Lengthening days with showers and warm weather mean growth is rapid for both garden plants and weeds. A haze of green softens the winter silhouettes of trees and shrubs as leaves unfurl, intensifying throughout April to cover the branches with new foliage. An ephemeral riot of blossoms decks ornamental and fruit trees, lifting the spirits with their delicate and often fragrant blooms and blanketing the ground with their petals. Butterflies and moths emerge on warmer days looking for nectar and places to bask. The dawn chorus, best in the hour or so before sunrise, is most exuberant in spring as birds defend their territory or try to attract a mate.
This year, the warmest February day since records began was recorded. Bumblebees and butterflies emerged early from hibernation looking for nectar. Phenology records the changes in the timing of the seasons, first bud, first flower, first nesting bird etc. In general signs of spring are emerging earlier. This can affect the whole spectrum of wildlife. Both temperature and day length encourage migrating birds to head to Britain to breed. In the past this has coincided with sufficient numbers of insects to feed their young. If there are fewer insects the fledglings can’t survive. Fewer chicks means less food for predators and a consequent drop in a wide range of populations. Early bud burst can leave plants vulnerable if the warm weather only lasts a short period and frosts return, damaging blooms and nascent leaves. This can affect the growth of a plant. With shrubs and trees the direction of growth changes and the pattern of frost damage remains throughout the plants life.
In the garden
The softly luminous, early season flowering bulbs such as daffodils and hyacinths are beginning to fade and jewel like Tulips are taking their place. Many Tulips are brilliantly coloured, a bright head on a single stem, and look beautiful in borders or in containers. Tulipa ‘Spring Green’ has creamy white petals streaked with green, Tulipa ‘Queen of the Night’ is an almost black purple with a rich sheen. In between there are Tulips of many hues, soft pinks, such as the blowsy ‘Angelique’, brilliant oranges such as ‘Ballerina’, Tulips with spidery petals such as Tulipa acuminta and twisted, ruffled petals on the parrot tulips such as Tulipa ‘Black Parrot’ and Tulipa ‘Garden Fire’.
April flowering shrubs include the rich yellow flowered Forsythia, the sensuous, red saucer blooms of the flowering Quince, Chaenomeles speciosa, and the elegant, drooping, pink clusters on the flowering Currant, Ribes sanguineum. Herbaceous plants are very much on the rise with the tartly citrus coloured blooms of spurges such as the Wood spurge, Euphorbia amygdaloides var ‘Robbiae’, the dainty, upright , orange, yellow or pinky racemes of Barrenwort sp, Epimedium, and the deep crimson drifts of Red campion, Silene dioica.
Blossom, blossom everywhere; on streets, in parks and open spaces and in the garden too for those lucky enough to have their own flowering tree. There is little more cheering on a cool and grey April morning than a blossoming tree or an avenue of them engulfed in a cloud of pink or white. A medium sized blossoming tree to plant is the Crab apple, Malus sylvestris, which comes with the added bonus of fruit for jelly later in the season. Several fruit tree cultivars will grow in a smaller space too – just be sure to check the label for anticipated growth. These can be planted into a large container – they may not reach full height but they will grow happily enough and provide lovely sources of spring nectar for insects. Attach some casters on the base of the pot and wheel it around to prevent it becoming an obstruction if the space is awkward and access an issue.
It is likely that there will be birds crisscrossing the garden and neighbouring gardens on a search for worms and other grubs to feed their chicks. These may well be familiar friends who come back to nest at the same spot year on year and many gardeners will be looking out eagerly for the return of their feathered family this month. Cheekier species, such as the robin, will keep close to any spade or trowel work happening in the beds to search out newly exposed grubs in the freshly disturbed soil. A garden will ideally have a range of natural food sources for birds such as insects, grubs and berries but there is no harm in keeping the bird feeders and water troughs nicely topped up all year around and not just during the colder months to take the edge off the constant hunt for food. Keep feeding stations clean and topped up with fresh treats such as nuts, fat or mealworms and the birds will reward this with regular garden visits and delightful song.
Pests are waking up to the warmer weather too. Keep an eye out for unwelcome critter activity during garden inspection such as chewed, distorted or disfigured foliage, or indeed catch the pests out in the act during cautionary plant inspections. However, try to exercise some tolerance for an acceptable level of pests as they play their part in the food chain of a healthy garden ecology. I rubbed a few green fly off the underside of a Corsican hellebore, Hellebore argutifolius, with my fingers the other day, a few probably survived but these will hopefully be a snack to a ladybird or other predator in due course. If the idea of squishing bugs turns the stomach they can be washed off under pressure from a hose or sprayed with a washing up liquid solution (taking care not to spray other insects). Avoid using chemicals but if there really is no alternative be sure to follow the manufacturers’ instructions to the letter, and do not apply in windy weather or during the day when many insects are on the wing.
Those fans of an immaculate lawn would insist on a weekly mow from now on, and there certainly are some benefits to doing that in keeping a symmetrical green patch firmly in check. However, left to grow a little longer a lawn provides shelter for wildlife and reduces the boredom factor of such a frequent mowing chore. If one less job a week is not motivation enough then consider how grass that is allowed to grow a little more than 2cm arguably has a softened, more natural appeal too. If you really fancy the flattened lawn square, at the very least, try to leave areas of sheltering long grass for wildlife to move across. It’s also a good time of year to renovate or sow a new lawn. Warm temperatures and frequent showers are the best conditions for sowing new seed and getting it growing.
