Posts tagged herbicides

Iowa’s weed season

   I’ve driven right past my plot in the city gardens, not recognizing it from what it was a week, or even days before. The rain and heat make the perfect recipe for weed season in Iowa. They grow fast and my combat methods are slower than the tillers many people use.

    Richard Jauron, extension horticulturalist at Iowa State University wrote the following about weed control in Iowa:

   Weeds are those annoying plants that gardeners love to hate. In the garden, weeds compete with desirable plants for water, nutrients, sunlight and growing space. They also may harbor insects and diseases. Allowed to run rampant in the garden, weeds can drastically reduce yields of fruits and vegetables. in addition, they hinder the performance of annual and perennial flowers.

    The first step in weed control is identification of the weed or weeds. The type of weed helps determine the best method of control. The two main types of weeds are annuals and perennials. Annual weeds germinate from seeds, grow, flower, set seed and die within one year. Perennial weeds live for three or more years. Most perennial weeds die back to the ground in fall, but their crowns or roots produce new shoots in spring. Weeds also can be classified as broadleaf weeds or grasses.

    There are three general methods of weed control in the home garden: cultivation (hoeing and tilling) and hand pulling, mulches and herbicides.

Cultivation and hand pulling effectively control most annual weeds. Perennial weeds are often more difficult to control. Repeated cultivation is often necessary to destroy some perennial weeds. When cultivating the garden, avoid deep tillage. The roots of many vegetables, fruits and flowers grow near the soil surface.  Deep cultivation will cut off some of these roots. Also, deep cultivation will bring deeply buried weed seeds to the soil surface where they can germinate. Hoe or till around plants or between plant rows, and pull weeds close to plants.

    To effectively control weeds, cultivation and hand pulling must be done periodically through the growing season. Small weeds are much easier to control than large weeds. It’s also important to destroy the weeds before they have a chance to go to seed.

    Mulches control weeds by preventing the germination of annual and perennial weed seeds. Established weeds should be destroyed prior to the application of the mulch. In addition to weed control, mulches help conserve soil moisture, reduce soil erosion, prevent crusting of the soil surface, keep fruits and vegetables clean and may reduce disease problems.

    Grass clippings, shredded leaves and weed-free straw are excellent mulches for vegetable gardens and annual flower beds. Apply several inches of these materials in early June after the soil has warmed sufficiently. Plant growth may be slowed if these materials are applied when soil temperatures are still cool in early spring. Grass clippings, shredded leaves and similar materials break down relatively quickly and can be tilled into the soil in fall.

Wood chips and shredded bark are excellent mulches for perennial beds and areas around trees and shrubs. Apply two to four inches of material around landscape plantings. These materials decay slowly and should last a few years. However, it’s often necessary to apply additional material annually to retain the desired depth.

   Herbicides can be used to supplement cultivation, hand pulling and mulches. However, several limitations prevent the extensive use of herbicides in the garden. Only a small number of herbicides are available to home gardeners. Additionally, most home gardens contain a wide variety of fruits, vegetables and flowers. No one herbicide can be safely used around all garden and landscape plants. If not applied properly, herbicides may cause unintended damage to fruits, vegetables and ornamentals. Herbicides are pesticides. When using any pesticide, carefully read and follow label directions.

Weeds are a persistent problem for home gardeners. However, weeds can be effectively controlled by cultivation, hand pulling, mulches and (on occasion) herbicides. Persistence is the key. Gardeners need to be as persistent with their weed control efforts as weeds are in coming back again, and again and again.

Comments (1) »

A Midsummer’s Garden

Linn County Master Gardener Claire Smith shares the following:

 

Can you believe it’s already July?  The favorite daughter’s corn (all 24 stalks—remember it’s her first garden adventure) are way taller than knee high.  Her two tomato plants are huge; the pumpkin plants absolutely covered with blossoms.  The kids are so anxious to see the fruits of Mom’s labors. What fun this is!

                So how is your vegetable garden fairing?

