Extension

Growing Fall Irish Potatoes

If seed potatoes are available and space permits, potatoes are a desirable supplement to the fall and winter food supply. Yields are usually lower than those from spring-planted potatoes, but proper storage is much easier to provide, and potato quality is excellent.

 

The practice of using potatoes from the fresh produce counter for planting purposes is not recommended. This kind of material frequently does not produce adequate growth and is considerably lower in yield.

 

One of the problems is getting a stand of plants early enough to produce a crop before fall frosts. This emphasizes the need to use matured, medium-to-large potatoes that require cutting into 1 or 1 ½ ounce size seed pieces.

 

Cut potatoes should be allowed to cure three to five days before planting, and they should be stored under cool (45° to 65°F) conditions during curing. The best time to plant seed pieces is around August 1 through August 15.

 

To have a more favorable (cooler) soil at planting time, deep furrows may be opened in the late afternoon, seed pieces planted, covered with two inches of soil, watered, and mulched with straw or other available organic material. This should provide more favorable conditions for growth. Space potato pieces 30 to 42 inches between rows and 10 to 16 inches within rows. Days to harvest will be between 90 to 110 days depending on variety.

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Successful Fall Gardening Starts with Good Plant Establishment

Gardening is a year-round activity. Those who garden develop an appreciation and a desire for fresh, nutritious vegetables and fruits. In many situations, the best way to obtain fresh vegetables is to grow them at home.

 

Some of the best quality garden vegetables in Oklahoma are produced and harvested during the fall season when warm, sunny days are followed by cool, humid nights. Under these climatic conditions, plant soil metabolism is low; therefore, more of the food manufactured by the plant becomes a high-quality vegetable product.

 

Successful establishment of a fall garden starts with the planting of seeds and obtaining transplants made available in the garden centers.

 

Climatic conditions of July and August involve high soil temperature, high light intensity, and rapid drying of the soil, resulting in an increase in problems of obtaining a uniform stand of plants. Achieving a full stand of plants in the heat of summer may require special treatments. This might include shade over rows when seeded and supplemental watering to reduce soil temperature and aid in seed germination.

 

Viable seed, to germinate or sprout, must have the proper temperature, adequate moisture, and sufficient oxygen. The surface of the soil, when exposed to the summer sun, may become very hot (140°F). Vegetable seeds should be planted no deeper than three times the diameter of the seed. With small seeds such as carrot, this would be no more than 1/4 inch deep. At this depth and exposed in the hot soil, death of the seed due to high temperature would probably occur. It is also likely that such soil, even when watered, might dry out quickly because of the high temperature. Unless the soil remains moist at the depth where the seeds have been planted, germination will not take place.

 

To achieve proper temperature and adequate moisture, apply mulch over the row following planting and watering or use materials such as screen wire strips, shade cloth, or boards to cover the row. This will moderate both soil temperature and soil moisture. Remove covers after seedling emerges.

 

Another desirable practice is to open the soil for the row somewhat deeper than in spring planting. The seeds are planted in this furrow, covered, and watered. In this manner, only the narrow trench would be watered, thus conserving a limited water supply. Later, one may cultivate along the sides of the row and fill soil to the same level of the remainder of the garden. In so doing, one may cover small grass and broadleaf weed plants that might be growing in the row.

 

Some vegetables are most easily grown by planting seeds in a small seed flat, setting them in individual containers to grow for approximately one month, and then transplanting them to the garden. Those that respond most favorably to this method of handling include broccoli, cauliflower, Chinese cabbage, leaf lettuce, Brussels sprouts, and cabbage.

 

Prior to setting them in the garden, transplants may be conditioned or toughened by a reduction in the amount of water supplied and by exposure to full sunlight. This might require three to five days. Plant them in the garden in late afternoon to early evening to reduce transplanting shock. Water the plants as they are set. A water-soluble fertilizer may be used at this time, if necessary—following label directions.

 

To achieve maximum germination of lettuce seed, the planted and watered seed flat should be kept cool. This can be accomplished by placing the seed flat in a cool (60° to 70°F) location for four or five days, at which time seed may begin germinating. The seedlings should be transplanted to individual containers within a few days.

