Leaves are 4 to 6 inches long, dark green above, light green beneath, narrow and spatula-shaped. Good yields of small, sweet-smelling, daisy-like flowers. The yellow spines on the heads lack the sticky secretion found on Flodman thistle. Many plant parts from the root to the flower are eaten. Place plants into large plastic garbage bags when removing them from fields to prevent seed spread, then burn or compost the plant material. Since milkweed plants are native and a major food source for the monarch and other butterfly species, control is discouraged. Stem leaves are alternate, and go from 4 inches long to less than an inch at the tip of the plant. However, this biological control agent has not been approved for release in the U.S. and interstate movement is not allowed. The daisy-like flowers have yellow centers and white ray petals making this herb attractive enough for the flower garden! Scouting along waterways and removal of ornamental plantings have been effective in reducing the spread of saltcedar in North Dakota. The best herbicide to use will vary depending on crop rotation. The plant has a large, deep taproot that allows it to grow well in dry and poor soil conditions. Products that contain metsulfuron (Escort, Cimarron Max, others) will control biennial thistles in the spring and will eliminate seed production when applied in the bolting to bud growth stages. Prior to 1950, O.A. Bull thistle often is referred to as edible. Herbicides used for mustard control in cropland such as MCPA and 2,4-D will kill Dame’s rocket and can be used in wooded areas as long as the herbicide is not applied to the tree bark. Dame’s rocket is in the same family as garlic mustard, an invasive plant that has invaded woody areas and forests in neighboring states such as Minnesota and Wisconsin. Bull thistle is the least serious of the introduced thistles in North Dakota. Grazing alone will not eradicate leafy spurge but will reduce the infestation, slow the spread of the weed and allow grasses to be grazed by cattle and horses. Therefore, more Canada thistle root-bud development occurs in the fall than any other time of the year. Stems are usually yellowish-green to green and often turn red with maturity. Chemical. The root system of leafy spurge is extensive and consists of numerous coarse and fine roots that occupy a large volume of soil. The leaves are shiny green on top with slight pubescence and are white and very pubescent below, alternate, rigid and deeply lobed. Researchers in Montana have observed that spotted knapweed may remain in a confined location for several years and then spread rapidly to adjacent areas. The best control is avoidance, but if the plant is found close to walking trails, near a home or in your favorite fishing area, herbicides that contain triclopyr such as Garlon are very effective. Common burdock often is found growing along roadsides and ditch banks and in pastures and waste areas. Garlon (triclopyr) has been effective when applied in the spring or late fall. Leafy spurge was once the most difficult noxious weed to control in North Dakota and infests all 53 counties. However, when used as part of an overall management program, glyphosate can reduce infestations. Mechanical. Seeds remain in the soil for several years, so sites should be revisited each year to keep the plant from reestablishing. Escort (metsulfuron) also will control St. Johnswort effectively. Each seed has a pappus, which allows it to float long distances in water or move in the wind. Bull thistle occurs in all 48 contiguous states and most of Canada, but is designated noxious in only a few states. Root bud development can occur nearly anytime during the growing season, but is greatest when soil temperatures are warm, air temperatures are cool and the photoperiod shortens to 13 hours. Mey.]. The plant often grows to 3 feet tall and is easily identified by the presence of many small white flowers. Cultural. Musk thistle tends to invade overgrazed or otherwise disturbed pastures, rangeland, roadsides and waste areas. Saltcedar became established in North Dakota as escapes from ornamental plantings or from seed floating along rivers. Palmer amaranth is a summer annual that emerges from seed throughout the growing season. As you can see, a good rose bush can produce quite a few hips. High rates of 2,4-D alone will control narrowleaf hawksbeard but can damage some crops. Flower color can range from purple to light lavender or even white. However, the control program must be uninterrupted for two to three years if the infestation is to be reduced. Chemical. Stems of the plant are erect, branching above, glabrous or slightly to densely pubescent below, and appear gray. Subsequently it was ob served in C. mucronata Desv. Some taxonomists place these plants in the genius Anthemis. Perennial sowthistle was introduced from Europe and placed on the state noxious weed list in 1935 when it became a severe problem, especially in the northwestern part of the state. In the vegetative stage, the plant appears as a basal rosette with many hairy leaves. Field bindweed is found in both cropland and pasture and rangeland in North Dakota. Pineapple weed flowers may become bitter by the time the plant blooms, but are still good to eat. Hand-pulling or digging can be an effective control method for small infestations if conducted prior to seed production. Rhopalmyia tripleurospermi, the scentless chamomile gall midge, forms a gall on the plant, which acts as a nutrient sink that can interrupt