Friday, January 21, 2011

The dreaded and feared Sandbur, aka The Sticker

If you don't have to deal with stickers/sandburs/Cenchrus then goody for you. The rest of us sorry individuals have this rather nasty weed to contend with every summer.
Let the battle begin.

From: Cummings, Dr. Hennen

Subject: Controlling field sand bur in your home lawn
Date: Wednesday, January 19, 2011, 3:19 PM

If you are interested in controlling sandbur (stickers) or crabgrass in your lawn this summer, now is the time. Please go to Home Depot in Granbury or Weatherford. The brand name is Lesco which is why you have to go to Home Depot. You are looking for a 50-pound yellow bag kept with the fertilizers. The product is Lesco 0-0-7 PRE-M. The active ingredient is pendimethalin. Apply it like a fertilizer according to the directions using a rotary spreader. Uniform coverage is very important to prevent weed escapes. The product will stain concrete, so make sure you blow if off your driveway when you are finished. It may also stain on your pants' leg and spreader. The product needs to be watered in with a 1/2 inch of water (run the irrigation until several tuna cans laid out across the lawn are half-full). The product will control summer annual weeds like field sandbur when applied in Feb. before the weed seeds germinate. It will not control perennial weeds like dandelion that come back from vegetative structures. The bag will cost about $21.00 per 12,000 ft². Be careful putting herbicides on St. Augustinegrass. The fewer herbicides placed on St. Augustinegrass the better. Even if St. Augustinegrass is on the label, it may still be stunted for a month or more. Fall preemergence herbicide applications for winter annual weed control (henbit, chickweed, annual bluegrass) are safer on St. Augustinegrass than spring applications, but they control different weed spectrums. The active ingredient can stunt root growth. Do not apply the product anywhere you plan to plant seeds like vegetables or flowers or have wild flowers. Apply 4 pounds/1000ft² of Lesco 0-0-7 Pre-M. You may need to apply again in July, but hopefully, a dense, aggressive turf will prevent sunlight from reaching the soil and stimulating summer annual weed seeds to germinate and a second application will not be necessary. It is too soon for nitrogen fertilizers, so do not apply a preemergence herbicide on a nitrogen fertilizer carrier. Apply the nitrogen once a month starting in April; May would be better if you can be patient. The more nitrogen fertilizer one adds, the more often one should mow. If one cannot mow more often than once a week, then use nitrogen fertilizer more sparingly. Always maximize the amount of slow release nitrogen and iron in the fertilizers for lawns.

Fire ant control measures are available in stores now, but you have plenty of time to get those applied. Products containing fipronil work well for a long period of time.

Rock on,

Hennen Cummings, Ph.D.
Assistant Professor and Director of Turfgrass Management
Tarleton State University

As the timestamp shows, this was THIS WEEK. In the middle of the winter, frost on the ground and colder than a well-digger's butt outside this college boy wants us to start on the yard NOW?
Why yes indeed he does and he is right.
Here is why.
Long before you want to have that cookout in the backyard and long before the seedheads form on the varying species of Cenchrus later this summer the seeds lie in wait for the warming sun of early spring to germinate. Once they have sprouted out of their infernal seedcoat and begun the process of producing more of these awful impediments to bare feet it is too late for this product mentioned to have any effect. The term pre-emergent is what we use to describe a product that prevents or kills a seed at or very close after germination. Now, for those that don't even know the term germination that is when the root and leaf or leaves emerge from the seed. Remember the bean in the cup? Root goes down, leaves go up and what a miracle it appears to be. In the case of the widely despised sandbur this is something we should try to prevent or inhibit as much as possible but not to the detriment of desirable plants.
Pendimethalin is mostly benign to critters that you might have including chickens or other fowl. Since we want to water it into the soil the risk of exposure to you or your animals or any other individual animal is minimal. I can hear that moaning too. Yes, you have to water it in. Yes, it has to be at least a half an inch. Don't tell me you can't come up with some cans resembling a tuna fish can. I can go in your kitchen right now and find some good candidates for water sampling. Don't trust your gut in knowing how much water your irrigation system puts out, whether it is an old school impact sprinkler, high tech rotor or your thumb over the end of a hose.
Do you think for one minute that Colonial or any other golf course would just fling water around willy-nilly with no accurate assessment of how much is actually going on the course? It isn't hard to accomplish the task. Get a dozen or so conveniently open and somewhat flat cans or other containers, spread them randomly but evenly over your given space and turn on the water.
Go away. Leave. Go have a beer, glass of wine or other beverage of your choice.
I'll take a double shot of whiskey, thanks.
Sip on it. Take your time. Check out your spreader. Does it need new tires or just some air?
Spray some WD-40 on the parts that move around and sometimes get stuck. Use duct tape on the parts that should not move but do.
Brace yourself it is time to calibrate this thing.
Got tired head already? Ok go hire somebody. Ask them the last time they calibrated their equipment. Don't remember? Thanks, buh bye. Click. I don't care about how much or how little they charge to apply pre-emergent. If they don't calibrate their spreader it is close akin to a nurse shooting you up with drugs from a syringe without a means of measuring. Gotcha some Demerol, half a tube ought to be about right. There ya go! Brilliant. Your yard is no different.
You need to know exactly how much of whatever you are putting out is going on your yard or pasture. If you are putting out a product over a large area it obviously is going to be more dollars that we are putting at risk, but in any case the effectiveness of the product and its level of impact are determined by the dosage. Duh. Just cranking open the chute on your spreader and stomping around the yard with no concept of how much is being flung around is quite possibly dangerous and certainly less than effective. In the case of pendimethalin it is not so much the risk of toxicity as it is the lack of effectiveness. Note that he says 4# per 1000ftsq. That means you need a way to measure exactly how much stuff your spreader is spreading at a given setting and adjusting that setting to get the correct amount over the desired area. This is called calibration of a spreader. Look it up. Follow the directions. Get on it.
If you know you have a yard that is prone to sandburs I would highly recommend using this product. If you have a yard that is prone to crabgrass, the same stuff works on them too.
I would recommend some old nasty boots or other footwear that you don't care what they look like being used for this operation. DO NOT USE WATER TO GET IT OFF THE SIDEWALK OR DRIVEWAY! YOU HAVE BEEN WARNED. It will dye it a nice bright yellow. Canary yellow, lemony lemon yellow. A broom will work and so will a blower. Save the water for the irrigation.
Speaking of which, you can go check the water now. Not up to a half inch yet? Repeat process until you do.

Believe it or not. Spring is right around the corner.