Flower Garden - May

Cut back spring-flowering perennials such as Pulmonarias and Doronicums. Old pulmonaria leaves often suffer from mildew - it’s best to cut them all off. Work a mulch of New Horizon Mulch & Mix around the plants to encourage new foliage.

Fix supports around tall and floppy perennials before they get too tall and bushy. There’s a wide range of ready-made supports in garden centres, or you can use twiggy sticks.

Prune early flowering shrubs such as spirea, kerria and flowering currant by cutting back flowered shoots to low sideshoots. Feed with your favourite J Arthur Bower’s or New Horizon general plant food – water it in if the weather is dry – then mulch with New Horizon Mulch & Mix.

Clear away bulb foliage once it has turned brown. It’s a good idea to mark where bulbs are planted – this will stop you chopping through them by accident later in the year.

Vigorous rock plants such as Aubrieta and Alyssum should be cut right back to promote a mass of new young shoots. Feed them with your favourite J Arthur Bower’s or New Horizon general plant food.

Pests can multiply fast in warm weather and it’s tempting to zap them with a cocktail of pesticides. This can do more harm than good as you will end up killing beneficial insects as well as the pests. Then there will be nothing left to eat the pests that remain and you’ll have to keep using the pesticide. In a small garden you can pick off infestations of nasties like aphids until the ladybird population can deal with them. Bright red lily beetles have become a very damaging pest – the beetles, eggs and grubs should be picked off and destroyed.

Biennials are plants that are sown one year to flower the next. Examples include Wallflowers, Canterbury Bells, Sweet Williams and Honesty. Seeds should be sown this month in a well-prepared seed bed before transplanting to their final flowering position in the autumn. Alternatively sow in modules using J Arthur Bower’s John Innes Seed Compost.

Clipped box has become very popular recently. To keep it looking good it needs a yearly trim – this can be done towards the end of the month. Make sure you don’t cut back into the old wood. After trimming feed the box with J Arthur Bower’s Fish Blood & Bone. For box topiary in containers, use J Arthur Bower’s Multi-Purpose Liquid Plant Food

Keep a close eye on your roses as the growing tips can quickly be overwhelmed by greenfly. If you have a small number of roses spend half an hour washing off the nasties using a small bowl of tepid water containing a few drops of washing up liquid. If you need to spray, choose a contact spray made from natural ingredients and spray in the evening – this way you are less likely to harm beneficial insects. Alternatively, you might like to try using natural predators such as lacewings and ladybirds – both of these can be bought by mail order.

The new growth of climbing roses can be very soft and floppy. Make sure you keep tying it in otherwise it make get broken in the wind.