What to do
Weed, weed, weed. If you lose control 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. You must train the wistaria on an initial framework of wires. Parallel lines are easiest. When the skeleton is established, then you can start cutting back excessive growths.
Sow forget-me-not and other biennials for bedding out next spring.
Divide primulas and polyanthus now that they have finished flowering and while the earth is 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 – tying and untying themselves in fast, convulsive knots; good entertainment.
What to see
The Cottesbrooke Gardeners' Fair in Northamptonshire has quickly established itself as a must-do June date. The best nurseries are there, the best craftsmen and the best tools. The fair continues today and tomorrow at Cottesbrooke Hall, Northamptonshire NN6 8PF. For more details, go to cottesbrooke.co.uk