Good news from the hayfield, two invasive plants are declining. Last year around this time I blogged about crown vetch and yellow rattle, weeds threatening our hay supply. Crown vetch was introduced to the roadside by the state and has slowly spread into our fields. Yellow rattle came to the fields from other farms, hitching a ride on haying equipment.
Crown vetch is a hardy and persistent perennial forming solid colonies as it kills grasses. The vetch is toxic to horses, not good in hay. The best way to kill it is to mow every few weeks, preventing it from blooming and seeding. Over time, as it is unable to reproduce and spread, it will be out-competed by faster growing grass.
Yellow rattle is an annual parasitic plant related to snap dragons. It feeds by pushing roots into the roots of other plants, weakening the surrounding grass and clover. The seeds are produced in round pods that rattle when they are ripe. By mowing before seeds are produced, rattle can be destroyed. Any seeds produced are viable for 2-3 years.
To kill the rattle, last year I had to sacrifice my hayfield by mowing early with the bushhog. If I had waited for the farmer who cuts my hay, the rattle would have bloomed and made millions of seeds. This year I estimate the weed has been reduced by 90%. Many areas infested last year are clear this year. Once again I am mowing with my bushhog, losing some nice hay, but gaining a hayfield. I hope next year we are 100% rattle free.
The crown vetch was mowed four times last year. It is severely curtailed. Where the vetch ruled last year, it is now struggling in the shadow of tall grass. By cutting it before it could bloom and seed, and repeatedly cutting it to allow the grass to dominate, I have won a major victory against vetch. This year the hay from former vetch areas can be used.
The victory is not complete. Many more hours of mowing will be required to eliminate crown vetch. It may not be possible to completely eradicate the weed. It sneaks along fence lines and crowds up against tree trunks, places where the mower can’t reach. A little here and there can be dealt with.