Snow is on the ground here and our potted Christmas trees are still green and lush. After several years growing Christmas trees in Air-Pot containers it has become a family tradition and I am buying trees for successive offspring as the larger ones move into their own homes.

The latest recently acquired Nordman Fir had roots bursting out of a tiny pot, so it was immediately moved on into a Large 20 litre Air-Pot container. Also continuing to provide welcome winter greenery is a Tree Fern (Dicksonia antarctica) which is keeping its bright emerald fronds despite a dusting of snow.

Another plant which is pretty cold-tolerant but has been moved into a greenhouse to protect it from wind and wet is the Chrysanthemum which is in full bloom.

Requiring more warmth are two varieties of lemon, which are in a frost-free outhouse. These can be outdoors for most of the year, but as their slowly maturing fruit looks tantalisingly close to ripeness they are being kept in an insulated shed. An 80 W tubular greenhouse heater keeps the temperature above 6 degrees C.These citrus have put on good growth this season in 20 litre Air-Pot containers in a slightly acid soil mix, with generous feeding.