Weeds usually top the list when it comes to destroying lawn care. Common weeds can invade even the best-manicured lawns. These invaders can crop up anytime in a year, ruining your lawn’s overall beauty and desirable crops.
Several factors encourage weeds to grow on a lawn, including soil texture, poor drainage, lack of fertilization, etc. How well you cope with them will depend on your overall lawn health, weed type, and eradication techniques.
Some weeds are too stubborn to eradicate whether you try on your own or hire an expert to tackle them.
However, understanding the common weeds of South Dakota can help you to deal successfully with intruders. To streamline weed defense, this article lists the common weeds of South Dakota lawns, spotlighting their key characteristics to identify with confidence quickly.
So keep reading to check them out and take the necessary action to eliminate them.
6 Common Weeds in South Dakota
Weeds are a nuisance, mainly because of their aggressive nature. Once they get established on a lawn, it becomes harder to control them. So try to spot them as soon as possible before their growth goes out of control.
Here are some of the common lawn weeds of South Dakota to help you identify them quickly.
1. Hoary Cress
|Scientific Name||Lepidium draba|
|Common Names||Heart-podded hoary cress, Thanet cress, Perennial peppergrass, White top, and White weed.|
This perennial weed can significantly hamper your lawn yields. Hoary cress bears a pleasant appearance that cloaks its insidious nature. However, they have an extensive root system known to release some chemicals. And those chemicals retard the development of cereals and horticultural plants like onions, tomatoes, and cabbage.
Apart from that, hoary cress serves as a good shelter for certain diseases and pests that spread to crops. This weed can be tough to eliminate once established. Chemicals like residual herbicides and hormone-type herbicides are labeled for their control. But they are recommended to use for only a few crops.
This weed can reproduce by seed as well as root fragments.
This rhizomatous perennial weed can extend up to 2 to 3 feet. They usually have short hair, but some plants can be hairless.
From April to July, you will see somewhat flat-topped white flowers appearing in clusters. Each flower consists of 4 petals. On the other hand, you will notice lance-shaped, blue-green leaves exhibiting alternate arrangements. Next, leaves show entirely smooth to irregularly toothed margins.
Stems are mostly upright, but some may have stems dangling on the ground. However, they show several branches close to the top.
Well, the hoary cress has inflated and rounded to nearly heart-shaped seed pods. They are hairless and dark brown, about 2mm (0.08 inches) long. Moreover, each mature hoary cress can produce up to 4,800 seeds.
Their rhizomatous roots occur at nearly 29 to 32 inches in depth, but they can expand up to 30 feet in depth.
When controlling, you can hand-pull the plants before their seed maturation. However, you can control younger plants by hoeing or shallow tillage. Make sure to eradicate both underground and aboveground structures to prevent re-growth.
But avoiding tilling established plants as root parts can give rise to new plants. Another good defense against this weed is by applying the appropriate post-emergent herbicide.
2. Salt Cedar
|Scientific Name||Tamarix spp|
|Common Names||Tamarisk, Saltcedar|
This weed can alter the ecology and hampers habitat quality. If a leaf of salt cedar drops, it minimizes microbial activity and elevates the soil salinity. Moreover, they can diminish streamflows while they transpirate more than native riparian varieties.
Fascinatingly, this weedy plant is characterized by a root crown that develops nearly 12 to 18 inches beneath the soil surface. Their seeds can float, get dispersed through water, and need moist soils to germinate and survive. Salt cedars even tend to dry off the soil.
Buds grow on this root crown, and new stems sprout rapidly from shallow lateral roots after the aerial parts of this weed are ripped off. However, strategies required to control this weed will differ based on their location and particular management objectives.
Salt cedars are deciduous, perennial, small shrubs that can grow from 5 to 25 feet. They have shallow, deep roots with lateral rhizomes penetrating to 30 feet or more in-depth. New plants usually emerge from roots or stems lying close to the ground or the disturbed root crown.
