Several Potential Problems Growing Tomatoes

Problems Growing Tomatoes

Brian Jervis: As A Master Gardener

Tuesday, June 27, 2017

Q: What is wrong with my tomatoes? They were doing OK, but now blossoms are dropping off before I get fruit. Also, some tomatoes are splitting and plants have yellow or curling leaves. Martha H., Tulsa

A: These are all common issues that Oklahoma tomato growers face.

The actual fruit comes from proper pollination of the blossoms, but when successful pollination does not occur, the blossoms die and fall off. This is commonly known as “blossom drop.” Weather is the chief cause of inadequate pollination in garden-grown tomatoes, with the most important factor being temperature.

Effective pollination does not occur once night temperatures are outside the range of 55-70 degrees or if daytime temperatures are consistently higher than 92 degrees, especially if it is windy. Too much rain or too high or low humidity are additional weather factors that reduce pollen fertility. Over application of nitrogen fertilizer also leads to blossom drop, as well as tall, lanky plants.

Tomato fruit splits, rots or develops blemishes for several reasons. The most common cause of tomatoes rotting before they ripen is “blossom end rot,” which is caused by a calcium deficiency in the plant. Overwatering, either from nature or the gardener, is the most common cause, rather than the lack of calcium in the soil.

Skin splitting 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 against the plant itself as it can lead to diseases.

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

There are several reasons that cause yellowing of leaves. It could either be from a small pest called a spider mite, from a fungal leaf disease, or from stress caused from either over or under watering. Check the soil to see if it is overly wet or dry before moving onto the other causes. Just like your lawn, water plants thoroughly (6-8 inches deep) to encourage tomato roots to seek water and nutrients deep in the soil. With an extensive deep root system, the plants will hold up better during dry spells.

Garden tips

·        Mulch ornamentals, vegetables and annuals. This reduces soil crusting, cools soil and conserves moisture during hot summer months. Mulch also helps prevent weeds and reduces likelihood of mechanical damage from lawn equipment. Mulching will reduce about 70 percent of the summer yard maintenance.

·        A disease called “fireblight” is prevalent now. It may infect more than 100 plants in the rose family but especially apples, crabapples, pears, quince and pyracantha. The bacterial disease is spread by insects and rain and enters the plant through open blossoms. Once infected, the leaves on the involved limb turn brown and the limb dies. The only treatment is to remove the dead limbs. An antibiotic spray can be helpful but only during full bloom and only used to prevent the disease. Some trees are more susceptible than others, consideration should be given to planting disease-resistant varieties.

Explore Edible Landscaping--Its Fun and Productive

Explore Edible Landscaping

Bill Sevier: Ask a Master Gardener

Tuesday, June 20, 2017

Q: I don’t have much gardening space and am interested in planting some vegetables in with my flowers. Is there any problem with doing this? Fran, Tulsa

A: There is no problem whatsoever with putting veggies in amongst your ornamentals. In fact, for those with no vegetable garden or who have restricted space, it is an excellent idea. What and where you may plant is limited only by the growing requirements of the veggie and your imagination. Many vegetables not only have attractive fruit, but also interesting colors and designs of their leaves that fit in well with a flower garden.

The process of growing vegetables and herbs in amongst your ornamentals is called “Edible Landscaping” and has become popular with gardeners. A lot has been written about the concept. One of the experts is Rosalind Creasy, who has published a series of books about this type of gardening.

Vegetables can be used effectively, not only in your standard flower bed, but also in raised beds, window boxes and many different types of containers. They can be worked in with your flowers to create a visually pleasing effect.

Plants such as lettuce, cabbage, kale and others come in several colors and can be used as a substitute for ornamental border plants such as vinca, begonia and Joseph’s Coat. Swiss chard, with its bright red stems and veins, could be an attractive addition as an edge or within the flowers.

A mix of different varieties of the same vegetable, such as purple and white cabbage, is one of the many combinations that may be created and used effectively. Other plants to consider are rows of onions and most of the herbs for the bed border.

Tomatoes and colorful peppers do well, especially cherry tomatoes. This adds greenery and the continuous production of red fruit to create a pleasing effect. Tomatoes probably perform better in the flower bed than they do in a conventional vegetable garden. In the flower bed, they are separate from other tomatoes and are less likely to develop disease and pest problems. In addition, tomatoes, which need to be rotated in the vegetable garden to prevent disease build up, can easily be moved from one area to another each year with the flowers.

Other ideas are to plant blueberries, blackberries and raspberries into the landscape. There are some ultra-dwarfed apple, peach, plum and other fruit trees that may be used in place of a shrub. Another idea is to grow a grapevine on a trellis, which works as a decorative plant and fruit producer.

Garden tips

·        Excessive rain can complicate fertilization of vegetables, ornamentals and lawns. If a quick-release fertilizer was applied before the excessive rains, much of the nitrogen may have been washed into deep soil or drain water. Nitrogen, the first of the three numbers on all fertilizer, is water soluble. The other two nutrients — phosphorus and potassium — are not soluble and remained fixed in soil where placed unless the soil particles themselves are washed into drains and streams.

·        Consideration should be made to reapply a nitrogen-only fertilizer if the above situation applies to you. Don’t over fertilize. Too much nitrogen may be worse than too little. Most plants, such as tomatoes, grow tall, spindly and produce few blossoms and fruits when too much nitrogen is used.

·        Also be aware that too much water in the soil may suffocate roots and cause plants to develop yellow leaves, which may fall from the plant. This can easily be wrongly confused with a need for more fertilizer.

