Pot luck: After years of experimenting with new, whizzbang plants, I’ve returned to the old stalwarts

Another year, another chance to go potty with your plants for next spring, says Anna Pavord

"Could do better". It's the dreariest phrase in the English language. Actually, "banqueting suite" is the dreariest, but the other comes close. It's what I was thinking as I was unpicking the pots, ready to replant them with tulips. It's always tulips for spring. I got into the habit of growing them all in pots when I gardened on heavy clay; then it was the only way to bring them through a damp, dreary winter. Now I'm on light soil that drains well, but the tulips still go in pots. It suits them.

The summer display isn't always the same, but after years of experimenting with new, whizzbang plants, I've returned to the old stalwarts: petunias and lobelias. There's a good reason why they are so popular. You plant them out in late May, when they will already be in flower and this season, they were still flowering as I yanked them out and tossed them on the compost heap. Poor things. It's not much of a reward. And during all that time they haven't been dead-headed, primped or poked in any way to keep them on their feet. They have been marvels.

It's not in any way adventurous to use petunias and lobelias, which is why the "could-do-better" thing was rolling round my head. But they come in so many guises, that even if you use nothing else but those two plants, you can make every pot in the garden look different. And while I'm away adventuring in other parts of the garden (arisaemas, arums, strangely fruited spindles) it's a relief not to have to fuss over the pots. This year they've scarcely even needed watering. It was obvious though, when I was dismantling them, that the biggest pots had done best. They were still looking as good as they did in August while the plants in the smaller ones were starting to give up. The biggest pot is nearly 60cm across, the smallest 26cm.

So the moral is that the bigger the pot, the happier the plants. That's not surprising, but big pots are difficult to move about and you need a great deal of compost to fill them. I ferry down bucketloads of our own compost from the heap to fill two-thirds of each big pot, topping up with Levington's multipurpose. At this time of the year, all the soil that the summer annuals have grown in gets emptied out. There's usually room on the border where the sweet peas have been. So the pots get filled again with fresh soil which makes planting bulbs very easy. I just space them out on the compost from the compost heap and then cover them with the bought stuff. I always top off the pots with Osmacote slow release fertiliser and a final dressing of 6mm gravel. The gravel looks good and it stops the blackbirds tossing the compost about.

This year for the summer display, I used just six different kinds of plant to fill eight pots and none of them ended up the same. Most of the pots had just two or three different things in them. The manger had four. The manger is mounted on a stone wall that faces south and annuals like it there, with sun on their faces all day. It's lined with the kind of matted coir that is sold for hanging baskets, and is consequently very good at holding in moisture.

Round the edge of the manger I planted a trailing petunia in deep velvety purple. It was just labelled Suntory Collection Petunia Surfinia Blue, but no petunia is truly blue. It was a winner though, incredibly free-flowering and vigorous. By the time I pulled them out, the plants were hanging almost to the ground, a metre away from where they started. The flowers were pleasantly loose and floppy, slightly paler on the backs of the petals than the front. I got them from our local garden centre and hope I can find them again next season.

In between the trailing petunias, also at the edge, I used silvery Lotus berthelotii, an evergreen shrubby sort of thing in the Canary Islands, its home, but a tender, summer-only visitor for us in Britain. It's a great plant for containers, especially where it can trail as far as it wants. By the end of the summer, the lotus, like the petunias, was touching the ground and would go on growing indefinitely if the frost didn't come along to stop it. The foliage is very fine, held in little thread-like bunches along the branching stems which

weave themselves in and out of other plants without ever swamping them. The parrot-beak flowers (a burnt caramel colour) come late in the season, but that doesn't matter because the lotus's chief attribute is its silvery foliage. It is less lumpy than helichrysum, lighter-limbed, without fault as a summer pot filler.

Two other plants filled the middle of the manger: a trailing petunia called Sky Blue, much paler than the other, not so frilly, with trumpets almost like a convolvulus, and a non-trailing lobelia of a good clear bright blue with plenty of bright green foliage. Blues can be tricky and putting three different kinds together in the same billet is not necessarily a good idea. But it helps if there is plenty of foliage in the mix, which is why the lotus is such a star.

So that pretty much was the theme: pale blue petunias and a very dark lobelia (dark-flushed leaves and deep blue flowers) in the pots by the porch; pale and dark-blue petunias with the dark lobelia in the pots by the front door; dark petunias with the mid-blue lobelia in the Chinese pot; dark lobelias with lotus in the pot on the terrace, with a variegated geranium (the sixth plant) in the centre. The best is 'Lady Plymouth' although it is slow to get going at the start of the season. By the end of October, 'Lady Plymouth' has made huge, buxom mounds of growth, but I've nowhere to overwinter such bulky plants. We take cuttings instead, which take up a tenth of the room.

So now I'm looking at bare pots, which is a pity, but dreaming of the outrageous show to come: double late 'Black Hero', the best dark tulip I've ever grown, 'Weber's Parrot', a sneezing fit of white, pink and green madder than you ever thought a flower could be, elegant 'Meissner Porzellan'. Roll on spring.