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SOME WEEDS GROW BEST WHEN IT IS HOT

GARDEN TIPS – written by Marianne C. Ophardt
WSU Extension Faculty
for the Tri-City Herald, Kennewick, WA Written July 23, 2015

SOME WEEDS GROW BEST WHEN IT IS HOT

Did you ever wonder why it seems like some weeds grow even faster in hot weather? It is because they do!

Growth of cool-season turfgrasses, like Kentucky bluegrass and fine fescues, slows during the sweltering heat of summer. However, some weeds are able to make the most of the heat and sun because they have a different type of respiration and function better when temperatures are between 85 to 117 degrees. Some of these warm-season weeds are Bermuda grass, crabgrass, foxtail, goosegrass, purslane and prostrate spurge.

I hate crabgrass because it sticks out like a sore thumb with its lighter green leaves and rapid growth, making it very obvious that there are major crabgrass infestations in many local lawns this summer. How could this happen despite applying a crabgrass “preventer” or preemergent herbicide? Even if the herbicide was applied at the recommended time, spring temperatures fluctuated up and down and may have thrown off the timing and resulted in applying the material too late or too early. If applied too early, the material may have lost its effectiveness before the crabgrass germinated.

Failure to control crabgrass could also be due to a lack of good coverage or not using the right rate. Always be sure to calibrate your sprayer or spreader before application. For more even coverage, apply half the amount of herbicide in one direction and then apply the other half in the direction perpendicular to your first pass.

A healthy dense turf is the best protection against crabgrass. Last summer’s extraordinary heat was tough on lawns and resulted in thinner turf that is now being stressed again by excessive summer heat and in some areas severe drought stress. Keep in mind that the grass in most lawns is comprised of cool-season turfgrasses that actively grow during the cooler months (March, April, May, October, and November) of the growing season. With the extraordinarily warm fall last year and very warm spring this year, many lawns have not been able to fully recover.

When (and if) cool fall weather arrives, fall fertilization at the recommended times of early September and early November will be important for green lawns that have made it successfully through the summer. However, only fertilize if there is adequate water available and the grass is green and growing.

A number of local residents have also been noting the proliferation of prostrate spurge in their lawns and gardens. There are four types of prostrate spurge, with spotted spurge being the most common in this area. These low-growing plants have tiny leaves and form a prostrate mat along the ground. As members of the Euphorbia family they have a milky sap that can cause skin irritation.

Spurge grows best in dry open areas and takes advantage of bare garden soil and dry lawn edges. In the garden or landscape, I recommend pulling or hoeing for spurge control. In lawns, you can kill spurge with an application of a “spurge killer” herbicide containing triclopyr, but you may find it easier just to dig up the plants if you only have a few here and there.
Of course, the weeds are the only green plants in some lawns where there has been restricted watering this summer. In a few weeks we will discuss what, if anything, can be done to bring these lawns back from the brink of doom.

HERBICIDES CAN CURL LEAVES TOO

written by
Marianne C. Ophardt
WSU Extension Faculty
for the Tri-City Herald, Kennewick, WA
published- JUNE 6, 2014

HERBICIDES CAN CURL LEAVES TOO

This is the time of year that weeds get our attention. As soon as warm weather hits they grow ‘like weeds.’ Then out come a variety of herbicides (weed control chemicals) aimed at killing these unwanted pesky plants in our lawns, landscapes, and gardens. Unfortunately, not using these chemicals properly can injure or kill our desirable plants.

Symptoms of herbicide injury vary depending on the chemical, but common culprits are the growth regulator type herbicides used to kill broadleaf weeds, like dandelions, in lawns. Exposure to the growth regulator herbicides can cause leaf cupping, twisted or distorted growth, and strap-like leaves. The common growth regulator herbicides found in home garden products for lawns are 2,4-D, MCPA, MCPP, and dicamba.

These products are available in liquid form for spray application or in a dry form for applying as a granular. It is very easy to awry when using them in liquid form because wind will cause the spray to drift away from the application ‘target’ area.

To minimize drift, herbicide sprays of any type should only be applied when there is no wind. In our region where it is frequently windy or breezy, this is difficult. The potential for drift can also be reduced by using large spray droplets instead of a fine mist and applying the spray as close to the ground as possible.

The other application choice is a granular herbicide, but desirable plants can still be damaged because of uptake of chemicals through the roots. The labels of products containing dicamba indicate that it should not be used ‘in the root zone of desirable plants.’

