TIPS on how to keep greenhouse in tip-top condition - plus, find out what else needs doing in the garden this week
The glory of the greenhouse
WHILE many of us will be turning up the central heating and closing the curtains as shorter nights draw in, others will be doing some serious pottering in the greenhouse.
Indeed, the greenhouse - heated or unheated - can provide a haven for gardeners who can still plant and sow, reaping the rewards of both edible and ornamental plants during the cooler months.
Indeed, you can have a greenhouse bursting with ornamentals from autumn through to spring, grow a variety of crops and safeguard tender flowering plants and fruit trees if you plan carefully.
If your greenhouse is unheated, you will be more limited but it is still possible to have lush, green displays of feathery ferns, ivies, scented shrubs which will give you a delicious waft of perfume every time you go in the greenhouse and some well-chosen bulbs and alpines towards springtime.
Plant shrubs such as Daphne odora ‘Aureomarginata’ in pots outside and then bring them into the greenhouse at the end of the autumn. It produces pale purple-pink flowers and glossy green leaves and is a star in the winter greenhouse.
Some foliage plants also look stunning in the greenhouse in winter. Fatsia japonica, with its exotic, glossy leaves, could easily be a stand-alone specimen, while shallow troughs of colourful alpines on waist-high staging, including cyclamen, chionodoxa and anemone, dwarf narcissi and colourful primulas will create a riot of colour in late winter and early spring.
Scented annuals can also be wonderful in the greenhouse. Plant heliotrope or mignonette in late summer, to bloom in the greenhouse in late winter
You can also be sowing and planting in the greenhouse over the cooler months. Many plants can be grown much earlier and produce crops earlier than would be achieved outside.
Salad leaves, particularly the cut-and-come-again varieties, can be sown all year round, grow quickly and taste great when they are picked young. They are suitable for growing in pots, trays or soil borders. In winter you can also sow broad beans and early peas if you have border space.
You’ll have more choice of what to grow if you have a greenhouse heater or at least a heated propagator to get tender veg off to a good start. Veg grown in traditional greenhouses, such as tomatoes, aubergines, cucumbers and peppers, are usually planted in spring. But you can sow greenhouse tomatoes in a heated propagator as early as December, for growing on in a heated greenhouse.
You can also have fresh herbs for the winter months if you pot up clumps of mint, thyme or oregano from your garden in early autumn and put them in the greenhouse, or try sowing basil in a heated propagator in pots, nipping out any shoots that threaten to flower.
Fruits can also do well in greenhouses - and for some it’s a necessity. If you’ve grown citrus fruits in a pot on a sunny, sheltered patio in summer, move them in and their fragrant flowers and glossy leaves come into their own. You may not harvest a lot of fruit, but seeing lemons growing just conjures up a flavour of warmer climes.
Nectarines, peaches and apricots all need warmth to survive and you’re best off training them against a south-facing wall in a lean-to greenhouse. In this country if they are left outside their blossom, which appears in early to mid-spring, will generally be caught by the frost which will mean no fruit.
Decide what you want in your greenhouse over the cooler months and plan carefully, choosing plants to suit the temperature and situation of your greenhouse, heated or unheated, and try to stagger the display so you have different plants coming into their own as the season progresses.
Here are some tips to keep your greenhouse in great condition:
1. Keep the glass as clean as possible at all times for maximum light.
2. Check that any electrical heaters are free from corrosion and that your connections are sound. If in doubt, have a qualified electrician check the equipment.
3. Use sticky-backed draught excluder around ventilators, panes and doors for good, long-lasting seals.
4. Remove rubbish, moss and algae growing between panes with a stick or plastic plant label.
5. Give the whole greenhouse a thorough clean with hot water and garden disinfectant before a new season of use.
Best of the bunch — Euonymus (spindle bush)
WE may enjoy the more common types of euonymus such as E. fortunei and E. japonica, but some of the less popular varieties actually produce the best autumn colours, in shades of red, purple and crimson.
E.alatus ‘Compactus’, for instance, which grows just to a metre and is therefore suitable for smaller gardens, produces the most amazing crimson and scarlet leaves in autumn and its purple and red fruits split open to reveal orange seeds.
The larger version of this deciduous shrub is great for the back of a mixed border or woodland garden and is also famed for its odd-looking corky flanges running along the trunk and branches, which provide winter interest after the leaves have fallen..
Among the more popular of these euonymus which provide autumn interest is E. europaeus ‘Red Cascade’, whose oval leaves turn crimson in autumn and fall to reveal bunches of lobed red fruits. Euonymus will thrive in most soils and prefers sun or light shade.
Good enough to eat - Planting spring cabbage
If you love tasty spring greens, you’ll just have time to plant spring cabbage, 10cm apart in rows 30cm apart.
The thinnings can be used as spring greens in March and the plants left in the ground can be used as a cut-and-come-again crop if cut after producing six or seven leaves.
Each plant should yield three or four harvests and they make an ideal space-saving alternative to the hearting summer and winter varieties.
Pick a sunny spot to grow the plants and work in plenty of organic matter beforehand. The ground must not be acid, so you may need to add lime in winter. Good varieties include ‘Durham Early’, which will give you an early crop of spring greens but is unlikely to develop a solid heart, and ‘Pixie’, a compact hearting variety which is ideal in mini vegetable beds.
Three ways to — create a low-maintenance garden
1. Plant trees and shrubs rather than annuals and tender perennials.
2. Think about ditching the lawn and create a wildflower meadow area instead, which is likely to be more colourful and attractive to insects and less time-consuming than a bowling green finish.
3. If you’re buying pots, make them big. Several strategically placed containers will look a lot more effective than a collection of mismatched smaller ones and should need to be watered less often than their smaller counterparts.
What to do this week
Sow rows of winter lettuce, baby spinach leaves and early carrots or mangetout under glass.
Move strawberry pots and baskets close to a sheltered wall over the winter.
If you haven’t done it yet, wash down the greenhouse glass with greenhouse disinfectant.
Continue to cut down marginal pond plants to 5cm (2in) above water level and fish out any dead water-lily leaves.
Prune blackberries and hybrid berry fruits after harvesting.
Lift Jerusalem artichokes, cutting the top of the plants off, dry the tubers and store them in trays.
Continue winter digging, adding well-rotted organic matter to improve the soil.
Complete the planting of all new evergreens.
Divide and replant waterside plants such as astilbes and trollius.
Finish planting up spring containers.
Prune autumn-flowering deciduous shrubs over three years old as they finish flowering.
Continue raking up leaves to make leaf mould.
Tidy asparagus beds as the fronds of asparagus turn yellow, when they can be cut back near to the ground.