I like growing cover crops to improve and protect garden soil. Dealing with a winter cover crop that has resumed vigorous spring growth can be a challenge. Here’s a bed of barley (planted mid-September) that I covered in mid-April with a brown tarp when it was 18-20 in. high. I was surprised that green growth was still visible after 3 weeks although the plants were greatly weakened. If you simply mow the crop, without weakening it first, it will likely regrow from the crowns.
I then mowed the barley to a 2-in. height and will plant through the residues using a bulb planter for transplants and a narrow hoe to make a furrow for sowing seeds.
Crimson clover is beautiful in early May and will return extra nitrogen to the soil when it decomposes. It’s a a little easier to deal with. Mowing it close to the ground will kill it when it’s in full flower. I’ll plant sweet potato slips into the residues.