Living in the Portland, Oregon area brings many joys, and having a well-manicured lawn is often one of them. Unfortunately, along with lush grass and vibrant flowers comes the potential for pesky weeds to invade your yard and cause you grief. But don’t despair! Simple Lawns has put together this guide to help you identify and combat these invasive intruders!
Weeds are plants that grow in places where they are not wanted. They can be found in gardens, lawns, fields, and other outdoor spaces. Weeds usually grow faster than other plants, and they often have deep roots that make them hard to remove. These pesky plants will compete with other, more desirable plants for space and resources, including water, air, and nutrients in the soil. They can also spread easily by releasing seeds or sending out runners above or below the soil surface. In your lawn, weeds will cause grass to become weaker and thinner as their roots spread in the soil, which is why it is so important that you know how to properly identify and remove lawn weeds before it’s too late!
Weeds come in a variety of different sizes, colors, and types, but many of them are pretty easy to identify in your lawn if you know what to look for. Some types of weeds develop flowers and distinctive leaves, which make them very easy to spot in a lawn filled with nothing but turfgrass, but they may blend into a flower bed or garden. On the other hand, some weeds look quite similar to the healthy turfgrass of a lawn, but you can expect lawn weeds to grow taller and at a faster rate than your desired grass. No matter what kind of weeds you may be dealing with in your lawn, they will always make your lawn appear discolored and patchy once an invasion has begun!
Key Characteristics:
-Faster and taller growth than surrounding plants
-Shallow or complex root systems
-Distinct leaves that differ from turfgrass
-Flowers that do not look familiar
-Patches of uneven growth in lawn
-Discolored and weak patches in lawn
Identifying the types of weeds you may be seeing in your lawn really comes down to which category those weeds belong to — broadleaf or grassy. Though both categories contain many species that have a number of different characteristics, there are some consistent traits that pertain only to one category or the other. Knowing how to spot these differences will give you a better understanding of what type of invasion you are dealing with and how to treat it.
Broadleaf weeds have broad leaves (surprise, surprise!) that vary in color from other surrounding plants. These leaves are often veiny and easy to differentiate from narrow, smooth grass blades. Depending on the species, broadleaf weeds may produce a single flower or a cluster of flowers. Broadleaf weeds can grow annually, biennially, or perennially, and they spread quickly via a combination of both seeds and runners that sprout new shoots throughout the area. The root systems of broadleaf weeds range from shallow and fibrous near the soil surface to deep taproots that penetrate deep into the earth.
Common Broadleaf Weeds:
-Dandelion
-Thistle
-Field Bindweed
-Chickweed
-Creeping Charlie
-Kochia
Grassy weeds are more challenging to spot in a lawn because they often mimic healthy turfgrass, both in growth habits and appearance. Though grassy weeds and turfgrass have similar growth patterns, you can usually differentiate grassy weeds by their taller, faster, and often more vibrant growth. Even if the leaf (grass blade) shape is identical to the grass in your lawn, you can usually identify patches where these undesirable plants are thriving by looking at differences between their growth habits compared with surrounding turfgrass varieties. Most grassy weed species tend to have shallow, fibrous roots that steal away all available moisture and nutrients for themselves, leaving little resources left for your lawn or garden. Many grassy weeds produce seed heads that will pop up when the weed is tall and mature, which is a strong indicator of weeds in your lawn.
Common Grassy Weeds:
-Any unwanted grass species
-Annual bluegrass
-Crabgrass
-Goosegrass
-Quackgrass
-Barnyardgrass
Weeds can come from a variety of sources, but they mainly spread through root growth and/or seed dispersal. Annual weeds tend to spread mostly by seeds because they only live for one growing season, which means roots don’t have as much time to develop and spread under your lawn. Perennials often utilize a mixture of both seeds and and root development to spread their invasion, as these types of weeds go dormant in winter and resume root growth in spring. Aside from these sources that physically spread the weed invasion, there are also a number of conditions and situations that make your yard more vulnerable and likely to invite a weed invasion. Below are some of the most common causes of lawn weeds:
-Poor Drainage: Poor soil drainage and low fertility create an ideal environment for weeds to grow, as many types thrive in overly moist soil.
-Overwatering: Too much water can create a soggy environment, which encourages weed seedlings to germinate.
-Inadequate Mowing: Mowing too low or infrequently can weaken grasses, allowing weeds to take hold.
-Improper Fertilization: Fertilizer helps to promote healthy grass growth, but too much or not enough nitrogen is an open invitation for weeds to invade.
-Excess Sunlight: Some sunlight is necessary for all plants, but too much sun exposure can weaken turfgrass and leave it vulnerable to weeds.
-Soil Compaction: Compacted soils have less oxygen and nutrients available for roots, which favors the shallow roots of many weeds.
Weeds seek out struggling lawns that are already in poor health, and, of course, their presence will only make the condition of your lawn or yard even worse. Some weed control methods are more effective than others, depending on the type of weed. Central taproots and shallow roots, for example, can sometimes be pulled right up without any tools. Digging out deeper roots with fibrous offshoots is also an option some homeowners implement. While methods like these can sometimes work, leaving even the tiniest fragment of roots or plant matter can easily cause a new weed to sprout back up. Maintaining a healthy lawn all year long is the best way to prevent a weed invasion, and be sure to keep the following tips in mind this season for the most weed-free lawn possible:
-Mow weekly, and set blade between 3-4 inches to choke out weed seeds.
-Water your lawn deeply and infrequently to reach deeper turfgrass roots.
-Use a season-appropriate fertilizer, and monitor nitrogen levels.
-Test soil regularly, and balance pH level when necessary.
-Apply a pre-emergent in spring to prevent weeds from growing.
-Last, but never least, call Simple Lawns for all your lawn care needs!