Controlling Nutsedge in Turfgrass

Controlling Nutsedge (Nutgrass) in Lawns

Brian Jervis: Ask A Master Gardener

Tuesday, June 13, 2017

Q: What is the best way to control nutgrass? I have several patches of it which are spreading. Stewart, Tulsa.

A: Nutgrass, or more correctly, nutsedge, is one of the most difficult weeds to control, both in the lawn and agriculturally. Because it is a sedge, not a grass or a broadleaf weed, its biological system is such that it does not respond to the herbicides commonly used for other weeds.

There are two types of nutsedge — yellow and purple. We primarily have the yellow variety. This plant can be recognized by its slim grass-like leaves and stems, which are triangular (basis of the adage “sedges have edges”). It also grows more rapidly than most turfgrasses and usually pops up in a lawn 2-3 days after mowing. This weed thrives in hot, full sun and moist soils. Because of the preference for wet soils, our record rains this spring will likely yield a bumper crop.

The weed’s ability to reproduce makes it difficult to control. Although it can spread by underground rhizomes and seeds, the main type of reproduction, and the one that gives it the name “nutsedge,” is the ability to produce a large number of nutlets — hundreds per plant in one growing season. Each nutlet can produce a new plant, and the nutlets may lie dormant for years before sprouting as growing conditions become favorable. This also is the reason that pulling the weed out by hand is frustrating — the nutlets remain and the weed returns.

Nutsedge is introduced into lawns from seeds but more commonly from using mulch or fill soil that is contaminated with the nutlets. It also may enter a lawn or flower bed by contaminated nursery stock.

Control of nutsedge should first begin with prevention. The single most effective preventative measure for all weeds is to have a thick healthy and mowed tall lawn that will compete with all weeds. Also, watering lawns only when needed will prevent overly moist soils in which nutsedge thrives. Another preventative measure is to be selective in all soil imported to your lawn for fill or from nursery stock.

Once nutsedge is established, the best approach to control is the use of an herbicide. Pulling up the nutsedge plants after they have formed nutlets is frustratingly ineffective.

The chemicals recommended for nutsedge, for the most part, cover other sedges. Several herbicides are available to homeowners that are labeled for nutsedge control. They are found in many brands, with the chemicals bentazon, imazaquin, sulfentrazone or halosulfuron being at the top of the list. Of these options, sulfentrazone and halosurfuron are preferred. Both of these are tolerated by our commonly used grasses. Because of the waxy coat of nutsedge, some will need a “spreader sticker” added to the herbicide. This helps the chemical to adhere to the plant’s leaves. Be aware that they will need to be applied twice in a summer, and it may take 2-3 years for complete control.

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 12 to 24 inches apart. Apply recommended fertilizer, pre-emergent herbicide if needed and keep watered.

·        White grubs will soon emerge as adult beetles. This group of beetles’ color may vary from green to brown and vary from ¼- to ½-inch long. Watch for high populations that can indicate potential damage from their grubs later in the summer after egg laying.

·        Continue to fertilize warm-season grasses at 1 pound nitrogen per 1,000 square feet. Don’t fertilize fescue and other cool-season grasses during the summer. Because nitrogen is soluble in water, much of it may have been lost due to percolation and runoff, if you fertilized before recent rain

Moles and Gophers

Dealing with Moles and Gophers

Bill Sevier: Ask a Master Gardener

Tuesday, June 6, 2017

Q: Something is creating tunnels and piles of soil in my yard. Is it moles or gophers and what should I do? B.L., Broken Arrow

A: There are some basic facts about these pests that will help you sort this out. Moles create superficial tunnels in your lawn that you can easily see and depress with your foot. They sometimes produce small mounds of fresh soil but not usually. Moles dental structure is such that they cannot eat plants or roots. They are not rodents but insectivores and eat only insects and worms. Moles are territorial, and a large lawn with significant damage may have only one to three moles.

Gophers make tunnels deep into the ground that almost never can be seen in the lawn. They make several mounds of fresh soil often over a foot wide shaped like a kidney. Gophers create colonies, perhaps 10-20 gophers, in a large lawn. They can and do eat the roots of plants and may be destructive.

So if you have tunnels you can see easily, you have moles. If there are several mounds of fresh soil, you have gophers.

Control of gophers is outlined in detail in OSU’s fact sheet “Controlling Pocket Gophers,” and good information about moles and control may be found in the University of Arkansas Extension fact sheet, FSA-9095. Read these before you get started.

Moles are a challenge to control. Because of this, many repellent-type products are available, most of which are thought to be ineffective. One exception is castor oil, which may have some short-term repellent activity, but studies about effectiveness have been inconclusive.

Moles are more common in well-tended lawns. Well-watered and fertilized lawns have more earthworms and, therefore, will better support a mole population. Moles’ diet consists mainly of earthworms and not white grubs as once thought. Do not use insecticides labeled for grubs to attempt to control moles.

The most effective way to eliminate moles is to use one of the various traps on the market. Another treatment thought to be effective is poison gel worms. These are similar in texture to the plastic worms used for fishing but contain poison.

Garden tips

·        Bermuda lawns will benefit from up to 2-5 pounds of nitrogen fertilizer per 1,000 square feet in divided applications from now until the end of August. Apply the first application now. Do not fertilize fescue lawns in summer; it will make them susceptible to heat and disease damage. The next recommended fertilization for fescue is in September and October.

·        Remain alert for insect damage. Add spider mites to the list. Foliage of most plants becomes pale and speckled; juniper foliage turns a pale yellowish color. Shake a branch over white paper and watch for tiny specks that crawl. Watch for first-generation fall webworm.

·        Some pests can be hand-picked without using a pesticide. Do not spray if predators such as lady beetles are present. Spraying insecticides early in the morning or late in the day will avoid spraying honeybees and other essential pollinators.