Gardening: Peculiar Plants

THE FLOWERS of peonies, lupins and mallows are so familiar that even non-gardeners can recognise them. But when they grow on trees they puzzle many people. Tree peonies of the mountain, or suffruticosa, type are among the most difficult and showy cultivated plants. They have dinner- plate sized flowers heavy with petals: these are the peonies of Chinese paintings. The one I want to grow appears in no nursery lists. Rock's peony was described by the plant-hunter Farrer in the early years of this century as 'refulgent as pure snow and fragrant as heavenly roses . . . an upright bloom with heart of gold, each stainless petal flamed at the base with a clean and definite feathered blotch of maroon'. Peonies like this, if one could acquire them, would succumb to frost and fungus diseases. They grow on gaunt and gawky stems. No wonder they are too rare to appear in The Plant Finder, the handbook which usually produces a source for the flower of one's dreams.

Much less rare, but with some of the excitement of the Chinese beauties, are the two smaller-flowered species of tree peonies. P. delavayi produces lacquer-red flowers a third of the size of its aristocratic dinner-plate relations in May and June. Now, the 6ft-tall woody bushes are covered in well- defined leaves that still look interesting at a time when everything else is parched or over. The ludlowii cultivar of P. delavayi has yellow, not red, flowers. It also has good leaves and grows to just over 6ft and almost the same width. Chance seedlings between ludlowii and red delavayi peonies come up in oranges and tawny yellows. They like the occasional helping of manure, but seem to be easy and unfussy in all soils. Their only fault is that when the leaves turn brown and die they cling to the branches, which looks depressing. If you have enough space and can face cleaning up the plants in winter, they are well worth growing.

The tree mallow 'Barnsley', with near-white flowers, has become almost too much of a good thing. It flowers for months on end in palest pink and you see it in every garden. Its parent, the cottage plant with rosy mauve flowers, is just as reliable but not such an easy colour to fit with other flowers. Less often seen is Lavatera 'Pink Frills', which struck me as being more useful than either of these when I saw it for the first time this year in a Somerset garden. Its flowers are pale pink, small and frilly (a little bigger than those of a Sidalcea). And it is in The Plant Finder.

Lupins are difficult to grow if you garden on alkaline soil. They do not like manure and they collapse as soon as they set seed. Dead-headed and guarded against slugs in acid sandy soils, they thrive. If you cannot make them happy, try tree lupins, lupinus arboreus, instead.

Their colours are gentler, no two-tone rusts and yellows but soft blues, yellows and whites, and occasional mauves. They grow very fast and flower very long. They do not fuss too much about the soil, but they do like the sun. Like the hybrid lupins, they should not be allowed to set seed, but if they do die they are quickly replaced either from seed or cuttings. Their feathery leaves are pretty and their flowers are scented - but not of pepper like their relations. For anyone who wants to grow something unusual, these tree forms are irresistible.

(Photograph omitted)