If you have trees located in or adjacent to your lawn, it is virtually impossible to avoid applying the chemical in their root zone. The root systems of trees can go out as far as a tree is tall and even further. Garden plants situated next to a treated area could also become damaged via root uptake.

Garden plants can also be exposed to herbicides when grass clippings from recently treated lawns are used as a mulch in the garden. Check product labels for how long you must wait before using the clippings in your garden after application. If you place treated clippings in a compost pile, it is best to compost them for several months before using the compost in the garden.

Other ways to reduce the chance of herbicide injury in the yard and garden include:

1. Avoid applying herbicides in late spring and summer. Herbicides can vaporize during warm (above 80 degrees) weather and float in the air, settling down on plants a long way from the point of application and causing damage. If you plan on using either granular or spray herbicides, do it when the weather is cool in early spring or fall.

2. If you have just a few weeds in the lawn, spot treat them individually or dig them out. A ‘weed popper’ tool works great for this.

3. In landscape beds, apply a three to four inch layer of bark mulch to discourage weeds.

4. In and around the vegetable and flower garden beds use shallow cultivation or simply pull the weeds. I like a stirrup type hoe with an oscillating head. Cultivate frequently to get the weeds when they are small. It is much easier.

I noted last week that the two main causes of curled leaves on garden plants were aphids and herbicide injury. Now we have covered both these culprits.

Published: 6/6/2014 11:43 AM

FALL A BUSY TIME FOR GARDENERS

written by
Marianne C. Ophardt
WSU Extension Faculty
for the Tri-City Herald, Kennewick, WA
published 9/6/13

As the garden season winds down, many gardeners may be thinking it is time to relax. It is not. Now is the time to make a checklist of fall gardening chores that should be done before fall’s end.

First on the list should be fertilizing the lawn. Early September and late October are the two most important times of year to fertilize your lawn. During the hot part of summer cool season grasses become stressed. Grass shoot and root growth slows to a stop. As the weather cools in fall, the grass begins to grow well again, establishing new roots and putting on sideways growth that increases lawn thickness. Nitrogen applied in the fall helps the grass recover from the stresses of summer.

Fertilizer applied now helps stimulate shoot growth. A late fall fertilization, applied after the grass stops growing, promotes root growth and the storage of food reserves needed for spring growth. This late fall application also keeps the grass looking greener through the winter and you should not need to fertilize again until April or May.

WSU recommends using a top-quality lawn fertilizer that contains some slow-release or controlled-release nitrogen, such as IBDU, sulfur-coated urea, or urea formaldehyde. These fertilizers release nitrogen over an extended period of time and allow for more even growth during the growing season. Fertilizers with soluble nitrogen, such as ammonium sulfate or urea, with nitrogen in a quickly available form are best for late fall fertilization.

Next on your list should be taking care of lawn weeds. If you just have a few weeds here and there, take them out with a weed digger. If the problem is more serious, you may want to consider the application of a broadleaf weed killers. October is a good time for applying these materials.

For weeds like black medic, bindweed, mallow, dandelions, plantain, and clover a combination herbicide product containing 2,4 D and MCPP should provide good control. A lawn product containing triclopyr will help with tough-to-control broadleaf weeds, like oxalis, prostrate spurge, henbit, ground ivy, and lawn violets. As with any pesticide product, be sure to read and follow label directions.

Now is also a good time to order or purchase spring flower bulbs for planting next month after the weather cools. Keep in mind that bigger (more expensive) bulbs produce bigger flowers. If your bulbs are packaged in a plastic or closed paper bag take them out and place them in an open well ventilated tray located in a cool (50 to 60 degrees Fahrenheit) spot.

Wait to plant the bulbs until the soil temperature drops below 60 degrees Fahrenheit. This temperature allows for root growth without stimulating leaf growth. Don’t forget the bulbs need water, so water them in right after planting and whenever needed during mild fall and winter weather to keep the soil slightly moist.

Other tasks to put on your list include:

raking up leaves

building a compost pile

dividing spring and early summer flowering perennials that have become crowded

cutting back to the ground the dead tops of perennial flowers

weeding and cleaning away plant refuse in garden and landscape beds

aerating your lawn if the soil is compacted

giving all your trees, shrubs and perennials a good deep watering before the water is shut off for the season

 

Whew! That’s a lot of work. You and I should get busy.

