass jar in your refrigerator until needed.
Adding one or two tablespoons of powdered milk in a cloth bag to reduce the humidity within the jar can also be very beneficial to maintaining the seeds’ long-term viability.
Summer annuals: One tendency shoppers have is to buy transplants of summer annuals only with open flowers. But it might be sparter to purchase young transplants with few or no flowers as they will grow larger before flowering. The result will be a more impressive floral display in your home garden.
William Johnson is a horticulturist with the Galveston County office of Texas A&M AgriLife Extension Service. Visit his website at


WHAT: Pecan grafting demonstrations
WHEN: 2:00-3:00pm, Thursday, April 13
INFO: Master gardeners will demonstrate how to properly perform inlay bark and four-flap grafts on small pecan trees. A small number of pecan scions will be available after the demonstrations.
LOCATION: 15102 Williams Street, Santa Fe
PHONE: Call 409-925-2718 or 409-771-8425 for assistance

WHAT: Beneficials In The Garden
WHEN: 6:30-8:00pm, Tuesday, April 25
INFO: Galveston County horticulture extension agent William Johnson will provide a PowerPoint program on the diversity of beneficial insects and other types of beneficial commonly found in local home landscapes and gardens. Knowing your garden friends can remove the anxiety of “Do I need to spray an insecticide?”
LOCATION: Galveston County AgriLife Extension Service’s Carbide Park office, 4102B Main Street, La Marque. Pre-registration required by phone at 281-309-5065 or e-mail at

Master gardener Sue Jeffco demonstrates grafting on a pecan tree. Photo Herman Auer

Beautiful gardens by William Johnson

HOW DO I decide on a topic or topics to discuss in my weekly garden columns? Typically, I do not have a firm concept until the weekend when I reflect on gardening issues presented to me during the preceding week. Not so this week.
One homeowner indicated that, after reading last week’s column about termites and improper mulching along a home foundation, he immediately went outside and removed mulch that had been applied over the first layer of brick at his home.
He indicated that a yard-maintenance crew had applied the mulch. He also indicated that his first thought was to call the crew and demand that they remove the excess mulch but then he had second thoughts about the matter as he had paid for the mulch and its application.
Then another reader e-mailed me the link to a local newspaper’s online article entitled Volcano Mulching Kills Trees that was authored by Robert Komarowski of League City and published on March 14.
Mr Komarowski was intrigued about the concept of volcano mulching and concluded his article with the query: “Perhaps Dr Johnson could provide us with his opinion regarding mulch volcanoes”.
Voila! The topic for this week’s column had been presented to me – and I finally got to use my high-school French course. As if that circumstance was not a sufficient matter of serendipity, I then came across another action that yelled: “Write about me”.
While on an evening walk around my neighborhood on Friday, I walked past a home that had been recently mulched. Even the landscape beds around my homeowners association are improperly mulched. Now I’m thinking it’s payback time – I should send my HOA one of those dreaded cease-and-desist letters.
I do not routinely carry a camera on my walks so I had to lug a camera along on my next evening walk to capture the photo accompanying this column. Not only had the tree in the picture been mulched volcano-style but the front landscape beds along the concrete foundation had been mulched above the house’s first layer of brick.
The benefits of mulch
Although mulch is not particularly glamorous, it can be your best friend. It can be used in a variety of locations to help with weed control and to help save water.
Research conducted through Texas A&M University shows that two thirds of the water applied by irrigation is lost through evaporation. That means the water evaporates from the soil surface without ever being absorbed by the plant it seeks to nourish.
When mulch is applied, evaporation is limited, leaving more water for plants to use and thereby reducing the need for water application.
Not only does mulch conserve water; it also moderates the soil temperature during our hot Gulf Coast summers. In winter, it helps to keep the soil warmer and promotes early root and shoot growth in spring.
Disease control is another benefit of mulch. Many soil-borne diseases in the vegetable garden can be reduced or prevented by eliminating “splash up” from the soil from water droplets. Mulch creates a barrier between the soil and the plant that keeps disease-causing pathogens such as fungal spores from splashing on to plant leaves.
Mulch should be applied to a three-to-four-inch depth to provide maximum benefit. This depth is thick enough to reduce the soil’s moisture loss from evaporation but will allow water that is applied by rain or irrigation to filter down and promote the development of a strong root system.
Properly applied mulch around the trunk of a tree has the added benefit of providing a physical barrier to help reduce damage from line trimmers.
Mounds of mulch that are 10, 12, 18 or more inches thick, piled up around the base of tree trunks have earned the name “mulch volcano”. Harmful to trees, this ill-advised yet well-intentioned practice is becoming more commonplace.
Mulch applied too thick on top of tree roots results in suffocation of the uppermost roots. In a struggle to survive, the tree then grows new roots into the mulch volcano.
Trees growing under this stressful condition can actually appear healthy for a while. Eventually, though, the aboveground roots can encircle the tree and strangle it to death as the trunk increases in diameter.
The root zone of an established tree extends far beyond its drip line, so mounding the mulch against the trunk does little for the roots. The mulch volcano can hold the water that was intended for the roots. Also, moisture trapped by the mulch can soften the tree’s bark, opening the door to insect pests and disease problems.
Now is a great time to get out there and mulch new beds or replenish mulch to existing beds. If you’ve never used mulch in your landscape, this is a great time to give it a try. You will be amazed at the fresh appearance it gives your yard right now and the water savings you’ll see in the future. Just be sure to say “no” to volcano mulching.
William Johnson is a horticulturist with the Galveston County office of Texas A&M AgriLife Extension Service. Visit his website at