Another identifying feature is their bluish-green flat leaves. They are small and scaly and look like evergreen needles. Moreover, you will notice smooth, lean, reddish-brown branches that can be quickly snapped off. And their bark turns ridged and furrowed with age.
Flowers with five petals bloom from March till October. They are tiny, white to pink, and produce tiny seeds resembling pepper. The seeds are short-lived and have a tip with tufts of hair that help spread via wind or animal.
You can implement the techniques that kill the above growth but won’t destroy the root crown to suppress this weed. But it won’t kill it. Other aboveground controlling measures include mowing, fire, foliage feeding, defoliating herbicides, and grazing with livestock like goats.
3. Common Tansy
|Scientific Name||Jacobaea vulgaris|
|Common Names||Tansy, Golden Buttons, Cow Bitter, Garden Tansy, Mugwort, and Bitter buttons.|
Common tansy is an aromatic perennial that can replace forage plants and diminish wildlife habitat and diversity. In addition, they are known to be harmful to livestock; however, their strong odor keeps animals away from them.
This rhizomatous, weedy plant has erect stems growing from 40 to 120 cm in height. Common tansy has few hairs, fern-like leaves, and milky sap.
However, they have numerous dotted stems, ranging from brown to reddish-brown. Leaves on the stems display an alternate arrangement and are petiolate. But they turn sessile upwards. Leaves emit a strong aroma when crushed.
You will notice basal leaves withering early. Moreover, leaf blades range from 5 to 15 cm long. They are pinnately separated into lanceolate and feature serrate t-lobed leaflets. On top of that, this plant bears gland-dotted and glabrate leaves and has a nearly winged main stem in the middle of leaflets.
Flowers appear in compact, fat-topped clusters – rayless and button-like. They consist of only 1-3 mm yellow-disc florets but no petals.
However, flower heads feature subequal-sized bracts creating 2-3 rows. In addition, the involucre inside the flower heads contains overlapping, green bracts with thin, translucent, and membranous tips and margins.
Common tansy has tiny seeds with ribs and gland-dotted and crown-shaped pappus. Well, while handling this weed, make sure to wear gloves. You can hand-pull individual plants and control small infestations.
However, cut or mow these weeds before they flower and produce seeds. And clean all your equipment and machinery after cutting to remove seeds.
4. Spotted Knapweed
|Scientific Name||Centaurea stoebe|
|Common Names||Gugler, Hayek|
Another common weed causing headaches to South Dakota gardeners is spotted knapweed. It crops up in heavily disturbed lands like field margins or irrigation canals. However, they also take advantage of vacant and unmaintained landscapes and can spread to meadows, rangelands, and other open habitats.
However, you will be fascinated to know that people used to spread knapweed in domestic hays before it was recognized as a potential weed.
It can choke out more than 95% of the prevailing plant community. Their infestations on lawns can elevate the sedimentation of streams and soil surface runoff.
So the recommended technique for controlling this weed is IPM (Integrated Pest Management). It involves choosing various mechanical, biological, chemical, cultural, and manual methods to cater to the management needs of a particular area.
This perennial, short-lived plant can grow up to 2-4 feet tall, exhibiting 1 to 10 upright stems. A strong, elongated taproot characterizes them. Spotted knapweed remains in the rosette phase throughout the winter, and their growth continues till April.
The plant has pale to grayish-green leaves with a rough surface. However, the basal leaves are deeply lobed and display a rosette arrangement. On the contrary, the alternately arranged stem leaves are more linear-shaped, less lobed, and smaller.
The stems are hairy, slender, and branched, reaching up to 4 feet in height. Younger plants usually have an unbranched stem with one flower head. On the contrary, you will see branched stems from large plants with over 100 flower heads. The stem starts growing in early summer.
Flowers appear between June and September at the tips of auxiliary or terminal stems. Each pinkish flower head is about 0.2 to 0.4 inches long and composed of fine bracts with vertical streaks. Furthermore, the comb-like, dark fringes on the flower head produce a spotted appearance.