 

When purchasing transplants in the fall from the garden center be sure to inspect them carefully for unwanted pests. Transplants coming from the greenhouse may also need to be conditioned before setting them directly into the garden. For additional tips on establishing a fall garden see OSU Fact Sheet HLA-6009: Fall Gardening.

 

Fall Planting Guide

 

1 = There may be advantages to planting earlier if soil moisture and climatic conditions are favorable

2 = Set plants into the garden 1 to 1 1/2 months after planting the seed. 

3 = Be vigilant about scouting for fall armyworms in whorl of seedlings and young plants.

* Unless using a cold frame or row covers to extend the season.

 

1 = Set plants into the garden 1 to 1 1/2 months after planting the seed.

Note: If planting or sowing into cold frames, plant two weeks later than date indicated.  With our abundant winter sunshine, be sure to allow for ventilation.  Also, check frequently for pests – especially aphids.

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August Pecan Management

Becky Carroll, Senior Extension Specialist

 

Depending on location, cultivar, and season, August is a time when pecans are transitioning from the rapid growth and water stages to shell hardening and gel or dough stages. This year, pecans look to be maybe a week ahead of schedule.

 

Crop Load Thinning:

Pecan trees tend to alternate bear, a big crop followed by little to no crop the following year. By assessing the crop and thinning at the correct stage, growers can help to have more consistent production, better quality pecans, and healthier trees. Timing is critical and should be done when pecans are in the water stage and 50-100% kernel expansion. Consult HLA-6251: Pecan Crop Load Management or watch this video with instructions on why, how, and when to crop thin - Pecan Load Management (YouTube)

 

Insect Monitoring & Control:

Check those weevil traps regularly to monitor for pecan weevil adult emergence. Read EPP–7190: Monitoring Adult Weevil Populations in Pecan and Fruit Trees in Oklahoma for information on weevil trapping. Weevil may cause some nut drop during the water stage but with heavy crops, that isn’t a problem. At the gel or dough stage, weevil can begin to lay eggs in pecans. During this stage, protection from weevil is critical. Knowing the pecan development stage is important for knowing when to spray. You may only need to spray specific early cultivars when they transition to gel or dough stages.

 

If hickory shuckworm has historically been an issue, spraying at shell hardening is helpful.

 

Watch for stink bugs or leaf-footed bugs that can cause bitter spots in the kernel after the dough stage initiates. Weeds or nearby crops may be harboring these insects. When these crops are removed or harvested, the stink bugs often move to the trees.

 

Observe trees carefully for aphids. Thresholds for yellow pecan aphid complex is 20-25 aphids per compound leaf. Black aphid thresholds are much lower at 2 aphids per leaf. Spray when necessary. Aphicides may need to be incorporated with weevil sprays to avoid outbreaks.

 

Prepare Ground for Harvest Time:

Keep vegetation mowed short. Smooth any wild hog damage, cattle tracks, or divots in the orchard. Remove any branches or limbs. Condition soil for cover crop planting.

 

Disease Control:

Continue scab spraying if scab model indicates need. Oklahoma Mesonet Pecan Scab Advisory . At shell hardening, unless severe, scab is more of a cosmetic issue.

 

Irrigation:

Irrigation is important during this stage to have the best quality pecans. Without water, kernels will be lightweight, and wafery. During kernel fill, two inches of water a week is needed. Supplement rainfall with irrigation as needed.

 

Grazing:

Cattle should be moved off native groves to allow time for the manure to dry and break down before harvesting.

 

Marketing:

Start planning for how the crop will be marketed and make connections.

For additional information, videos, and webinar recordings on specific management topics go to Oklahoma Pecan Management.

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Help Your Lawn Survive the Summer Drought

Mingying Xiang

 

After a wet start to summer, many areas are now entering extended dry periods. Lawns, golf courses, and parks, etc., may be showing signs of drought stress—and ironically, the earlier rainfall could be part of the problem. When turfgrass grows under consistently wet conditions, it tends to develop shallow root systems and excessive shoot growth, making it more vulnerable when dry weather sets in.

