Witch grass, Panicum capillare
Weed Control Options 
Life Cycle
AnnualPropagation
Reproducing only by seed.Stems
Stems 5 - 120 cm high, erect, or spreading.Leaves
Leaf blades and leaf sheaths densely hairy, the hair 2 - 3 mm long and becoming harsh and prickly as the plant matures; leaf sheath split (B), its margins (a) either separate or overlapping; ligule (b) a dense fringe of hair 1 - 2 mm (1/25 - 1/12 in.) long; no auricles.Flowers and Fruit
Inflorescence (C) a large, loose, open, fluffy panicle with numerous, very fine branches and tiny spikelets (d) at the ends of those branches; the much-branched panicle often wider than long and, on small- to medium-sized plants, often making up ½ to 2/3 the total height of the plant; mature spikelets 0.7 - 0.8 mm wide by 2.0 - 2.3 mm long florets (“seeds”) 0.6 - 0.7 mm wide and 1.3 - 1.4 mm long shiny gray-brown with 5 parallel beige veins. At maturity, the stem breaks easily below the inflorescence and the whole panicle is rolled and tumbled by the wind, dropping seed with every bounce. Flowers from July to September.Roots and Underground Structures
Fibrous root system.Habitat
Witch grass is very common in fields, waste areas, roadsides, backyards, gardens and occasionally in lawns throughout southern Ontario and sporadically in northern and northwestern Ontario.Competitiveness
Corn yield loss (%)*:1 % at 1 plant/m2
5 % at 5 plant/m2
Soybean yield loss (%)*:
1 % at 1 plant/m2
4 % at 5 plant/m2
*assumes that the weed has emerged with the crop and has been left uncontrolled all season.
Distinguishing Features
It is distinguished from Fall panicum by its densely hairy leaves and leaf sheaths, its very fine, bushy panicle and its smaller seeds; and from Proso millet by its much smaller seeds that are only gray-brown in colour. Seedlings of Witch grass can be distinguished from those of Proso millet only by the size, shape and colour of the mother seed clinging to the primary root.Toxicity
Witch grass is not known to be toxic.Human Health Issues
Witch grass is not a known allergen.Forage Quality
No information exists at this time.Species Benefits
No information available at this time.Power Ranking Corn
Power ranking↑ 22
Power Ranking Soybeans
Power ranking↑ 35
Biological Control
Currently none available for this weed. For the latest research on biological weed control: Click here
Biopesticide Control
Currently none available for this weed.Herbicide Resistance
Triazine resistant (WSSA group 5) populations exist in Grenville, Grey, Haldimond/Norfolk, Prescott and Wellington counties (ON).For more information on weed resistance:
Click here
Media Items
Figure 1: Witch grass: A. Base of plant B. Leaf-base C. Panicle Top
Figure 2: Ligule: hairy. Top
Figure 3: Leaf blade: hairy on the upper and lower surfaces. Top
Figure 4: Leaf sheath: extremely hairy, leaf sheath margins are also hairy. Top
Figure 5: Seed head. Top
Figure 6: Whole plant. Top