What to do in your allotment in June

Strawberry Sweet Colossus from Suttons

Written by Lee Senior

It’ll soon be mid-summer and at this time of year our plants need more water. Soils that are rich in well rotted organic matter are the best for retaining moisture as the organic matter acts like a sponge. Mulches are also great for retaining moisture. When applied to already damp soils, mulches reduce requirements for water. Water butts are a boon all year round, but especially so in the heat of summer. Having more than one is a good idea as they can soon empty.

We can relax, safe in the knowledge that all our half hardy crops are now outside in their final growing positions. Our emphasis now turns to weed and pest control. Common pests on my plot aside from slugs include aphids, cabbage white butterfly caterpillars, and cabbage root fly.

Courgettes, outdoor cucumbers and sweet corn don’t like cold weather while they’re still establishing outdoors. Although the risk of frost has passed for most, do still keep an eye out for cold nights. A combination of cold and wet conditions can be damaging to these young plants and set them back.

Over the weekend I planted out some cabbage seedlings next to a contained area of mint. I inadvertently brushed against the mint and the aroma hung beautifully in the damp morning air while I went about my work. This was a welcome and unexpected sensory delight. There are many different types of mint. All are easy to grow from seed or young plants. They’re all very vigorous too so they’re best planted in a container to prevent the mint from taking over your plot.

Allotment flowers in June

  • Sow sunflowers, cornflowers, nasturtiums and poppy seeds directly into your allotment beds this month.
  • Scented wallflowers are easy to grow from seed sown in June or July, ready to put on a fine flowering display next April and May. They’re members of the brassica family so it somehow seems appropriate to grow them on your allotment.
  • 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.
  • Dahlias have traditionally been grown on allotments for generations. Smaller, dwarf annual dahlias, though not as flamboyant as their larger cousins, make an attractive display around the edges of beds or in a sitting area. It is possible to buy them as plug plants for quicker establishment.

Allotment vegetables in June

  • Around the middle of the month cease cropping of your asparagus crowns and give a top dressing of fertiliser or manure to revitalise the crowns.
  • Sow beetroot, kohlrabi, lettuce and turnip seeds successionally every 2-4 weeks depending on your preference.
  • 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.
  • Ensure you cover all your brassicas with fine netting to prevent cabbage white butterflies from laying eggs on the foliage.
  • Earth up your potato plants as required and keep an eye out for any early signs of blight
  • 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

  • Blackcurrants and redcurrants should be covered at this time of year, inside a fruit cage or under netting as the fruit begins to develop and ripen. Blackcurrant ‘Summer Pearls’ is an early dwarf patio type that has a lovely sweet flavour.
  • Redcurrant ‘Summer Pearls Red’ is very prolific and a reliable cropper. The fruit is perfect for jams or puddings and when very ripe I’ve even been known to eat a few straight from the bush.
  • Once your strawberries have flowered and the fruit begins to set, it is time to cover them with netting to minimise theft of those tasty juicy berries being stolen by birds.
  • 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.
  • Early peas should begin cropping now. Early sowings generally miss the pea moth caterpillars.
  • Early sown fast maturing pointed cabbage will be ready from mid-June onwards.
  • June sees the first of the early sown broad beans ready to harvest. There is nothing to beat the taste of the first crop of these succulent young, freshly picked beans.
  • 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.
  • Lettuce, salad leaves, rocket and spinach will all make a refreshing freshly picked salad on hot days.
  • Rhubarb continues to give its all and can be harvested until the end of the month.
  • Keep checking and picking courgettes through the next few months. They turn into marrows if not picked regularly!
  • Asparagus can be harvested for the first half of June.
Weed suppression fabric

Image: Maciej Bledowski/Shutterstock

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.