Tomato Growing Challenges in Oklahoma

Tomato Growing Challenges

Brian Jervis: Ask a Master Gardener

Sunday, June 24, 2018

This time of year, we get a lot of questions about one of our favorite garden crops: tomatoes. We love our tomatoes, but there are a variety of challenges associated with growing them.

One of those challenges is Septoria leaf spot. Septoria leaf spot is a common fungal disease in Oklahoma. Starting at the bottom of your plant, you will notice leaves with yellow areas that become circular with grayish centers and dark borders. The spores from septoria can be quite aggressive, spreading upward throughout the plant.

When you see this, it’s time to begin a fungicidal spray program of copper fungicide on a 7- to 14-day schedule. This will not cure the infected leaves but will diminish its ability to spread. Infected leaves should be removed.

Also, to minimize exposure and spreading of fungal diseases, tomatoes should not be watered via an overhead sprinkler system, as the splashing water tends to provide a means through which the disease can migrate. Drip irrigation is preferable in most instances.

If you are having problems with fungal diseases, be sure you are rotating your crops. Planting the same crop in the same spot year after year tends to encourage these fungal diseases to develop. However, when rotating crops with tomatoes, do not put peppers, eggplants or potatoes in the same rotation as they all tend to be susceptible to many of the same diseases.

Another common challenge to growing tomatoes successfully is blossom-end rot. Symptoms manifest in an expanding, tan, water-soaked area of the blossom end of the fruit. Blossom-end rot is a complex disorder, which is thought to be caused by a calcium deficiency. However, the solution is not often as simple as adding calcium to the soil.

High temperatures and wind, fluctuating water availability and a little drought stress thrown in (sounds like Oklahoma) create an environment in which you may see blossom-end rot. Somewhat ironically, excessive soil moisture for a long period of time can also contribute to this problem, as it tends to damage the root system and diminish the plant’s ability to uptake calcium. Excessive fertilization with nitrogen can also be a contributing factor.

Just remember, calcium deficiency is rarely a direct cause of blossom-end rot. It is similar to how a fever is an indicator of a problem and not the actual problem. Adding calcium can be of little value if the blossom-end rot is the result of environmental conditions mentioned above.

These are only two of the many challenges we face growing tomatoes. You can find several relevant fact sheets on the topic by visiting the Lawn & Garden page of our website, tulsamastergardeners.org, and then clicking on “vegetables.”

Garden tips

• Vigorous, unwanted limbs should be removed or shortened on new trees. Watch for forks in the main trunk, and remove the least desirable trunk as soon as it is noticed.
• Most varieties of mums are more productive if “pinched back” now. Either pinch off with fingers or cut to remove an inch or so of limb tips above a leaf. This results in the growth of new limbs and a fuller plant. Do not pinch after mid-July or it will interfere with fall blooming.
• Watch for tiny, sap-sucking insects called aphids on roses, perennial flowers, shrubs and vegetables (especially tomatoes). They produce a sticky substance called “honeydew." Many can be dislodged with a hard spray from your garden hose or two applications of insecticidal soap will usually greatly reduce any aphid damage to your plants.
• Crapemyrtles are one of the few shrubs that should be planted in the middle of summer. Growth of new roots of these plants occurs best with summer soil temperatures.

Summer Challenges for Your Gardens

Protecting your garden from summer temps

Allen Robinson: Ask a Master Gardener

Sunday, June 10, 2018

Q: It seems to be getting hotter earlier each year, and 2018 is no exception. What are the most important things I should be focused on to ensure a successful lawn and garden season throughout the summer? Alicia M., Broken Arrow

A: Hot and dry days of summer not only put a stress on people, but also on yards, plants and gardens. Like people, keeping them healthy is the best way to prevent diseases and other problems. Proper weeding, mulching, fertilizing and watering will go a long way to help create and maintain a healthy landscape.

Weeding: Nobody likes to weed, but it’s a necessity. The key is to apply pre-emergent herbicides at the proper time, visit your gardens often and pull weeds as they appear, and to keep gardens properly mulched and lawns properly fertilized. Remember — the best countermeasure to weeds in a lawn is a thick, healthy turf.

