Exercise 3 solution

Chickweed: an annual weed. Hoe or pull it while small and before it sets seed. It roots shallowly and comes out easily, especially after rain. Do not let it flower.
Dandelion: a perennial with a taproot. Dig down with a hand fork or trowel and take out the whole root; a left-over piece can regrow. Remove flowers before they seed.
Bindweed: a perennial with creeping roots that twines around crops. Fork out the white roots carefully, removing every piece, and repeat whenever new shoots appear (it can take months). Do not chop it up and dig it in, and do not compost the roots. Keep it from climbing your crops; persistent removal weakens it over time.