Weed, weed, weed. If you lose control of weeds this month, they will be with you for the rest of the summer. Pay particular attention to those that are on the point of flowering. An average weed will shed 5,000 seeds.

Do something about the long, waving shoots of wistaria. Good flowering depends on hard pruning but you cannot prune until you know what you want to keep. Initially you must train the wistaria on a framework of wires. Parallel lines are easiest. When the skeleton is established, then you can start cutting back excessive growth and stimulate buds instead.

Clumps of mossy saxifrage have a maddening habit of going bald in the middle. Cut out any brown, dead growth and pep up the underlying soil with bone meal and a sifting of fresh top soil. Sow forget-me-not and other biennials for bedding out next spring.

Nip out the tops of broad beans to discourage black fly. Nip out side shoots of single stem tomatoes and tie them in to their canes as they grow. Continue to sow radish and lettuce in short rows.

Continue to spray disaster-prone roses every two weeks against black spot and mildew. Murphy's Tumbleblite will at least do them both at once. On the other hand, you could grub them out and replace them with healthier varieties this winter. Dead-head roses by cutting back to a strong outward-facing shoot.

Divide primulas and polyanthus now that they have finished flowering and while the earth is still damp. Watch for the black, yellow and white caterpillars of the mullein moth on your verbascums. They strip plants almost overnight, but are wonderfully acrobatic in the process. They tie and untie themselves in fast, convulsive knots - good entertainment while you are weeding.