Clematis armandii is a great favourite of mine but, it has its drawbacks. First of all, it is not the hardiest member of its tribe, and being evergreen, once its foliage becomes frost damaged this becomes a permanent feature.

Although it is said to prefer full sun, it is in this position that damage is most likely to occur; not just frost damage on cold nights but also from sun burn too. Bob Brown, from Cotswold Garden Flowers, firmly believes that clematis armandii will thrive on a north-facing wall and I really do not see why it shouldn't, so bearing in mind that I now have considerable wall space to fill in the garden here, I shall try this for myself.

It is also a very vigorous variety too, easily covering a wall space of around 5 x 5 metres (16 x 16 feet), but this can be controlled and the large amount of growth easily manipulated – it's really just remembering to prune at the right time. Clematis armandii flowers in April on its old wood that was made the previous year, and that is your clue to its pruning regime. As soon as its flowers are on the wane that is the time to get busy with the secateurs but, even then, the plant will have already begun to make new wands of fresh, young, vigorous growth. However, don't let this bother you for to retain any semblance of order you need to prune all the old growth back hard.

What exactly is meant by 'pruning hard'? Well this cannot be measured exactly, and to a certain extent you will have to learn by experience but, given that this is a very vigorous plant, you will have to relate the hardness of your pruning to the amount of space that can be allowed for this plant to develop. As I am starting from scratch, I shall prune my plant back to a stump, rather like pollarding a willow. As the new growths lengthen they must be tied in neatly throughout the growing season; this will ensure that you get a really good and even display of blossom the following spring. This type of pruning can be made to any clematis that flowers before the end of June, but never be tempted to prune them in autumn, which you might be, for that is the traditional time to tidy the garden.

Clematis armandii in both its pink and white-flowered forms pick really well for the house; their blooms last well in water and you will also enjoy the benefit of their rather wonderful vanilla scent. Of course, if you have a large old tree in the garden, you could plant one to grow through it, in which case ignore all the above information. You can let nature take its course and enjoy great cloudy, cascades of sweetly scented white or pink blossom.In time, your plant will become overgrown and full of old birds' nests. All you will need to do is cut it back every five or six years – if you can be bothered!

Actually, taking this pruning theme one step further, it works equally well with the kinds of roses that are once flowering. These can be pruned in June removing lots or all of the dead and flowered wood; you can be pretty brutal for they will then have the following four months to make new wood on which they will flower next year. After this pruning give your bushes a good dose of a well-balanced general purpose fertilizer, and do remember to keep them irrigated – they will then produce lots of lovely new shoots and become totally rejuvenated.

One rose that really should not be pruned at all hard is the double yellow Banksian rose, for I have known this to take several years to flower as it needs warmth and shelter to build up enough strength to oblige us. It can take several years of tying in the new, long whippy shoots before they ripen enough to flower. Just don't give up on it. I have planted one on the wire netting that surrounds one of our rare breed chicken runs and at the moment am diligently tying in the young shoots. Once this early flowering beauty does decide to blossom, the only pruning that should be needed is the careful removal of the old flowered shoots, as the ripening of the wood is tantamount to flowering. You might help the plant by giving some fertilizer high in potash in midsummer for this aids the ripening process.

Isn't it strange how some people's sense of smell is so much better than others? My sense of smell is low but, at the moment I am enjoying the sharp, sweet scent of daphne bhoula 'Jacqueline Postill', borne on the air from as much as 10 metres (30 feet) away. However, there are some scents that I never get. I remember reading that Christo Lloyd was much taken by the scent of heliotrope that was given off by the foliage of olearia solandrii, and this is further enhanced in its August flowering season. For myself, I have never had one measly sniff of the scent of heliotrope on my plant, although as a shrub I like it well enough, but Graham assures me that he can smell it. It grows up to aabout 2.5 metres (8ft) and it is a shrub that I like very much. However, it is one that gradually creeps up on your consciousness, for when you first encounter it, you might wonder what all the fuss is about.

We first grew olearias here because they are wind and salt tolerant; most of them come from New Zealand which makes them ideal for coastal gardens in this country. Olearia solandrii is not as showy as some, but because its evergreen foliage is very small, each miniscule leaf being olive green on the top with a bright golden underside as are the twigs and stems, the whole shrub tends to glow, especially in the winter when the sun's rays are low. This is why it is one of the stars of our winter garden at the moment, heliotrope or no heliotrope!