The ill-advised yet well-intentioned practice of piling up mounds of mulch around the base of tree trunks is harmful to the trees.William Johnson

Beautiful gardens by William Johnson

IN GENERAL, insects have a bad reputation – the vast majority either cause no harm or are actually beneficial to mankind. However, a few cause us problems. Among those that most homeowners dread, termites certainly rank at the top. “Know thine enemy” is key to winning the war against the worthy adversary.
Termites are more likely to be seen during spring as it’s the primary season when they are likely to swarm. However, termite season is really a year-round activity. Even though they are usually out of sight during most of the year, these unwelcome guests are still carrying out their mission. Most people do not become aware of them until they pull out some wood and find either the termites or the damage they cause.
A few simple precautions will help reduce the chances of subterranean termites turning your dream home into a nightmare. When they invade a home, hundreds, even thousands, of dollars in damage can occur. They often go unnoticed because you don’t see them crawling around. They do their damage inside the wood.
There are certain conditions that might make your home conducive to termite activity:
• Prevent soil coming into contact with brick, especially weep holes, siding or any type of wood-to-ground meeting.
• Do not stack firewood next to the house or garage.
• Check for rotten or decaying wood. Whether inside or outside, what looks like rotten wood could be termite damage.
• Check for areas around plumbing leaks that stay wet. Subterranean termites require a source of moisture and are attracted to wood that stays wet.
• Be sure that mulch does not make contact with bricks, weep holes, exterior wood, etc. This is very important and I’ve seen far too many cases of excessive use of mulch in such areas.
Any of these conditions creates an inviting and easy route for termites to gain access to homes. If you have any of these conditions, they should be corrected.
Certain indicators of possible termite activity should be checked by a termite professional as soon as possible. The first is the presence of “swarmers” or male and female reproducing inside the home. They look like flying ants and often collect near windows, glass patio doors and other sources of light.
Termite swarmers are most commonly encountered in spring. A few to several dozen can occur for a short time. Sometimes you only see them once and they die quickly. They are a likely indication that there is an active colony in your home.
The second indicator is the presence of mud “shelter tubes”. These are usually small tubes that range from pencil diameter upwards and have the consistency of a dirt dobber nest. They usually ascend ffrom the ground, up the side of a foundation to an exterior wood siding or to a weep hole in the brick.
Weep holes can be found on most brick homes and serve a vital structural function. I’ve seen termites, fire ants, roaches, crickets, earwigs, wasps, millipedes and other insect pests take advantage of this “open door” to what amounts to a great nest site inside wall voids where it’s  warm, shady, moist and protected!
If you knock the termite shelter tubes down or crush them, the termites will build them back or construct other shelter tubes elsewhere. Fire ants also oftentimes construct shelter-like tubes to gain access to a home’s interior through weep holes, as shown in the photo above.
However, fire ants’ shelter tubes easily break down if poked with a stick or finger whereas termites’ tubes are hard and require more pressure to break apart. You cannot get rid of termites by destroying the tubes or by spraying an insecticide through the tubes.
If you have noticed any of these signs indicating the presence of termites, contact a termite control professional but do not panic. Termites won’t destroy your home overnight or even in a week – they work slowly.
You should, however, arrange to have your home inspected by one or more licensed pest-control companies. Most companies will inspect your home for termite infestation free of charge and provide an estimate for treatment if an infestation is confirmed. Pest-control companies are required to provide you with a disclosure statement containing the names of pesticides to be used, details of any warranties and other pertinent information.
Homeowners faced with dealing with a termite infestation will probably not be consoled when informed that termites serve a highly useful function in nature because they break down decaying wood, which returns valuable organic matter and nutrients to the soil.
In essence, these insects are recyclers of plant life. However, as long as we live in houses made of wood and its products, they will keep such dwellings on their menu list.
William Johnson is a horticulturist with the Galveston County office of Texas A&M AgriLife Extension Service. Visit his website at

