Nick Bailey's guide to March pruning

In colder parts of the UK, there’s still time to prune apples, pears and late summer-flowering clematis (Group 3), but in warmer areas it’s getting too late. Climbing roses, hybrid teas and floribundas are still fine to prune, but the sooner the better, so they don’t waste their energy growing leaves that will be pruned off. Borderline-tender perennials, such as penstemons and phygelius, can be pruned too.

But the key plants to prune this month are evergreens and shrubs that flower on this year’s growth, such as buddleias. Check them for birds’ nests first, and leave alone if nests are in use.

More spring pruning advice:

• Your spring pruning jobs
• Prune shrubs for more flowers
• March pruning with Frances

Plants to prune now:

March is one of the busiest months for pruning, with a wide range of trees, shrubs and other plants, such as those featured below, requiring their annual prune.

Climbing roses

When pruning climbing roses, establish a balanced framework of older stems, then shorten side-shoots by two-thirds to encourage abundant blooms in summer.

Cotinus and catalpa

To get huge ornamental leaves on cotinus and catalpa, cut these shrubs back hard. They will re-sprout vigorously, even from old wood.

Phygelius and penstemons

Now the worst of the frosts are over, cut top growth of penstemon and phygelius down to 15cm from the ground, to prevent them getting straggly.

Winter-flowering deciduous viburnum

Remove a third of the oldest stems of winter flowering deciduous viburnums such as Viburnum x bodnantense 'Dawn' at the base annually, so the shrub continues to flower well.

Avoid pruning:

• Grapevines: Sap pressure is currently very high, so if you prune them this month they’ll bleed profusely. This could weaken or even kill them.
• Buddleja alternifolia: Unlike the more familiar B. davidii (see below), this species blooms on last year’s wood, so prune after flowering in summer.
• Mediterranean shrubs: Delay pruning the more tender forms, such as French lavender and hyssop, until April, especially in colder regions. This ensures that the subsequent re-growth won’t get damaged by late frosts.
• Rambling roses: Unlike climbing roses, ramblers bloom on stems produced the previous year, so prune and re-train them straight after flowering.

Step-by-step: Pruning Buddleja davidii

The popular buddleia species Buddleja davidii is best pruned in early spring, between late February and early April. Pruning before it starts into growth means the plant doesn’t waste energy growing new stems that are destined to be removed. Buddleia is a vigorous shrub and can be cut back hard annually, 50-100cm from the base. This triggers the production of new stems that will carry lots of butterfly-friendly blooms from July onwards.

Step 1

Cut back into the old woody framework of the buddleia, aiming to leave it about 50-100cm tall. With thick branches, make life easier by using a clean, super-sharp, sickle-shaped pruning saw. Cut at a slight angle to ensure rainwater runs off easily.

Step 2

Make your cuts just above a dormant bud or new shoot. It’s not always easy to spot dormant buds on old stems, but do your best. Prune thinner stems with sharp secateurs and be sure to cut cleanly, so you don’t leave any snags or tears.

Step 3

Tidy up the cut stems – those under 1cm thick can be chopped up and put directly onto the compost heap. Thicker stems can be piled in a quiet corner of the garden, where they will provide food and shelter for many kinds of wildlife.

• More on pruning buddleia

Also prune this way:

Several other fast-growing garden shrubs will benefit from the same pruning technique as buddleia. This will trigger either fresh growth that will go on to flower later in the season or cause plants to produce larger, more dramatic leaves.

• Catalpa can be given a hard annual prune to keep it as a multi-stemmed shrub and to ensure the leaves stay large
• Cotinus can also be cut back annually in spring to encourage bushy new growth and large leaves
• Hybrid tea and floribunda roses can be cut down hard every year. Pruning bush roses in this way encourages them to flower freely on strong new growth
• Sambucus can be pruned down to a few stumps to maintain its shape. Hard pruning Sambucus nigra will give bigger, stronger-coloured leaves