Mulching: Mulching protects tree trunks from lawn equipment damage, reduces water loss due to evaporation, keeps the soil cooler in the summer and warmer in the winter, prevents grass and weed growth, adds beneficial organic material to the soil as it decays and, quite simply, looks better. Remember that most plants get oxygen through their roots, not from leaves, and will suffocate without air in the soil. So, a maximum of 2-4 inches of a loose material, such as shredded tree bark, wood chips or compost from your own compost bin, is sufficient. The desirable mulch pattern should look like a doughnut around the trunk, not a volcano.

Fertilizing: Having a soil test conducted is the best way to know exactly what your lawn and gardens need. A test should be done about every three years. In general, Bermuda grass needs about 5 pounds of nitrogen per 1,000 square feet each active growing season, applied between spring and fall. So, a good rule of thumb is to apply 1 pound of nitrogen per 1,000 square feet in each of the five months between and including April and August. Fertilizing after August will increase the chances of spring lawn diseases (e.g. Spring Dead Spot) next year. Fertilize fescue in the spring, then again in September and November. Do not fertilize fescue or any cool-weather grass in the summer.

Watering: Watering more infrequently and longer is preferred over watering often and shorter. This method allows the moisture to go deeper into the ground, thus coaxing roots to do the same. By doing this, your lawn will sustain itself through hot/dry conditions much better. Generally, the equivalent of 1 inch of water per week is sufficient. If it’s very hot and dry, up to 2 inches per week may be necessary. Water early in the morning to avoid heavy evaporation and to give the plants a chance to dry off before nightfall. For gardens, drip irrigation is the most efficient way to water.

Garden tips

• Renovate overgrown strawberry beds after the last harvest. Start by setting your lawnmower on its highest setting and mow off the foliage. Next, thin crowns to 12-24 inches apart. Apply recommended fertilizer, pre-emergent herbicide (if needed) and keep watered.
• White grubs will soon emerge as adult June Beetles. Watch for high populations that can indicate potential damage from grubs of future life cycle stages later in the summer.
• Thatch is a layer of dead and living stems, shoots and roots that pile up on top of the soil at the base of lawn grasses. If it is over ½-inch thick, it should be removed with either a core-aerator or power-rake. Now is the time to de-thatch Bermuda and zoysia. De-thatch fescue, if needed, in the fall.

Match Plants for your Soil and Weather Environment

Selecting the Proper Plants for Your Gardening Conditions

Tom Ingram: Ask a Master Gardener

Sunday, May 27, 2018

Q: I am planning on making some improvements and enhancements to my garden this year. With so many options, how do I decide which flowers and shrubs would be best for my garden? DS

A: The first thing to consider is the sun. A site would be considered full sun if it gets 6 or more hours of sunlight each day. Part sun would be 4-6 hours and shaded would be less than 4 hours of sunlight per day. Almost every plant you consider is going to have a sun rating on its tag. Pay attention to it. If you purchase a plant that wants full sun and you place it in a shady location, it will not thrive, may not bloom and may not even make it.

When considering the sun, also consider environmental hot spots, such as along a wooden fence or against the house. These structures can decrease circulation and increase ambient temperature to the point only the strongest can survive.

If you are considering a location close to the house, take into consideration which side of the house. The north side tends to get less sun. The east gets primarily the cooler morning sun. And the south and west sides will get the sun in the hottest part of the day, so plant accordingly.

Soil type is another important consideration. Do you have sandy soil or a more clay-like soil? Sandy soils will drain quicker, where clay soils will retain water. Some plants will specify “well-drained soil.” If you have something you want to plant in a location with clay soil that requires well-drained soil, you will need to amend the soil to increase drainage. Or plant something that can tolerate wetter conditions.

Speaking of water, many plants will come with watering recommendations. Take that into consideration as well. If you purchase a plant that needs a lot of water in a location that gets full sun, plan on spending part of your summer watering.

Soil chemistry is another factor to consider, as some plants, like azaleas, prefer a more acidic soil. A soil test is always good to be sure.

