What to do in your allotment in April
Written by Lee Senior
The key watchwords for April are seed-sowing and frost protection. Patience remains a virtue and please do remember that seeds sown later will catch up. Many parts of the UK had snow at the beginning of April last year, so keep a keen eye on the temperature!
It’s all systems go on the seed-sowing front this month. Early crops like parsnips and beetroot can be sown directly from mid-April in a pre-warmed, well-drained raised bed if the weather is good. Use cloches to cover the row and trap any sunlight, and also to afford protection from frosts. Nighttime temperatures are still fluctuating quite wildly, so I always have a roll of frost protection fleece close by.
As the season begins to unfold, April is an exciting month filled with the joy of watching things grow. I’m looking forward to seeing my asparagus crowns sprout into life, heralding the start of the cropping season of this spring delicacy!
- Spring-flowering varieties of Anemone look great in containers alongside daffodils. One of my favourites is Anemone ‘Mr Fokker’.
- After indoor hyacinths have finished flowering, why not plant them in a quiet corner of your allotment while in the green? The bulbs should come back next year as long as the soil isn’t waterlogged.
- Harden off and plant out your autumn-sown sweet peas that you’ve grown under glass over winter, 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. Don’t forget to label where your bulbs are so that when the foliage dies you won’t inadvertently dig them up as I’ve done in the past!
- 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.
- 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. Keep a roll of frost-protection fleece on standby as the tops are very susceptible to frost and can be wiped out overnight. If the tops do get frosted, new growth will come but it will set the plants back by 2-3 weeks.
- 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’.
- Parsnips should be sown directly as soon as soil conditions allow. Use cloches as the seeds need a fairly constant temperature to germinate (can take up to four weeks). ‘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.
- Brussels Sprout seeds should be sown early in the month under glass. It’s essential to provide shade for the seedlings, and don’t expose them to heat or they will become stunted
- Sow marrows, courgettes, pumpkins, squashes and tomatoes in a heated greenhouse or propagator. Give priority to crops like sweet corn and squash which require a long season to give their best.
- Apple trees, pear trees, plum trees and cherry trees should start flowering in April. If you’re growing dwarf varieties or have trees in a container, covering the blossom with fleece to protect it from frost is a good idea.
- 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, feed strawberry beds with a slow release balanced organic fertilizer, and use Fyba Mulch Mats to protect the fruit from soil splashes. Cover the plants 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.
- As kale, leeks, parsnips, winter 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.
- I’m harvesting radishes, winter lettuce and spring onions this month too.
- 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!
- 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.
Suttons Seeds recommend these areas which may also be of interest.
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