How to Plant a Tree in Oklahoma Soil

Become a Master Gardener

Classes start in September each year. Register at our office on 15th Street for more information.

Garden

• August is a good month to start your fall vegetable garden. Bush beans, cucumbers, and summer squash can be replanted for another crop. Beets, broccoli, carrots, potatoes, lettuce, and other cool-season crops can also be planted at this time. (HLA-6009)
• Soak vegetable seed overnight prior to planting.  Once planted, cover them with compost to avoid soil crusting.  Mulch to keep planting bed moist and provide shade during initial establishment.  Monitor and control insect pests that prevent a good start of plants in your fall garden.
• Continue protective insect applications on the fruit orchard.  A good spray schedule is often abandoned too early.  Follow directions on last application prior to harvest. (EPP-7319).
• Water compost during extremely dry periods so that it remains active.  Turn the pile to generate heat throughout for proper sterilization.
  Always follow directions on both synthetic and natural pesticide products.
  Watch for high populations of caterpillars, aphids, spider mites, thrips, scales and other insects on plant material in the garden and landscape and treat as needed. (EPP-7306).
  Water all plants thoroughly unless rainfall has been adequate.  It is better to water more in depth, less often and early in the morning.

Lawn

• Grassy winter weeds like Poa annua, better known as annual bluegrass, can be prevented with a preemergence herbicide application in late August. Water in the product after application. (HLA-6420).
• Areas of turf with large brown spots should be checked for high numbers of grubs. Mid-to-late August is the best time to control heavy white grub infestations in the lawn. Apply appropriate insecticide if white grubs are a problem. Water product into soil. (EPP-7306).
• Tall fescue should be mowed at 3 inches during the hot summer and up to 3� inches if it grows under heavier shade. (HLA-6420).
• For areas being converted to tall fescue this fall, begin spraying out bermudagrass with a product containing glyphosate in early August. (HLA-6419).
• Irrigated warm-season lawns can be fertilized once again; apply 0.5 lb N/1,000 sq ft in early to mid-August.
• Brown patch of cool-season grasses can be a problem. (HLA-6420).
   

Landscape

The transition from summer to fall marks the best time to plant trees and many shrubs, as well as cool-season grasses (rye, fescue, bluegrass). Late winter into early spring (March, April) are also acceptable times to plant, but this allows less time for root systems to develop before the growing season gets in full swing. As Oklahoma summers go, 2014 has been one of the more pleasant ones in history, but your landscape still needs a bit of TLC to get through the final days of summer, and to get ready for the winter ahead.

When it comes to watering, most of us know that turf grass needs about one inch of water per week in order to survive (even more to thrive in dry weather). But, did you know that plants, especially new ones, sometimes need more water and trees, especially in their first year of growth, need even more water in order for their roots to grow strong enough to make it through a potentially hot, dry summer or a very cold, dry winter (or both). Natural rainfall is usually not adequate to provide the needed moisture. Newly planted shrubs and trees should be watered well at the time of planting. Then, young plantings need the equivalent of one to two inches of rain per week. And for trees, new plantings need a deep watering two or three times per week in hot, dry, windy conditions because their root systems cannot take up the amount of water needed to replenish the water lost through leaves (called transpiration). Water slowly so that the roots have time to absorb the water that is percolating into the ground. If you have several young shrubs and trees, a trickle irrigation system would be a wise choice. Not only does it minimize wasted water by directing it straight to the root zone but it minimizes certain diseases (mold, mildew, etc.) that can be caused by water being sprayed onto and remaining too long on leaves. Finally, be cautious not to overwater or the amount of oxygen in the soil could be lowered to a level that might damage roots.

