Some may want to move from a purely ornamental greenhouse to also producing items for the table but worried this may result in the greenhouse not being ‘quite as pretty’. Well Citrus may be your answer. No other choice is so good looking the whole of the year, so neat, so reliable, and gives a harvest of tasty fruit in deepest winter. This Christmas just imagine your greenhouse brim full of oranges and lemons, a welcome, even festive sight. And their floral scent, the perfume is wonderful, and why the first Orangeries were built (to later develop into our modern greenhouses).
There is one more advantage of making your cool/frost free greenhouse into a modern Orangery, as the Citrus go outdoors all summer so their space becomes available for summer displays or crops such as tomatoes, peppers and melons.
Fortunately Citrus are compact and one of the more amenable of fruits to tub cultivation so making their transport simple. Furthermore, confinement to a tub reduces growth so Citrus seldom need pruning, which seldom happens as these over-crop naturally.
Because of this Citrus need thinning as leaving them all on exhausts them! This also means Citrus need really heavy feeding, and with rain or soft water as they’re not fond of lime. Unusually, I recommend a commercial compounded Citrus feed (or two, summer/ winter) as it’s then possible to feed heavily accurately. Ericaceous compost in terracotta pots is preferable, these stay upright and also ‘breathe’. (Never plant Citrus deep as their roots like a well aerated soil.)
Citrus can be grown from seed, but take two decades to fruit, so better order your winter orchard now as ready grown bushes, as large as you can run to. Now Lemons crop heavily, are most useful to have, and come in several varieties so two or more are a priority. Then Satsumas, Clementines, Tangerines or Mandarins, all delicious, and as for Lemons small so you can ripen many on a bush. (This is important- you just can’t ripen many Grapefruit on a shoulder high bush, I’ve tried!) Oranges come in a huge range with hybrids as well such as the Ortanique. Limes are productive but the more miffy of the family. Then there’s the closely related Kumquats and Calamondin oranges, pretty and productive these can even be grown as houseplants.