One way to get ideas for your garden is to look at other gardens. Knowing this, the Master Gardeners have our yearly garden tour coming up June 9 and 10. On the tour this year, we will have five Master Gardener gardens (plus our demonstration garden at the Extension office) to tour. We have been working hard this spring to make them beautiful for you. In addition, one of the homes will have lectures throughout both days on a variety of topics, such as environmentally friendly gardening, succulents, annuals and perennials for the shade, azaleas, landscape design 101 and monarch butterflies. Visit our website at tulsamastergardeners.org for more information and to purchase tickets.

Garden tips

• Plant warm-season vegetable crops, such as watermelon, cantaloupe, cucumber, eggplant, okra, sweet potatoes, etc., now.
• Fruit trees, especially apples and peaches, must be thinned out for best production. Prune apples 4-6 inches apart and peaches 6-8 inches. This will ensure larger fruit and less damage to limbs. If not thinned, the tree's resources will be used to such an extent that next year’s crop will suffer.
• Late May is the best time to control borers in the orchard. Contact OSU Tulsa Master Gardeners for fruit tree spray recommendations.

Attracting Monarch Butterflies to Your Garden

Attracting Monarch Butterflies to Your Garden

Brian Jervis: Ask a Master Gardener

Sunday, May 13, 2018

Q: I am intrigued by the beautiful butterflies that are around Tulsa each year but know very little about them. Could you tell me how I can attract them to my garden? Melissa H., Tulsa

A: Most of us would agree with you that butterflies are such a visual blessing to our gardens. They are beautiful and do wondrous work in the pollinating world. Two of the most common types of butterflies in our area are monarchs and Black Swallowtails (the Oklahoma state butterfly).

Food is obviously an essential part of their life cycle, but they are somewhat picky eaters and will feed exclusively on particular plants, called host plants. Having these plants available will not only draw butterflies in to lay their eggs, but also will allow you to watch the development of the caterpillars. One of the keys to having beautiful monarch butterflies around your garden is having lots of milkweed. Monarch caterpillars feed exclusively on milkweed (Aesclepias) and cannot survive without it. With almost 20 different species of milkweed native to Oklahoma, you’re sure to find some that fit your garden area. When planting milkweed, be sure to plant multiples (three to five or more). A single plant simply will not be sufficient for monarchs as they are eating machines. If you want lots of monarchs, plant lots of milkweed. Planting milkweed is a great way to help other pollinators too, as the plant provides valuable nectar resources to a diverse suite of bees and other butterflies. Other nectar sources include marigolds, petunias and asters. While milkweed is a beautiful plant to look at, be sure to keep milkweed sap out of your eyes as it can be irritating. Caterpillars of the Black Swallowtail feed on parsley, dill and fennel. So, if you garden with these, plant enough for you and the caterpillars.

A few key tips to coax these beauties to your yard include providing “roost” stations for them at varying heights and protection to shield them from wind and predators. They are attracted to plant color, structure and height. Provide moist areas with shallow puddles to encourage gathering. Butterflies are cold-blooded and enjoy warming themselves in the sun so provide rocks or exposed soil that will warm to the sun’s exposure. Use few, if any, insecticides as they can easily kill good insects, along with bad ones, and no bug zappers please.

Because of modern changes, habitat destruction and shifting land management practices (suburbanization), there is a lot less milkweed today than previously. This has caused a decline in monarch butterfly populations and numbers to be at an all-time low for the past two overwintering seasons. Many pollinators are declining as well. By planting milkweeds and nectar plants for adult monarchs and pollinators, you can help maintain the monarch migration and sustain the pollinators whose pollinating services maintain our ecosystems.

Monarchwatch.org is a terrific resource to learn more about monarch butterflies and milkweed. Also, consider attending a free seminar called “Monarchs, Milkweeds and More” on May 26 at the Tulsa fairgrounds, hosted by the Tulsa Master Gardeners. Detailed information can be found at tulsamastergarders.org.

Garden tips

• Clean out water garden and prepare for season. Divide and repot water garden plants. Begin feeding fish when water temperatures are over 50 degrees.

• Plant warm-season vegetable crops, such as watermelon, cantaloupe, cucumber, eggplant, okra, sweet potatoes, etc., now.

