I was walking around town the other day and found two different climbing members of the potato family growing almost side-by-side in a Masterton street. One has flowers that look identical to a potato, while the other has flowers very reminiscent of the native poroporo. They are, of course, both members of the vast solanum family.
This family [known to botanists as the Solanaceae] is very large and includes every kind of plant from an annual to a tree. Some of them are among the most valuable vegetable crops, some are very pretty stars of the flower garden, some plants have psychoactive properties, and some are nasty weeds. A real mixed bag.
We rely on a few of these for our summer gardens. The most famous is, of course, the potato. Still, the tomatoes, peppers, chillies and eggplants are all part of the same family – tomatoes and potatoes are closely enough related for growers to be able to graft one onto the other. Among the ornamentals, petunias take pride of place but nicotiana are also much valued for their flowers, and of course, for their tobacco.
The nightshades [including the deadly one] are also part of the family, as are the psychoactive Datura plants – surely among the prettiest, but also among the most dangerous.
Among the many species is the native poroporo, well-known for its purple flowers, its yellow fruit and its way of leaving slightly too many seedlings in its wake. It is pretty enough and, if trimmed, can make a nice canopy tree to protect newly planted shrubs, but on the other hand, it is not particularly handsome and growing it does result in an awful lot of seedlings.
It also has another drawback – both the leaves and the unripe fruit are poisonous, as is the case with many members of the family. All-in-all, I enjoy seeing this in the environment, but it is probably best left out of the garden.
If you want those purple flowers on an attractive plant, there is an easier way to get them. The Chilean Solanum crispum, sometimes called the Chilean potato vine, is an interesting climber/trailer. It will need tying to a trellis or wires if you want to grow it as a climber, but you can leave it to flop about, as in the case of the plant I found this week. It is happily traipsing over a fence, its clusters of deep lilac petals looking great against its bright green leaves.
This is not seen very often, but it makes a great shrub/climber for the gardener looking for something a little different and also for something that will reliably flower during summer and early autumn.
Just around the corner from the “Chilean potato vine” was the better-known “White potato vine” – S. jasminoides. Those of you who endured Latin in a previous life will know that the “oides” at the end of the specific name means “like”, so this is the potato that looks like jasmine.
And indeed it does. This vigorous climber has masses of 2cm white star-shaped flowers over summer, each with a boss of golden stamen in the centre. Left to its own devices, it can easily reach three meters, so it needs a little judicious pruning from time to time.
In one respect, it fails the “like a jasmine” test – it does not have any scent, but it is hard to beat for a very hardy climber and is generally long-lived.
Both these climbers are pretty tolerant of soil conditions as long as they are not planted in very moist soil. They prefer [like most climbers] to have their heads in the sun and will certainly flower best under those conditions.
There is another pretty member of this family that I sometimes see in Wairarapa gardens – the yesterday, today and tomorrow plant, Brunfelsia pauciflora. The minute you see this attractive shrub in flower, you will understand how it came by its common name – the plant will be covered in lots of small petunia-like flowers, in shades that vary from blue-violet, through mauve and white. As the name suggests, these flowers open with the deeper colour, then slowly fade. Ironically, this is a member of the solanum family that does have a generous sweet fragrance.
Relatively dwarf in habit, it is a great plant for the summer garden. It prefers full sun or perhaps light shade, but needs good drainage and a little bit of water over the hottest months.
It does not like the worst of frost, so pop it into as warm a spot as you can. It has a naturally tidy habit and will not need pruning.
I know it is sometimes used as an informal hedge but is more commonly planted in a mixed bed, with lower growing annuals and perennials.
