THE LOUISIANA iris continues to be a popular plant in local landscapes. Despite their common name, Louisiana irises are grown in much of the United States and even in Canada and other parts of the world.
Gardeners tend to be surprised to learn that they originated in America and are well adapted to the soils and climate along the Gulf Coast. Those commonly found in local landscapes are derived from five iris species, most of which are native to a limited area of south Louisiana and the Gulf Coast marsh areas between Texas and Florida.
These five species are closely related and have been crossed with one another to produce the amazing array of outstandingly beautiful hybrids that also are called Louisiana irises. Most of the Louisiana irises you find for sale will be hybrids of these five species, although the basic species is also beautiful and worthy of use in the garden.
Because all the primary colors are inherent in the various species that contributed to this group, there is no limit to the color range.
Louisiana irises can be divided and transplanted at any time from August until early October. Some varieties go dormant during the heat of summer, so now is the ideal time to divide them.
If you have Louisiana irises in your landscape that are well established, you might notice some brown or yellow leaves on your plants now. Even if you decide you don’t need to divide them this year, it’s a good idea to get in and clean out the unattractive foliage before the new growth starts in earnest. This will make the planting more attractive.
Each year Louisiana irises grow and spread, creating more rhizomes and shoots. Eventually, the plants may become crowded, which can lead to lower vigor and poor flowering. This generally occurs two to three years after the bed is planted, depending on how close they were planted to begin with and how much room they have to spread.
Clumps also may grow beyond their allotted space and dividing will help keep them the size you want and prevent the irises from taking over areas where they were not intended to grow.
The first step in dividing them is to use a shovel or garden fork to lift the Louisiana iris plants from the bed. Try to get as much of the root systems as possible and do not damage the fans – leaves – of new growth at the ends of the rhizomes. Put them aside in a shady area and hose them down to keep them from drying out.
Once the bed is empty, take the opportunity to improve the soil in the bed before you replant the irises. Spread a two-inch layer of compost or other organic matter over the soil, sprinkle a light application of a general-purpose fertilizer over the area and thoroughly incorporate into the soil.
To divide your irises, look over the clumps carefully. You will see that young rhizomes branch off from the older ones. The younger ones have a fan of green leaves at their tips with roots growing out from the rhizome at the base of the leaves. Break or cut off the young rhizomes at the point where they branch off from the old rhizome. Discard the old rhizome and replant the young ones.
Plant the rhizomes horizontally with the fan of foliage facing the direction in which you want the plant to grow and carefully cover all of the roots. Space the rhizomes about a foot apart. The top of each one should be just below or barely show above the soil surface. Apply two to three inches of mulch to the top of the soil and water thoroughly. If you have any rhizomes left over, pot them to share with friends.
Should extended periods of dry weather occur over the fall, winter or spring, water your irises once or twice a week to keep the plants well supplied with moisture. In addition, an application of fertilizer such as ammonium sulfate 21-0-0 in February will keep them growing vigorously into the blooming season.
You might also need to divide and repot Louisiana irises growing in containers in aquatic gardens and this is a good time to do that as well. Remove the plants from the pot and divide them by following the same procedures as those for irises growing in the ground. Fertilize them by using pond fertilizer tablets according to label directions.
One other note – there are a few other perennial plants grown in local landscapes that should be transplanted or divided this month. Like Louisiana irises, they tend go into a period of summer dormancy when temperatures are hot and will begin to grow actively some time in October as the weather cools.
Agapanthus, or lily of the Nile, Easter lilies and calla lilies can also be divided and transplanted. If you’d like to divide or transplant spider lilies – lycoris radiata, also called hurricane lilies or naked ladies – you may do so as soon as they finish blooming.

William Johnson is a horticulturist with the Galveston County office of Texas A&M AgriLife Extension Service. Visit his website at

Louisiana iris                                                William Johnson

The extraordinary beauty and reliability of Louisiana irises grown in the landscape have made them increasingly popular. They can be divided and transplanted at any time from August until early October.

