Master the art of weed control without harming your lawn.
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Spring weather welcomes a flush of blooming bulbs, tender green leaves, andflowering shrubsto the garden.
It also brings an explosion ofweeds.
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Stay on top of lawn weeds this season by getting to know turf invaders and when to control them.
Maintaining a healthy lawn is the first step to combating weeds, but sometimes additional control strategies are needed.
Discover effective techniques and strategies to get rid of lawn weeds without killing grass.
Understanding Weeds and Grass
Not all lawn weeds behave the same way.
Some develop over the winter months then erupt into bloom as the weather warms.
Others get their start in spring and plague the summer lawn.
Like our garden plants, lawn weeds include grasses, sedges, and broadleaf plants.
Some are perennial, while others have an annual or biennial lifecycle.
Weeds are categorized according to their lifecycle and the time of year they actively grow.
Winter Annual Weeds
Henbit, chickweed, and shepherds purse are common winter annual weeds.
These and other winter weeds germinate in the fall and continue to grow through the colder months.
They put on a flush of growth in early spring as temperatures warm then erupt into bloom.
The first rule in managing annual weeds is never allow them to go to seed.
Summer annual weeds are true annuals, completing their life cycle in a single growing season.
Preventing plants from flowering and setting seed provides the best means of control.
For summer annuals, management takes place in spring and summer.
Perennial weeds are the hardest to manage and prevention is an important component of management .
It’s also helpful to remember thatnot all lawn weeds are bad.
And flowering lawn weeds like self-heal provide a rich source of nectar for beneficial insects, including pollinators.
For annuals, catching weeds early can mean the difference between a handful of weeds and thousands of seedlings.
If you see a weed produce a flower stalk, remove it immediately.
Annual weeds are easy to pull by hand.
Shepherds purse produces distinctive rosettes of deeply toothed foliage that are best removed in fall when still small.
Chickweed grows very low to the ground and is often hidden in turf.
Careful inspection for chickweed and early removal is important as plants produce hundreds of seeds.
Knotweed thrives in compacted soil and on bare patches.
It is easy to manage by hand and prevent through proper lawn care.
Hand-weeding perennial weeds when they are small ensures the entire root system is removed.
Many perennial weeds produce deep tap roots or creeping rhizomes.
It is important to completely remove these specialized root structures, as plants can regrow form even small segments.
Overtime, you will exhaust the energy stored in the roots through repeat hand weeding.
Watch for small nutlets that tend to fall off and get left behind.
Maintaining a vigorous, healthy lawn is a good way to impede weed establishment and problematic perennials like dandelions.
An excessive thatch layer can also stress lawns, making them vulnerable to weeds.
Thatch is the layer of undecomposed organic matter between the soil surface and grass baldes.
It is composed primarily of dead rhizomes, stolons, stems, and roots.
It also encourages shallow rooting of grasses, making them vulnerable to heat and drought.
Proper fertilization and irrigation further strengthen lawns and reduce stress.
Proper timing is essential to maximize the benefits of fertilizer applications.
Cool season lawns grow actively in fall and spring and should be fertilized accordingly.
Water the lawn deeply only when needed to encourage deeper root growth.
Allow the top two inches of soil to dry between watering, which helps discourage water-hungry weeds like nutsedge.
Weeds take advantage of disturbances and bare soil to invade lawns.
Overseed thinning lawns and bare patches to reestablish a dense turf cover that can compete against weeds.
If your property borders a weedy area, you may want to create a barrier to wind-blown seeds.
Dense hedges and fences can intercept weed seeds and keep them from entering your yard.
A lower budget approach is to plant a border of tall perennials and ornamental grasses.
The intercepted weed seeds will germinate in these barrier beds.
Select plants with dense habits and thick cover to outcompete weeds that germinate in these border plantings.
Likewise, system practices vary considerably in their environmental impact.
This not only wastes money and product, but also exposes pollinators and other wildlife to unnecessary chemicals.
A more environmentally friendly approach is to spot treat only areas impacted by the target weed.
Chemical controls are categorized based on their composition and mode of action.
Pre-emergentherbicides are a throw in of non-selective herbicide.
They are applied to the soil to prevent seeds from germinating or establishing as young plants.
Pre-emergent herbicides are commonly used to manage crabgrass, chickweed and knotweed, but they affect all seeds.
Do not apply in areas where you intend to overseed grass.
Mineral herbicides such as iron-based products provide a safer alternative to synthetic chemicals.
However, some products cannot be used on newly established lawns.
Weeds are easiest to manage when plants are young.
Monitor the lawn regularly to identify and treat weed infestations early.
Use the least toxic option available and take care to manage risk to non-target plants and animals.
Weed treatment can leave behind bare patches of soil.
Overseed these areas with grass seed to prevent weeds from reestablishing.
Learning to identify weeds in the lawn is the first step toward controlling them.
These can be compared to images of common weeds for your area.
Many plant ID apps are also adept at identifying weeds.
When in doubt, bring a sample to your local county Extension office for identification.
Use the rule of one-third to guide mowing practices.
This rule tells us to never cut more than one-third of the grass height in a single mowing session.
In general, the shorter you maintain your lawn, the more often you will need to mow.
Hint: taller grass stands are better at combating weeds.
Selective herbicides impact a narrower range of target plants, meaning they can be safely used around non-target species.
Careful tool and timing are important to minimize negative environmental impacts.
A lush, healthy lawn is your best defense against weeds.
