16:04 - 11 June 2010
As the summer develops into what we all hope will be a great garden season, the greenhouse enters a new phase of productivity. It’s role as nursery for countless seedlings and tender plants is now drawing to an end as the majority of juvenile plants are planted out into the borders and vegetable patches. Hanging baskets and planters filled with patio plants are also ready to go outside as soon as the danger of frost has passed. What remains are the greenhouse plants that need the accentuated warmth and humidity of the greenhouse environment to perform at their best. These include tomatoes, peppers, cucumbers and a variety of other vegetables and flowers.
There is now room to sow a late batch of seeds and to nurture plenty of summer cuttings, which will quickly root in moist and warm compost.
Keep plants well watered but not waterlogged. Check on them twice daily where possible.
Feed established plants with a suitable plant fertiliser. Choose a dedicated tomato food for these specialist crops and tailor your fertiliser choice to the plants that you grow.
Ventilate freely. At this time of year you need to ensure that there is excellent airflow around your greenhouse. Keep top and side vents open and if necessary the door too, but barricade it against unwanted visitors.
Think about shading the south facing side of your greenhouse to limit the temperatures inside. You can fit bespoke shading blinds or create your own temporary blinds using screening, shading or even sacking material.
Pinch out the side shoots of cordon tomatoes as they form. If the side shoots have become quite large then treat them as cuttings and root them in a good cuttings compost to increase the number of plants that you grow. Tie in your plants as they develop, especially as fruit starts to form or they will quickly topple over and be damaged.
When the first tomato flowers start to form mini fruits, feed the plants. Use a dedicated Tomato Food for great results.
Pot up individual tomato plants into larger pots in the greenhouse or plant up three tomato plants into a large, deep growing bag.
Pot up cucumbers, aubergines and peppers into large pots or deep growing bags in the greenhouse or outdoors according to their variety. Check your seed packet for more information.
Don’t allow tomato plants to dry out. Stress, inconsistent watering and a lack of calcium can lead to split fruits and Blossom End Rot. Feed with a good Tomato Food that contains vital trace elements to reduce the risk of this disfiguring disease.
Plant out other established plants such as runner beans, sweet corn, courgettes, squash and others when they are large enough to handle and when all danger of frost has passed.
Sweet corn, courgettes, marrows, squash and other tender plants can be sown in the greenhouse or even into the garden during June. For the best results sow seed into individual modules, small pots or into Root Trainers to give the plants plenty of room to develop and mature. Plant them out when they are large enough to handle.
Several plants growing in a container will quickly use up the fertiliser held in the compost. For the best results you need to feed them regularly throughout the growing season.
Deter an invasion of vine weevils in your pots and containers by applying the nematode based biological control to all your tubs, pots and containers, but especially those with Fuchsias, Begonias, Busy Lizzies and Pelargoniums. This will keep the compost around your containerised plants free from these voracious pests.
As the weather warms up you can hang your hanging baskets in their final positions. Choose a spot that is protected from the wind, as windy weather will quickly dry out the compost. Be sure to supply the baskets with a rich source of nutrients. For complete convenience opt for controlled release plant food tablets or granules which are specially designed for hanging baskets and actually regulate the rate that nutrients are delivered to your plants, encouraging the correct rate of growth according to the environmental conditions.
Sow hardy biennials such as Wallflowers, Foxgloves and Sweet William into small pots of good quality seed compost. Although they may not flower this year, they will produce strong healthy blooms next spring and summer.
Take softwood cuttings of Fuchsias, Geraniums and other patio plants. Alternatively purchase one or two well-grown plants now and take plenty of cuttings to grow on into flowering plants this season.
Sow annual flower seeds such as Ageratum, bedding Salvias, Tagetes, Diascia, annual Stocks, Nemesia, Nicotiana, annual Phlox and bedding Rudbeckia in pots in warm greenhouse.
