Darling Buds of May
With blossoming hawthorn, May has arrived. The days are longer and warmer, growth everywhere is rapid, wildlife fills gardens with frantic activity. Our native bluebells carpet the woods, creating a haze of violet blue, the hedgerows are laced with cow parsley and meadows are dotted with buttercups. Butterflies are emerging from hibernation, hoverflies and bumblebees flit from flower to flower seeking nectar for themselves and their young. There is so much to see, to enjoy and to do, seed sowing, planting, cutting back, weeding and simply appreciating our green spaces and countryside.
In the garden
Gardens are blooming this month with the flowers of many plants on show or emerging. These include the dainty looking Clematis montana flowers borne on their rampant and vigorous climbing stems; the elegant, hanging flowers of wisteria; the trumpets of columbine, reminiscent of old fashioned bonnets, Aquilegia sp., the intoxicating scent of lilac flowers, Syringa sp. and Mexican orange blossom, Choisya ternata and the distinctive purple globes of the ornamental alium, Allium Hollandicum ‘Purple Sensation’. Brilliantly coloured geum cultivars are beginning to flower with euphorbias bringing a range of lime greens to spring borders.
Gardeners with acid soils may be treated to a showy display from vividly coloured Azaleas and Rhododendrons. These create a wonderful spectacle in woodland gardens such as the Isabella Plantation in Richmond Park at this time of year. Many other woodlanders also flower in May, trying to reproduce before the tree canopy becomes too dense and restricts the light. Foam flower Tiarella cordifolia, bleeding heart Lamprocapnos spectabilis, corydalis Corydalis flexuosa and siberian bugloss Brunnera marophylla are all putting on a good show.
With all of this growth, colour and nectar, the garden wildlife is flourishing and working hard; pollinators are fluttering and buzzing away collecting nectar and pollinating plants; caterpillars are beginning to emerge and looking for a snack; the dawn chorus is rousing and throughout the day birds are foraging for food for their fledgling chicks. Pause a moment and appreciate the cycle of life that is taking place.
It’s time to prune back spring flowering shrubs when they have finished flowering such as Bachelor Button’s, Kerria japonica, and the flowering currant, Ribes sanguineum, to tidy them up and allow them put on growth for next years flowers. Firstly prune out old and dead wood and crossing or congested stems. For Kerria prune back all shoots that have flowered either to ground level or to a strong side shoot, whilst aiming to maintain an even form. For Ribes, cut back a quarter of the oldest branches. These shrubs can be renovated if they are very old and congested by cutting back all stems to ground level. It seems brutal and not all shrubs respond well to such extreme treatment, which is hardly surprising as to have reached that point they will be old and tired, but many will be given a much needed boot up the backside and will reward the hard shearing with refreshed and invigorated growth.
It can be an onerous job but get those box hedges, balls, cones and triangles and whatever other box topiary forms there are, pruned into shape. It is often a fiddly job as hand shearing is better than a bruising mechanical trimmer but if the trim is kept close to the desired shape it should hopefully not need to be done again until mid – late autumn. Best to prune on a still day to prevent the cuttings from flying away before they can be collected.
Early May is a good time to stake or support tall, fleshier herbaceous perennials such as delphiniums and mullein, verbascum sp. to encourage their emergent foliage to grow through and envelope the supports to create a more natural display. Indeed, some supports such as ornamental wire frames or grids or cane or metal wigwams or cloches are positioned to become a focus of a bed, adding visual structure to the scheme as well as support to the plants within it. Either way, without them it is possible that taller plants or flowering stems may collapse or snap in wind or rain and be ruined. It can be tricky to retrospectively stake a flopping plant without making it look like a restrained and bedraggled creature. If plants have already leapt ahead and it is too late to stake them it is worth trying to strategically place canes or sticks around the plants so that they have at least a little support. If all else fails it is also possible to cut the offenders back hard to let them grow up again in a more supportive, staked environment yet with time still to flower this year, albeit a little later. Better that than a bed full of collapsed, broken or restrained flowers.
Plants for pollinators
Pollinators are on the wing; bees, ants, hoverflies, butterflies and moths all rely on the nectar of flowering plants for their food. In the process they also pollinate these plants, transferring pollen from one flower to another so fertilizing them and allowing them to reproduce and develop seeds and fruits. Without pollinators agricultural economies, our food supply and our countryside would fail. Pollinators tend to prefer simple and wild flowers. A succession of flowering annuals, perennials and shrubs can provide nectar and pollen throughout the growing year. Think about planting some plants for pollinators; lavender Lavandula angustifolia, yarrow Achillea sp, giant hyssop
Agastache sp, sage Salvia sp, catmint Nepeta x frassenii, purple coneflower Echinacea purpurea and coneflower Rudbeckia can all be planted now, kept well watered they will then provide nectar and pollen for visiting wildlife later in the year.
Ponds are a haven for many creatures, supporting large numbers of invertebrates. They provide breeding grounds for amphibians, drinking water for mammals and birds and hunting grounds for bats. Even a half barrel or old sink, filled with rain water and a few plants with benefit your local wildlife.