 

 

Published: 9/6/2013 2:28 PM

A CREEPY LAWN PROBLEM

written by
Marianne C. Ophardt
WSU Extension Faculty
for the Tri-City Herald, Kennewick, WA

One of the most common lawn problems brought into our local WSU Extension Master Gardener Plant Clinic is creeping bentgrass. Lawn owners note that patches of this grass seem to die or turn brown in the middle of summer but then come back again in the fall. The owners also note that when they pull on patches of the grass, it comes up much like a carpet or a loose piece of sod. We like to see samples of the grass to confirm its identification, but the offending grass is usually creeping bentgrass.

Creeping bentgrass is a low-growing, perennial cool-season grass that spreads out horizontally via above ground stems (stolons). These stolons can root where ever they touch the ground, resulting in circular patches of grass that stick out like sore thumbs in the typical Kentucky bluegrass lawn. That’s because the bentgrass has a finer texture and a blue green color that makes the spots obvious, especially when the bentgrass goes dormant and brown during the heat of summer. Walking on large areas of creeping bentgrass feels like you’re walking on a soft carpet. That’s no doubt why another common name for creeping bentgrass is ‘carpet bentgrass.’

Creeping bentgrass is an invasive grass that often shows up in older lawns, especially ones that are watered and fertilized heavily and mowed too short. You might wonder how creeping bentgrass first invades a lawn. Bentgrass can get started via seed in irrigation water or even as a contaminant in the original lawn grass seed. Because creeping bentgrass also reproduces via pieces of the stolons, it can be spread by mowers and other lawn equipment used on bentgrass infested lawns.

When it comes to control of bentgrass Jenny Glass, WSU Plant Diagnostician, notes that ‘there are no “magic bullet” herbicides available for removing one unwanted grass species from the desired types without hurting the wanted turf.’ Because creeping bentgrass has very shallow roots, one approach is to cut small patches out of the lawn using a spading shovel, digging down one to two inches to remove the both the grass and roots. The resulting hole is filled with clean soil and reseeded with grass that matches the rest of the lawn. However, one is seldom able to remove all pieces of bentgrass with digging and it will eventually return in that spot.

The other alternative is treating the bentgrass patches with glyphosate. Glyphosate, the active ingredient in Roundup and other non-selective grass herbicides, kills perennial grasses including the desirable lawn grass. When trying to kill a patch of creeping bentgrass in a lawn with a glyphosate product, the patch as well as an area six inches beyond the patch should be treated. The effective time for treatment is when the grass is green and actively growing in spring or fall, not when it’s brown and dormant in mid-summer. Once the grass in the treated area is dead, rake it out and reseed the spot.

If a creeping bentgrass infestation involves large areas of lawn, not just a few patches, you will need to renovate the entire lawn by killing all the grass and starting over… or you may decide to just live with it.

As with many yard and garden problems, your best defense against a bentgrass infestation is keeping the lawn in a healthy condition with deep, infrequent irrigation, proper fertilization, and mowing the lawn regularly at a height of 2.5 inches.

Need help with a lawn or garden problem? Call the WSU Extension Master Gardener Plant Clinic at 736-2726 Monday through Friday from 9 to 12 and 1 to 4. You can also stop by their table at the Pasco Farmer’s Market on Saturday mornings.

Published: 5/11/2012 2:19 PM

SOME THOUGHTS ON WEED WAR

written by
Marianne C. Ophardt
WSU Extension Faculty
for the Tri-City Herald, Kennewick, WA

In the Art of War, Sun Tzu is quoted as saying, ‘Strategy without tactics is the slowest route to victory. Tactics without strategy is the noise before defeat.’ When it comes to winning in the war of weeds you need both a sound strategy and smart tactics.

Get the Weeds Before They Go to Seed: We have just experienced a rather long spell of very hot weather. During this scorching heat, many of our garden plants and lawns hunkered down and stopped growing. Not so for some of our most troublesome weeds. They love seem to love the heat.

A number of summer annual weeds have their greatest rate of growth during the middle of summer. That’s because these weeds have a different photosynthetic pathway (C4) that provides for optimum photosynthesis and rate of growth when temperatures and light are very high. Optimum growth for most of our garden plants and winter annual weeds occurs when temperatures and light are lower because they have a different photosynthetic pathway (C3).