Spotted knapweed produces oval, brown, or black seeds with vertical lines. Moreover, each seed has a small, bristly pappus tip that aids wind dispersal. Some of the seeds can stay dormant for several years.
This weedy plant reproduces entirely by seed. After the flower heads bloom from June to August, the bracts reopen and spread the seeds.
Each plant produces nearly 1,000 seeds that sprout all over the growing season. However, seeds can spread through water, wind, wildlife, farm machinery, and contaminated hay besides seeds.
The key to weed control is detecting early and preventing them. You can easily spot knapweed once flowers start blooming from June to July. But your control options will become limited. So try to spot them before the weed reaches its rosette stage.
|Scientific Name||Cynoglossum officinale|
|Common Names||Gypsy flower, Dog bur, Rats and mice|
Here is a noxious biennial weed that suppresses cultivated crops in lawns or gardens. Weeds are labeled as locally toxic, usually upon the consent of the South Dakota Weed and Pest Control Commission.
Houndstongue produces an aggressive amount of bur-like seeds that cling to clothes and animals like Velcro. However, they are poisonous to animals who consume them.
This plant is known to have pyrrolizidine alkaloids that can destroy liver cells in horses, goats, cattle, and other animals. But dead houndstongue plants can be eaten in the hay. On top of that, they can result in dermatitis if you come in contact with it.
So it’s essential to identify this weed immediately and take quick actions to eliminate them from your lawn or garden.
In its first growth year, houndstongue develops as a rosette and produces 1 to 4 feet tall stems. Then, a woody, thick, black taproot emerges with branches. And every part consists of hairs.
They feature upright, coarse, hairy stems that branch at the ends. However, their rough and hairy leaves will also help you identify them.
Lower leaves come with leaf stalks and measure 4 to 12 inches in length and nearly 1 to 2 inches wide. While they look like a hound’s tongue, this plant is named so.
On the contrary, upper leaves are alternately arranged and have no petioles. Flowers appear in clusters at the end of the upper stems, as 5-lobed. And their color ranges from burgundy to reddish-purple. Furthermore, each flower bears four grayish-brown to brown nutlets, each containing one seed.
Nutlets have short, hooked bristles attached to clothes and animals for dispersal. You can mechanically control the plant’s growth by pulling the entire root out of the soil. So always clean off the seeds before getting out of a weedy lawn.
You can even cut the rosettes below the root crown. But keep an eye on seedlings and re-growths, as it’s important to control the weed before seed production.
If they are already blooming, rip them off or mow to the base and dispose properly to stop seed production. You may have to repeat the process as required for effective control.
More significantly, consider treating the affected areas by planting grasses or any competitive plants, such as native perennials, for competition.
6. Canada Thistle
|Scientific Name||Cirsium arvense|
|Common Names||California thistle, Cursed thistle, Corn thistle, Green thistle, Field thistle, Hard thistle, and Perennial thistle.|
Canada thistle typically infests disturbed grounds like overgrazed pastures or tilled fields. This weed even pops up in soils where moisture is adequate. They can thrive in various soil types and soils with 2% salt content.
This aggressive perennial plant develops a strong root system and invades new spaces by producing new shoots. Canada thistles can reach up to 5 feet in height. Stems are mostly smooth. However, they are often slightly grooved and covered with short hair.
The next identifying feature is the leaves. This plant characterizes lance-shaped, alternate, and irregularly lobed leaves with toothed margins.
You will usually see pink and purple flowers and rarely white flowers. Moreover, flowers emerge as clusters at the stems’ ends.
Canadian thistle spreads both by seeds and roots.
More than 3 million acres have been infested in South Dakota. And the poisonous weeds cause over $100 million in loss statewide annually.
Unfortunately, the cost and area infested are expected to elevate. Thus, gardeners and homeowners are recommended to take appropriate controlling approaches to get rid of the weeds on their property.
However, this article will help you to identify the common weeds that can intrude on the South Dakota lawn. Then, immediately act as soon as you see any of these invaders popping into your beautiful garden.