As well as termites, fire ants are among the insects that take advantage of weep holes’ “open door” to a great nest site inside houses’ exterior wall voids. – Photo: Genevieve Benson

Beautiful gardens by William Johnson

LAST SATURDAY, I was able to tour some sites on this year’s Azalea Trail sponsored by River Oaks Garden Club. Even though the prime flowering period for most of the azaleas had passed, the remaining flowers provided ample glints of colors to lighten up the drab and cloudy day. Azaleas really are spring showoffs!
With the introduction and more common use of varieties that bloom in other seasons, such as the increasingly popular Encore variety, it’s not unusual to see azaleas blooming during the late summer, fall and winter.
When they are in full bloom, few shrubs in the landscape can rival them for flower power. Although the floral display might be relatively short-lived for many of our traditional azaleas, such as Indica, it ensures the continued popularity of this time-honored southern shrub.
Surprisingly, azaleas will grow and bloom in many different light intensities all the way from filtered shade to bright sunny exposures. However, they will not bloom in deep shade.
There is no secret formula to growing them except for giving them proper care. That means being careful in your preparation of the planting bed, proper fertilization, pruning and special attention to water requirements.
Certainly, azaleas can be planted in spring. This is the time of year when garden centers have the best selection and gardeners can see potted plants in bloom. Be aware, though, that spring-planted azaleas might take a little longer to become established than those planted in the fall or winter.
The fall and winter months would be the best time to plant. Fall and winter planting encourages root growth before spring bloom and shoot growth commence.
Summer planting really should be avoided, although you can be successful planting at that time by providing extra care, primarily in watering.
Before purchasing azaleas, make sure you ask the mature size of the plants you intend to buy. Depending on the cultivar, azaleas can mature at less than two feet tall up to 10 or more feet.
Don’t purchase a type of azalea that will grow too large for the spot where it will be planted. When mature, large varieties like the Indica require from four to eight feet of space between each plant; you may plant smaller varieties two feet apart.
Azaleas require good drainage but also need an even supply of moisture. Uniformity in soil moisture is important for good growth and establishment in the landscape.
If you find that a plant’s outer roots are matted together when you take it out of its container, be sure to cut through the matted root layer with a sharp knife. This is a very important step to promote development of a vigorous root system after transplanting into the soil.
It is also very important to never plant azaleas too deep! Set them into their planting holes so that the top of the root ball is at the same level or slightly higher than the soil line of the planting bed.
After planting, water thoroughly and place three to four inches of mulch – shredded pine bark or pine needles – around the plant. Mulching serves several purposes. In addition to conditioning the soil, it also helps retain moisture and stifles the growth of weeds and grasses.
The first two years that the azalea is in the garden are the most critical for its survival. The young plant requires consistent soil moisture during this time when the feeder roots are developing and spreading. During dry spells, keep it well watered but not soaking wet.
Azaleas should be fertilized with a specialty fertilizer made for them. There are many excellent commercially prepared brands on the market. Fertilize once soon after blooming has stopped in spring and repeat four to six weeks later. No other feeding should be done after May.
Azaleas do best in soil that has a slightly acid pH. Acidifying the soil periodically might be required if their leaves turn yellow.
Pruning can be done any time up until the flower buds start to form in midsummer. Pruning after bud formation commences will reduce flower production in the following spring. Plants can be safely pruned up to one third or more of their height at one trimming. Azaleas should be kept trimmed to avoid legginess and to promote lush green foliage.
William Johnson is a horticulturist with the Galveston County office of Texas A&M AgriLife Extension Service. Visit his website at

At a Glance:
Upcoming programs
Basics For Home Composting 1:00-2:30pm, Saturday, March 11
Tomato Stress Management 9:00-11:00am, Saturday, March 18
The Culture And Care Of Palms 1:00-3:00pm, Saturday, March 18
All programs conducted at Galveston County AgriLife Extension Service’s Carbide Park office at 4102B Main Street, La Marque. No fee is required but pre-registration is requested by phone at 281-309-5065 or e-mail at

When they are in full bloom, few shrubs in the landscape can rival azaleas for eye-catching flower power. Linda Steber