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Ontario Weeds: Yellow rocket
Table of Contents
- Scientific name
- Other names
- General description
- Flowers and fruit
- Often confused with / Distinguishing features
- Herbicide resistance
- For more information.
Herb barbara, Herb of St. Barbara, Winter cress, barbarée vulgaire, herbe de Sainte-Barbe, cresson d’hiver
Mustard Family (Cruciferae)
Usually biennial or perennial, but some plants flower, set seed and die after their first growing season; reproducing only by seed.
Yellow rocket is common throughout most of Ontario in meadows, pastures, waste areas, roadsides, railways and along watercourses. It is especially common in moist rich soil and is apparently still spreading rapidly in such areas. Its occurrence in grain fields is increasing.
- Stems form in the spring
- 1 to several stems per plant
- Stem is erect, 20 – 80 cm high
- Young plants produce a rosette of smooth, shiny, dark green leaves during the first year
- Leaves stay green throughout the winter and may turn slightly purple by spring
- Leaves are long-stalked, hairless and divided into one rounded terminal lobe with several smaller lobes along each side
- Upper leaves are alternate (one per node), short-stalked or stalkless
- Upper leaves are coarsely toothed (or without teeth), or sometimes deeply lobed but always with a pair of basal lobes which clasp the stem
Flowers & fruit:
- Flowers are golden-yellow and 10-16 mm across
- Seedpods and their stalks either nearly erect and overlapping one another forming a dense raceme
- Or the stalks spread with the seedpods standing outwards or curving upwards and usually not overlapping one another, forming an open raceme
- Stalks are usually 3-6 mm long, pods 1.5-3 cm long with a slender, seedless beak 2-3 mm long
- Seeds egg-shaped 1-1.5 mm long and a metallic gray-brown colour
- Flowers from mid-May to early July and sometimes again briefly in late autumn.
Often confused with / Distinguishing features:
Yellow rocket is often mistaken for wild mustard. Yellow rocket is a perennial or biennial, so flowers much earlier in the season than wild mustard and has smaller and deeper golden-yellow flowers. Its leaves are dark glossy green or somewhat purplish, hairless, and distinctly clasp the stem, and the seedpod is tipped by a very slender beak which does not have a seed in its base.
No documented cases of herbicide resistance to date.
Figure 1. Yellow rocket seedling
Figure 2. Leaf of yellow rocket with basal lobe clasping the stem
Yellow rocket is a winter annual or biennial. The leaves which are glossy dark green, develop in a rosette. The basal leaf consist of a round terminal lobe with smaller lateral lobes that form opposite on the leaf petiole. The plant can reach heights of 2- to 3-feet, but it can tolerate mowing in a turf situation. The root of yellow rocket consist of a taproot with a fibrous root system. The flower of yellow rocket is yellow in color and appear in the late spring. The flowers form in a cluster at the end of stems, with individual flowers consisting of 4 petals. Yellow rocket spreads by seed. Yellow rocket is mostly found in the eastern portion of the United States, but it can be found throughout most of the United States.
Weed Photos: Courtesy of Dr. Lambert McCarty . Clemson University. Clemson, SC.
Since yellow rocket is a winter annual which germinates in the fall, post-emergence herbicide applications will be most effective at this time. Use a selective post-emergence application timed after germination when plants are young and actively growing.
WeedAlert.com features detailed color photos of over 100 weeds allowing turf professionals to search and identify weeds by name, appearance or region. Detailed information about each weed includes description, non-chemical cultural practices in how to control the weed, geographic coverage maps of where they grow and when they are prevalent in the various growing zones, as well as herbicide use and recommended control products.