Oklahoma is no stranger to many types of weeds. These pesky plants can be a real nuisance, especially for those who have tried different methods to kill them, only to watch them grow back bigger and stronger than ever. Fall can be a nightmare season for gardening because everything is dying down from summer, there seems to be an endless supply of leaves needing to be blown off your yard (if you’re having issues with that, see this list) and weeds are just as annoying! While many weeds don’t pop up until the spring, the best time to treat for them and start your weed control regimen is in the fall and winter months.
At Acenitec, we recommend starting our six-step lawn care program during the fall to control weeds and get your lawn ready for the winter months ahead. By getting ahead of the game, you can help ensure that you’ll have the prettiest lawn when the weather starts to warm up again.
We’ve detailed the common types of weeds found in Oklahoma lawns to help you better identify them and know when and how to go about treating them this fall.
What are weeds?
A weed is simply a plant growing where it is not wanted or where it was not intentionally planted. Some weeds can actually be useful or attractive, but most fall under the “bad news” category.
Weeds are naturally strong and competitive. Those that best adapt in nature tend to dominate over other plant species, competing for water, sunlight, necessary nutrients, and even space. They commonly reproduce and spread through the dispersion of their seeds (whether by nature, animals, or humans), and can pretty much grow anywhere the soil or ground has been disturbed in some way.
Most weeds have the following common characteristics: abundant seed production, seed dormancy (meaning they do not grow until certain environmental conditions are present), rapid population establishment and spreading, long-term survival of seeds underground, and an ability to occupy spaces that have been disturbed by animals or humans.
Types of Weeds
The first step toward clearing these unwanted plants from your lawn is figuring out which type of weed you’re dealing with. Knowing the weeds that commonly grow in your lawn will help you and our Acenitec lawn care specialists treat and eradicate them from your yard more efficiently.
Unfortunately, there are many types of weeds that commonly grow in the Oklahoma area. If you aren’t sure which weeds are plaguing your otherwise healthy yard, start out by determining if they are grassy weeds or broadleaf weeds.
Grassy weeds are plants that can resemble turfgrass, but typically have longer and narrower leaves than traditional blades of grass. They also tend to differ in color and the ways in which they grow. Grassy weeds are usually difficult to control due to their similarities with turfgrass. In fact, many types of grasses that may be considered weeds in one area can be seen as desirable types of grass in another.
Broadleaf weeds are what most people picture when they think of weeds. They are easily identified and stand out from surrounding turfgrass due to their larger, broader leaves and net-like veins. Unlike turfgrass and grassy weeds that have fibrous root systems, broadleaf weeds grow from taproots, meaning their roots growing vertically downward.
Is the Weed Annual, Biennial, or Perennial?
Once you’ve determined if the weeds are grassy or broadleaf, you’ll want to determine if it’s an annual, biennial, or perennial weed to better understand when it grows. Most common weeds fall into one of the following three categories:
Annuals—Annual weeds germinate each year and typically grow, flower, produce seeds, and die within one year. They spread throughout your lawn by the transfer of their seeds and can come back as long as seeds are present in the soil. Some seeds may be newly introduced to the area by the weed or other factors, while some seeds will lie dormant in the soil until the ideal weather conditions are present and they are able to germinate.
Biennials—Biennial weeds have a two-year life cycle. In their first year, they will germinate, grow, and usually form a rosette (circular cluster of leaves). In their second year, biennials will produce a stem, flowers, and seeds. Once the weed has fully matured over the two years, it will die.
Perennials—Perennial weeds can live up to three years or more and will typically return each year. These weeds can reproduce by both seed and creeping stems, either above or below ground, that can re-root wherever they touch the soil. Perennials are the most difficult type of weeds to get rid of because they can regrow from any piece of root that is left behind after removing the plant.
Like other types of plants, there are weeds that grow best in cool weather and those that prefer warmer weather. Weeds are often classified as either “winter” or “summer” varieties within the three categories of annual, perennial, and biennial.