It’s not surprising to find weeds that have made the most of recent scorching hot weather while we were inside sipping lemonade. Now is the time to fight those summer annual weeds that have become very apparent. Get rid of them before they have a chance to spread their seeds for next year’s battle. If you retreat without roguing out the annual weeds now, you’ll have many more weeds to fight next year and the next year and the next year. I know because five years ago I let weeds take over a wine barrel planter that went unused for the season. I’ve used that planter for the last four years and the weeds continue to keep coming up from the weeds that were allowed grow five years ago.

Mulching to Prevent Weed Growth: Mulches help control weeds by excluding light and preventing seed germination and growth. I use a three to four inch layer of shredded bark to control weeds in my landscape beds. It effectively prevents most weeds from coming up. I don’t use any landscape fabric, plastic, or any other material between the soil and the mulch. The bark mulch also helps keep the soil cooler during hot weather, conserves soil moisture, and adds organic matter to my sandy soil. Gusty winds don’t lead to blowing bark for me because the soil grade of the beds is four inches below the grade of the surrounding lawn.

Note: When using bark or other mulches around trees and shrubs, keep the mulch about four inches away from the base of the plant. Mulch that touches the bark can lead to crown rot by keeping the bark moist and may also encourage damage from rodents during the winter.

As much as I like bark mulch, I don’t advocate its use in areas vulnerable to wildfire. In those areas, inorganic gravel or stone mulches are advised, but keep in mind that they keep the soil and the area around the plant warmer.

In vegetable and annual flower beds, grass clippings (no more than a two inch layer), sections of newspaper (uncolored paper only), and finished compost can be used as organic mulches. Landscape fabric can also be used for some vegetable crops, such as tomatoes and peppers.

Next time we’ll continue our talk of the ‘art of war against weeds’ and focus chemical weed control.

Published: 8/31/2012 2:12 PM

NEW HERBICIDES HAVE PROMISE FOR CONTROL OF WEEDY LAWN GRASSES

written by
Marianne C. Ophardt
WSU Extension Faculty
for the Tri-City Herald, Kennewick, WA

A couple of weeks ago I mentioned that there wasn’t any herbicide available for selective control of Bermudagrass in Kentucky bluegrass lawns. Until now, the only option was the use of glyphosate (Roundup and other products) to spot treat patches of Bermudagrass or to kill the entire lawn and start over. Dr. Rick Boydston, Weed Scientist for USDA-ARS at WSU Prosser, sent me a note to alert me that there is a chemical available to homeowners for selective control of Bermudagrass in lawns.

The chemical is fenoxaprop‑p‑ethyl. It’s contained in two Bayer homeowner products and is labeled for use in Washington. The two products are Bayer Advanced Bermudagrass Control-Lawns RTS (Ready-To-Spray) and Bayer Advanced Crabgrass Killer-Lawns RTS. They have the same active ingredient, but one has directions for Bermudagrass control and the other for crabgrass control.

The label indicates that one bottle treats 5000 square feet of lawn. That’s the good news. The bad news is that it may take up to seven applications of the product spaced one month apart to control Bermudagrass!

Applications should start in spring when the grass starts to green up and should stop when the Bermudagrass goes dormant in the fall. This is because fenoxaprop‑p‑ethyl works by being absorbed by green leaves and translocated throughout the plant. Don’t expect immediate results. It will take from 4 to 10 days before any visible symptoms, characterized by yellowing or reddening of the leaves, will appear.

You may not be able to get all seven applications in during the same season and may need to continue the applications the following year. However, Boydston indicated that he found that about four applications did a good job controlling the Bermudagrass in his lawn.

Another new herbicide is available to homeowners, but not as readily available as the Bayer products. This product is called Tenacity. Tenacity is labeled for selective control of creeping bentgrass in Kentucky bluegrass lawns. It’s marketed and labeled primarily as a commercial turfgrass product by Syngenta, but it is legal for use on home lawns.

I know of one local homeowner who has used it for bentgrass control and is happy with the results. In addition to bentgrass, Tenacity is also labeled for control of a variety of broadleaf weeds., plus it provides pre and post emergence control of crabgrass, yellow foxtail, and barnyardgrass.

