Hairy cat's ear is difficult to control chemically because it is resistant to several herbicides. However, application of MCPA salt or ester or a 2, 4-D herbicide in the fall or in early spring may be effective in inhibiting its growth. MCPA-salt or ester kills a variety of broadleaf weeds like hairy cat's ear. This is safer on crops like oats, flax and peas than 2,4-D herbicide, but it still poses a risk of drifting to nearby crops such as turnips, grapes and cabbage that may be vulnerable to damage by the herbicide. 2, 4-D herbicide is more ideal for controlling hairy cat's ear in lawns because it is selective, attacking the weeds and not your grass. It is absorbed into the plant and works well to inhibit growth in deep-rooted weeds. Use of 2, 4-D herbicides in your gardens can kill vegetables and some flowers. If treating your lawn for hairy cat's ear, avoid letting the spray drift to other areas where desirable plants might be affected.