Gardening: Where I learnt to love the triffids

The art of dangerous gardening is thriving. At Great Dixter, banana trees mix with giant lilies.

Anna Pavord tries to keep her feet on the ground.

Nowhere in England is being gardened as vividly, as joyously and as dangerously as Great Dixter in Sussex, where Christopher Lloyd, in happy cahoots with his head gardener, Fergus Garrett, is galloping into October surrounded by blazing dahlias, and forests of zinnias, cannas and banana palms.

Each time I visit, I stagger out, high as a kite with visions: dark-veined crocus piercing rough meadow turf; topiary birds carved from yew, perched primly above explosions of pampas; and sky-blue trumpets of morning glory flung carelessly over hydrangea bushes. It is the most generous garden imaginable, and one of the few that looks as exuberant in late autumn as in May. Most of us by this stage have begun to pack our gardens away. Not him. "How could you? There's such a lot to look forward to." He points to a kniphofia that hasn't even begun flowering.

The bones of the garden were laid at the turn of the century by Nathaniel Lloyd, Christopher Lloyd's father, working with the architect Edwin Lutyens. They are good bones, defined by generous yew hedges, wide borders, flagstone paths, and the curving circles of steps - a Lutyens trademark.

The approach to the house, with its wonky, tipsy porch, lies along a straight stone path with meadow grass on either side. In spring there are sheets of small crocuses. Then fritillaries. Then cranesbills. Now the autumn crocuses, with fat colchicums rolling around them.

The approach, with its rough grass and eclectic range of trees, needs to be taken slowly, but this is your chance to throw out all assumptions about what can be achieved, and open your mind wide.

Take paulownias. Handsome trees. Big leaves. But nowhere else in England are paulownia leaves as big - in the new tropical garden, the stems are stooled down each year, so that the tree throws fresh growths with leaves as big as tablecloths. It's a technique used on other plants at Dixter, too, such as the handsome cut-leaved Rhus x pulvinata and the tree of heaven, Ailanthus altissima.

Then look at the pots clustered by the porch. Most of us feel proud if we manage to get a pot of petunias and helichrysum through summer without them folding up with thirst, being attacked by earwigs, sat on by the cat or devoured by mildew. But why do we always reach for the same small palette of plants?

Clustered here by the porch are sweet-smelling acidantheras in pots, with pseudopanax, daturas, rusty foxgloves, coleus, and pale grey succulents with leaves the shape of cows' tongues. Mixed in with them are the tall, blue flowering spikes of Salvia farinacea and elegant umbels of tulbaghia. Where has tulbaghia been all my life? It's a bit like an allium but lighter in build, the flowers pinkish-mauve, the heads smaller than those of most alliums.

Bedded out in the big, curving bed behind the lawn are tall zinnias in a wild mix of colours, backed by the sober foliage of bupleurum and variegated dogwood. These (the zinnias) I can admire without feeling the need to grow them myself. I've tried, and found them tricky. Christopher Lloyd sows seed late - the first week of May - and grows the seedlings on in single pots. But he had to sterilise the soil before he could get zinnias to thrive. They are martyrs to soil-borne diseases.

The great "set-piece" is the long border running away from a corner of the house to a Lutyens seat hugged by yew. As late as August, it was being recast, the lupins which had provided a first burst of red being replaced by dahlias such as the orange `Ellen Houston' and dark, sulky castor oil plants.

But at this time of the year, instead of making straight for the long border I veer off to the right, go down the circular flights of steps and make for the yew-enclosed patch that used to be a rose garden. The yew, and the sturdy old tiled building that closes off the space on its west side, look as Olde Englishe as a Tourist Board poster. But inside there is the most outrageous tropical garden that you are likely to see this side of the Caribbean.

Leaves rule here, though there is plenty of blazing colour, too. The palm leaves of a banana, each at least 4ft long, arch over the even stranger foliage of a fabulous aroid. This has huge, arrow-shaped leaves, like our wild arum blown up to 20 times life-size. But the leaves, rather than being held in the same line as the stalk (as our arum is), hang down from the top of it and swing slowly from side to side like giant pendulums.

Christopher Lloyd noticed that the aroid "sweats" as regularly as clockwork between 5pm and 8am, dropping beads of moisture every five seconds on to the ground below. One early morning, wandering in his jungle, he came across a contented toad, sitting under the drip like an old man taking his morning shower.

The aroid, like many other plants in this extraordinary jungle, is not hardy. Two extra glasshouses have been added since Christopher Lloyd and Fergus Garrett started gardening dangerously. There are now many plants here that need to overwinter in frost-free conditions. But it is extraordinary to see what some things, such as papyrus and begonia, that we think of as house plants, will do, if they are given their heads outside.

Dahlias are planted to great effect against tropical foliage in this area. Glowing `Orange Mullet' is used with the tender Bhutan ginger, Hedychium greenei. The rich pink dahlia `Pearl of Heemstede' is partnered with the velvety Mexican salvia, S involucrata `Bethellii'. Neither is uncommon, but I have never seen them combined to such effect. The third plant in the group, dark-blue-flowered Solanum rantonnetii, was new to me. It's an evergreen shrub, lax in growth, the kind of thing you might normally use in a conservatory. Forget the conservatory, says Lloyd robustly. Live dangerously. Plant a canna.

The garden at Great Dixter, Northiam, East Sussex TN31 6PH is open until 15 October daily (2pm-5pm) except Monday. The nursery is open all year, Monday to Friday, 9am-12.30pm and 1.30pm-5pm, Saturday 9am-12pm. Plants can be sent by mail order. Send four first-class stamps for a catalogue. Look out for Christopher Lloyd's new book, `Gardener Cook', coming out at the start of October (Frances Lincoln, pounds 20).

WEEKEND WORK

Start to clear out summer bedding plants if you plan to replace them with wallflowers or sweet williams. It is difficult to throw out plants that are still flowering, but if you delay the best of the spring bedding will be gone. Choose wallflowers with the growing tips pinched out, to make compact, bushy plants.

Lawn edges get tough treatment from dogs and children. You can repair the worst bits by cutting a rectangle of turf behind the edge and then re-laying it round the reverse way so that the worn edge is on the inside. Sift a little earth over the join.

Mildew has been appalling this year, and both Michaelmas daisies and phlox have suffered badly. The spores are formed in spring and summer and will overwinter on stems and leaves. Cut out all diseased stems after flowering, and burn them. You can control mildew by using a systemic fungicide such as Systhane or Nimrod T, but you have to start spraying in the spring and then at fortnightly intervals thereafter. Alternatively, replace mildew-prone Aster novi-belgii varieties with other species such as A frikartii.

The biggest disaster in my garden has been the collapse of all the nicotianas, even the big N sylvestris. Some say the culprit is mildew again. But a nurseryman I was talking to recently said that the problem was not mildew but a new virus that lifted the epidermis off the foliage. I'll have to find out more before relying on them in the garden again.

Continue to harvest vegetables regularly, particularly courgettes, runner beans and French beans - worth eating only when young and tender. Outdoor tomatoes have been late to ripen, and you may have to finish the ripening process inside.

Check stakes and ties on trees, to make sure they are secure and are neither rubbing nor throttling the trees. This is also a useful time to remove any dead, twiggy growths and, if necessary, one or two of the lowest branches.