Tenacity contains mesotrione a new chemical that kills weeds by inhibiting the synthesis of chlorophyll. It’s applied as a spray and is absorbed through both the leaves and the roots. Weeds will stop growing after the application, turn white, and die within three weeks. A second application may be needed for control of existing weeds. When trying to control bentgrass in Kentucky bluegrass, research indicates that repeat applications of Tenacity will be needed and that the second application should be applied two to three weeks after the first.

Since Tenacity is intended primarily as a commercial product, it’s not as easy to use. Application rates are indicated as ounces per acre, so your math skills will need to be utilized. Be sure to calibrate your sprayer before applying the material, plus you’ll need a surfactant for controlling existing weeds. For safe and effective use of Tenacity, read and heed the warnings on the label.

These are two new chemicals that offer great promise for control of tough grassy weeds in lawns, but it’s important to understand how they work and to follow label directions.

Published: 9/28/2012 1:10 PM

MORE OF THE WAR ON WEEDS

written by
Marianne C. Ophardt
WSU Extension Faculty
for the Tri-City Herald, Kennewick, WA

Sun Tzu was the expert when it came to the ‘art of war.’ ‘He who knows when he can fight and when he cannot will be victorious,’ also applies to the war on weeds especially, when using chemicals

If you just have a few dandelions or other weeds in the yard, your best bet is to dig them out as soon as they’re noticed. This doesn’t have to be back breaking work. I just ordered a Fiskars Uproot Lawn and Garden Weeder that is supposed to make the job of pulling lawn weeds easy with no bending or kneeling necessary. You just place the steel claws at the end of the long handle over the top of the weed and step on a foot platform. It pops out the weed, roots and all. I’ll let you know how well it works. There are similar tools available at local garden and hardware stores. Pulling may not be practical for extremely weedy or expansive lawns. Also, certain weeds, such as patches of clover or black medic, aren’t easy to pull.

Chemicals are sometimes that only effective way to manage certain lawn weeds, but knowing what, when, and how to use these materials effectively is important.

For broadleaf lawn weeds, like dandelions, plantain, black medic and clover, the right time to apply the appropriate lawn weed killer (herbicide) is fall. Once the weather cools, September through October, is when these perennial weeds are sending food reserves to their roots. Most broadleaf weed herbicides available to homeowners contain a mix of 2,4-D, MCPP (mecoprop), and dicamba (Banvel). When applying a lawn herbicide in the fall, you may think the material hasn’t worked because the weeds don’t die quickly. However, by springtime the weeds should disappear.

Fall is also a good time to apply broadleaf weed herbicides because you’re less likely to damage garden plants through direct misapplication, drift, or volatilization. Also, labels of mixes containing dicamba caution against using them in the root zone of trees and shrubs. Where nearby woody plants may be at risk, it’s a good idea to spot treat the weeds in those areas of lawn.

Many perennial grassy weeds, such as Bermuda grass, in lawns can only be effectively controlled by spot treating with a product containing glyphosate. Glyphosate is a non-selective herbicide that is taken up by green plant tissues and transported down to the roots. The chemical gradually kills the roots and the weed dies. Glyphosate is often the only effective material for managing dastardly tough perennial weeds in landscape beds, such as field bindweed.

Here are some tips on using glyphosate effectively:

Apply to actively growing, healthy perennial weeds that aren’t drought stressed.

The more green leaf surface that’s treated with glyphosate, the more chemical gets into the plant, and the more effective the treatment. Don’t mow or pull weeds immediately before treatment and don’t mow or pull for at least seven days after applying.

When treating Bermuda grass, the most effective time of year is late summer when it’s flowering.

When treating field bindweed in landscapes, the most effective time of year is right after it begins to flower in early summer and then again when runners reach a foot in length.

Avoid getting glyphosate on nearby landscape plants by shielding them with a large piece of cardboard.

Remember to follow Sun Tzu’s advice and know when you can and can’t fight weeds with chemicals.

Published: 9/7/2012 12:48 PM

NOW IS THE TIME TO HELP LAWNS RECOVER FROM SUMMER & CONTROL WEEDS

written by
Marianne C. Ophardt
WSU Extension Faculty
for the Tri-City Herald, Kennewick, WA

Whether your lawn is pampered or neglected, weed free or overcome with weeds, fall is the most important time of the year to give it the attention it deserves.

Recovery:
Summer heat stresses the cool season turf grasses in our lawns. As the weather cools in early fall, lawns start to recover. You can help that recovery along with properly timed fertilizer applications. An early September (Labor Day) plus a late October (Halloween) or early November application are recommended for our region.

