What to do in your allotment in April

Asparagus Crowns ‘Guelph Millennium’ from Suttons

Written by Lee Senior

Hello! Here we are at one of the busiest and exciting points in the allotment calendar! My greenhouse is full of recently-sown tender crops like courgettes, cucumbers, beans and sweet corn, and at home my windowsills are crammed with tomato plants.

Although the sun is surprisingly strong in April, I find that nighttime temperatures still fluctuate quite wildly so I always have a roll of frost protection fleece close by. I’ve had to make a few unscheduled late evening trips to the allotment over the years to protect my early potatoes when the temperature suddenly drops! If a significant frost is forecast, earth up your young plants, completely covering the vulnerable foliage with soil. An extra layer of fleece never hurts either. Most healthy plants usually recover from frost, but they can be set back by as much as four weeks. There’s lots at stake at this time of year and we put a lot of trust in the Met Office!

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.

Allotment flowers in April

  • 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

  • Plant your first early potatoes this month — choose ‘Maris Piper’ for a multi-purpose tuber with great flavour and ‘Foremost’ for a traditional new potato.
  • Now’s the time to harden off and plant out any veg that was started undercover in January, like rooted onion sets and broad beans.
  • Through the month, keep sowing succession crops directly outdoors into prepared seed beds. This includes crops like spinach, spicy leaf mixes, radishes and roots like carrot and beetroot. Use a cloche to speed up germination and growth rate.
  • Erect a barrier of fine mesh to prevent carrot fly from reaching your developing crop and plant strong smelling alliums to mask their sweet smell.
  • Sow squash seeds in an unheated greenhouse in modular seed trays. Try ‘Crown Prince’ for delicious, sweet, meaty flesh and an attractive blue skin. Or for a smaller squash, the bright orange ‘Uchiki Kuri’ has excellent flavour.
  • Sow larger varieties of lettuce seeds like the crisp iceberg variety ‘Match’, or butterheads like ‘All The Year Round’ for silky leaves.
  • Sow rows of ‘Rainbow Chard’ and Chard ‘Bright Lights’ to brighten your plot.
  • 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.
  • Sow climbing bean ‘Blue Lake’ in modular seed trays this month. This variety produces stringless straight pods and reaches about 150cm in height so needs support. For something smaller, sow dwarf French bean ‘Safari’ in modular trays too.
  • You can direct sow all types of broad bean seeds this month. Try ‘Karmazyn’ for green pods with beautiful purple beans.
  • Start your Halloween pumpkins off in small pots on the kitchen windowsill. ‘F1 Becky’ produces small, cute pumpkins and ‘Hundredweight’ produces large orange fruits. Both are edible.
  • 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

  • Give your strawberry plants attention in April. Remove dead foliage to improve airflow and pluck out any weeds to reduce competition for water and nutrients.
  • Keep horticultural fleece to hand in case of late frosts. Use this to protect tender blossoms of nectarines, apricot and peach trees. Pollinate the blossoms by hand using a soft-tipped paint brush to transfer the pollen between flowers.

Crops to harvest in April

  • 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 garden 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.
  • Sow ornamental gourds for cutting, drying and decorating the house in autumn and winter. These inedible, but brightly coloured shapes look fun growing on the plot towards the end of summer.
  • 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 25 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 more recently had the pleasure of meeting Joe Swift. Now over two 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. Small-scale food growing is my passion and I can’t wait for my two daughters, one who is 8 years old and the other who is 5 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 says Lee, no matter where they live. Lee has also written his two books; ‘Pennine Way, The Highs and Lows’ which is a humorous, personal account of walking this momentous iconic walk. His second book ‘Walking in the Aire’, features 14 short walks in Yorkshire.