April in the garden has to be the busiest month bar none. I like it most for the diversity of jobs that it brings, be it sowing seed, potting up, planting out, pruning, or simply just mowing the lawn.
The weather tends to be a right old mixture too. Chilly starts, torrential downpours, or those afternoons with just a T-shirt on your back, it’s all there.
With the warmer sunshine comes the full spring experience – lush green growth, the hum of distant lawnmowers, blossom seemingly everywhere, and the oh so vibrant colours of beds and borders. Everything’s properly bursting into life.
As much as anything it’s a time of hope and expectation. Amidst all the to-ings and fro-ings, just make sure you take the time to take it all in – I’m like a child on Christmas eve me!
Sow hardy annuals
As per last month, for filling gaps in beds and borders. Subjects to try include those previously mentioned, as well as Clarkia, Godetia, annual poppies and nasturtiums.
If you didn’t sow sweet peas either in the autumn or earlier in the year, direct sow now at the base of a wigwam, obelisk or arch, working plenty of organic matter into the soil first. Keep well watered, pinch out the growing tips once a few leaves have formed and loosely tie in until established.
Plant out sweet peas raised under cover.
‘Harden off’ bedding plants
Once annual plants are growing away strongly, move to an unheated greenhouse or coldframe to harden off, opening doors and vents on mild days, closing at night. The idea is to gradually acclimatise tender plants to the great outdoors – keep an eye on the weather though and drape fleece over pots and trays on cold nights.
Pot up plug plants bought from garden centres into 9cm pots of multipurpose. Tidy up, repot and start feeding overwintered fuchsias and pelargoniums.
Plant up hanging baskets
I like my baskets planted up early and then popped into a coldframe to harden off until the middle of next month when they’re ready to hang. Use a mixture of multipurpose and John Innes No.3 with a handful of granular fertiliser high in potassium.
If you struggle to keep up with the daily watering regime in high summer, consider succulents, dwarf grasses, convolvulus and trailing pelargoniums.
Deadhead spring flowering bulbs
Such as daffodils, hyacinths and tulips as they fade to conserve energy for next year rather than producing seed. Sprinkle a granular fertilizer around clumps or drench with a liquid feed.
Sow annual climbers
Have a go at growing your own climbers, such as the cup-and-saucer vine, black-eyed Susan, morning glories and Rhodochiton. They’ll bring a tropical feel to your garden, flowering from July to October if sown now and given a little TLC until planting out late next month.
Plant summer bulbs outdoors
Such as gladioli and lilies. Plant deeply, incorporating plenty of grit if you garden on heavy clay. Gladioli corms can be planted every few weeks to stagger flowering times over summer.
Get supports in place
With herbaceous perennials seemingly growing by the day, hoops, stakes and supports need to go in place now. Lupins, delphiniums, campanulas, oriental poppies and achilleas are just a few early-mid summer plants that’ll benefit greatly from a little help. Get supports in place now, foliage will quickly disguise them as it grows.
Put border edging in place to stop plants spilling out over lawns and pathways.
From new shoots of delphiniums, lupins and dahlias. Dip into hormone rooting powder, pop into pots or trays of well-drained cuttings compost and provide a little bottom heat - a great way of propagating plants for free.
Plant out Dahlias
From the end of the month. Plant deeply or cover with a few handfuls of garden compost. Provide protection from slugs and snails until they get going. I plant a few tubers in the kitchen garden – Dahlias make great cut flowers for the house.
April is a good time to transplant seedlings growing in the wrong place. Lift and move the likes of alchemilla, hellebores, grasses, evening primrose, verbena bonariensis and immature foxgloves. Keep well watered until firmly established.
Trees and shrubs
Repot container grown trees and shrubs.
Knock plants out of pots, shake old compost from the roots and replant into fresh John Innes No.3 and some slow-release fertiliser. Mulch with gravel, pebbles or chipped bark to conserve moisture.
Repot camellias, rhododendrons and azaleas after flowering with a loam-based ericaceous compost. Deadhead regularly in the meantime to maintain the plant’s appearance.