IT HAPPENS so very slowly that I am not aware of it. As I was looking out of my living room window last weekend, it occurred to me that the days are getting shorter. No more working outside at 9:00pm with sufficient sunlight to see.
Ever so slowly and by one minute or so on one day and two minutes or so on another day, daylight has become shorter in length since June 20, the official start of summer. Now I will look forward to December 21, when the cycle reverses and day length ever so slowly starts to increase.
Ahhh, but September has at last arrived. Weather-wise, the 2015 summer season has been hot and, until recently, on the dry side. The 15-inch-deep crack in a grassy area of our master gardener demonstration garden at AgriLife Extension Service has closed up and is no longer visible.
Kids are back in school and the hope of cooler days is becoming more of a reality. Although it might not seem like it, September marks the beginning of a new season in our area. The change is subtle, to be sure, but the weeks of warm summer days are coming to an end and the fall growing season is here.
One good thing about our Texas Gulf Coast summers is that we get to anticipate and to better appreciate the cooler temperatures of the fall season, so here’s your gardening checklist for September:
Master gardener horticulture demonstration garden tour: The county’s master gardeners will conduct a Garden With The Masters program tomorrow, Thursday, September 3, at Carbide Park, 4102B Main Street in La Marque.
A guided tour of vegetable beds as well as the fruit orchard and Asian garden will start at 9:00am. Gardeners are also welcome to casually tour the garden and orchard until 11:30am.
Fruit splitting on citrus trees: Soon after our area received plentiful rainfall that ended the extended dry spell, I started receiving inquiries about the cause of citrus-fruit splitting.
This type of damage typically occurs when citrus trees rapidly take up water from rain or irrigation after a long dry period. The fruit expands and bursts the peel in a crack across the bottom, or blossom, end of the fruit.
The buildup of excess fluids produces sufficient internal pressure to cause the fruit’s skin to burst. Young trees have the highest incidence of splitting. Navel oranges are most susceptible, followed by tangelos, some tight-skinned types of mandarin and other oranges. In contrast, grapefruit is rarely affected by the problem.
Maintaining adequate and even soil moisture levels by regular irrigation during extended periods of dry weather is the best defense against fruit splitting.
Pruning shrubs and bushes: September is a good time to trim unruly shrubs and bushes. Pruning too late in the season can encourage tender new growth that could be susceptible to cold weather. Be careful not to prune plants like gardenias, camellias and azaleas at this time as they have already formed next spring’s floral buds. Pruning them now will result in fewer flowers next year.
Divide perennials: Late September is time to divide spring-flowering perennials such as irises, shasta daisies, gaillardias, cannas, day lilies, violets, liriope and ajuga. Reset divisions into well-prepared soil with generous amounts of organic material worked into the top eight to 10 inches.
Fall vegetables: Vegetables to plant at the beginning of September include corn, cucumber, eggplant, green beans, lima beans, pepper, squash and tomato.
Toward the end of the month, this list can be expanded to include broccoli, cabbage, carrots, cauliflower, celery, collard, endive, lettuce, mustard, onion, radish and turnips.
Annual ornamentals, perennials and fall vegetables sale: The 2015 plant sale is an “absolute must” for gardeners in our area. This is an early notification so you can pencil in this popular event on your gardening calendar for Saturday, October 10. A diverse variety of fall vegetable transplants will be available at this year’s sale. More information about this and other activities at Carbide Park will be provided in upcoming columns.

At a glance

WHAT: Square-foot gardening
WHEN: Tuesday, September 15, 6:30-8:30pm

WHAT: Growing onions and garlic
WHEN: Saturday, September 19, 9:00-11:00am

WHAT: Kitchen gardening
WHEN: Saturday, September 19, 1:00-3:30pm

LOCATION: All programs conducted at the Galveston County AgriLife Extension office in Carbide Park, 4102B Main Street, La Marque. Pre-register by e-mail at or by phone at 281-534-3413, ext 5065.

Citrus rind splitting                                               William Johnson

Many home citrus growers have reported that the rinds of maturing citrus fruit started splitting soon after plentiful rainfall occurred after the summer drought. This type of damage typically occurs when citrus trees rapidly take up water from rain or irrigation after an extended period of dry weather.