As for fertilizing, warm season grasses (Bermuda, zoysia, buffalograss) need to be fertilized during their growing season. August is about the latest in the season you want to fertilize any warm season turfgrass. Bermuda grass needs about one pound of nitrogen per 1000 square feet per month. This translates to a total of about five pounds of nitrogen per 1000 square feet per season. Zoysia requires nitrogen as well but a bit less, around three pounds of nitrogen per 1000 square feet per season. Cool season grasses, such as fescue and rye, need to be fertilized just before their growing season starts, in either October or November, then again at the end of their growing season in March or April. Potassium and phosphorus should not be applied unless a soil test indicates it is needed. This is because these nutrients tend to remain in the soil longer than nitrogen. Nitrogen can be swept through the grass root zone by rain or watering, and will be depleted quicker in sandy soils than in clay soils. By far the best way to determine if and how much nutrients your turfgrass needs is to have a soil sample analyzed by the OSU Extension Office. Instructions on how to take the sample can be found here.

One of the more common questions received by the Master Gardeners regard problems that arise with tomato plants. One common problem is a condition called "blossom end rot". It is not a disease or insect problem and needs no treatment other than perhaps altering your management of the plants. This problem may occur not only in tomatoes but in several other vegetable fruits such as peppers, eggplant, squash, cucumber, zucchini and watermelons.

Blossom end rot is caused by calcium deficiency in the tomato. Calcium is absorbed by the roots and delivered in the plant by the circulation or flow of sap. If there is not enough calcium delivered to the developing fruit, the part furthest from the stem, the blossom end, can develop a localized calcium deficiency. This will begin to deteriorate and develop a leather-like brown discoloration called necrosis which may rot.

The calcium deficiency is usually not due to a lack of calcium in the soil--our soils have plenty--but is a problem with supply to the fruit. When the circulation is reduced, either due to dry soil or hot and windy weather, the plant tends to send most of the calcium containing sap to leaves and not fruit. Leaves are more important for survival.

Other factors contributing to blossom end rot are roots too small for the plant, overly wet soils and too much nitrogen fertilizer.

Excessive soil moisture smothers roots, preventing calcium absorption. Too much fertilizer causes tomato plants to grow more leaves than tomatoes, directing calcium flow into leaves. The type of fertilizer may also be important-ammonium types of nitrogen fertilizer can interfere with calcium absorption, while the nitrate forms do not.

To prevent the problem, water regularly, but don't overdo it. Most tomato plants need about 2 inches of water per week in 2-3 applications The goal is to moisten the soil down to 12 inches or so. One should avoid daily shallow watering. Also, a 2-3 inch layer of organic mulch will help reduce water loss and moderate temperatures.  

There are some varieties of tomatoes that are less susceptible to blossom end rot than others; this includes Celebrity, Jet Star, Mountain Pride, Pik Red and Sunny. Consider this group for your next tomato garden.

How was THAT for July in Tulsa, Oklahoma? It was indeed one of the coolest on record...the 5th coldest since records began in 1905! True, there were a few triple-digit afternoons...there usually are. But there was also a string a four straight days with highs below 80 degrees (ended by an afternoon which topped out at exactly 80 degrees), a couple of record lows, and enough rainfall to satisfy most. Thus, we end July every bit as green as we started it...and probably greener than at any time during the spring.

The weather definitely helped our pocketbooks, at least in terms of utility bills, but a more relevant question would be...did this impact the drought? In the short term, yes it did. Rainfall since June 1 has been very close to, or slightly above normal...Tulsa International Airport saw close to 9 inches during the two-month period. Longer-term drought conditions are still very much alive however, with a year-to-date deficit of over 7 inches. As dry as the year started out, normal early summer rainfall probably seemed like a torrent by comparison.

Now, on to the question that I am sure is on all our minds at this point...will this keep up through August? Early indications are that the overall pattern will favor below normal temperatures and perhaps above normal rainfall (the two often go hand-in-hand in an Oklahoma summer) through August 17 (per the 8-14 day outlook issued on August 3). That doesn't necessarily mean more rainy, 75 degree afternoons or record lows are on our way, or that we are done with triple-digit heat. It does suggest that any dangerously hot weather would be short-lived. And whatever happens, we are on the downhill side of summer.