What to do in your allotment in June

Strawberry Sweet Colossus from Suttons

Written by Lee Senior

The allotment is such a friendly and inviting spot at this time of year. Indeed it’s a hive of activity, and there’s so much going on at every turn! One of the reasons I enjoy my plot so much is the generous sense of community. Having suffered a fatal problem with my Brussels sprouts seedlings last month, an allotment neighbour stepped in to offer trays of spares. Allotmenteers are, by nature, generous with their time and advice and it’s a real privilege to grow vegetables in an environment shared with like-minded gardeners.

Most of my half-hardy veg are already planted out including courgette, pumpkin, sweet corn and squashes, though they’re far from fully established yet. Keeping the young plants moist and free of slugs are the immediate priorities until they get a little stronger. There’s still time to plant yours out if you haven’t got around to it.

Over the course of June I’ll be busy earthing up my maincrop potatoes and, excitingly, harvesting some of my earlies. This is one of the highlights of the allotment calendar for me. There’s nothing quite like that first serving of buttered new potatoes! Happy growing!

Allotment flowers in June

  • Sow sunflowers, cornflowers, nasturtiums and poppy seeds directly into your allotment beds this month. 
  • Sow a tub of wildflower seeds. They attract beneficial insects like hoverflies and lacewings to pollinate your crops and prey on pests.
  • It’s time to position your containers and baskets full of annual bedding plants around the allotment for bright summer colour. 
  • Alternatively, plant up containers and baskets with herbs and allow them to flower, for a dual purpose crop and insect magnet.
  • Deadhead your allotment flowers, especially dahlias as they start to bloom towards the end of the month.

Allotment vegetables in June

  • Direct sow turnip and swede seeds into a prepared seedbed. Cover swede, radish, and turnip seedlings with enviromesh to deter flea beetles from attacking your crop as it develops.
  • Sow rows of savoy winter cabbage, kale ‘Black Magic’ and broccoli ‘Purple Sprouting Continuity mixed’ directly outdoors. You’ll appreciate these crops in late autumn and winter.
  • Sow quick summer salad crops outdoors including lettuce, loose mixed salad leaves, radish and spring onion. 
  • Sow beetroot and carrot seeds every three weeks to ensure continuity. Thin your developing carrot seedlings in the evening to reduce the risk of carrot fly attack.
  • Direct sow herb seeds in June, especially sweet basil and coriander to use as summer crops.
  • Plant out your half-hardy veg like courgette, sweet corn, pumpkin and squashes.
  • Transplant leek seedlings into their final positions on the allotment. Bury them deeply into the planting holes (to half their height) and water in well. This encourages long white stems to form.
  • In June, stop using nitrogen-rich feeds on your broad bean plants to reduce the risk of a blackfly infestation. Pinching the tips off your plants helps too. Ladybirds are great allies against blackfly, so encourage them to your plot by avoiding chemicals and leaving a few ‘messy’ areas for them to live.
  • Cover brassicas like cabbage with very fine netting to keep the cabbage white butterfly away. Collars keep cabbage-root fly away from the roots too.
  • Earth up your maincrop potatoes to keep the developing underground tubers covered with soil.
  • Pinch out the side shoots on your cordon tomato plants. When the first fruit truss sets on cordon and bush tomatoes, give your plants a feed with a high potash liquid fertiliser.
  • Provide plenty of humidity around your greenhouse cucumber plants to deter red spider mite infestations. Simply spray the greenhouse paths with water on warm sunny days.
  • If you live in a very cold area, keep frost protection fleece ready to cover tender outdoor plants like cucumbers and tomatoes, just in case of a very late frost.
  • Watch out for wind rock in taller brassicas like Brussels sprouts, especially as they get taller this month. If there’s any give around the roots in the soil or if the stem moves too much, earth up the plant base and stake the plant until the roots strengthen.
  • Check your climbing and runner beans. Tie them in loosely with string if they need a bit of help climbing up their frames.

Allotment fruit in June

  • Cover developing fruit with netting to protect it from birds. Brightly coloured strawberries and currants will be under threat, so take action well before they start to change colour.
  • Try to use rainwater to irrigate your acid-loving fruits like blueberries.
  • Water all of your fruit trees and soft fruit plants regularly this month as they start to produce crops. 

Crops to harvest in June

  • First early potatoes are ready to harvest this month. Prolong the harvest by only digging them up as you need them. 
  • Broad beans and peas should be cropping nicely now too.
  • Your strawberries will be just starting to redden in June, ready to enjoy fresh from the plant.
  • Start harvesting your overwintered onions and garlic this month. 
  • Enjoy salad crops like lettuce and spring onions.
  • Keep checking and picking courgettes through the next few months. They turn into marrows if not picked regularly!
  • Keep cutting asparagus throughout June, but stop harvesting towards the end of the month to allow them to grow and create enough energy for next year’s harvest. Give your crowns a good feed to encourage healthy summer growth.

General June allotment jobs

  • Donate any surplus vegetable plants to your allotment neighbours. This is preferable to overcrowding your beds, and who knows what you may get in return!
  • Hoe your plot regularly using careful swift strokes between crops to nip weed plants when they’re young, before they become a chore to remove.
  • Keep slugs and snails under control using deterrents like slug pellets, copper tape and traps.
  • If you haven’t already, install a water butt to catch rainwater. Add guttering to sheds or greenhouses to fill up your butt or make your own collector to put up in heavy rainfall.
  • Keep on top of watering in June to ensure that your water sensitive plants don’t go without. This is especially important for recent transplants and young plants that haven’t had time to develop strong root systems. These crops can struggle to get enough moisture by themselves during dry periods.
  • Control weedy areas without using chemicals by strimming and covering the cut area with weed suppressant material. This gradually weakens and kills off any tough perennial weeds for easy digging over.

Planning ahead

  • Make sure to leave plenty of time to visit your allotment regularly over the next few months. Summer means rampant growth and visiting the plot little and often keeps everything tidy and healthy. 
  • Make a plan for watering over the summer. There’s nothing worse than seeing dry allotment beds and wilting plants.
  • Get ready to deal with any gluts, stocking up on jars for preserving and keeping freezer space available.
Lead image: Strawberry Sweet Colossus 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.