Keep growing this winter in your Greenhouse

AS winter sets in, the garden can become a quiet place as many plants are dormant and the cold weather keeps people indoors.

But for those green-fingered gardeners who wish to continue growing in their Greenhouses or Glasshouses during the colder months, here are some seasonal tips from Hartley Botanic.

The award-winning Greenfield-based company, whose entire product range is endorsed by the RHS, has more than 80 years’ experience producing handmade, and bespoke Greenhouses and Glasshouses.

Find out more online www.hartley-botanic.co.uk or call 01457 819 155.

DECEMBER – Christmas cuttings
Take root cuttings from plants, like Oriental Poppies, Phlox, Verbascum, ‘Drumstick’ primulas, shrubs like ‘Japanese Quince’ and exotic ‘Passion Flowers’.

Once the leaves have fallen, take a hand fork and carefully tease the soil from around the plant to expose some of the roots. Remove near to the main stem any that are at least ¼” diameter but don’t take too many or it weakens the plant.

Wash off any soil and cut off any fibrous side roots. Cuttings need to be 2-6” long.

Fill pots of peat substitute compost with added grit and make several holes about 2” apart with a pencil, cane or dibber, insert the cuttings, then cover with a thin layer of grit and water.

From then on keep the compost moderately moist. Feed monthly with a general fertiliser, water through the summer and plant them out the following autumn.

JANUARY – What to grow
If you have a heated Greenhouse, aubergines can be sown at 18-21°C (65-70°F) late in the month in pots or modules of peat-free seed sowing compost in a propagator. Once the seeds have germinated, grow lights will maintain compact growth.

Sow summer cauliflowers and make small sowings of onions, radish and early carrots in a cold Greenhouse towards the end of January. Peas, lettuce and radish can be sown in Greenhouse borders.

If you missed sowing broad beans in autumn, sow some now under glass for an early summer harvest, 5-8cm apart and 2.5cm deep in deep trays of peat multipurpose compost or singly in small pots.

Put them in a cool frost-free Greenhouse, and ‘harden off’ before planting outdoors in early spring.

Strawberries that were lifted and potted up last summer can now be brought into the Greenhouse and put on the bench for maximum light. When they start flowering, pollinate them by transferring pollen from one flower to another using a fine artists brush.

Keep the compost moist and feed with dilute tomato fertiliser every two weeks to encourage flowering and fruiting. They can be ‘hardened off’ and planted outdoors in mid spring.

FEBRUARY – Pruning and planting
If you are growing C. orientalis and C.tangutica; Clematis texensis, Clematis viticella and their cultivars and the large flowered hybrids like ‘Hagley Hybrid’ and ‘Perle d’Azure’, now’s the time to prune.

There’s now a good selection of potatoes in garden centres, catalogues and on the internet.

Sprouting or ‘chitting’ early potatoes before planting is useful for earlier varieties in cooler climates and maincrop potatoes if they’re being planted late.

If you’re preparing to sow vegetables, warm the soil with polythene or a cloche for a couple of weeks before sowing.

This raises the temperature by a few degrees and dries off the surface making a warm, crumbly seedbed that’s perfect for the germinating seeds.

It is worth investing in a soil thermometer, to check temperatures below the surface, too.

Wysteria should be pruned now, as they will bleed if left too late.Hardy evergreen hedges need tending and conservatory climbers should be pruned back before birds begin nesting.

Apple and pear trees should be pruned by the end of February. Roses can now be planted – if you are planting in an area which has previously grown roses, use mycorrhizal fungi to prevent replant disease.

Bare root fruit trees can be planted now if ground is not waterlogged, and towards the end of February is also a good time to plant onions, shallots and garlic.

Prepare vegetable seed beds for spring planting by digging over the soil, incorporating compost and removing any weeds.

Keep potted outdoor plants raised off the ground to protect from frost.