Christmas House Plants

Thousands of poinsettias will have been bought for Christmas. With care, they can stay as colourful additions to a room until Easter. They have been developed from a wild species, Euphorbia pulcherrima, which grows in Mexico so they like warmth and good light – but not too much water. Ideally, place your poinsettia near a sunny window.  Do not let the plant touch the glass. As with all house plants, avoid draughts.  Water only when the compost feels dry then soak the pot. Euphorbias have a bitter white sap, so if a stem is broken take care not to get any sap in your eyes. If your poinsettia drops its leaves or wilts despite good care, it may mean it suffered cold conditions before you bought it e.g. sitting outside a shop.  Poinsettias are grown using dwarfing chemicals and special light regimes which means they are not really worth trying to keep for another Christmas.

Florists’ cyclamen are another popular winter pot plant. They were developed from Cyclamen persicum and, unlike some of the dwarf species, they are not hardy. They do not, however, like very warm rooms. Keeping them in good light in a cool, well it room or conservatory will make them last longer. They can be grown on to flower in another year. Feed while still in growth then allow the leaves to die back as they naturally become dormant as summer approaches. Only repot if the corm is filling the pot. If a cold frame is available, they can sit there – though some very fine cyclamen are grown on window sills. In autumn water and feed again.

Paperwhite narcissus

Most of the pots of bulbs which are bought as Christmas decorations are outdoor types such as hyacinths which were specially treated to advance their normal flowering time. They will flower again if planted out into the garden, but not at Christmas time.   Paperwhite narcissi are not hardy in our Scottish climate so are not worth saving.

The large flowered Hippeastrums are still usually called Amaryllis by gardeners and are definitely indoor bulbs. The size and number of flowers depends on the size of the bulbs.  The two stems on Red Lion have 12 flowers between them. The Friends of Saughton Park had an Amaryllis challenge and Sarah Bennett’s Apple Blossom was one of the entrants. The plant has not needed staking as it has been grown in good light. A heavy clay pot helps.  Some people have trouble getting them to flower in succeeding years. Remove the flowers as they fade and use liquid feed as the leaves develop. Keep well-watered and in good light as growth continues. Move to a greenhouse if available. By autumn the leaves may start to die back but even if they are still green withhold water but keep in good light to ripen the bulb. Give them around eight weeks dry and cooler. When growth restarts try replacing the top layer of compost around the neck of the bulbs. They do well in relatively small pots so only repot when they obviously need it. With plants that will be in the same pot for more than one season most growers prefer a soil-based compost such as John Innes.

All sorts of plants are sold for the Christmas market. As a general rule, flowering plants need more light than foliage plants.  Some are really outdoor plants like this little rose. It was in ornamental packing which has had to be removed to allow it to grow. Plants like this need to be in maximum light and in as cool a room as practical.

Stan da Prato
January 2021