Mulching the borders, individual plants or containers can be very beneficial. April, after a good season of wet weather, is a good time to do this. The range of mulches can be confusing. Essentially mulch is layer of material spread on the soil to carry out a number of functions. Mulches can conserve soil moisture by reducing evaporation, suppress weed growth by preventing light reaching the soil, even out soil temperature fluctuations and protect the surface soil from capping or creating an thin compacted layer that reduces water penetration. Organic mulches will eventually be incorporated into the soil, so improving the soil structure. A number of materials can be used, they need to be spread to a depth of at least 5cm. Organic mulches can be made from stable manure, spent mushroom compost, cocoa shells, bark, leaf mould or garden compost. Inorganic compost, such as gravel or pebbles will help retain moisture and reduce weed growth but are not useful as a soil conditioner.
Sowing from seed is the cheapest way to increase the quantity of garden plants and is very rewarding. It can be done easily on a windowsill or balcony, in pots, seed trays or in the open ground. Seeds need warmth, moisture and oxygen to germinate; April usually has all the ingredients. Good growing conditions for seeds will be apparent when weed seedlings begin to appear everywhere. Seeds take different lengths of time and need different temperatures to germinate successfully but many will germinate with a bit of warm and damp weather. Whether it’s in a seed tray or the open ground you need a fine, crumbly soil with small particles, if your soil or compost is too heavy add some horticultural grit. Sow the seed thinly as too many seeds close together will compete for the available light and moisture. Once the seedlings have appeared and have at least 2 pairs of leaves, you can thin them out or transplant them carefully, lifting them from their nursery bed or tray by a leaf, not the stem and firming and watering them into individual pots. Make sure all your seed trays or positions in the ground are labelled; it’s easy to forget what you sowed where. Check seed packets for individual instructions, sowing times and specific conditions can vary. Hardy annuals, herbs, wild flowers and many perennials can all grow well if sown at this time of year. If you end up with too many they will make welcome presents for gardening friends.
Gardening tasks in April
- Plant or relocate evergreens as winter winds subside
- Plant evergreen hedges such as holly and yew
- Tie in climbing and rambling roses in a horizontal direction to encourage more side-shoots and flowers
- Tie in climbers such as honeysuckle and clematis as they shoot up
- Deadhead daffodils – but leave the foliage to die back for a few weeks to feed the bulb for next year’s flowers. The old foliage can be hidden amongst emergent plants
- Plant perennials to allow them to establish while the soil is cool and moist. Keep them watered as spring winds can be drying
- Sow hardy annuals, herbs and wild flower seeds outside
- Divide clumping herbaceous perennials and replant, swap or give away the spares
- Plant summer bulbs in succession over a few weeks such as gladioli and dahlias for a long sequence of flowering later in the season
- Plant out hanging baskets and containers for a colourful summer
- Sow melon seeds under cover
- Begin regular liquid feeding of container grown fruits
- Prune cherries and plums once the leaf buds have opened
- Prune figs
- Remove any rhubarb cloches and harvest long stems
- It’s too late to plant bare root fruit trees and bushes but container-grown specimens are still available
- Plant grape vines and strawberries
- Protect blossoms, particularly peaches and apricots, from frost with horticultural fleece
- Feed blackcurrants and blackberries
- The nesting season is underway so leave food and water for adult birds
- Do not cut hedges, climbers or ivy where birds may be nesting
- Hedgehogs are emerging from hibernation. During the day they often rest in long grass or piles of leaves. Leave out food (meat based dog or cat food) and water if you know they visit your garden
- Leave caterpillars on plants for birds to feed on
- Make a bee hotel for solitary bees, there are many instructions online
- Keep emerging weeds under control before they take over, hoe borders and dig out the roots of perennial weeds such as bindweed and couch grass.
- Apply a general fertilizer such as blood, fish and bone to beds, borders, trees and shrubs especially hungry plants such as roses and young or weak plants.
- Keep an eye out for pests and disease. Consider nematodes or beer traps to combat snails and slugs.
- Renovate or sow a new lawn and commence your preferred lawn-mowing regime.
- Loosen and break up compacted soil around plants with a small fork to help rainwater penetration.
- Mulch soil to help retain moisture, reduce weeds, improve soil structure and keep the soil organisms happy.
Michael Jordan (Author) and Kelly Louise Judd (Illustrator)
Trees are an important part of the cityscape, providing shelter, shade, wildlife habitat and improving air quality. The book looks at trees in cities, telling their stories, describing their relationship with city dwellers and exploring their environmental, social and cultural importance.
A Sting in the Tale
An entertaining and informative tale of one man's research into bumblebees, our relationship with them, their importance for pollinating agricultural crops and how modern practices and habitat degradation are reducing populations to extinction.
Things to see, places to go
Better Together: Companion Plants and Natural Pest Control
Come and find out how to combine plants to create mutually supportive plant communities to enhance fertility and strengthen resistance to pests and diseases.
9 April 2019, 6pm - 8.30pm
Rainbow Grow, Hackney CVS, 24-30 Dalston Lane, London E8 3AZ
Freshwater Invertebrate Survey of Thamesmead Canals
This is a great oppurtunity to learn about surveying freshwater invertebrates and how they are used to assess the health of freshwater ecosystems.
19 April 2019, 10am - 3pm
Meeting near Abbey Wood Station