Use Preemergent Herbicides Now to Prevent Crabgrass and Other Summer Weeds

Use Preemergent Herbicides Now to Prevent Crabgrass

Brian Jervis: Ask a Master Gardener

Sunday, February 18, 2018

Q: When should I use crabgrass preventer on the lawn? And what is suggested to use? Steve C., Tulsa

A: There are several approaches one may take concerning lawn weeds. Some people simply ignore them, while others will wish to eliminate or prevent weed growth. The most effective preventative measure is to cultivate a healthy, thick lawn, which prevents weed seed germination and crowds out existing weeds. Any additional measure you may take toward a weed-free lawn, whether it is Bermuda or fescue, includes herbicides.

Herbicides for lawns come in two categories: pre-emergent and post-emergent. The pre-emergents are applied before the weed germinates; the post-emergents are used after the weed is growing. Pre-emergents should be applied to the lawn in February or no later than March 15 to prevent crabgrass and other summer weed growth. Pre-emergents for control of winter weeds should be applied in late August up to mid-September.

Always apply according to label instructions. When applied correctly, they are effective but still may not provide 100 percent control of all crabgrass. Activation requires all products to be watered into the lawn. Watering causes the soil surface to be coated with a thin layer of the herbicide and, because they dissolve poorly in water, may last for several weeks.

Some of the more popular herbicides that you will find in the Tulsa area are (brand names with the generic names in parenthesis): Amaze (benefin+oryzalin), Balan (benefin), Barricade (prodiamine), Hi-Yield Crabgrass Control (benefin + trifluralin), Dimension (dithiopyr), Halts (pendimethalin) and Portrait (isoxaben).

Generally, the products with benefin, alone or in combination with trifluralin, have a shorter duration of activity. A second application may be needed again in 10-12 weeks for control of late germinating crabgrass and goosegrass. Barricade, Dimension and Halts all have a much longer period of control of crabgrass and may need no second application. However, if allowed on the label, a second application can be an insurance policy that is to be applied no later than the second week of May in the Tulsa area.

All of these products, except Portrait, are excellent in preventing crabgrass growth and will have some effect on controlling broad leaf weeds from seed as well. The types of broadleaf weeds controlled vary by product. Dimension, Barricade and Halts all have good activity in preventing broadleaf weeds. Portrait is unique because it is formulated for broadleaf weed control alone and has little to no effect on crabgrass.

Whatever your choice, if you do use a pre-emergent, February/March and August/September are the times for application. However, do NOT use in late summer if you plan on reseeding fescue in the fall. Pre-emergents may be used on all Tulsa lawn grasses.

If you have questions about these products or lawn care in general, the OSU Cooperative Extension has two excellent condensed information sheets on Bermuda and fescue grasses. They are available for free at the Tulsa Master Gardeners website (tulsamastergardeners.org, under “Lawn & Garden Help”, then “Turfgrass”), as well as at the OSU Extension Office, 4116 E. 15th St. near the Tulsa Fairgrounds.

Garden tips

• Mid-February is a good time to begin pruning and fertilizing trees and small fruits.
• February is a good time to begin cutting back your perennial ornamental grasses, such as Pampas grass. Cut back to remove the dead grass, but avoid damaging new buds and early green growth at the base.
• Begin planting blackberries, raspberries, strawberries, grapes, asparagus and other perennial garden crops this month. Contact Tulsa Master Gardeners at 918-746-3701 for specifics about these plants.

Mistletoe’s History as Oklahoma's State Floral Emblem

Mistletoe’s History in Oklahoma

Tom Ingram: Ask a Master Gardener

Tuesday, February 06, 2018

Q: A few weeks back, you wrote an article about mistletoe. Isn’t mistletoe the state flower of Oklahoma? DH

A: The history of mistletoe in Oklahoma is quite a story, and the answer to your question is a resounding yes and no.

As the story goes, Oklahoma territory was to have a pavilion at the Chicago World’s Fair in 1893. The fair proposed states should consider selecting a floral emblem to represent them at the exhibit. So, even though Oklahoma was still a territory rather than a state, Rep. John Wimberly introduced a bill to the Territorial Legislature meeting in Guthrie that would identify mistletoe as the territory’s official floral emblem.

Even though a variety of flowers were considered to fulfill the honor of serving as the official floral emblem of Oklahoma territory, Wimberly argued that during the previous hard winter, no flowers could be found to put on graves. The only greenery around to serve that purpose was mistletoe, and because of this, mistletoe should be selected. His argument must have been compelling because mistletoe prevailed to become Oklahoma’s official floral emblem.

Later, before Oklahoma became a state, Bill Murray, who would later become governor of Oklahoma and be known as Alfalfa Bill Murray, lobbied to change the floral emblem from mistletoe to (you guessed it) alfalfa. He asked the question most of us have considered: Who in their right mind would designate a parasite as the state flower? His desire was for Oklahoma to be known as the Alfalfa state, which would align with the success of this crop in the area. However, his efforts were unsuccessful, and mistletoe prevailed.

Years later when Oklahoma became a state, members of the constitutional convention made it official: mistletoe would be the floral emblem of the state.

In 1986, Rep. Kelly Haney of Seminole introduced a bill that would identify the Indian Blanket as the official wildflower of the state. The bill passed, and the new symbol was celebrated at a ceremony attended by more than 20 Native American tribes. However, with some amount of apology, it was announced the lowly parasite mistletoe would remain Oklahoma’s official floral emblem.

With some degree of predictability, every few years someone would propose a change to no avail until 2004 when Gov. Brad Henry signed into law a bill making the Oklahoma Rose the official state flower of Oklahoma. However, mistletoe continues to remain our official floral emblem.

However, none of our rather unique history with mistletoe should be surprising from a state whose official vegetable is the watermelon, but that is another story.

Garden tips

• Most bare-rooted trees and shrubs should be planted in February or March. The roots of these plants are easily damaged and should never be left exposed to air. Plant them at the same depth as in the nursery and make sure good root and soil contact is made by gentle tamping and irrigation after planting.
• Finish pruning shade trees, summer-flowering shrubs and hedges. Spring-blooming shrubs, such as forsythia and azaleas, may be pruned immediately after flowering. Do not top trees or prune just for the sake of pruning.
• Dormant oil can still be applied to control overwintering insects.