Barley Grass (Hordeum spp.)
Barley grass is one of nature’s survivors. Not only does it grow where and when other grasses fail to thrive, but it has developed a flexible seeding technique which allows it to grow unnoticed until the day length, temperature and soil moisture level is suitable for seedhead development and dispersal.
Over the years it has gained a nasty reputation with those raising sheep. Those sharply awned seedheads get caught in the fleece, can penetrate pelts and blind lambs. The problem is compounded because barley grass finds a ready home on well trodden soil such as sheep tracks or stock camping areas. Dry soil and dry winters are less of a deterrent than for, say, ryegrass. And when the seeds hit the ground they germinate, whatever time of year it is.
While the foliage prior to seed formation can be similar to other grasses, once seedheads begin to form the leafage dies back, leaving just seedheads on stalks which can be 30cm or more tall with around 40 seeds in each head. Leafage is soft, and grazing animals may show a preference for other grass species, unless compelled to eat it through grazing management techniques.
For small infestations a common practice is to pick and remove all visible seedheads, or to mow flowering tillers before seed maturity. In earlier years strong weedkillers were sometimes used, but these are mainly no longer available. But even these weedkillers were often ineffective in the longer term, because of barley grass’s ability to recolonise bare areas rapidly with any remaining viable seed.
Barley grass does not compete well with more aggressively growing species, and removal of seedheads, coupled with pressured grazing management, may deter it sufficiently or even eradicate it.
A number of the most frequently used herbicides these days do not control barley grass. Those that do include Dalapon and Teedal (although not when flowering). Another group of products contain ethofumesate, although the latter harms clover. Seek advice from your supplier on which products contain this. Usual spray period for these is April-July, giving a residual effect of up to 10 weeks to allow for control of seeds germinating.