Searcy, Ark. – Gardening has both rewards and challenges, and one of the biggest challenges every year is weeds. No matter how bad weather conditions get for growing plants, weeds seem to grow undaunted. Weeds are tough performers able to survive and thrive in a wide range of growing conditions.
Learning to identify the weeds you have is often the first step to controlling them. If you can catch them as they are getting started, you may be able to limit their spread and return.
I often recommend the best method for weed control in a vegetable and flower garden is the Santa Clause method—Hoe, Hoe, Hoe, but there are herbicides that can control them. If you do opt for chemical control, know there are differences in what can be sprayed around ornamentals, turf and edibles.
Summer weeds can be divided into annuals and perennials. While the annuals are just here for one season, they often aggressively set seeds providing an unhappy return the next season. Perennials can also set seeds, but they come back from their root system as well, often making them more difficult to kill.
Top 10 Summer Weeds (alphabetically)
- Bermudagrass – While Bermudagrass is a desired lawn grass, when it escapes into flower
beds and vegetable gardens, it is a tenacious weed. It thrives in hot, dry conditions
in full sun. It does not compete well in the shade. Bermudagrass spreads by rhizomes
and if left unchecked, can outcompete flowers and vegetables. Make sure to give yourself
a buffer zone of 6-12 inches between where your lawn ends, and your vegetable and
flower gardens begin.
- Chambers Bitters – Chambers Bitters is the rabbit of the weed world. This annual weed
doesn’t get growing until the soil temperature warms up, but when it starts, stand
back. The compound leaves resemble a miniature mimosa tree. The plant begins to flower
and set seeds at a young age. The seeds are produced on the undersurface of the leaves.
The plant grows upright and can get as tall as 4 feet or more if left untouched. It
has a strong taproot, which makes it quite drought tolerant. The key to controlling
this weed is to catch it early.
- Crabgrass is a summer annual grassy weed that germinates when soil temperatures are
approximately 60º F for 3-5 days. It begins flowering and setting seeds some years
by late May and continues until a frost. Crabgrass is a common weed in lawns and flowerbeds
which can quickly generate a seed stalk in between mowing. In lawns, the most effective
way to control crabgrass is to create a dense, healthy turf and/or use a pre-emergent
herbicide. I typically don’t recommend using a pre-emergent herbicide in flower beds
or vegetables, since these products can inhibit vegetable and flower seeds as well.
It is shallow-rooted so pulls out easily or can be uprooted with a hoe.
- Greenbrier is a vining perennial weed that is covered in thorns. It has a deep root
system which makes it quite difficult to kill. The plant is both heat and cold tolerant
but goes dormant with a killing frost. If you can wear protective clothing and pull
it out from the root system it will help, but rarely will you kill all the roots,
and it will sprout back. Spot spraying at the base of the plant with a glyphosate
product (Round-up) can help. It will grow in sun or shade, and often intertwines with
shrubs in the flower bed.
- Lespedeza - common lespedeza is a very common summer weed that can easily choke out
thin lawns. Lespedeza is a low growing annual weed with tough, wiry stems that forms
a mat-like growth. It has dark green trifoliate (arranged in threes) leaves. Lespedeza
has a semi-woody taproot and grows close to the ground, making it difficult to cut
with a mower, it flowers in late summer with tiny pink to purple, single flowers found
in leaf axils.
- Mulberry Weed is so named because the weeds look like tiny mulberry trees, however,
mulberries have smooth stems, while the weed has prominent hairs on the stems and
the leaves. This annual weed forms a taproot and easily grow to three feet or more
in height and produces flowers at the nodes, which quickly turn into seeds. Similar
to the copious seeds on the Chambers Bitters, if left unchecked, it can easily set
enough seeds to take over your garden.
- Nutgrass is actually not a grass but a sedge, nutsedge to be more precise. Although
it looks grass-like, nutsedge has a triangular stem, while grass stems are hollow
and round. This is a tenacious perennial weed that forms a small underground nutlet
or bulb-like structure. We have both yellow and purple nutsedge, along with a close
relative Kyllinga. These plants thrive in moist soils with full sun. Shade is a limiting
factor. Eradication is difficult, so if you spot a new patch, don’t ignore it, but
dig it out from the root system. They are a pest in lawns, flower beds and vegetable
- Pigweed is the common name for several annual species of weeds in the amaranth family,
which are more of a problem in a vegetable garden than in lawns. These plants grow
quickly and form tall bushy plants. They thrive in hot, dry weather and quickly respond
to the fertilizer you are putting out for your vegetables, often outcompeting the
vegetables you are trying to grow. They produce a prolific amount of seeds - a single
large plant can mature 100,000–600,000 seeds, and can begin to set seeds within 6
weeks of emerging in your garden. If you allow them to bloom, you can be assured of
seeing them next year.
- Poison Ivy is a terrible perennial weed that pops up in lawns and gardens across the
state. This perennial vine or woody plant can take on a wide range of leaf shapes,
but the leaves are always in groups of three. The entire plant is poisonous since
all parts contain an oil called urushiol, which is what causes the irritating rash
on folks who are allergic to it. Gardeners often overlook the plant in the winter
when it is dormant, but dormant tissue still contains the oils in the roots and stems.
Burning the remains of poison ivy can be dangerous since the oils can escape in the
smoke, and people who are highly allergic can suffer tremendously. Learn to recognize
this plant and try to get it out from the roots, being sure to clean your gloves or
tools after working around it, as the oil can be transferred from objects just like
it can from the plant. It has great fall color and in recent years has set a copious
amount of seeds, which the birds eat and drop all over your garden.
- Spurge is a large family of plants in the euphorbia family, which exude a white, milky
sap when the leaves are cut. Prostrate spurge is a mat forming annual weed that can
spread up to two feet across from a central taproot. While it is a common weed across
the board, it is even more prevalent in exposed, compacted soil in the sun, often
appearing in the crevices of sidewalks and driveways. Although the flowers are small,
the plant blooms continuously from late May through frost, setting plenty of seeds
to come back next year.
- Virginia buttonweed is a common perennial weed in lawns that often resists chemical control. The plant forms a thick matted growth that is particularly aggressive in moist areas. It is a spreading broadleaf perennial with opposite leaves that often have a mottled, yellow appearance due to a virus that commonly infects the foliage, but doesn’t slow down its growth. It produces showy white star shaped blooms above ground, and uniquely it also has another set of flowers it produces below ground. Virginia buttonweed produces deep taproots and rhizomes that often start at the nodes. Rhizomes can be found as deep as several feet below the soil. If you spot this weed, the sooner you can control it, the better.
There are a whole host of weeds which live and thrive in Arkansas gardens and lawns. Learning to recognize them and get rid of them when you see them is step one. Some sound management practices will also be a step in the right direction--maintaining a dense lawn to outcompete lawn weeds, mulching flower and vegetable gardens, and healthy management of all gardens will help. No matter how good a gardener you are, no garden will ever be weed free 100% of the time, but ignorance is not bliss, it will simply allow your weeds to take over. So be diligent and watch for problems and handle them as quickly as you spot them.
By Sherri Sanders
County Extension Agent - Agriculture
U of A Division of Agriculture
White County Cooperative Extension Service
2400 Old Searcy Landing Road Searcy AR 72143