Green thoughts in a green shade

Foliage is the architecture of a garden. From giant fennel to parsley fronds, Anna Pavord suggests some striking leaf combinations

All the gardeners I know (including me) are wandering round with soppy smiles on their faces. So far, it has been a fantastic spring. Soon the doom and gloom merchants will be reminding us of April's treachery and counting up the number of times snow has fallen this month to smother the pear blossom at birth.

But I'm on a roll. Already, I've weeded and wafted one large area of the bank. Wafting is the children's term for the fiddling sorts of jobs that you do to round off a session of heavier, more demanding tasks. It includes snipping dead bits from the leaves of irises, taking off a few dead twigs from the roses, nipping dead heads off the daffodils, training tendrils of clematis in different directions. Individually, none of the jobs amounts to much, but taken together, the effect is noticeable.

When the paths have been raked of winter debris and top-dressed with fresh gravel or crushed bark, bits of the garden will be looking almost kempt. That is unusual so early in the year. Having heavy clay, I am not used to being able to garden all through the winter, as we have this season. Last spring was so slow, so cold. This year, since the snowdrops, there has been a tumult of flowers: primroses of all kinds, scillas, narcissus, pulmonarias, grape hyacinths, blue and white striped "Columbine" violas, spurges. The big spurges such as Euphorbia wulfenii are spangled with ladybirds.

But paradoxically, although it is the flowers we talk about, it is the great swelling mounds of foliage in the garden that make the whole place look rich and furnished again. Particularly vivid and brilliant is the fountain of growth from the giant fennel, Ferula communis, a different family of plants from the fennel that you eat, but with the same fine, thread-like foliage.

In good soil, this plant will make a fabulous mound of lacy green three or four feet across, and perhaps two feet high. Then when it feels it has built up enough of a foundation, it sends up a huge flowering stem, topped by flat heads of yellow flowers. But the leaves are its chief glory, though leaf sounds too meaty, too hunky a term for this filigree spun wirework. Next to it are the spear leaves of a tall white-flowered iris, Iris orientalis and a mound of brunnera, covered now with forget-me-not flowers.

Iris leaves, that is the tall spear-like kind that go with beardless irises such as I. orientalis, I. sibirica and I. monspur are very useful at this time of the year, acting like exclamation marks among low mounds of geranium leaves or thalictrums just heaping themselves up into action. You couldn't use bearded iris like this. They would resent having their rhizomes covered or shaded by vigorous neighbours. But I. orientalis seems to grow anywhere in sun or shade, the leaves eventually reaching three feet in height.

There ia new giant cow parsley (Selinum tenuifolium) on the bank, too, not such a hypnotically vivid green as the giant fennel, nor as finely cut in its foliage. But one of my heroes, the Edwardian gardener E A Bowles called it "the queen of the umbellifers". So I had to have it. Planted out as a baby, it seems improbable that it will eventually top five feet. Height is a difficult thing to bear in mind when you are placing plants. I find it easier to feel their width, to be aware of sideways growth.

The selinum flowers with typical flat umbellifer heads, white, rather than yellow, but, as with the giant fennel, it is planted for its leaves rather than its flowers. They help to disguise the bottom of the multi- stemmed Judas tree. That is about to erupt in its abrupt way into purple flower. They burst, stemless, straight out of the trunk and branches. It is a weird trick. You can imagine the flower inside, head butting the imprisoning bark and - although you would not have put any money on it - winning.

Bowles, who as a writer never wants to leave you in any doubt as to his opinions, also called Selinum tenuifolium "the most beautiful of fern- leaved plants". Not at the moment, it's not. The laurels go to sweet cicely, Myrrhis odorata. That is because it is one of the few of the fern-leaved umbellifer tribe to get its act together this early in the year. The foliage is a wonderfully fresh green, and it is already in full flower, heads of greenish, greyish white, not showy, but quite sweet-smelling. Does the plant get its "odorata" tag from the flowers? Or from the leaves, which smell of aniseed?

It grows in deep shade in our garden, partnered by the hefty spotted leaves of pulmonaria and the shiny strap foliage of hart's tongue ferns. Gerard, one of the early herbalists, said that to eat it was "exceeding good, holsome and pleasant among other sallade herbes", but perhaps they were keener then on the taste of aniseed than we are now. In the north country, the plant was once used as a polish, rubbed into oak panelling and buffed up to a shine when the juice had dried off.

Sweet cicely is a compact plant, no more than two feet high and wide. You wouldn't want it in a starring role, but it is usefully early and unfussy about shade. It makes a good backdrop for low mats of Primula vulgaris sibthorpii which are flowering now, short-stemmed mauve flowers, each with a yellow eye. It doesn't seed around like the common primrose, but the clumps are easy to split up, once flowering is over.

Variety in form is perhaps the first thing you notice in contrasts of foliage plants: upright iris sword leaves against chunky brunnera leaves, lacy sweet cicely against the stout, spotty foliage of pulmonaria, but there are other contrasts to bear in mind too, contrasts of texture, of colour, of variegation, of habit.

The drooping quality of the alliums' leaves, growing first up, then turning over on themselves so that their tips touch the ground, is a distinct landmark among the determinedly upright spears of peony foliage, pushing through the ground now with knobby flower buds firmly and bossily in place on top. And the peonies' leaves themselves, with their strange bronzed finish, make a good foil for the tulips.

Although you do not think of either alliums or peonies as being primarily foliage plants, they are both positive assets at the moment. Their real moment of glory will come later when they flower. But how many plants is the garden carrying that contribute very little outside their flowering period? I have already started sniffing around nurseries for new plants to fill in some holes. Each time I look at a possible candidate I ask it "So what do you look like when you are not at your best?" How fortunate I don't have to answer the same question.

Giant fennel and the giant cow parsley, Selinum tenuifolium, can be got from Tim Ingram, Copton Ash. 105 Ashford Rd, Faversham, Kent ME13 8XW (01795 535919). The nursery is open Tues-Thurs and Sat-Sun (2-6pm). Plants can be sent mail order. Send four first class stamps for a catalogue.