William Johnson is a horticulturist with the Galveston County office of Texas A&M AgriLife Extension Service. Visit his website at

Johnson, William            William Johnson

WE ARE IN the middle of the dogs days of summer but the month of August signals the start of the fall gardening season. Last week’s generous and widespread rainfall was a welcome relief to the recent weeks of dry summer weather.
During a conversation with several of my master-gardener friends at the county’s horticulture demonstration garden last week, there were exchanges of who was planting what during August to start off the fall gardening season. Experienced gardeners know that the late-summer and fall weather favors more productive growth than the harsher spring climate.
Our greenhouse is now ready and I was proud to see trays of tomato and broccoli transplants growing very well despite the hot days.
If the heat of the Texas summer has put a fizzle on your gardening enthusiasm, try some cool season vegetables. Not only does the taste of many fall-grown vegetables excel that of spring crops; fall gardening can reinvigorate the spirit.
Many vegetables will have a longer harvest period than those planted in the spring as they mature during the cooler temperatures of the fall in contrast to the maturing of spring crops as the summer heat sets in. In fact, fall-grown vegetables have better flavor and are of higher quality than spring crops.
Even though we’re still struggling through the warmth of late summer, novice gardeners can overlook the fact that, here in Galveston County, August and September are times to plant many of the popular fall vegetable crops such as tomatoes, peppers, eggplant, beans, okra and squash.
Before discussing how-to tips for establishing a fall garden from scratch, I should address a common gardening situation. What should you do with your spring-planted tomatoes, peppers and suchlike? Is it best to take them out now or start over?
Well, it’s not always easy to decide whether or not to terminate a relatively successful spring garden or try to carry it through until the first killing frost in the fall. If your plants are still vigorous and relatively healthy looking, it might be satisfactory to carry them through the fall season.
I recommend that gardeners in this area critically evaluate the quality of their spring-planted crops. If your plants have disease or insect problems, or if they have simply fizzled or petered out, then start with new plants. This is especially true for tomatoes and squash.
Okra, eggplants and peppers – especially hot peppers – can be readily carried over if they are still in good vigor.
In starting a new garden, the home gardener should consider several items before establishing a fall garden. A light application of nitrogen fertilizer may be warranted given generous rainfall over most areas of the county.
Vegetables adapted to fall gardens can be divided into four groups based on their tolerance to freezing temperatures. The first group, which should be planted now, includes warm-season vegetables that are adapted to fall gardens but killed by frost. I’ll discuss the other three groups as their planting dates approach.
As with spring gardening, the best practice is to use transplants for certain vegetable crops, such as tomatoes, peppers and eggplants. During the critical adjustment after planting, it is almost an absolute necessity to provide transplants with protection from excessive heat for a while after they have been planted. The sudden exposure of tender transplants that have grown under greenhouse conditions to the hot sun and blasting winds can result in a quick death.
To get started on the right track, make plans to attend our educational program entitled Successful Fall Vegetable Gardening on Saturday, August 29, from 9:00-11:30am at the Galveston County AgriLife Extension office in Carbide Park, 4102-B Main Street, La Marque. Pre-registration is required, so call 281-534-3413, ext 5065 or e-mail to ensure availability of handouts.
Luke Stripling, who will be our program speaker, is a certified Texas master gardener and has accumulated a wealth of knowledge and hands-on experience on home vegetable gardening.
He will provide information on a variety of topics including soil preparation, the types of vegetable that do well during the fall and winter seasons, variety selection, fertilization and pest control.
Successful fall gardening begins much earlier than the official start of the fall season. Proper timing is probably the most important factor if it’s to be successful. Regardless of variety selected or cultural practices used, if a gardener does not do the right thing at the right time, his or her success rate will decline.
If you start this month, fall will be a great time to garden in Texas.

William Johnson is a horticulturist with the Galveston County office of Texas A&M AgriLife Extension Service. Visit his website at

Fall vegetable harvest 2015                                               William Johnson

Even though we’re still struggling through the heat of late summer, novice gardeners could overlook the fact that August signals the start of the fall gardening season. The county’s AgriLife Extension office is to conduct a seminar on fall vegetable gardening on Saturday, August 29.

