Gardening tasks in May
In May, perennials grow quickly and many plants are already in bloom. It’s a wonderful time to enjoy the fresh green foliage, romantic blossom, the first flowering perennials, and spring bulbs such as tulips and daffodils. It’s also an excellent time to add new plants to the garden – perennials, summer-flowering bulbs, annuals and water plants. There’s plenty to do in the garden in preparation for a flower-filled summer.
Planting annuals
The annuals you sowed indoors in April – or the ones you’ve just bought – can now be planted out in garden beds, pots or hanging baskets. Summer-flowering annuals look stunning in large groups in borders, among perennials, or in containers. Or why not create an entire annuals border? To help them settle in, add a handful of compost to the planting hole. Allow enough space for growth, and be wary of late frosts, which may still occur until mid-May.
Wild shoots
Some garden shrubs – especially roses – may produce wild shoots from the rootstock. Most garden roses are grafted onto vigorous understock, which can send out shoots with smaller leaves or completely different flowers. Variegated shrubs may also produce all-green shoots. If left unchecked, these shoots can overwhelm the original plant. Standard roses, in particular, often sprout shoots from the stem or even the roots. Pull them off as close to the base as possible rather than cutting, which may encourag...
Tree bases
The area around a tree trunk – known as a tree base – is a wonderful spot for attractive planting. A ring of beautiful foliage or colourful flowers looks fantastic in lawns or in paved areas with open soil. Ensure the soil is loose and enriched with compost. Good choices for tree bases include lady’s mantle (Alchemilla), hardy geranium (Geranium), Bergenia, barrenwort (Epimedium), hosta (Hosta) and periwinkle (Vinca minor), along with bulbs such as bluebells (Hyacinthoides) and Camassia.
TIP
Water summer-flowering plants in pots and hanging baskets generously every day and feed with liquid fertiliser every fortnight. You can also use slow-release fertiliser granules, which dissolve gradually and only need applying once. Deadhead regularly to encourage repeat flowering.
May bloomers in the spotlight
- Allium, Allium spp.
- Columbine, Aquilegia vulgaris
- Leopard’s bane, Doronicum orientale
- Spurge, Euphorbia griffithii
- Spanish bluebell, Hyacinthoides hispanica
- Peony, Paeonia hybrids and Paeonia suffruticosa
- Rhododendron
- Tulip, Tulipa
Garden jobs for May
Planting and sowing
- Plant perennials to fill out your borders
- Move frost-sensitive plants, annuals and dahlias outside after mid-May (Ice Saints)
- It’s not too late to plant summer bulbs such as lilies
- Fill pots and containers with annuals
Pruning, trimming and supporting
- In late May, consider the ‘Chelsea chop’ for summer-flowering perennials
- Trim evergreen hedges at the end of May
- Tie in climbers
- Remove untidy foliage from Alliums once flowering starts
Feeding and mulching
- Feed terrace plants and annuals with suitable fertiliser
Other tasks
- Water during dry spells – don’t forget pots and containers
- Keep on top of weeding
- Maintain or sow a new lawn
Text: Modeste Herwig.
