In this series of monthly articles Bob explores the incredible range of plants you can grow in a greenhouse, conservatory or plastic tunnel. Not just the purely decorative but the scented and edible also, and maybe those plants that are just downright interesting. This month Bob nominates lemons.
Everyone should have at least one lemon tree in a tub. These are tremendous value, not only are they very decorative but you get fruits in abundance and masses of blooms as well. Indeed a lemon tree or bush would be worth having if only for those myriad white waxy flowers which perfume your greenhouse or conservatory for many weeks on end. Even more conveniently lemons love to be outside from late spring until the return of frosts in late autumn thus freeing up covered space for summer plants such as tomatoes and chilli peppers.
Lemons do have a few simple requirements though these are easy to satisfy. They need to be in a light frost free place for winter but really don’t need much heat. Even if cut back by a hard frost they invariably recover with a host of new shoots coming from the thicker older parts. Lemons need a free draining compost preferring a fifty fifty mix of ericaceous with a John Innes loam based one to keep their lime level low.
Do not plant them deep but with the roots just below the surface. I find they do better in containers with well aerated compost so drill extra drainage and side holes in plastic containers. It’s best to use only rain water, adding a nitrogen rich feed twice weekly in spring and summer. Keep their compost just moist, never waterlogged or dried out, and be especially vigilant in winter, preferably then using pre-warmed water.
Of course you don’t have to stop with lemons though they are by far the best value- after all one lemon is useful on it’s own. Oranges are just as easy and even more sweetly perfumed. However you don’t get that many oranges on the same sized bush or tree. Maybe a dozen or so on a modest bush. The Seville or Bitter oranges are for jam making, what you want are Sweet oranges such as Navel or Valencia, With even larger fruits the grapefruit plant may carry only a fortnights’ worth of breakfasts, tasty though.
Oddly grapefruits are the hardiest of the commoner citrus even occasionally surviving outdoors. Limes are the most tender, and less generally useful, though great for flavouring curries. However Satsumas, tangerines and mandarins are all very similar, and small fruited so you get a worthwhile number from each plant. Wonderfully often just in time for Christmas.