Time to Start Growing your Vegetables

A greenhouse is suitable for growing vegetables in a number of ways:

What to plant this Spring

A productive greenhouse can be in use for most of the year. Heated greenhouses allow for maximum, year-round use but are rarely cost effective.

Mid-spring

Late spring to early summer

  • Plant summer greenhouse plants into their final positions indoors
  • Harden off and plant out young plants of outdoor crops once the frost has passed

Using your Greenhouse

1. Planning

  • Measure out your greenhouse beds and floor space for growbags. Check you have room to space out all the summer greenhouse crops you plan to grow
  • Benches should provide plenty of space for seedlings, many of which will be moved outside when the space is needed for summer greenhouse crops
  • A catch crop of salad leaves can be sown in greenhouse borders before the space is needed for summer greenhouse crops

2. Sowing seeds indoors

  • Use clean pots and trays and fresh, peat-free seed or multipurpose compost
  • Follow instructions on the seed packet
  • Seeds will germinate on a sunny windowsill indoors or a heated propagator unit in the greenhouse (be aware that in cold weather, in unheated greenhouses, the propagator may struggle to maintain warm temperatures)

3. Growing on

  • Once germinated, seedlings will need somewhere light and frost-free to grow on; an unheated greenhouse may not be sufficiently warm until April
  • Consider fleecing and heating a partitioned section of your greenhouse to make a suitable environment for growing on tender plants
  • Watch weather forecasts and be prepared to protect young plants with fleece on frosty nights or provide supplementary heating when needed

4. Planting

  • Plant protected crops into their final positions as soon as they are sturdy and well-rooted
  • Plant into greenhouse borders,containers or growing bags
  • Growbags can be used for autumn salads – remove a long panel from the top to create a shallow bed
  • Ensure climbing plants such as cucumbers and melons have sufficient support and tie cordon tomatoes into strings or canes

5. Summer maintenance

  • Check watering daily or install irrigation; uneven watering can result in problems such as blossom end rot in tomatoes
  • Ventilate greenhouses on warm days by opening doors and vents; automatic ventilation is ideal
  • For warmth-loving okra and cucumbers, vents can be kept closed but humidity must be raised by damping down. Alternatively, partition off a section of the greenhouse with fleece or clear plastic
  • Some shading will be necessary; it is best to add this gradually, as it will initially reduce growth
  • Hang yellow sticky traps to provide early warning of pests.Biological controls can then be ordered promptly
  • Tie new growth into supports regularly; pinch out side-shoots of cordon tomatoes