You still need to irrigate your lawn, but as the weather cools you should be cutting back on the amount of water being applied. If you’re watering everyday, you may only need to water every second or third day. By watering everyday when the lawn doesn’t need it you’re wasting water, washing away needed nutrients, and encouraging the growth of weeds.

Weed Management:
One of the best ways to manage lawn weeds is to encourage a healthy turf with properly timed fertilizer applications and irrigation. However, weeds still find their way into lawns and October is the best time to apply herbicides for the control of broadleaf weeds. That’s because many of the perennial broadleaf weeds in our lawns, such as dandelions and plantain, are actively growing during the cool fall weather. Herbicides applied when they’re actively growing are more effective.

There are also winter annual broadleaf weeds, such as chickweed, that germinate in the fall and grow during late fall and early spring. These are more easily controlled in the fall when the plants are young and small. Efforts made in the fall to encourage a dense, healthy turf, can also help control summer annual weeds, such as crabgrass, purslane, and pigweed, that will germinate in the spring. A dense turf makes it more difficult for weeds to germinate and grow.

Also, fall is a good time of year to apply herbicides to your lawn because landscape plants are not actively growing and not as susceptible to damage from the herbicides.

Which Herbicides?:
There are a number of broadleaf weed control products on the market. Most broadleaf lawn weeds can be controlled with a combination of 2,4 D, MCPP, and dicamba. However, products containing dicamba should not be used in the root zone of desirable trees and shrubs because they can cause damage. This includes trees and shrubs growing in the lawn area or along the lawn border. Even if trees and shrubs are in a landscape bed, they’re still vulnerable if their roots are growing into the lawn area. Keep in mind that the absorbing roots of a tree can be located in areas as far from a tree as that tree is tall and beyond! If you have vulnerable plants with roots throughout the lawn, it would be advisable to simply spot treat weeds or use a product that doesn’t contain dicamba.

There are also certain lawn weeds that are particularly difficult to control, including bindweed, black medic (Japanese clover), clover, creeping wood sorrel (oxalis), ground ivy, henbit, mallow, prostrate spurge, violet. Better control of these can be achieved with lawn herbicide products containing triclopyr.

Before purchasing any herbicide product for your lawn, identify the weeds you’re trying to kill. WSU Master Gardeners can help you identify your weeds. Just dig them up and place them separately in zipper-locked plastic bags. Bring them to the Extension office (735-3551) in Kennewick in the Benton County Annex at 5600-E West Canal Dr. Of course, read and follow all label directions and precautions on the herbicide product you select.
Published: 9/3/2011 11:48 AM

PERSISTENCE KEY TO CONTROLLING BERMUDA GRASS IN LANDSCAPE

written by

Marianne C. Ophardt

WSU Extension Faculty

for the Tri-City Herald, Kennewick, WA

I recently heard a group of gardeners talking about the problem of controlling Bermudagrass in landscape beds. Calling it a problem is an understatement. Control of Bermudagrass is a colossal challenge and can’t be achieved easily. Before we talk about control, let’s talk a little about this pernicious grassy invader.

Bermudagrass didn’t come from Bermuda. This low growing, blue-green perennial grass was introduced to this country from southeast Africa in 1751 and has been used both as a forage grass for livestock and as a lawn grass in the warmer regions of the country where cool-season grasses are difficult to grow. In fact, there are cultivated varieties of Bermudagrass that don’t produce seed developed for use in these regions.

In this area, few people purposely plant Bermudagrass lawns, but end up with lawns and landscape beds invaded by this aggressive warm-season grass. Bermudagrass can propagate itself from plentiful seed that develops in late summer. Seeds stay viable in the soil for at least two years.

Bermudagrass also spreads by both tough, wiry rhizomes (root like stems in the soil) and stolons (trailing aboveground stems that can root at base of every leaf or node). Pulling or simple cultivation are not effective ways to control Bermudagrass because pieces of rhizomes or stolons left behind can grow into new plants. However, a persistent program of cultivation and withholding water over an entire season can end in success… if there are no desirable plants in the bed that will suffer from a lack of water and regular cultivation.

Many gardeners use glyphosate (such as Roundup or other brand names) in their attempts to control Bermudagrass. To be effective, glyphosate should be applied when the grass is actively growing in mid-summer. Two to four applications timed three to four weeks apart may be needed for satisfactory control of any regrowth. Perseverance is essential.