Prune Group 1 clematis
Once they finish flowering, including C.armadii, cirrhosa, alpina and macropetala varieties. There’s no rule of thumb here – simply cut out any dead growth and prune to fit their allotted space, or cut back harder neglected specimens in new of renewal.
C.montana’s are best tackled in the same way next month once flowering is over.
Lightly prune winter heathers
As per last month. Trim all over with garden shears, never cutting back into old wood.
Those who grow roses will appreciate just how much they’ve been under attack during recent wet summers – blackspot, rust and aphids have all had a field day! Spray every few weeks early in the season to limit the threat of pests and diseases. Use a proprietary fungicide/insecticide to gain a measure of control from the off.
Prune early spring-flowering shrubs
Such as Forsythia, flowering currants and Viburnum tinus as soon as they finish flowering. This allows them to put on plenty of new growth to ripen for flowering next year. Cut back all flowered shoots by a quarter to a third, removing very old and unproductive shoots lower down. Shred and compost prunings, mulch plants thereafter.
Plant remaining seed potatoes
Second earlies and maincrops can be planted any time this month. With recent wet summers, I like to get mine in as early as possible as blight tends to strike in August by which time I hope to have a plentiful supply of good-sized tubers.
Earth up rows of first earlies planted last month as the foliage grows away. Plant up a few tubers in containers. Dig up and dispose of any ‘volunteer’ potatoes sprouting in the garden or on the compost heap.
Plant out onion and shallot sets asap.
Sow, sow, sow
April’s incredibly busy on the veggie plot. Look to sow small rows of beetroot, radish, carrots, salad leaves, spinach, rocket and spring onions every few weeks to stagger harvests. Leeks, parsnips, peas, oriental greens and broad beans are just a few other crops to be direct-sown now. Work from scaffold boards if it’s wet to avoid compacting the soil, provide slug/snail protection and have fleece to hand should it turn cold overnight.
Keep sowing indoors
Tomatoes, chillies, sweet peppers, sweetcorn, squashes, cucumbers, climbing beans and the like can all be started from seed indoors now.
Order in ‘baby veg’
Not all of us are blessed with greenhouse space, or, indeed, the time to raise vegetables from seed. Buying young plants from mail order co’s or the garden centre is also a great way for novice gardeners ‘growing their own’ for the first time.
If you’re short on space, try growing veg in containers – pretty much anything can be used as long as it’s large enough for the job and has adequate drainage.
Feed the soil
Top dress vacant beds with a balanced granular fertiliser such as ‘Growmore’, lightly rake in and leave to settle. Add a sprinkling of blood, fish and bone or bonemeal to potato trenches pre-planting. Top up raised beds with garden compost.
Put up climbing bean supports
At the end of the month in readiness for sowing climbing beans. Lash canes together firmly if growing on exposed sites. Start beans under glass if you’re keen to get them going and always look to grow legumes in a rich, fertile soil – over a compost trench if you’ve taken the time to prepare one.
Insert pea sticks or rig up netting for those sown in the autumn.
Get growbags and pots ready
For planting the likes of tomatoes, cucumbers and sweet peppers next month. I grow mostly cordon tomatoes (those with a single stem trained up canes or lengths of twine) in growbags, well away from the potatoes in the veg garden so as to limit the possibility of blight transferring between the two.
Net soft fruit
Soft fruit is best netted early in the season to stop small birds pecking at fruit buds, and then to stop them stripping fruit later on. If you’re not lucky enough to have a fruit cage, fashion a makeshift frame yourself out of canes and netting.
It’s rhubarb season, so harvest stems whilst young and tender. Snap stems from the base with a downward twist. Never pick more than a third of the stems at any one time. If you’ve forced plants, stop doing so now, mulch heavily, and leave uncroppped for the rest of the year.
Pollinate peaches, nectarines and apricots
Lend partly self-pollinating trees a hand by pollinating with a soft brush or ball of cotton wool. Gently transfer pollen onto the stigma and repeat regularly until the petals start to fall.
As fruits begin to form later on, thin to two or three per cluster for better-sized fruits, and to prevent branches snapping with the weight. Keep polythene ‘roofs’ in place for another month or so to protect against peach leaf curl.
