BEWARE JACK FROST
Damaging frosts are increasingly likely this month, all over Britain.
Half-hardy and tender plants will be at risk. If you have any outside which you value, move them somewhere frost-free.
If you have a greenhouse or conservatory, move your nonhardy plants into those. An unheated greenhouse will only give partial protection. If outdoor temperatures fall below zero, the average greenhouse interior will also fall close to freezing point.
You can increase protection by laying horticultural fleece over delicate plants. That could give another two degrees centigrade of protection. But for guaranteed safety, you’ll need a heat source. Large non-hardy plants may be difficult to move inside.
UK-based gardening expert Nigel Colborn shared his advice for protecting plants from frost throughout winter
But they’ve a chance of surviving outside if given extra protection. With herbaceous plants such as ginger lilies, canna and dahlias, a thick mulch with homemade compost is often enough.
Vulnerable shrubs or climbers are easier to protect. Pinning shade-netting or loose-woven hessian can help. You can also use heavyweight anti-frost fleece. Expect to pay around £10 for 15m of 1 m-wide material.
Vulnerable plants in large containers can be made safer if packed together. A sunny wall can hold its heat through part of the night. So if you leave plants close to that, covered with fleece, that might keep them alive.
BRING IN CHRYSANTHEMUM STOOLS
If you have a greenhouse and grow large chrysanthemums for cut flowers outside, it’s easy to raise new stock for next year. Cut all stems to ground level and dig up the plants. Re-plant those into large pots using ordinary garden soil and place them on the floor of your greenhouse.
In February, water more and move them into light. Remove shoots. Set the cuttings in a mix of sand and potting compost. By May, you’ll have strong, rooted cuttings.
TULIP EXTRAVAGANZA AHOY
November is the best month for planting. When blending tulip varieties, check heights and flowering times. Early tulips such as Fosteriana hybrids flower from March. Late cottage varieties don’t peak until May. When buying, check packs for quality. Bulbs must be firm to the touch. Plant deeply, tops of the bulbs should be about 10cm below the soil surface.
PLANT OF THE WEEK: CORNUS ALBA ‘SIBIRICA’
Nigel chose Cornus Alba ‘Sibirica’ as this week’s plant
Also known as Siberian dogwood, this is a shrub for all seasons. In autumn the young stems begin to turn maroon. As winter starts, the young bark revs up to a hotter, more vibrant red. At the same time the leaves will have turned butter yellow, deepening to old gold before falling. For best results, grow it as a cutback or ‘pollarded’ shrub. Each year in late March, cut all the previous season’s shoots back hard, leaving short stumps. If you repeat that each spring, stout trunks develop, producing multiple wands each year. Moist but well-drained soil suits it best. It will grow readily in shade, but for healthy growth, full sun is better.
In a village garden last week, I noticed snowdrops in flower. They didn’t have any leaves, however. What variety would they be? Where can I buy bulbs?
Mr. J. Pratt.
They were probably Queen Olga’s snowdrop, Galanthus reginaeolgae. The naked flowers appear in October. The leaves follow in late winter and must be allowed to die down again naturally in early summer. This is snowdrop for sun or gentle shade, in freedraining soil.
The out-of-season flowers are a delight, but they’re often spoilt by slugs and snails. Deter them with sharp grit.
Specialist nurseries such as avonbulbs.co.uk supply them.