After the long spell of warm weather this autumn, the first few days of January, possibly longer, are set to be cold, with snow in some areas.
Protect plants in unheated greenhouses with fleece, removing the cover during warmer days. 70g fleece, provides protection to around -5C, 30g fleece protects plants to about -3°C and standard 17g fleece provides protection to just below freezing. Added protection from your greenhouse will shield plants, too.
If you missed the autumn the sowing broad beans in autumn, you can do so now under cover for an early summer harvest, 5-8cm apart and 2.5cm deep in deep trays of multipurpose compost or singly in small pots. Put them in a cool frost-free greenhouse, and harden them off before planting outdoors in early spring. Use the hardy varieties ‘The Sutton’ and ‘Robin Hood’ – both dwarf and ideal for windy sites; ‘Aquadulce’ and ‘Aquadulce Claudia’.
It is not always practical to grow everything from seed so it is worth listing plants which you intend to sow and those to be bought as plug plants, check the prices to get the best deal before buying. Plug plants save time and space in the greenhouse and heating costs.
Only water if plants show signs of stress, remove leaves showing signs of grey mould as soon as you spot them and control pests like whitefly, aphids and red spider mite when they appear. Check regularly for slugs hiding under plant pots. Ventilation should be opened on warmer days but closed well before temperatures drop, usually by mid-afternoon at the latest. Beware of draughts on cold days.
Wash pots and clean labels using environmentally friendly disinfectant and an abrasive pad to remove plant names written in pencil, dip the ends of bamboo canes that have been in compost which supported tomatoes and cucumbers in summer, in environmentally friendly disinfectant to prevent disease problems next year. If the ends have begun to rot, cut them back to sound material and put the decaying ends in the council waste bin. Bamboo takes a while to rot, especially in smaller compost heaps.
Strawberries that were lifted and potted up last summer, can be brought into the greenhouse towards the end of the month and placed near the glass for maximum light. Once they start flowering, pollinate the blooms by hand, 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 early flowering and fruiting. After harvest, they can then be acclimatised to outdoor conditions by putting them outdoors in a sheltered sunny spot during the day and bringing them in at night, then planted outdoors later in the season.
Bring containerised peach trees into the greenhouse to avoid problems with peach leaf curl, a problem which begins to show in spring. Affected leaves showing puckering and red tints should be removed as soon as they appear, well before the onset of the white bloom of spores which spreads the disease. Dispose of infected leaves immediately, away from the garden.
Bring potted camellias into the cool greenhouse to encourage early blooms, so they are then protected from frost when flowering.
Happy New Year! I hope that 2026 is good to you and your garden. Take care and stay well, Matt