Spray top fruit
Only really suitable for wall-trained trees and those on dwarfing/semi-dwarfing rootstocks – spray with a suitable fungicide to prevent mildew this month. Also spray trees prone to scab, and look out for woolly aphid infestations – either scrub off by hand with a stiff brush or use a pressure washer.
Remove greasebands previously put in place for winter.
Water newly planted fruit trees & bushes
Particularly if the month is dry, paying particular attention to wall-trained trees or fruit grown in containers.
As per last month. Grass will now be growing apace so treat to a spring lawn feed to green it up for summer.
Sow grass seed over any bare areas, mixed with a few handfuls of topsoil.
Dig out perennial lawn weeds, taking all the root with it if possible. Walk the lawn every now and then, rooting out dandelions, plantains and thistles as you spot them – a nice and easy job on a mild evening.
Most of us have a certain amount of moss in our lawns and now is a good time to tackle it. Moss competes with fine grasses, weakening lawns and causing it to lose some of that sheen, and is particularly prevalent in shadier areas. Apply a moss killer now, leave for a few weeks and then rake out with a lawn rake. Dispose of moss rather than composting it.
Spring rains and spells of warm sunshine sees the grass growing strongly. Keep blades on the high side still, up the frequency of your mowing and continue to compost clippings.
As per last month. Lift and replant overgrown marginals, split and replant large water lilies, add more oxygenators.
Keep the water clear
Barley straw can be picked up relatively cheaply from good garden centres or specialist water garden companies, the idea being to inhibit algal growth and stop the water turning that pea green colour! Stuff a few handfuls into old pairs of tights and submerge into a few places around the pond’s edge.
Clean out filters regularly.
As per last month. Provide bottom heat where possible. Successional sowings of basil and coriander can be cropped right through the season.
Prune shrubby herbs
Such as bay and sage. Trim lavender, being careful not to cut into old wood.
Plant herbs in containers
For easy pickings, pot up a few herbs for growing in containers near the back door. The majority like things on the dry side so I tend to use a gritty mix of John Innes No.2 and multipurpose topped with grit, the obvious exceptions being ‘thirstier’ herbs like mint & basil.
Alternatively, plant up an all-in-one herb container – they can certainly be attractive as well as useful.
Tackle slugs and snails
All gardeners have their ways of means of tackling these undesirables, be it via chemical control or through organic means. Whatever you choose, protect the likes of delphiniums, hostas, dahlias and salad leaves from an early stage or they’ll quickly be decimated. I use a mixture of preventative control and organic slug pellets – in a professional capacity, nothing can touch them for getting hard and fast results.
The likes of whitefly, red spider mite and aphids will now be on the wing, particularly under glass. Hang up sticky traps, spray if it’s your thing, or order in biological control from online stockists for use from May/June.
Treat wine weevil if you’ve a problem with it by drenching pots with a suitable insecticide. Look out for lily beetle from this month, squashing adults as you spot them.
Install water butts
Experienced gardeners will tell you that you really can’t have enough water butts. Set up new ones, wherever you can harvest water from – sheds, garages, outbuildings, greenhouses. Spring rains will fill them quickly, giving you a ready supply of water whenever you need it.
Ventilate greenhouses, coldframes and cloches
On warm days, open up doors, roofs and vents. Good air circulation helps combat diseases such as grey mould and mildew, hardens tender plants and generally makes for good hygiene. Frosts are still likely though, so keep an eye on the weather forecast.
Weed paths and patios
As per last month. Apply a residual weedkiller via a watering can for small areas, use a knapsack sprayer for larger areas. Alternatively, use a grubbing tool and grout out weeds by hand. Either way, do so now to get paths and patios looking good for summer.
Empty out the compost bins
Well-rotted compost can go onto veg beds, as a mulch on beds and borders, or into potting mixes. Leave half ‘cooked’ waste until autumn, giving it a good stir and adding fresh grass cuttings to speed up the decomposition process.
Repair slats on wooden bins so your heaps are ready for this year’s waste.
Clean bird baths and tables
As birds are now nesting and raising their young. Provide fresh water and food whenever possible.