and stunt the growth of the plant. Scotch thistle is an aggressive species that can out-compete and decrease desirable forage. Permalink. Burdock plants bolt in the second year of growth and grow 3 to 10 feet tall. Mechanical. Dame’s rocket overwinters as a rosette. Feeding by T. horridus larvae on musk thistle growing tips causes the plant to produce multiple shoots. Rosette leaves are alternate and have petioles almost as long as the leaf blades. Second-year plants are much less susceptible to 2,4-D. Plateau (imazapic) at high rates will control houndstongue both pre- and post-emergence, but grass injury, especially to the cool season species is likely when Plateau is applied at the maximum rate. Biological. Perennial and marsh sowthistle can tolerate variable environments and can adapt well to wet areas with little soil disturbance. The seed weevil Rhinocyllus conicus was introduced from Eurasia to control musk thistle by reducing seed production. Houndstongue is a biennial that forms a rosette the first year of growth and bolts and flowers the second season. Narrowleaf hawksbeard traditionally was found along roadsides and disturbed land in North Dakota but now has become especially troublesome in no-till cropland, cropland seeded with cereals, pulses or oilseed crops, hay fields, and along newly established pipelines. The leaves are pale green and 3 to 4 inches long. Chemical. Canada thistle is considered to be naturalized in the northern Great Plains. (Caution: Never eat any plant if you aren’t 100 percent sure!) The burs can be problematic for hikers, hunters and fishermen and also to their pets. This publication was originally authored by Rodney G. Lym, Professor of Weed Science, NDSU Department of Plant Sciences and Andrea J. Travnicek, Natural Resources Specialist in 2010. A single plant can produce as many as 150,000 seeds, of which 90 percent or more are viable and can remain dormant in the soil for a few years. Chemical. Several other insects have been evaluated for biological control of houndstongue; however, initial results were not nearly as promising as those of the root weevil. As with chamomile, pineapple weed is very good as a tea. Glyphosate (various trade names) will provide good control of purple loosestrife when applied from July to early September. (Asclepias syriaca L. and Asclepias speciosa Torr.). County Listed Noxious Weed – annual sowthistle only. St. Johnswort is a taprooted perennial herb that typically grows 1 to 5 feet tall. Mow whenever the plants are in the early bud growth stage to prevent seed-set. Flowering typically occurs from July to September. In the first year of growth, the plant forms a rosette of large, heart-shaped, thickly hairy leaves similar to rhubarb. This insect is credited with controlling St. Johnswort on millions of acres in California and the Pacific Northwest. The adults and especially the larvae feed on the leaves and flowers of purple loosestrife. Hoary cress is an aggressive plant that can form dense monocultures on disturbed land. Seeds are borne in pods, which contain three gray-brown, oblong, smooth seeds. She suggests not only sipping chamomile tea while bathing in it, but also tucking a chamomile sachet under the pillow at night to insure a restful sleep. The peak period of germination is late May and early June, but seeds can germinate and seedlings become established throughout the growing season. Today chamomile commonly is found in air fresheners, cosmetics, insect repellents and potpourri. Dalmatian toadflax is native to the Mediterranean region, specifically the Dalmatian Coast of Croatia, while yellow toadflax is from Eurasia. Spring and fall-emerging plants can reduce wheat yields by 20 percent to 60 percent if left unattended. syn. For instance, it infested four southern Iowa counties in 2016 but was found statewide in more than a third of the counties one year later. Disking is often ineffective, unless tilled 4 to 6 inches deep in order to bury seeds and prevent germination. In the remaining releases, flea beetles have not established. Carelessness in allowing just a few plants to become established can result in large crop losses in only a few years. The plants grow 2 to 4 feet tall with one or more stems. A careful follow-up program is necessary to control missed plants and seedlings. Long-term control of field bindweed from herbicides depends on movement of a sufficient amount of herbicide through the root system to kill the roots and root buds. Four of the six established insects are flea beetles (Aphthona spp. Rosette leaves are up to 6 inches long, 1 inch wide and coarsely toothed with a pointed tip. The seed generally germinates in the summer and fall, and the plant overwinters as a rosette. Also, no differences in Canada thistle control occurred when herbicides were used alone or combined with a prescribed burn. Saltcedar is the common name for several introduced species of shrubs or small trees, including Tamarix chinensis, T. parviflora and T. ramosissima. Annual and perennial sowthistle species are not true thistles and control options differ between these weed families. Cultivation in late fall or very early spring will remove this weed from cropland. Leaves are alternate, oblong to ovate, coarsely toothed to shallowly lobed and grayish green. The bindweed gall mite (Aceria malherbae) is microscopic in size and feeding by nymphs causes galling of field bindweed stems. Leaves are strongly undulated or wavy, which gives the plant its common name. A variety of