What to do in your allotment in April

Asparagus Crowns ‘Guelph Millennium’ from Suttons

Written by Lee Senior

The second half of March saw an amazing transformation on the allotment. As the warm sunshine arrived, dormant plants began to burst into life. Insects appeared and, with them, the final proof that Spring is finally here. But wait… The weather turned extremely wintery again at the end of March and, in Northern England, several centimetres of snow fell as we entered April. It’s a timely reminder to keep a close eye on the forecast. Nighttime temperatures still fluctuate quite wildly, so I always have a roll of frost protection fleece close by.

It feels really strange to be thinking about next winter already when we’ve only just (hopefully!) seen the back of the last one, but I’ll be sowing winter cabbage, kale and broccoli seeds in the coming weeks to make sure the allotment stays productive all year round. Prioritising how you spend your time on the plot pays dividends now, more than at any other time of year. It’s essentially a combination of preparation, planting and maintenance – remembering to keep on top of watering and weeding as well as sowing and planting. That said, what could be nicer than the excitement of watching things grow as the season unfolds.

Have a great April, whatever the weather!

Allotment flowers in April

  • Spring-flowering varieties of Anemone look great in containers alongside daffodils. One of my favourites is Anemone ‘Mr Fokker’.
  • Hyacinths are looking lovely right now too. I love the stunning white-flowered variety ‘Carnegie’. The fragrant, striking blooms brighten up even the darkest corner and are ultra-reliable.
  • Plant out your autumn-sown sweet pea seedlings, or sow sweet pea seeds directly into their final flowering position now.
  • Plant gladioli corms in April. These summer-flowering bulbs make excellent cut stems so plant plenty of rows on the plot.
  • Move dahlia plants out this month, making sure they’re protected by horticultural fleece if there’s any risk of frost. They won’t tolerate below zero temperatures.
  • Fill large containers or even an old bath with a wildflower mix to attract pollinators.

Allotment vegetables in April

  • April is a key month in the potato calendar. I try to plant out early varieties at the start of the month and then second early or maincrop 2-3 weeks later. Hold off if the ground is cold and wet – the plants will catch up. 
  • I’m also hardening off my trays of indoor grown onions and shallots. I’ll plant them in a prepared weed-free bed and cover them with cloches or fleece if the weather turns inclement. If you buy onion and shallot sets, plant them outdoors in well-spaced rows.
  • I’m a big fan of asparagus! Over the years I’ve grown asparagus crowns but recently I’ve had success with seed too. It’s a very cost-effective option. The variety ‘F1 Ariane’ is easy to grow and can be germinated in the normal way in the greenhouse. A light harvest can even be achieved in August of the first year, but I prefer to wait until year two to begin cropping.
  • Most vegetable seeds can be sown this month. One of my favourites is Runner Bean ‘Scarlett Emperor’ which I’ve grown for thirty years. 
  • I also grow a lot of Climbing French Beans ‘Cobra’ and ‘Blue Lake’
  • Direct sow next winter’s parsnips under cloches as the seeds need a fairly constant temperature to germinate. ‘F1 Gladiator’ has good resistance to canker and a RHS Award of Garden Merit. Along with the winter parsnips, sow other winter crops like kale, cabbage and broccoli ready for harvests at the end of the year.
  • It’s time to plant out your Brussels sprouts if you want them in time for Christmas. They need a long growing season to mature.
  • Sow marrows, courgettes, pumpkins, squashes and tomatoes in a heated greenhouse or propagator.
  • It’s time to plant out your Brussels sprouts if you want them in time for Christmas. They need a long growing season to mature.

Allotment fruit in April

  • Apple trees, pear trees, plum trees and cherry trees should start flowering in April. Frost can damage blossom and young buds before they open, so use fleece if the weather turns. Try to avoid planting new fruit trees in frost pockets.
  • Mulch around your fruit trees with well-rotted manure or straw mulch.
  • Check for damage in your tree ties. Replace any that have snapped or re-tie to prevent damage to the trunk or the roots from too much movement.
  • Traditional fig trees are very vigorous and should be planted in containers to restrict the roots and encourage cropping. Ultra-reliable is ‘Brown Turkey’ which grows well in a sunny location. Ironically, I grow two trees in rather poor, shallow soil, on my allotment. This has the effect of restricting vigour and the trees crop well most years.
  • For a dwarf fig tree, consider ‘Little Miss Figgy’. Suitable for patio containers, it can provide two crops per year, in Spring and Autumn. 
  • Give your strawberry plants attention this month. Remove dead foliage to improve airflow and pluck out any weeds to reduce competition for water and nutrients. Cover them with cloches to speed up flowering and fruiting.
  • If any rhubarb flowers appear, cut them out near the base to stop them stealing food and energy from the plant. Harvest your forced early rhubarb this month when the stems are roughly 25cm in length.

