Open the vents in your greenhouse on sunny December days, shutting them before temperatures drop early in the afternoon to retain the heat. Good air circulation is essential but chilling draughts should be avoided, so don’t leave the door open or open the vents too far. It is a matter of getting it just right!
Leaves left on cushion alpines will cause them to rot, do pick them off then cover them with a sheet of perxpex, polycarbonate or similar, allowing air to circulate but keeping them dry, it is also worth covering Helleborus niger, the ‘Christmas Rose’ to prevent the soil from splashing onto the flowers and spoiling them when it rains.
During winter, annuals like ‘Chickweed’ and ‘Bittercress’ germinate, flower and seed rapidly during milder periods, building up a seed-bank in the soil that will create mayhem next year; do keep weeding. There is a case for retaining a covering of weeds to stop erosion on the vegetable plot and hold on to nutrients until they are dug in or composted next spring. If you decide to experiment, don’t let them flower or set seed. Alternatively, cover the soil with a layer of well rotted organic matter, several inches deep, to be forked into the seedbed next spring.
If you are growing winter pansies, do remove fading flowers to encourage further blooms along with yellowing leaves and cover pots of bulbs for spring displays with horticultural fleece or wire netting to protect them from squirrels.
Don’t walk on the grass during frost to prevent damage otherwise you’ll leave yellow foot prints that won’t grow out until spring or walk on the grass when it is waterlogged.
During the traditional period from leaf fall through winter, hedging, fruit, roses and some shrubs are sold ‘bare root’. They are cheaper than containerised plants, but do buy early, for the greatest choice.
Do start Hippeastrum’s into growth by watering sparingly at first; just a trickle of tepid water around the bulb, increasing the volume as more growth appears, there are some lovely colours available from garden centres and on the internet – ‘Black Pearl’ has velvety dark red flowers. Once they are growing strongly, keep them moist but not waterlogged and take care not wet the growing tip. A bright window sill is ideal; err on the side of cool to prolong flowering (15-18 C (60-65F) is ideal – this applies to ‘Indian Azalea’s’, ‘Poinsettia’ and ‘Christmas cactus’ too. Do stake the flowering stems of Hippeastrums carefully to prevent them from falling over, rotate the pot a quarter of a turn each day, then sit back and enjoy the display. Don’t forget to remove any of your houseplants from the windowsill at night, so they aren’t damaged by the cold, mist round plants or stand them on pebbles in a water filled tray to increase humidity and don’t put them too close to the radiator. Cover bunches of holly berries for use in indoor displays, with horticultural fleece to protect them wildlife for a full on flowers and berries display and you’ll have all you need for the festive season. Do have a happy Christmas and a Peaceful and prosperous New Year to you all. Thanks for reading my diary.
Take care, Matt