Plant up patio pots or borders with erysimum, more commonly known as wallflowers, for a cheery spring show. Although they can be grown on their own, try planting tall-growing tulips in a contrasting colour first and planting the wallflowers over the top. The tulips will then grow up through them to provide an extra layer of height and colour.

Pot up a few good specimen summer bedding plants to continue flowering on a porch or windowsill indoors. Any tender plants you want to save for next year can also be potted this month, so they are established and ready to bring under cover when the weather turns cooler.

Make the most of free seeds produced by perennials and other garden plants by saving them when they are fully ripe. Collect mature seed-heads in paper bags and hang them in a warm place to dry out. The seeds can be cleaned and sorted, then put in labelled envelopes and stored in a cool, dry place. Swap your seeds with your friends to share in each other's successes.

Prepare areas for sowing new lawns in September.

Pinch out the shoot-tips of cordon tomatoes grown outdoors once their third or fourth truss has set fruit.