With warmer weather, the water heats up rapidly and it is the best time to plants pond plants, they will quickly fill out. Try water mint Mentha aquatica, water plantain Alisma plantago, marsh marigold Caltha paulustris, flowering rush Butomus umbellatus or water forget–me-not Myosotis scorpiodes. To keep pond water clear and healthy, nutrient levels need o be kept low. Top up your pond using rainwater from a water butt or tank as this is much better balanced than tap water and use only aquatic soil, low in nutrient levels, for your pond plants. Plant native plants rather than exotics. Invasive non native species can escape into the natural environment and cause havoc with local biodiversity.
Around 50% of the surface of a pond should be free from vegetation. Thin out areas that become overgrown, taking care to leave the thinned plants on the pond’s edge for 24 hours to allow pond creatures to make their way back into the water. Use a twirling stick to remove excess blanket weed and a net to skim unwanted duckweed from the water’s surface. Enjoy watching the watery activities, pond skaters, tadpoles, water boatmen and the local birds and bats that visit your pond.
Gardening tasks in May
- Prune back spring flowering shrubs when they have finished flowering such as Bachelor Button’s, Kerria japonica, and the flowering currant, Ribes sanguineum and Japanese quince Chaenomeles japonica to tidy them up and let them put on growth for next years flowers.
- Prune box hedges, balls, cones and triangles into shape. It can be a fiddly job but keep the cut close to the desired shape ideally using hand shears.
- Evergreen hedges can be pruned this month to maintain their health and form. Check first for nesting birds and use hand tools until the end of the breeding season to avoid disturbing them. If you see a nest do not attempted pruning until the fledglings have left.
- Stake or support tall, fleshier herbaceous perennials such as delphiniums and mullein Verbascum to encourage their emergent foliage to grow through and envelope the supports. This creates a more natural display. Use ornamental wire frames, grids, canes or metal wigwams depending on the plant and the desired effect.
- Keep newly planted shrubs and perennials irrigated. Watering in the early morning or evening will reduce water evaporation and therefore the amount of water used. If you haven’t got one, consider installing a water butt to save water.
- Later flowering perennials can be encouraged to have a longer flowering period by giving them the ‘Chelsea chop’. Prune around one third of the stems by a third and another third by two thirds.
- Tie in fast growing climbers such as clematis.
- Hanging baskets and container grown plants will need increasing irrigation. Do not be fooled into thinking that rain will help. Rain water is likely to wash away from leaves and over the edge of the container leaving the soil dry.
- Feed container plants every 2 – 4 weeks with a balanced liquid fertilizer to keep them healthy.
- Thin out annual plants such as sunflowers, Helianthus annuus, Cosmos bipinnatus, and night scented stock, Mattiola incana, that have been sown in situ to prevent them getting crowded and leggy. Thin out to one healthy seedling per 10-15 cm depending on anticipated growth. If done carefully enough the rejects could be transplanted elsewhere.
- Harden off any seedlings for 10-14 days before planting outside. This means gradually introducing them to cooler and more erratic weather conditions, first leaving them without cover during warmer days and eventually all night till they have acclimatized.
- Continue to deadhead spring flowering bulbs such as daffodil, Narcissis and grape hyacinth Muscari. This directs energy to the bulbs for next years growth rather than to creating new bulblets from seed. Also feed them with a liquid fertilizer to maintain and improve flowering the following year. Congested clumps can be lifted, divided and replanted.
- Cut back dying allium foliage to keep beds looking spruce.
- Keep an eye out for any late frost forecasts and protect tender plants with a covering. Bring in or shelter any plants that are hardening off outside.
- After the danger of frosts has passed, sow half hardy annuals and plant out tender plants such as Dahlias and Cannas and any summer bedding.
- Continue to hoe weeds regularly, warm days are best when the weeds quickly dry out and die. Remember that weeds can provide food and habitat for wildlife too, so don’t be too tidy and leave some if you have the space.
- Check for pest and diseases. Viburnum beetle and Lily beetle will start to appear, vine weevils may damage container plants, aphids proliferate and roses may show signs of blackspot. Try to treat with manual or biological methods rather than using pesticides or fungicides that may damage the garden wildlife. Slugs and snails may also be a problem, try nemaslug or wool pellets as oppose to slug pellets.
- Mow lawns weekly. If you would like to try a more wildlife friendly lawn leave a patch to grow longer, clover, daisies and buttercups are likely to appear and support pollinators in you garden.
- Try sowing an area with annual meadow seed, also a boost for pollinators.
- Put out mealworms for blackbirds and robins trying to feed their young.
- Create a deadwood habitat for small invertebrates with mini piles of twigs and stones in beds, great places to hide.
- Fill a hanging basket or open container with sheep’s wool and dried grass for nesting birds to pick from.
RSPB Gardening for Wildlife by Adrian Thomas
The book sets out how to encourage wildlife into your garden no matter how small your space is. It lists the most useful plants and describes how to create habitats that will draw the wildlife in.
London’s Street Trees by Paul Wood
Time for an urban walk and this book will provide a field guide to the urban forest. Over 300 species of street trees are gown in London and each borough has its own selection. Discover the fascinating history of their selection and planting and see the city in a different light.
Things to see, places to go
It’s Chelsea Flower Show this month but also the Chelsea Fringe, an alternative mix of public spectacles, horticultural happenings and community celebrations.
Garden and wildlife events
Wildlife Gardeners Day: Saturday May 19th 2018.
At the London Wetland Centre, Barnes, London SW13 9WT.
Tickets from the Wildlife Gardening Forum.