Mild weather means that aphids start to appear earlier in the year. They suck the sap from tender young growth in plants and can excrete a substance called honeydew, which causes sooty mould and plant viruses. Keep inspecting your plants to nip an infestation in the bud!

Caught early, you can just squash aphids between your fingers (wear gloves if you’re squeamish!). Alternatively, apply a systemic insecticide to ornamental plants, which is absorbed by the plant and poisons the aphids as they feed on it. Do keep in mind that this can also eliminate beneficial insects. Attracting ladybirds and hoverflies by planting single flowers (not the double varieties) helps.

Bright red lily beetles arrive in May
Become familiar with the larvae of ladybirds so you don’t squash them by mistake – they are relatively large and black with yellow spots. One plant that I always spray is Solomon’s seal (Polygonatum x hybridum). I use Provado ultimate bug killer in May, otherwise the Solomon’s seal sawflies eat them to ribbons practically overnight!

Other plants that need watching are lilies and fritillaries. This is the month that bright red lily beetles will arrive. You can either pick them off or use Provado on them as well.

Climbing roses support clematis as they grow
Climbers grow like crazy this month with the sun and showers. Keep tying them in, especially the soft stems of the clematis, or they could get damaged in the wind. I use thin circular rings, which are cheap to buy in packs from the garden centre and easy to use without damaging the stems. I tend to grow my clematis through climbing roses, which help to support them as they grow.

Sow some runner beans as the soil warms up, making a wigwam of bamboo canes for the beans to twine up. The cultivar ‘White Lady’ is very pretty if you fancy white flowers for a change.

Elegant foliage and arching stems of heart-shaped flowers
Keep a look out for the lovely Lamprocapnos spectabilis (or Bleeding Heart) in garden centres and nurseries this month. This is a shade-lover with elegant foliage and arching stems of heart-shaped flowers, which is a mainstay of the spring garden. The Lamprocapnos spectabilis ‘Alba’ is my favourite with its beautiful white flowers. Plant it in a sheltered position in dappled shade and mulch it annually with weed-free organic matter to keep it happy. The leaves die down in summer so don’t think you have killed it, but mark where it is so you don’t disturb it. This plant goes very well with any sort of ferns.