Crops to harvest in April

  • As kale, leeks, parsnips, savoy cabbage and sprouts reach the end of their season, we’re heading towards the ‘hungry gap’. But there are still some real treats. Purple-sprouting broccoli is cropping heavily this month. 
  • I’ve just harvested a tub of overwintered finger carrots. They’d been in a pot of multi-purpose compost for seven months but survived well. Try Carrot ‘Amsterdam Forcing 3’.
  • Look out for the first few asparagus spears as they begin to appear. This is an April delicacy to be picked and enjoyed as fresh as possible. Keep an avid eye out for slugs before they get to your hard earned crop. Try using an organic slug repellent if they become too much of a nuisance.

General April allotment jobs

  • Dig over your beds of green manure in April. Work the plants into the soil, making sure they’re well chopped up.
  • Keep your eyes out for weeds. They’ll compete with your young plants for water and need to be removed.
  • Slugs and snails emerge this month as temperatures rise. Put measures into place to keep them off your precious plants.
  • Keep an eye on greenhouse temperatures this month. Nights can still dip below freezing while day time temperatures can get quite warm.
  • Stay on top of greenhouse watering. Seedlings shouldn’t be allowed to dry out and wilt.
  • Clear out any winter crops that are over, like the stems of Brussels sprouts and the tip foliage of Jerusalem artichokes, digging up and eating the edible roots as you go. Don’t add any diseased foliage to the compost. Burn it or add it to your household waste instead.
  • If you find seed sowing tricky or time consuming, have a go with seed tape. These biodegradable tapes come with the seeds pre-spaced at the optimal distance apart. Our carrot seed tape has been prepared to produce successional crops from August to January, so there’s no need for repeat sowing!

Planning ahead

  • Make sure you’ve got all the vegetable seeds you need to make successional sowings of spinach, leaf mixes and rocket.
  • Keep an eye on compost levels in the potting shed this month, and order in any seed sowing supplies that you may run short of in May. Next month is a busy one at the allotment in terms of getting plants into the ground.
Lead image: Asparagus Crowns ‘Guelph Millennium’ from Suttons
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About Lee Senior
Lee Senior is an experienced horticultural writer, RHS Yorkshire in Bloom judge and horticultural consultant. He has also had an allotment for over 30 years. After initially spurning horticulture as a career option, to pursue his boyhood dream of becoming a train driver, Lee soon realised he couldn’t resist getting his hands dirty to make a living. Horticultural College training led to getting an allotment at the tender age of 18 (in the days when you could actually get a plot quickly). “My gardening hero is Geoff Hamilton” says Lee. “It was Geoff who convinced me that you didn’t have to spray everything that moved in the garden. Watching him on Gardeners’ World in the late 1980’s and early 1990’s was a revelation. I was lucky enough to meet Geoff and I’ve also had the pleasure of meeting BBC gardener, Joe Swift. Now, over three decades of practical experience has taught me to work with mother nature, not to fight against her and don’t try to tame her, as so many gardeners seem to be on a mission to do. I feel strongly that we should all respect nature and do our bit txwo help our ailing planet. Small-scale food growing is my passion and I can’t wait for my two daughters to hopefully pick up the baton in the future. Nothing beats the flavour and satisfaction of growing your own food. You simply cannot buy the same quality and freshness. Everyone can have a go at growing something, no matter where they live and it is great to see how growing food in containers is taking off now,” says Lee. When he isn’t writing for the gardening press, Lee runs his own Allotment Consultancy business, advising individuals and organisations and Councils on how to get the best from their land, either in person or remotely. Lee’s website is: https://allotmentsandgreenspaces.wordpress.com or you can email him directly at: allotmentsguru@gmail.com. Away from horticulture, Lee is a keen walker and he has written a number of successful walking books which are available at his online bookstore: https://www.etsy.com/shop/WalkingintheAire/