Johnson, William             William Johnson

MANY PEOPLE living in urban areas would like a kitchen garden but feel that lack of space limits them. Regardless of where you live – even if it’s an apartment with limited patio space – you can usually create an enjoyable and productive kitchen garden by using containers.
If you are curious about, or interested in, container gardening, I recommend attending an educational seminar titled The Patio Garden With Vegetables, Herbs And Fruit Trees to be presented locally by Tom LeRoy on Saturday, August 22.
Tom is now retired but began his 35-year career with Texas A&M AgriLife Extension Service right out of college, after receiving a bachelor’s degree in horticulture in 1975 and a master’s degree in plant breeding in 1977, both from Texas A&M University.
He is an experienced home gardener and has co-authored three gardening books, Growing Fruits And Nuts In The South, Common Sense Vegetable Gardening In The South and The Southern Kitchen Garden.
Rather than acquiring your container gardening skills by trial and error, I highly recommend attending Tom’s seminar at the AgriLife Extension office in Carbide Park at 4102-B Main Street, La Marque, from 9:00-11:00am on Saturday. Pre-registration is required, so phone 281-534-3413, ext 5065, or e-mail to ensure availability of handouts.
Container gardening is a simple and fun way to grow edible crops in just about any situation.  It’s growing in popularity because it’s easy to get started and enables anyone to succeed –including those who think they have a “brown thumb”.
A container garden can be an attractive part of the landscape of an urban home or apartment, whether on a windowsill, patio, rooftop, balcony or doorstep. Container gardening is the city dweller’s answer to the big backyard garden when America was more rural. You might not have half an acre to plant but you can achieve a similar goal by growing plants in pots.
What can be grown in these small spaces? The possibilities for container gardening are endless. Apartment dwellers can grow vegetables in containers on balconies and some varieties have been developed specifically for container use. When given proper growing conditions and adequate care, many vegetables grown in a typical backyard garden will also grow well in containers.
A lot of us like to grow tropical plants, such as citrus trees or dwarf bananas, in containers. Citrus is very adaptable to container growing in five-gallon or larger containers. Provided you start out with potting soil with good drainage, you can probably keep a citrus tree in the same pot without root pruning or repotting for several years.
Citrus grown in containers can be rolled around. This comes in handy over the winter should a cold snap happen our way. You are not likely to corner the market on citrus-fruit production but a lot of people get a fair amount of production by growing this way.
You don’t need a large garden to grow herbs. Most are perfect container garden plants and will thrive on your deck, patio, balcony, fire escape or front steps, provided you offer them the right growing conditions.
The most important factors for successful container gardening are sufficient sunlight, proper moisture, adequate fertility and, perhaps most important, a little tender loving care.
While it’s true that container gardening is ideal for limited spaces and that most vegetables will grow in containers, be aware that some are more suitable and easier to grow than others. Therefore, you should plan to grow vegetables that will produce a large quantity of food for the amount of space and time required.
The size of the container will vary according to the crop selection and space available. Pots from six to 10 inches in size are satisfactory for many herbs and ornamental peppers. For most vegetable crops such as peppers, eggplant and tomatoes, you will find five-gallon containers are the most suitable size. They are fairly easy to handle and provide adequate space for root growth.
Does container planting take more water? It takes less, overall, than a garden plot but might require more frequent watering.
The type of container helps determine water needs. The sides of the container will be exposed to hot sun, so choose one with thick walls that do not conduct heat readily. Metal and plastic containers are least desirable. Ceramic pots are better but wooden tubs are best from the standpoint of low heat conduction.
Provided there is adequate sunlight, you can place container-grown vegetables and fruits at entryways, on patios and decks, or anywhere you have a need to add a living component to enhance the appeal of an area. Each planted container will have its own personality and you can even create container scenes. They can range from dramatic to subtle and from grand to petite.
So, even if space is limited, if you can’t “contain” the itch to give gardening a try, give container gardening a try! The rewards will be delicious as well as satisfying.

William Johnson is a horticulturist with the Galveston County office of Texas A&M AgriLife Extension Service. Visit his website at

Container Gardening 2 Container Gardening 1                                      Tom LeRoy

Tomatoes are among the plants that do well in kitchen-garden containers.

