Try and give the glasshouse and any covered areas where plants are growing a good winter clean out. Open all the vents on a dry day and wash the glass down with an ecological detergent. Keep a close eye out for pests such as mealy bug and aphid and make sure the temperature does not creep up too high in conservatories or sun rooms.
Plants that have flowered indoors such as orchids, jasmine and Christmas cactus can be roughed off now in a cool glasshouse. Stop feeding regimes for these and stop watering too, they can be put outside when the weather warms up after Easter when the worst of the frost is over.
Many thanks to Dancing Bee.