Tips of the month – June

The weather has not been as warm and sunny as we would expect for this time of year, but at least we have passed the danger of frost and night temperatures are getting milder. The longest day of the year falls on June 20th, bringing warmer temperatures and extra sunlight. June is the month when we can finally move those tender plants outside including houseplants. 

June is a month of plenty in the garden: plenty to harvest, plenty to grow and plenty more to do!

Refresh your roses 

They will benefit from extra attention now to provide plentiful blooms in the weeks to come.

  1. Regular deadheading to encourage new flowerbuds.
  2. Give them plenty nutrients: sprinkle a granular feeds around the base or water on a liquid rose feed.
  3. Control pests by rubbing them off by hand or using an organic spray.
  4. Tie in climbing or rambling roses. 

Tidy spring perennials  

Chop scruffy-looking spring-flowering perennials for potentially a second flush of flowers. Cut Alchemilla mollis, early geraniums and Oriental poppies back to ground level and remove flowering stems of lupins and delphiniums for more blooms.

Sow poppies

If sown direct now, when the soil is warm, many varieties flower within eight weeks. Poppies prefer to be sown direct rather than into a seed tray as they hate root disturbance. Follow Sarah Raven rule of the 4 T’s to succeed with direct sowing: 

  1. Sow into a fine Tilth.
  2. At the right Time (when the soil is warm and moist). 
  3. Sowing as Thinly as you can. 
  4. Thin the seedlings to leave them spaced 10-12in (25-30cm) apart.

Plant ahead for next spring: sow biennials

Next spring’s biennials, such as wallflowers, sweet williams, foxgloves and honesty, need time to establish. 

  1. Sow them now direct into seedbeds spaced a couple of inches apart. 
  2. Thin in three or four weeks to 30cm (12in), and transplant to their flowering position in early autumn. 

If you are short of space, sow them in pots in a sheltered spot until the autumn when they can be planted in their final positions. 


You can now bring your tomatoes out of the greenhouse.

  1. Plant them: at the base of pre-prepared supports. The key for a good harvest is to make sure you dig in plenty of garden compost just before planting and to keep the roots well watered. Tomatoes are hungry plants!
  2. Train them: train cordon tomatoes (also known as vine tomatoes) by pinching out the side-shoots that sprout from the joints between the leaves and the main stems. For bush tomatoes, let them develop naturally by leaving the side-shoots unpruned.
  3. Feed them: when the fruits start to set. 

Plants cucurbits

Young courgettes, marrow, squash and pumpkin plants started off indoors can be planted out. They need a sunny site with rich soil enriched with garden compost. 

Direct sow outdoor

Regularly sow and harvest beetroots, spring onions, radishes, herbs and salads leaves. Water well in dry weather to reduce risk of them running to seeds.

It is not too late to direct sow in the ground, runner beans and french beans, courgettes and squash.

Plan for a winter harvest

Sow slower-growing vegetables such as cabbages, broccoli and kale for harvesting in winter. Sow seeds in module tray or seedbed for transplanting to final position later. 

Don’t forget 

  • Keep on top of weeds … but don’t worry about a few weeds: you don’t want them to smother young seedlings but a few left in borders will support wildlife.
  • Get slug hunting: watch plants closely for signs of slug damage.
  • Deadhead flowering plants: to ensure the plant keeps producing more flowers rather than putting its energy into forming seeds.
  • Cool down the greenhouse:  At this time of year temperatures inside can rise to extremes, causing plants to become stressed and to dry out. Make sure that vents are open on sunny days. Drape shade nettings over the outside of the greenhouse. Damp down in the morning, wetting hard surfaces inside the greenhouse (floor and shelves) to help plants cope with the heat.
  • Top up water features.
  • Use water wisely: use water butts as much as possible and re-use water from the kitchen  such as water that has been used for boiling food or washing vegetables. Try to water early morning or late evening when it is cooler, to slow evaporation. Soak the soil around the plants roots once or twice a week rather than watering little and often every day. This will allow the water to seep deeper into the soil so the roots will grow down in search of it.  Create a shallow bowl in the soil around young plants – this ill act as a well.