Extension Master GardenerSM Volunteers of Buncombe County

herbicides

Investigate Before You Invest in Any Pesticide

Deciding among the plenitude of pesticides on garden center shelves, all in colorful packages with large print promises, can be challenging. When buying a pesticide, you’re making an investment. And, as in making any purchase, you want to know what you’re investing in before you put your money down.

Oregon Dept of Agriculture_Pesticide Inspection_CC BY-NC-ND 2.0_Flickr
Investigate before deciding if, when, what, and how to use a pesticide.

Plan ahead before you buy
Are you sure you have a problem that a pesticide can solve? Have you identified the real cause? Weather can lead to some strange plant/environmental reactions, so make sure you have the correct problem identified. An insecticide won’t do you much good against a fungus! If you’ve experienced the problem in the past, investigate and exhaust alternative solutions before you start searching the pesticide shelves.

Read the label before you invest
The pesticide label is the contract between you and the product’s supplier. The label tells you what the product will do and what you must do to make it work effectively.

Like any legal document, the label must carry some words that have very specific meanings. On every pesticide label, you’ll find one of these three words in large, bold print: 

  • CAUTION: The product is slightly toxic if eaten, absorbed through the skin, or inhaled, or it causes slight eye or skin irritation.
  • WARNING: The pesticide is moderately toxic if eaten, absorbed through the skin, or inhaled, or it causes moderate eye or skin irritation.
  • DANGER: This pesticide is highly toxic by at least one route of exposure. It may be corrosive, causing irreversible damage to the skin or eyes. Alternatively, it may be highly toxic if eaten, absorbed through the skin, or inhaled. If this is the case, then “POISON” must also be included in red letters on the front panel of the product label.

    Malathion Directions_by Chris_Alberti_CC BY 2.0_Flickr
    Pesticide label tells what product does, explains how to use effectively, and gives warnings.

Be knowledgeable about product application

  • Will you need to mix the product with water or do you want to spend a little more for the convenience of a ready-to-use concoction?
  • What equipment will you need? Rubber gloves? A sprayer? Make sure your sprayer is in good working order by testing it with water on the driveway . . . not on valuable plants!
  • If you need to measure, make sure you have a measuring cup used only for pesticides! And rinse well after every use. Even a tinge of herbicide can work havoc with roses!
  • Refresh your memory and adhere to the contract uses of the product. What does it say about application under certain weather conditions—wind, temperature, precipitation? Does the product advise on use near water bodies or when pollinators are present?

Keep a pesticide inventory
Take a rainy afternoon to inventory your pesticide collection! Check the expiration dates and plan environmentally safe disposal of out-of-date pesticides. Maintain a pesticide usage record, including plants, problems, timing, and effectiveness. Your attention to up-front investigation and appropriate usage is a good investment, not only in any pesticide but also in your garden. 

Article written by Glenn Palmer, Extension Master GardenerSM Volunteer.

Time to Maintain: Stop Crabgrass Before It Starts

Act now to stop dreaded crabgrass from invading your lawn this spring and summer. Late February to late March—around the time Bradford pear trees start to bloom, but before the dogwoods—is the ideal time to apply a pre-emergent herbicide. It’s important to spread the pre-emergent and to create an herbicide barrier for the roots and shoots of those crabgrass seeds before they germinate. If germination has occurred, applying a pre-emergent is not effective as a weed killer.

crab grass_wintersoul1_CC BY-NC-ND 2.0
Digitaria sanguinalis or crabgrass weed

A summer annual weed
Crabgrasses are summer annual weeds that germinate as temperatures warm up in the spring, grow through the summer, then set seed and die in the fall. Once established, crabgrasses can quickly spread and devastate your lawn.

Using a pre-emergent herbicide
An application of a pre-emergent herbicide will last about 6 to 12 weeks, depending on the chemical used. Oryzalin and trifluralin are common pre-emergent ingredients. In addition to crabgrass, these herbicides will also control other summer annual weeds such as cocklebur, goose grass, and purslane. You can use most pre-emergents available to homeowners around ornamental plantings and in vegetable gardens, but always read the label! The label instructions will also tell you if you can use the pre-emergent on newly seeded or sod lawns, and how long to wait before mowing.

Using a post-emergent, selective herbicide
You didn’t get your pre-emergent down in time and crabgrass is invading your lawn? Consider using a post-emergent, selective herbicide such as 2,4-D (Weed-B-Gon, All-In-One, and other brands). Spray directly on the crabgrass weed, just to the point of runoff, rather than broadcasting. A rain-free day when your lawn has not been recently mowed is best. Again, be sure to read the label.

Mechanical control
For ongoing crabgrass management, I like to simply hand-pull. A weekly walk over my lawn with my handy weed-digger tool, and an eagle-eye to spot emerging leaves, keeps crabgrass and other lawn weeds in check—and I appreciate the exercise bonus!

Chemicals and manual labor aside, a thick, healthy lawn, that denies weed seed from coming in contact with the soil and getting adequate light for germination, is the best defense against crabgrass.

Article written by Beth Leonard, Extension Master Gardener Volunteer.

 Resources
http://www.turffiles.ncsu.edu/alerts/weeds/preemergent-herbicides-for-summer-annual-weed-control-in-turfgrass

Pesticide Use: Do You Need a License or Certificate?

Home gardeners do not need to have a license when using unrestricted pesticides—insecticides, fungicides, weed killers, and such that are sold to the public—in our own gardens. If we help someone else with these pesticides—with the property owner’s permission, of course—and if we do not get paid, then we don’t need a license. 

Caution!
Applying unrestricted-use pesticides for pay or as part of a job could require a license or certificate. If your neighbors pay you to apply a pesticide to their property, you may need a license. If you ask an employee to put pesticides down at a school or church where you are helping with a landscape, they may need credentials.

The Law
Cliff Ruth, Extension Area Agent Agriculture for Commercial Horticulture, sent out a checklist you can use to see if a license or certificate is indeed required in a given situation. To review it, click this link:
https://buncombe.ces.ncsu.edu/2016/11/do-you-need-a-pesticide-license-or-certificate/

Article written by Glenn Palmer, Extension Master Gardener Volunteer.

Contact Us

Buncombe County Extension Office
49 Mount Carmel Road
Asheville, NC 28806
Helpline 828-255-5522

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