It is beginning to feel a bit more like Spring now, the grass is growing, the daffodils are blooming & the birds are singing. Unfortunately April is going to get off to a chilly start with bands of rain & strong winds likely, especially in the northwest. This continues into the middle of the month with the possibility of more settled & drier conditions following with near average temperatures for the month. Make the most of warm sunny afternoons but there is still the threat of overnight frosts during dry spells & the further north you are, so keep protecting your tender plants.
With the weather warming up it is time to get set for the summer before all the Spring growth prevents you accessing your borders. Tidy your beds, split perennials & make space for summer flowers. If you haven’t planted summer flowering bulbs before they are as easy as spring bulbs & can be used to fill gaps – gladioli will give height at the back of a border & come in a fantastic range of colours, many lilies will give you a delicious scent & crocosmia will give deep yellow or orange hues from midsummer to late autumn. Our blog also has a great range of articles giving sowing & planting advice for a range of plants including vegetables & herbs. These are also accompanied by video tutorials on our YouTube channel which should answer any questions you have, so turn your hand to something new this summer.
The more you prune, the more the plants branch.
- Prune spring flowering shrubs such as Forsythia & Quince when flowering is over & evergreens such as Photinia, Choisya & Viburnum.
- Prune mophead Hydrangeas in April, cutting off the old flower heads back to the first pair of plump buds. You can also remove any dead or damaged stems, weak growth or stems that affect the shape of the bush.
- Shrubs which do not flower until after the longest day (21 June) can be pruned now. This includes varieties such as Buddleia davidii, Ceanothus and Hypericum.
- After pruning Buxus give special buxus fertiliser with magnesium and trace elements immediately.
- This is your last chance to prune the roses. It should really have been done in March.
- Also prune your false acacia (Robinia pseudoacacia ‘Umbraculifera') or Indian bean tree (Catalpa bignonioides ‘Nana').
- Heathers can be tidied up after flowering but before new growth breaks out. Trim with shears just below the old flower spikes. Cut out any straggly growth to leave a nicely shaped mound.
- Shrubs which flower from buds which formed during the previous season should only be pruned when they have finished flowering.
- Many shrubs benefit from a tidy up at this time of year, removing dead or damaged stems & having one in three stems removed each year over a three-year period starting with the oldest, to rejuvenate the shrub. Check pruning guidelines on your individual shrub before starting.
Planting & Sowing
- Plant summer flowering bulbs & corms now including lilies, alliums, crocosmia & gladioli. If you plant your gladioli in succession over a few weeks you will have flowers for longer.
- Plant out shop bought sweet pea seedlings or those that were sown in the autumn.
- Indoors you can also sow basil, then courgettes & pumpkins at the end of the month for planting out in late May.
- Plant early flowering roses to give them plenty of time to establish, including the single golden blooms of Rosa xanthina ‘Canary Bird’.
- Evergreen shrubs can be replanted now which is later than the deciduous varieties because many evergreens are not fully winter-hardy. This is less important if they are pot-grown, but many evergreens are also sold with their rootball wrapped in sacking.
- Perennials may have been pushed up above the soil by frosts; this exposes their roots to drying out. Replant them to the right depth.
- Birches are famous for being difficult to (re)plant. This is the best time to do it.
- Sow annual flowers such as Nigella, Calendula & poppies direct into the soil where you want them to flower.
- You can now sow plenty of kitchen herbs, spinach, rocket as well as vegetables like carrots & 1st early, 2nd early & maincrop potatoes.
- Beware of night frost! Protect plants which are sensitive and possibly already flowering with garden fleece if a night frost is forecast.
- Ventilate greenhouses & cold frames on sunny days.
- Lots of annuals are available to buy now - make sure you give them frost protection. Keep them watered, as temperatures increase this is when they will start growing well.
- Put supports in pots & borders for tall growing perennials. Also tie in climbers that twine such as honeysuckle & clematis before they are out of control.
- It is still an excellent time for sowing a new lawn or restoring a lawn. Now is also an ideal time to aerate. The grass will recover very quickly. If your lawn is not enclosed by hard surfaces, the edges will grow irregularly. Restore the shape by edging the lawn neatly again. You can now mow the lawn every week. Mow an ornamental lawn to two centimetres and a play lawn to three centimetres.
- Feed plants which have to work hard for their living with a general purpose fertiliser. This includes container plants, soft fruits & hungry roses.
- Remove all dead and withered plant material from your plants, remove any winter protection from less hardy plants & give them all a good mulch to improve soil texture & a general purpose feed. All the waste can go in the compost bin.
- Check out any winter flowering non-woody plants such as pansies & violas for downy mildew or blackspot. Remove any infected leaves or plants but do not compost this material.
- In the meantime, now is a good time to get the pots and troughs ready for planting. Rinse, ensure good drainage and get in supplies of fresh potting soil, water holding crystals and slow release fertilizer.
- If you have not done so yet, now is certainly the time to tidy the garden, clean the patio and the garden furniture. Flagstones and all sorts of other stepping stones and tiles can become green and slippery during the winter. Turn them over now to get rid of the problem. The green underside will then automatically be cleaned by creatures in the soil, so that you can repeat this trick every year. Otherwise use an environmentally friendly algae cleaner such as Algon.
- Rake any gravel areas you may have to stop the first weed growth.
- Keep watch for pests such as greenfly & caterpillars & control populations of slugs & snails.
- Increase watering and feeding of indoor plants including citrus trees. Repot any that are pot-bound or topdress larger container plants.
Ponds & Water features
If you do not have a pond in your garden yet, and you've got space, then now is the time to build one! Read our blog if you are interested in 'How to Make a Wildlife Pond'. If you already have a pond, as it comes back to life here are some things to think about, or read our blog on '6 Steps to a Happy Pond':
- Remove all dead plant residues and decide which plants need pruning.
- Divide pond plants such as water lilies and get rampant varieties back under control.
- Plant new plants in baskets with fresh pond soil, oxygenators will help control algae. Give the plants special water plant fertiliser granules by the roots in the soil as you plant. Also think about feeding your existing plants: there are special water plant food pellets which help the plants thrive.
- Turn the pump back on and examine your pond. Check fish are healthy and are beginning to feed.