§  You may be surprised to know that you will want to water soon, if you haven’t started already.  Gardens – vegetable and flower -need about one inch of water per week.  Remember it’s best to water thoroughly early in the day. 

§  Fertilize leafy vegetables and sweet corn when the plants are about half their mature size. Peppers, tomatoes, cucumbers and beans should be fertilized when they have started producing fruit. Spread about two cups of a low-nitrogen fertilizer about six inches from the plant for every 100 feet of row.  Never put fertilizer directly on the fruit.

§  Continue to monitor for pests, add additional mulch if needed and remove weeds to prevent competition for water and fertilizer.

§  If you feel you must use a weed killer be careful to not get any on your ground cover.  Herbicides will kill any plant they touch.  A helpful hint is to cut the top and bottom from a milk jug, cover the weeds with the milk jug and spray the weeds inside the container.  Once the herbicide is dry, move the jug on to the next group of weeds.

§  Does your garden have a hot spot—lots of sun and dry?  There is still time to fill in. Plant some annuals.  Zinnias, Sunflowers, Dusty Miller and Cleome are both heat and drought resistant.  Deadheading (removing dead flower heads) will increase flower production.

Do enjoy your garden where the fruits (and vegetables) of your labor will be a tasty and safe special treat for the entire family. 

 

Another reminder – if you would like to become a Linn County Master Gardener  contact the Extension Office at (319) 377-9839 for information regarding the program.

Leave a comment »

Home lawn care

      The following is from Master Gardener Claire Smith: 

 Remember a few years ago when the TV helicopter pilot upon seeing a tornado shouted, “I see it!  I see it!”?  That’s how I felt today when I finally saw my lawn.  While all of the snow did provide a great deal of insulation and protection for our plants, I’m so glad it has finally melted.  Robins are searching for worms and squirrels are scavenging for any unburied nuts. And, on St. Patrick’s Day, I did see a bit-o-the-green peeking through.

     Oh! How I want to get to work on the lawn right now.  My goal this year is a strong turfgrass stand.  An ISU bulletin titled Home Lawn Care:  Weed Control indicates that weeds in a lawn are often a sign of a thin turfgrass stand.  (FYI, Turfgrass is defined as a spreading or stoloniferous [a horizontal branch from the base of a plant that produces new plants from buds at its tip, called a runner] grass as opposed to a tufted grass.)  Maintaining a dense turfgrass stand prevents weed infestations so: 

  • Choose the correct species of turfgrass. Kentucky bluegrass grows best in full sun.  A mixture containing fine fescues is suitable for shady areas.
  • Routine mowing will eliminate weeds with an upright growth habit.
  • Mow at a 3-3 ½” height
  • Inadequate or too frequent irrigation damages turfgrass
  • Identify weeds to determine method of removal.  A visit with your weed sample in hand to your Extension Office (in Marion at 3279 7th Ave. Ste 140, in the professional building in the strip mall next to the farm store) will provide not only an identification of the plant, but a suggested eradication plan as well.

          Weeds can be mechanically removed by pulling or digging. Chemical weed control may be your choice using an application of pre and/or postemergence herbicides.  Most herbicides selectively kill certain weeds.  A second application 7-10 days later may be necessary.  Apply preemergence herbicides in Southern Iowa around April 10th and around May 15th in the North.  A guide for crabgrass control is application of the chemical by the time the forsythia blossoms begin to drop or when the redbud trees are in full bloom. Optimum control of broadleaf weeds occurs when postemergence products are applied during the plants’ early bloom stage.  2-4-D and DSMA will control certain weeds without injuring the turf grass. Early spring applications are safer as some products vaporize and drift under high temperatures and humidity potentially damaging flowers and shrubs.       Apply when air is calm and rain is not expected for 24 hours.Use proper caution when mixing or handling any pesticide.  Most products available consist of a prepackaged mixture of two to three chemicals.  I’m off to pick up branches that are no longer frozen to the ground and watch the critters that are enjoying the advent of nicer weather as much as I am.  Happy Spring!! 

Leave a comment »