herbicides can be applied for St. Johnswort control and are most effective when applied to seedlings and young plants. Native Americans used bull thistle to treat hemorrhoids, which they likely learned from French fur trappers. Cultivation or hand-digging the rosette prior to bolting will kill the plant and prevent seed-set. Leaves are wider at the tip than the stem and often have a pair of small lobes at the base and curled edges. Leafy spurge produces a flat-topped cluster of yellowish-green petal-like structures called bracts, which surround the true flowers. Most yellow starthistle seeds are plumed and disperse when mature. Canada thistle is a long-lived perennial that usually grows 2 to 3 feet tall and bears alternate, dark green leaves that vary in size. Once introduced, Palmer amaranth can spread quickly. Several herbicides will control common mullein, but all must be applied with a surfactant to overcome the extreme pubescence of the plant. Established field bindweed is difficult to control. Leaves clasp the stem with rounded basal lobes (auricles) that resemble a ram’s horn. The bracts are very narrow and resemble spines. It’s wise to know the facts before eating chamomile plants. Seeds are tiny, dark brown, 3/64 inch long, somewhat cylindrical, slightly pointed at the ends and coarsely pitted. It is tolerant to high salt concentration in soil but not as tolerant as Canada thistle. The second season, the plant bolts and a single, stiff, erect stem of 2 to 6 feet tall emerges. Spiny sowthistle, as the name implies, has sharp, stiff prickles along the stem and leaves. Black henbane is native to Europe and was cultivated as a medicinal and ornamental plant. Common tansy reduces overall pasture productivity because the plant displaces desirable grasses and forbs and animals are reluctant to graze it. The large size and showy flowers of the plant makes it quite noticeable in pasture and rangeland, but it has little economic or ecological consequence. Biological. Close-up photos of flower and stem courtesy of Lindsay Green, Minot State University. Several mowings a year are needed because plant populations vary in maturity. of Agriculture or NDSU weed specialists for the latest information on which agents may be successful in the state. The seed capsule is two-celled and contains many very small seeds (1 millimeter long or less). The first introductions to North America began in the 1660s and the plant is now considered naturalized. The roots were boiled and used in soup. Long, straight awns are attached to florets that are 3/8 to 5/8 inch long and are usually purple at maturity. Seeds mature rapidly and are able to germinate within eight to 10 days after pollination. Seeds are black, with two to five contained in capsules, and resemble pepper. It can grow as a small shrub or vine and is found in North America from Canada to Mexico. Given the opportunity to spread and become established, common milkweed is extremely difficult to control. Also, mowing will reduce seed production if repeated every two to four weeks during the growing season. False chamomile (aka German chamomile) and scentless chamomile are members of the aster family and have flowers that resemble the common daisy. Leaves are light to olive green, 2 to 5 inches long and divided two or three times into deeply lobed leaflets. Mature narrowleaf hawksbeard has bright yellow dandelion-like flowers, which are found from late May through September in North Dakota. The showy, yellow bracts appear in late May and early June, giving the plant the appearance of “blooming.” However, the true flowers, which are small and green, do not develop until mid-June. Many farmers were concerned because false chamomile was tolerant to all herbicides then available for use in crops. Seed capsules are shaped like an inverted heart and usually contain two seeds. Sheep and goats are best suited to control leafy spurge on large infestations or along waterways and tree areas where chemical control is restricted or cost is prohibitive and/or where success with biological control agents has been minimal. Dame’s rocket flowers are found from early May through June, fragrant and generally purple but occasionally pink or white. Downy brome is a prolific seed producer with production ranging from 25 to 5,000 seeds per plant. The plant’s growth is generally too compact to offer cover, and cover may be as crucial to wildlife as food. Seed capsules are two-chambered and contain many small brown seed. The wings are very spiny and are continuous along the stem and not interrupted as musk thistle. The most effective herbicides for spotted and diffuse knapweed control include Milestone (aminopyralid ), Tordon (picloram) and dicamba (various). Where possible, the use of soil-applied PPO inhibitors Spartan/Authority/Portfolio (sulfentrazone) or Valor/Payload (flumioxazin) products provides several weeks of residual control. Poison ivy is a perennial native small shrub that spreads by both rhizomes and seeds. Seeds generally germinate in late fall but germination can occur anytime throughout the year. [Linaria dalmatica (L.) Mill.] During wet years, the weed has spread rapidly throughout the black and gray soil zones of Saskatchewan. Of these insects, the two Galerucella spp. This plant is found most often in gravely, dry soils, waste areas and bottomlands. Biological. A single plant can produce between 1,200 and 4,800 seeds each year, with a single flowering stem capable of producing as many as 850 seeds.
2020 false chamomile edible