The potato vine starts to flower in late July and August, producing clusters of pure white flowers – so white that they could be made of sugar icing. They have a crystalline quality that positively sparkles.

The plant continues to flower into early winter, depending on the weather, and, apart from climbing roses, it has the longest flowering period of any climber. The flower clusters are carried generously on most specimens seen in gardens. Even at the tail-end of the display, there can be a good show going on.

While the flowers have a considerable similarity to those of the true jasmine, they are not related. It is part of the potato family, having the name Solanum jasminoides, while the potato’s botanical name is Solanum tuberosum, so it is very closely related.

A close look at the individual flowers shows how similar they are to potato flowers, including the central tube-like group of yellow, pollen-bearing anthers, a feature which true jasmine does not have.

Potato jasmine is often credited with having a jasmine-like sweet scent, but the flowers of most specimens are not fragrant or do not seem to be. But this could be due to different clones, time of day or the temperature. In any case, this is such a good plant, that this failing does not hugely diminish its value.

Like many members of the potato family that are grown in gardens, the potato vine comes originally from South America, and is native to Brazil. It is not fully hardy, but it is not tender like potatoes, tomatoes, nicotiana, petunia and others.

In fact, it survives remarkably well in gardens. It has been known to tolerate frosts of –10°C, which is much colder than occurs during most winters in a wide strip around the coast, only being surpassed in cold inland areas.

In areas where hard frost is likely, this special climber can survive on a wall that offers some protection from the worst frosts. It is noticeable that young stems of this plant that are close to a wall start into growth earlier in spring.

Potato vine can be evergreen, or nearly so, semi-evergreen or deciduous, losing some or all of its leaves, depending on the weather’s harshness. Cold winds can cause leaves to fall as well as frost.

Some of the smaller flower-carrying shoots can also be killed, but the main stems usually survive and sprout to make new flowering stems the following year.

While it thrives in a warm sunny location, flowering most profusely, it can be a great success on a north-facing wall, getting little or no direct sunshine all day. It might be a bit slower to begin flowering on a north-facing wall, but it will carry on late in the season.

The usual form seen in gardens is white-flowered, but the species also has white flowers flushed with blue. This is very pretty, but it is only occasionally seen in gardens. White potato vine is a very easy plant to grow and easy to propagate from cuttings in summer.

It will grow well in any soil that is not too heavy, although a lighter soil will promote more sturdy growth that is less likely to be damaged by frost.

It can grow quite large, to more than four or five metres high on suitably solid support. It looks good on a bower or pergola too. It is generally quite vigorous and tends to swamp other climbers, so give it enough space to expand.

It would be best to wait until spring to plant, as young plants can be vulnerable to frost damage. Clip away frost-damaged parts or surplus growth in spring. CL

Virginia or Boston?

Virginia creeper is a popular, self-clinging creeper for walls and it has been showing autumn colour very early this year. Every year, it makes a wonderful display of orange and red leaves on walls and house walls and it looks great when it is allowed to scramble up a large tree that can take the competition.

However, it is often confused with Boston ivy, which is closely related, but comes from China, not Virginia.

The Virginia creeper has five separated leaflets, while Boston ivy has undivided, three-pointed leaves. Both are related to the grapevine and can lose leaves due to grape mildew, ruining the autumn display because the affected leaves are shed ahead of their time. Rose sprays, applied to the new leaves next year can help.

Flowers

Soil conditions are ideal for sowing hardy annual flower seeds, as it is warm and moist. Buy and plant spring bulbs as soon as possible. Put some coarse sand under the bulbs when planting tulips, alliums and lilies and only plant in a well-drained area to avoid rotting.

Trees, shrubs and roses

Young trees and shrubs have enjoyed the sunshine and showers this summer and have grown well in most cases. If you are planning to plant trees or hedges this autumn, prepare now by controlling weeds and grass with glyphosate-based spray, and plant into the dead sod.

Fruit, vegetables and herbs

Pull up overgrown vegetables and compost them, if they are not diseased. Take the opportunity to clear out weeds. Plant spring cabbage now, as it benefits from making root growth while there is still a little heat in the ground. Lift potatoes if slugs become more active.

Lawns

There has been good growth of grass. Keep mowing as necessary and remove fallen leaves in the process. If the lawn looks a bit tired, apply autumn lawn fertiliser or a low N, high K product to strengthen grass before winter and increase soil fertility for the following year.

Greenhouse and house plants

Greenhouse tomatoes are ripening still, and it is worthwhile to leave them for another few weeks. Remove flowers and small fruit. Be careful not to over-water from now on. The soil and compost should be just moist, not wet. Open the vents on dry, breezy days.