• Fruit trees, especially apples and peaches, must be thinned out for best production. Prune apples 4-6 inches apart and peaches 6-8 inches. This will ensure larger fruit and less damage to limbs. If not thinned, the tree's resources will be used to such an extent that next year’s crop will suffer.

• Late May is the best time to control borers in the orchard. Contact OSU Tulsa Master Gardeners for fruit tree spray recommendations.

Attracting Hummingbirds Using Feeders and Flowers

Attracting Hummingbirds

Tom Ingram: Ask a Master Gardner

Sunday, April 29, 2018

Q: I am starting to see hummingbirds. How can I attract them to my garden and take better take care of them? DJ

A: Humming birds are the smallest of native birds in North America and are typically about 3½ inches in length, weighing only about ¼ of an ounce. As most of us know, the humming sound is created by their wings, but did you know they average about 55 strokes per second?

During courtship, males can exhibit rather dramatic behaviors by ascending and then diving straight down toward either the object of their affection or irritation. When this happens, their wings can beat up to 200 beats per second, which creates a louder than normal humming sound, as well as a colorful display of their feathers.

While many people think hummingbirds use their tongues as we might use a straw to drink, they actually drink via a licking motion at a rate of about 13 licks per second. Hummingbirds also capture small flying insects in the air, especially when raising their young.

All hummingbirds of North America are migratory with the exception of one species found in California. The species found most often in Oklahoma is the ruby throated hummingbird. This hummingbird may travel more than 2,000 miles during migration, including 500 nonstop miles over the Gulf of Mexico. To make this journey, they must add about half of their body weight in fat before the trip.

With all the energy expended during flight apart from migration, hummingbirds must feed every 15 minutes during the day to survive. So, the best way to attract them to your garden is through nectar-producing plants or by providing a supplemental food source. Placing the feeder near your garden will encourage feeding from natural sources.

When placing feeders near the house, be sure to get several feeders and place them some distance apart as hummingbirds can get territorial and aggressive around a single food source. Also, be sure to use a feeder with a bee and wasp guard, as this will eliminate aggressive competition for nectar between these insects and the hummingbirds. There is no need to be concerned with small insects found at the mouth of the feeder, as they will typically help fulfill the hummingbird’s need for protein.

You can make your own feeding solution using one part granulated sugar to four parts boiling water. Of course, cool the solution before pouring it in the feeder. The use of red food coloring in the solution is unnecessary and unhealthy for the birds. Feeders should be cleaned every two to three days, especially during warm weather.

Garden tips

• Prune and feed all of the spring-blooming shrubs, such as azaleas and forsythia immediately after blooming, if needed. Azaleas need less fertilizer than many shrubs and often a yearly addition of mulch, as it decays, it will add all the nutrients they need.
• Cool-season lawns — tall fescue and bluegrass — can be fertilized again. If you did not fertilize in March and April, do so now. Do not fertilize these grasses in summer.
• Seeding and sodding of warm-season grasses, such as bermudagrass, Buffalograss and zoysiagrass, is best performed in mid-May through the end of June. The soil temperatures are warm enough for germination and growth. These grasses need a long summer growing season to promote winter hardiness.

Tomato Growing Tips

Tips on Growing Tomatoes in Oklahoma

Allen Robinson: Ask a Master Gardener

Sunday, April 15, 2018

Q: My family loves to eat fresh tomatoes off the vine, but my friends tell me they have trouble growing tomatoes around here. Can you tell me why it is difficult to grow tomatoes here and what I can do about it? Tracy A., Tulsa

A: You are certainly not alone when it comes to loving tomatoes fresh off the vine, as well as having trouble growing them in northeast Oklahoma.

One of the most common issues is known as “blossom drop,” which occurs from poor pollination. Weather is the chief cause of inadequate pollination in garden-grown tomatoes, with the most important factor being temperature. Effective pollination stops occurring once night temperatures are consistently over 70 degrees and/or when daytime temperatures are consistently over 92 degrees, especially if it is windy. Too much rain or too high or low humidity are additional weather factors that reduce pollen fertility. Also, over application of nitrogen fertilizer leads to blossom drop, as well as tall, lanky plants.

