Gina Parkinson has failed to grow phlox before, so has she been any more successful this summer?

SEVERAL years ago I tried growing a number of perennial border phlox but without success. They didn't flower and had badly distorted leaves, a possible sign of eel-worm, so I gave up and moved on to other things.

The failure occasionally niggled at the back of my mind, especially when seeing beautiful specimens of these plants in other people's gardens. So last year I decided to try again and bought a couple of plants.

One was a variegated variety, the other a plain leafed, white flowered type. The past tense is appropriate for the first because it failed to appear this summer. There was no sign it had ever had a place in our garden; even the label had disappeared, which is why I have failed to give it a name.

The second plant was slow to start and, when it did get going, the stems were thin and the leaves distorted; it looked as though the eel-worm were still around.

The plant was ignored for several weeks over the summer until, after help from the August weather, I was surprised to see it was looking superb.

The stems had thickened up, the foliage was looking as it should and each shoot was topped with a large clump of slightly scented pure white flowers.

I had by chance made a good selection since Phlox paniculata 'Mount Fuji' is a vigorous, unfussy plant with an Award of Garden Merit (AGM) and H4 rating (see below).

It has grown around a metre tall and will eventually have a similar or slightly smaller spread with flowers appearing between July and September, making it a useful mid to late summer plant.

Phlox prefer full sun and a well drained but fertile soil. Overgrown clumps can be divided in autumn or spring.

Another plant that has done well in our garden this year is a knotweed, labelled Persicaria filiformes 'Variegata'.

Since my research has failed to find this plant listed in any book, including the Plant Finder, it must have been labelled wrongly and I think it is in fact Persicaria virginiana, possibly 'Lance Corporal'.

Thin stems carry rough green leaves marked with a dark chevron and topped with long wiry stems covered in minuscule red flowers.

Persicarias are generally disease and pest free and prefer semi shade and moist soil, although they can also be grown in full sun so long as the soil doesn't dry out. Some species can be invasive and need to be split either annually in spring or when they have outgrown their space.

The Award of Garden Merit

An Award of Garden Merit is given to a plant after it has undergone a period of assessment by the Royal Horticultural Society's Standing and Joint Committees.

An AGM plant must;

Be readily available

Be of outstanding excellence for garden decoration or use

Have strong, healthy growth

Be easy to grow and not need specialist care or conditions

Not be particularly susceptible to any pest or disease

And must not be susceptible to too much reversion.

An AGM is followed by an H rating which refers to the hardiness of the plant. This starts with H1 - plants needing heated glass in the British Isles, H2 needing unheated glass in the British Isles, H3 needing protection from frost in the British Isles and finally H4 being hardy throughout the British Isles.

Updated: 08:50 Saturday, September 11, 2004