The problem with using glyphosate in landscape beds near established trees, shrubs, and perennial is that it’s “non-selective.” If glyphosate is applied to green leaves, stems, or even thin young bark it can enter these desirable plants and cause damage. I have had several plants brought into me this year that were exposed to glyphosate last summer or fall and were showing signs of herbicide injury this spring. Symptoms include stunted, distorted, and narrowed yellowing leaves along with dieback of growth. To avoid this problem, many gardeners will use a shield of cardboard between their desirable plants and the Bermuda grass when applying glyphosate.

Some gardeners have discovered that there are “selective’ herbicides that will kill perennial grasses, including Bermudagrass, but will not harm most non-grasses like trees, shrubs, roses and perennial flowers to which they are applied. The two selective grass herbicides available to home gardeners are sethoxydim ( Monterey Grass Getter) and fluazifop (Ortho Grass B-Gone). They work best in spring when the Bermudagrass runners are 4 to 6 inches long and not drought stressed. Re-treatment will usually be necessary and should be done when the regrowth reaches six inches again throughout the season.

Any of these herbicides are not a one-time “silver bullet” for control of Bermudagrass in landscape beds. Tenacity using both the non-selective glyphosate or the selective grass herbicides will be needed.

Garden Note: Many gardeners now have ornamental grasses in their landscape beds which can be damaged if exposed to these herbicides. Before using any of these products, read and follow the label directions.

Published: 7/2/2011 9:31 AM

ATTACKING GARDEN WEEDS EARLY

written by

Marianne C. Ophardt

WSU Extension Faculty

for the Tri-City Herald, Kennewick, WA

Some gardeners have other interests to keep them busy during winter months, some head south for the season, and others wait impatiently for spring to arrive. If you’re in the last group, take a tour of your garden and landscape to look for winter annual weeds that may have already started growing. These are weeds that germinated in the fall, are growing during the warmer parts of winter, and will flower and go to seed in the spring. There are a bunch of these evident in the landscape outside my office!

A swipe with a sharp hoe will make easy work of these annual weeds, but first take some time to get your favorite hoe in shape. Remove any rust that may be on the hoe’s blade by soaking it vinegar and then using a steel wool cleaning pad with the vinegar to scrub off any rust that remains. Be sure to use rubber gloves to save wear and tear on your hands. There are commercial rust remover products that can be used if the rust is extreme. Avoid those that contain harsh caustic chemicals and look for one that’s non-toxic and non-corrosive.

After the rust is gone, smooth the surface with 80-grit sandpaper. Next use an 8 to 10 inch mill bastard file with a handle to sharpen the blade using “push” strokes directed away from you and following any existing beveled edge. If the blade is in bad shape, sharpening with a grinder or belt sander may be needed. Don’t forget to wear your safety glasses.

After sharpening remove any burrs that have formed on the back of the blade using 300-grit wet-dry sandpaper and then apply a light coating of WD 40 or other high quality oil to the blade. Also, unpainted wooden handles will benefit from a coat of linseed oil to keep the wood from drying out and cracking

Did you know that new garden tools need to be sharpened before use? For obvious reasons, stores find it advantageous not to ship or display tools with sharp blades. So even if your hoe’s blade isn’t rusty, check to make sure the blade is sharp. The sharpening process isn’t difficult, but if the thought of taking on the sharpening task is too daunting, you may be able to find a local sharpening service.

Now is a good time for anxious gardeners to sharpen their trusty hoes. Then on a mild sunny day, go out looking for those winter annual weeds. The sharp blade will make easy work of cutting them off right below the soil.

Best Hoe: The traditional garden hoe is a versatile tool that allows gardeners to chop off big weeds, move soil around, and create furrows for planting. However, many WSU Master Gardeners favor other types of hoes for garden weed patrol. One of their favorites is a stirrup or shuffle hoe, also known as the Hula-Hoe or a scuffle hoe. These hoes have a blade shaped like a stirrup that oscillates when pushed and pulled. The blade slides into the soil at a horizontal angle and cuts off young weeds just below the soil surface. It isn’t effective on big tough weeds, but works well on smaller seedling weeds. This type of hoe doesn’t take as much effort to use, is easier on your back, and does its job with minimal disturbance of the soil.

Published: 1/8/2011 3:10 PM

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