THE sweet peas gave their final harvest last weekend and were removed from their bed. It was easily done, a swift tug and everything was gone.

It is surprising to see how small the root system is on these plants. How can such little underground things support the upper growth for all those months these plants bloom through?

Sad to see the sweet peas go, but they really had had their day, although one plant does still remain. Instead of being in the middle of a bed, this one has had a warm brick wall to grow against and it has bloomed the best of all.

It will give a few more bunches yet and the tatty foliage is well hidden by a dark leafed clematis for the moment.

Sentiment cannot get in the way of tidying the garden and when the job is done, other plants are often exposed that become the new best friend for a while.

One suddenly on show which had sheltered behind the sweet peas is the tall Verbena bonariensis.

Growing to two metres/six feet or more, this lovely plant has become a very popular border plant over the past few years. Once grown, it is easy to see why.

Despite its height, it is a dainty specimen with narrow, dark green foliage and long, thin stems topped with pom-poms of purple flowers. In the sun these attract plenty of summer insects, including butterflies.

Now that autumn is here mine are cobwebbed, enterprising spiders waiting in their sticky abodes for the next meal to arrive.

Verbena bonariensis is a slightly tender perennial often grown as an annual since a cold winter and wet soil can kill it off. It is worth over-wintering it in the garden in a warm well-drained site, but I always sow or buy a few in spring just in case.

Thick mulch around the crown of the plant will help to keep it safe over the winter. It can be grown en masse towards the back of the border, but it also looks good dotted in the middle or even near the front of a bed. The airy nature of growth stops it blocking other plants, which will happily grow around and through the stems.

The hardy geraniums have also done very well in our garden this year, with at least one specimen flowering every month since the early Geranium phaeum in spring.

At the moment, Geranium soboliferum is doing its best in a sunny spot in a bed recently created. The magenta flowers are similar in colour to Anne Folkard and contrast warmly with the delicate, deeply cut mid-green foliage, which is tinged with bronze in October. The occasional leaf becomes completely bronzed or reddened, echoing the colours elsewhere in the garden.

Geranium soboliferum is unusual in that it requires damp soil and full sun. The leaves droop very quickly if the soil dries out, so constant watering is needed if the soil isn't naturally damp.

Mine was grown in a pot for several years, but it had got too large for the container and dried out very quickly.

The new position should suit it well since the bed is opposite the back door and the recipient of regular tea and coffee swillings, which should keep everything nicely damp.

Gardening TV and radio

Tomorrow

8am, Radio Humberside, Gardening Phone-in. Telephone number 01482 225 959.

9am, Radio Leeds, Gardening: with Tim Crowther and Joe Maiden.

2pm, R4, Gardeners' Question Time. John Cushnie, Bunny Guinness, Pippa Greenwood and chairman Eric Robson are in north Yorkshire where they help members of High Bentham Women's Institute with their gardening problems. The gardening weather forecast is at 2.25pm.

Friday

8pm, BBC2, A Passion For Plants. A new eight-part series in which Alan Titchmarsh takes us behind the scenes at the Royal Horticultural Society's headquarters at Wisley in Surrey.

8.30pm, BBC2, Gardeners' World. Monty Don plants vegetable crops in order to harvest early produce in spring.

Weekend catch-up

OCTOBER is a good time to start propagating shrubs by taking hardwood cuttings.

Hardwood cuttings are simple to do and worth trying with most shrubs, apart from more tender grey green foliage subjects such as lavender and santolina.

Most common shrubs will respond well including buddleja, dogwood, snowberry, privet and forsythia.

Take several cuttings from the shrub to allow for a certain amount of failure, making them 30cm/12in or so in length.

Then trim the top of each of the cuttings with a sloping cut, which will allow moisture to run off, just above a leaf joint or bud.

Trim the bottom of the cuttings just below a bud with a straight cut, leaving them 24-30cm/9-12ins long. The bottom end of the cuttings can be dipped into hormone rooting powder or solution although not all gardeners do this.

Then place in a trench in a sheltered, well-drained part of the garden. The base of the trench can be covered in mixture of sharp sand and compost or soil to aid drainage.

Fill in trench, firm down, water and label.

The cuttings should have formed good roots and be ready for planting into their permanent spot in 12 months. They can be left alone for much of the time, but may need firming down after a heavy frost and watering during dry periods, especially when the weather is warm.