Winter annuals germinate in late summer to early fall. They will then grow throughout the fall, winter, and into the early springs months before dying off in the summer. Winter annuals will typically produce and spread their seeds in mid- to late-spring, just before the weather gets extra hot in the summer.
Common winter annual weeds in Oklahoma:
- Annual bluegrass (a grassy weed)
- Shepherd’s purse
- Mouse-ear chickweed
- Downy brome (a grassy weed)
- Common chickweed
Summer annuals germinate in the spring months, mature throughout the summer, and then release their seeds and die off when the weather gets cold in the fall. These plants are known for producing large numbers of seeds that will remain in dormancy in the soil for many years.
Common summer annual weeds in Oklahoma:
- Crabgrass (a grassy weed)
- Goosegrass (a grassy weed)
- Black medic
- Spotted purge
- Prostrate knotweed
- Sandbur (a grassy weed)
Winter perennials follow a similar growth pattern as winter annuals, germinating in the fall and maturing through the winter and spring. However, instead of dying off in the summer months, winter perennials will go dormant at the end of the growing season and wait to germinate again until the conditions become more ideal in the fall
Common winter perennials in Oklahoma:
- White clover
- Wood sorrels
Like their winter counterparts, summer perennials will lie dormant at the end of their growing season rather than dying off. This means that they will germinate in the spring, mature during the summer, and then fall dormant during the fall and winter.
Common summer perennials in Oklahoma:
- Dallis grass (a grassy weed)
- Curly dock
- Broadleaf plantain
- Buckhorn plantain
- Common yarrow
- Nutsedge (a grassy weed)
Biennial weeds germinate in the spring to early summer, forming a leaf rosette in their first year. These weeds will then over-winter (cease growing during the winter months) and resume growth in the spring, produce flowers and seeds before completing its two-year life cycle in the fall.
Common biennials in Oklahoma:
- Bull nettle
- Bushy aster
- Wild carrot
As we already mentioned, treating for weeds in the fall and winter months sets your lawn up for success the rest of the year. Fall weed control treatments target both annual and perennial weeds and can actually play a key role in wiping out established, hard-to-kill perennials such as dandelion or clover.
Some weeds can be easily removed by hand. If you only have a few weeds in your yard, you can remove them one at a time, lifting as much as the root out as possible. Weeds can most easily be removed by either hand or garden tool immediately following a rain storm, as the ground is soft and pliable.
This method works best for broadleaf annuals with shallow taproots. For well-established perennials with complex root systems, hand pulling is often discouraged as even as small piece of root left behind can help the weed to regrow. For perennials, a herbicide treatment is recommended.
Pre- and Post-Emergent Herbicides
Fall weed control treatments will target fall-germinating weeds, such as winter annuals, as well as the winter perennials that are beginning their dormancy process. During this process, the weeds will begin shifting their internal food sources from their leaves to their roots. By treating perennials during this time, the herbicides can essentially move from the leaves to roots and kill the weed.
Weed control programs targeting both annuals and perennials require both pre-emergent and post-emergent herbicides. The pre-emergent herbicides will take out any weeds that have not yet sprouted, and the post-emergent herbicides will kill off any weeds already growing.
Acenitec’s six-step lawn care program combines both pre- and post-emergent weed control treatments that will be applied in the fall (October or November), winter (December-January), and spring (February-March).
Healthy turf and soil are the best combination for preventing weeds from taking root. Thin, weak beds of grass and unhealthy soil provide the perfect environment for weeds to flourish. However, by keeping your lawn mowed, fertilized, and watered, weeds will have a much harder time establishing themselves. When mowing, make sure you’re cutting your grass to the proper height. Mowing the grass too short exposes the soil to too much sunlight and increases the potential for weeds.
The following are also known to increase your chances of weeds invading your lawn:
- Incorrect watering
- Improper fertilization
- Soil compaction
- Lawn diseases
- Poor drainage
- Improper sunlight
- Excessive wear on turfgrass
Want a green, healthy, weed-free lawn all year-round? Contact Acenitec today to learn more about our six-step lawn care program and get a free lawn inspection and pricing estimate!