Johnson, William            William Johnson

DO YOU remember the date that Hurricane Ike made landfall? Whether you sheltered in place or chose to evacuate, you probably do remember.
Do you remember what the weather was like in 2011? While you might not remember the year, if you lived through the record summer temperatures and summer drought, you are not likely to have forgotten that occasion either.
Extended periods of drought during summer often lead to formation of large cracks in soil that is high in clay content. I’ve had many requests about what to do about cracks in soil in the landscape in addition to those distinctive gaps between concrete foundations and soil.
The most prevalent type of soil in Galveston County is heavy clay. Local gardeners often refer to it as gumbo clay, a generic term for a clay-based soil that is highly elastic, expanding and contracting due to extremes in moisture levels.
Gumbo clay soils are notorious for expanding during wet spells because of their ability to absorb enormous amounts of water. At the other extreme, during extended periods of drought, as has been the case for the past few weeks, gumbo clays shrink in size. As the soil dries and shrinks, gaps develop along the side of the foundation and giant cracks develop in the lawn.
This is easier to imagine if you think of gumbo clay as a sponge or an accordion in that it expands significantly as it absorbs water and correspondingly shrinks when that water evaporates or is absorbed by the roots of landscape plants. This process is a very powerful force. As gumbo clay shrinks, it damages foundations and forms cracks in a lawn many feet deep.
Concrete foundations crack as they are stressed by the powerful pressures that move the soil. Although this is a continual process that occurs throughout the year without major impact on the foundation, when we get into an extended drought, the gumbo clay contracts tremendously. That’s when your foundation is at its most vulnerable. It’s the continual expanding and shrinking over time that can wreak havoc on a foundation.
Experienced gardeners know that, when properly managed, gumbo clay is a productive soil for growing vegetables but, when it comes to concrete slab foundations, it can be a home wrecker.
To put it in very simple terms, with gumbo clays, when it rains, the clay in the soil absorbs the moisture and swells. When the soil dries out, the clay loses its moisture and shrinks.
Avoid the practice of just watering the front yard to keep it lush for the neighbors and homeowner-association enforcement folks while letting the backyard go dry. This will result in portions of the soil under the foundation being wet and expanded while other parts are dry and contracted.
This can lead to cracking of the exterior brick veneer and to doors of rooms, closets or cabinets coming out of alignment and becoming difficult to open or close. Cracks may also develop in drywall and in tile floors.
Homeowners can help protect their foundation by keeping the soil next to it at a fairly consistent moisture level throughout the year. Water the soil evenly and frequently around the entire foundation during extended dry periods. This should prevent a gap from opening between the soil and foundation edge.
If you have a sprinkler system in the landscape beds around the perimeter of your home, you will be in good shape as long as you use it.
If you don’t have a sprinkler system around the perimeter of your home, place a soaker hose or series of connected soaker hoses around the entire foundation. Do not lay the soaker hose right next to the foundation gap. Lay it six to eight inches away from the foundation.
Do not turn the faucet handle to the fully open position when watering by soaker hose – the goal is to apply only enough water so the soil can absorb it without runoff or puddling.
It is important to avoid direct, heavy watering into gaps and cracks along the foundation using a regular water hose because a heavy flow of water can travel along the cracks for several feet in all directions and move dry soil particles in the process.
This approach can cause an opposite problem – sudden expansion of gumbo clay soil can also cause a crack in the foundation.
Now to the question of how often to apply water along the foundation. The key is to maintain a slow flow of water. This may require watering every day to start and perhaps every two to three days when soil moisture levels have been stabilized and the drought has ended.
Finally, if you have landscape beds around your foundation, apply a three-to-four-inch layer of mulch over the soil. Mulch not only keeps the weeds down; it also helps prevent the dramatic loss of moisture through evaporation.
Do not apply mulch above the slab layer into the brick line or exterior siding as you will be inviting trouble from insects such as termites and ants.
Even though gaps along the foundation become most noticeable during extended periods of dry weather, homeowners should monitor their foundations throughout the year to keep constant moisture levels around the foundation.

William Johnson is a horticulturist with the Galveston County office of Texas A&M AgriLife Extension Service. Visit his website at

Measuring tape in cracked soil 2015                                               William Johnson

Extended summer droughts often lead to the formation of large cracks in high-clay-content soil, leading to gaps between house foundations and the surrounding earth that can go quite deep.