The solution to this is to plant healthy plants as soon as possible after the last frost has occurred. Then, pick the fruit as soon as it turns pink and let it continue to ripen indoors. Do not let it sit on the vine until it becomes overly ripened and soft.

Another common issue is called “blossom end rot,” where the fruit develops blemishes on the blossom end of the fruit. This is caused by a calcium deficiency in the plant when the fruit is young. Overwatering, either from nature or the gardener, is the most common cause rather than the lack of calcium in the soil.

Skin splitting, called “cracking,” is also caused by plants going from too little to too much water. Be consistent about watering. Mulch plants to provide consistent moisture at the root level, but do not mulch directly against the plant as it can lead to diseases.

Speaking of diseases, avoid splashing soil upon the plant and onto tomato fruits, as this carries related fungi and bacterial diseases. Instead, either use a soaker hose or drip irrigation system or carefully water at the base of the plants. Avoid damaging tender roots by not hoeing too deeply or too closely to the plants.

In addition, several pests love to live off the stems and leaves of tomato plants. For a listing of pests and how best to battle them, go to tulsamastergardeners.org and search for OSU Fact Sheet EPP-7313 (Home Vegetable Garden Insect Pest Control).

Experts say the best weed control in a lawn is to simply grow a healthy lawn. The same is true for vegetables. Look for high quality varieties at reputable nurseries around town and ask which varieties are the most disease resistant. Several varieties are available.

Tulsa’s climate is a challenge to growing tomatoes in the summer but, with a little attention to details, you can have good success. And, remember, there’s always fall.

Garden tips

Fruit and Nut

• Don’t spray insecticides during fruit tree bloom or pollination may be affected. Disease sprays can continue according to schedule and label directions.

• Control cedar-apple rust. When the orange jelly galls are visible on juniper (cedar), following a rain, begin treating apple and crabapple trees with a fungicide.

• Fire blight bacterial disease can be controlled at this time. Plant disease-resistant varieties to avoid diseases.

• Continue spray schedules for disease-prone fruit and pine trees.

Trees and shrubs

• Proper watering of newly planted trees and shrubs often means the difference between success and replacement.

• Remove any winter-damaged branches or plants that have not begun to grow. Prune spring-flowering plants as soon as they are finished blooming.

• Control of powdery mildew disease can be done with early detection and regular treatment. Many new plant cultivars are resistant.

• Leaf spot diseases can cause premature death of foliage and reduce plant vigor.

Flowers

• Most bedding plants, summer-flowering bulbs and annual flower seeds can be planted after danger of frost. This happens around mid-April in most of Oklahoma. Hold off mulching these crops until spring rains subside and soil temperatures warm up. Warm-season annuals should not be planted until soil temperatures are in the low 60s.

• Harden off transplants outside in partial protection from sun and wind prior to planting.

• Let spring -flowering bulb foliage remain as long as possible before removing it.

Vegetables

• Wait a little longer for it to warm up before planting cucurbit crops and okra.

• Plant vegetable crops in successive plantings to ensure a steady supply of produce, rather than harvesting all at once.

• Cover cucurbit crops with a floating row cover to keep out insect pests. Remove during bloom time.

• Watch for cutworm damage and add flea beetle scouting to your list of activities in the vegetable garden.

Landscape 

• Hummingbirds arrive in Oklahoma in early April. Get your bird feeders ready using 1 part sugar to 4 parts water. Do not use red food coloring.

• Keep the bird feeder filled during the summer and help control insects at the same time.

• Lace bugs, aphids, spider mites, bagworms, etc. can start popping up in the landscape and garden later this month. Keep a close eye on all plants and use mechanical, cultural and biological control options first.

• Be alert for insect pests and predators. Some pests can be hand-picked without using a pesticide. Do not spray if predators, such as lady beetles, are present. Spray only when there are too few predators to be effective.

Lawn

• Warm-season grass lawns can be established beginning in late April from sprigs, plugs or sod.

• Fertilizer programs can begin for warm-season grasses in April. The following recommendations are to achieve optimum performance and appearance of commonly grown species in Oklahoma.

