In The Greenhouse This May

Apply shade paint to the outside of the glass or use blinds on sunny days to prevent temperatures from soaring.

Open doors and vent on greenhouses to increase ventilation on warm, sunny days.

Damp down the floor of the greenhouse regularly on hot days, to increase humidity levels. This benefits plant growth and also reduces the risk of pest problems such as glasshouse red spider mite.

Don’t forget to give greenhouse plants more space as they put on new growth. This will help to prevent disease, and to contain early pest infestations.

Harden off your half-hardy bedding plants that were started off early under cover. By placing them outside for a short period only, at the warmest time of day, and then gradually increasing the length of time they are outside, you can avoid the ‘shock’ that they otherwise experience when moved outside suddenly and permanently.

Check plants at least every few days, to see if they need watering. Seedlings will need daily attention. Use rain, grey or recycled water wherever possible.

Continue to prick out and pot on new seedlings and cuttings.

Top Tip:

Hang fly traps throughout the greenhouse to monitor levels of whitefly, thrips and other pests.

This Month's Key Tips
  • Mow lawns weekly.
  • Plant out summer bedding towards the end of the month, when the weather gets warmer.
  • Open greenhouse vents and doors on warm days.
  • Watch out for late frosts. Tender plants will need protecting.
  • Water early and late to get the most out of your water, recycle water when possible.
  • Check for nesting birds before clipping hedges.