 

Now is an ideal time to help turfgrass adapt to drier conditions and build drought resilience. Smart irrigation practices can encourage deeper rooting and improve stress tolerance. Here’s how:

 

• Water deeply but infrequently. Deep watering promotes root growth, helping turf better access moisture during dry spells. Apply enough water to moisten the top several inches of soil—depending on how much topsoil you have and the rooting depth of your grass species.
• Avoid watering too early. Delay irrigation until you observe early signs of drought stress—such as a bluish-gray hue or footprints that linger. You can also use soil moisture sensors to irrigate just before moisture reaches a critical low threshold.
• Adjust to changing weather. During extended heat and drought, consistent irrigation may still be necessary. However, by sticking to these best practices, you can gradually reduce watering frequency—saving water, lowering costs, and keeping your turf healthier in the long run.

 

In addition to smart irrigation, following proper turf management practices—such as timely fertilization and appropriate mowing—is essential to maintaining a healthy, resilient lawn.

 

For more information, visit the following OSU Extension fact sheets:

• Turfgrass Management in Oklahoma
• Preparing Your Lawn for Drought
• Lawn Management in Oklahoma

 

Root Rot Disease in the Landscape

Many plant pathogens inhabit the soil, and they are often favored by wet soil conditions. One group of root rot pathogens is known as the water molds because they are the most severe in wet and poorly drained soils. Two of the groups of pathogens in this group are species of Phytophthora and Pythium. There are other types of root rot pathogens, but we will focus on these today.

 

Diagnosing root rot can be difficult because we do not examine the root system of plants daily. The aboveground symptoms that are observed may include wilting, dieback, poor vigor, yellowing, leaf drop, stunting, and/or a general unthriftiness of the plant. If any of these symptoms are observed, address any possible issues such as insect problems, poor fertility, or inadequate irrigation. Once these factors have been ruled out, it’s time to dig a little deeper. Literally.

 

Carefully dig the soil out around the plant roots to examine them. Note if the soil seems especially wet or dry. Sometimes growers will find that there is a foul odor that can be associated with anaerobic soil conditions and/or decay.

 

Healthy roots should be abundant, and young roots are light colored. The roots of shrubs and trees will become woody and darker over time as a normal process. Touch the roots to confirm that they are firm, and they are not breaking apart. If the root system appears sparse, discolored or if the roots are softened, it is likely that a root rot problem has developed.

 

To have the plant tested to determine the exact pathogen responsible, remove an entire plant that is in decline, but not dead, if possible. For large plants like trees and shrubs, a portion of the root can be removed and sent in for diagnosis. Some of the soil associated with the roots should be included and the entire root system should be placed in a plastic bag. Seal the bag with tape or a rubber band at the soil-line to prevent soil from contaminating the foliage. The entire plant can be loosely wrapped in a larger plastic bag such as a trash bag and taken to the County OSU Extension Office so it can be sent in for diagnostic testing.

 

With problems due to Phytophthora and Pythium, it is critical to remove and discard plants and associated soil in the trash as soon as possible. It is best to leave the area fallow (no plants) and to occasionally turn the soil. It is helpful to use soil solarization to reduce the number of propagules in the soil. The addition of organic matter may be helpful and in studies, has shown to reduce the level of propagules of Pythium and Phytophthora in the soil. In planting beds, it is critical to have soil that is well drained and to avoid overwatering. Planting beds may need to be amended to improve drainage. Planting on slightly raised hills or digging a trench can help redirect water away from plants. In many cases, downspouts can be redirected to reduce water flowing into planting beds.

 

If you immediately replant into contaminated beds, it is best to select plant material that is resistant or tolerant to Phytophthora. Pythium is less aggressive, and, in most cases, the cultural methods listed above will adequately manage the problem. In general, we do not recommend fungicides for treating root rot problems in the landscape.

 

For more information contact becky.carroll@okstate.edu or (405) 744-6139.