• Zoysiagrass: 3 pounds nitrogen per 1,000 square feet a year
• Buffalograss: 2-3 pounds nitrogen per 1,000 square feet a year
• Bermudagrass: 4-6 pounds nitrogen per 1,000 square feet a year

When using quick-release forms of fertilizer, use 1 pound of actual nitrogen per 1,000 square feet per application; water in nitrate fertilizers.

• Mowing of warm-season lawns can begin now. Cutting height for bermudagrass and zoysiagrass should be 1 to 1½ inches high, and buffalograss 1½ to 3 inches high.

• Damage from Spring Dead Spot Disease (SDS) becomes visible in bermudagrass. Perform practices that promote grass recovery. Do not spray fungicides at this time for SDS control.

• Grub damage can be visible in lawns at this time. Check for the presence of grubs before applying any insecticide treatments. Apply appropriate soil insecticide if white grubs are a problem. Water product into soil.

Bradford Pear Trees are Very Invasive and Short Lived

White Flowering Bradford Pears Have a Dark Side

Brian Jervis: Ask a Master Gardener

Mar 31, 2018

Q: What are these beautiful trees I am seeing all over town with the white blossoms? TP

A: You are probably referring to the Bradford pear. While they are beautiful and quite popular, they have a dark side. But first, let’s talk about what they are and how they got here.

The Bradford Pear (Pyrus calleryana “Bradford”) was first introduced to the United States in the early 1900s as a way to help control fire blight of the common pear. By the ’80s, it had become the second-most popular tree in America, primarily as an ornamental tree.

The Bradford grows rapidly (12- to 15-foot increase in height over an 8- to 10-year period), to a height of 30 to 50 feet tall and 20-30 feet wide with a short to moderate life span of 15 to 25 years (less if we get an ice storm).

Most people are attracted to the Bradford Pear for its showy white flowers that appear in spring. The flowers are beautiful but, unfortunately, have an unpleasant fragrance. Early spring flowering can last two weeks, but late frosts may reduce bloom time.

Sounds like a great tree. Well, that’s what many of us thought until we got to know its dark side.

Although the Bradford pear was originally bred to be sterile and thornless, they easily cross-pollinate and produce fruit. These fruits are like tiny, hard apples, round, ½-inch in diameter, greenish-yellow flecked with whitish spots, inedible, with 2-4 black seeds. After it freezes in the fall, the fruit softens and becomes palatable to birds that help spread the tree.

Unfortunately, these offspring revert back to the thorny variety of their origin. They are not usually noticed until spring when we see them along the highways. These descendants are also quite invasive and tend to displace native plant communities, disrupting natural succession. All those white-blossomed trees you are seeing outside the fence line of the highway are likely the thorny offspring of the Bradford pear.

So, what do we do in response to what we now know about the Bradford? In spite of the fact that Bradford pear trees are well adapted for Oklahoma climatic conditions, just say no. There are a variety of other trees that work well in Oklahoma without the Bradford’s invasive side effects. They are also quite weak, making them poor choices to deal with Oklahoma winds and ice.

If you have a Bradford pear, you might need to consider replacing it, and if you are looking for a spring-flowering alternative, you should consider a redbud or dogwood tree. For more information on which types of trees do well in Tulsa, visit the Hot Topics section of our website, tulsamastergardeners.org, and download a copy of our info sheet: “Trees for Tulsa.”

Garden tips

• Most bedding plants, summer-flowering bulbs, and annual flower seeds can be planted after danger of frost. This happens around mid-April in most of Oklahoma. Hold off mulching these crops until spring rains subside and soil temperatures warm up. Warm-season annuals should not be planted until soil temperatures are in the low 60s.
• Don’t plant tomato sprouts too early. The soil temperature is key and should be above 60 degrees before planting. If the soil is too cool, the plants will sit there and not grow. Remove the blossoms from any tomato plant at the time of planting; it needs roots before making tomatoes.
• You can find some wonderful tomatoes, herbs and flowers for your garden by shopping online during our plant pre-sale. This is the last week of the sale. Visit our website, tulsamastergardener.org, for information.