Choosing a vine for dappled shade

Question from Veronica:
I am a landscape designer. I have a client who wants to build a pergola and plant an easy vine that will give dappled shade.

His garden is in Sunset Zone 22 or 23. Can you suggest a climber for dappled shade?

Answer from Pat:
For dappled shade from an easy-to-grow climber, I recommend Lady Banks Rose (Rosa banksiae ‘Lutea’). This is an evergreen Chinese species rose with a massive display of small fringed spring flowers, once the climber is mature, and in coastal zones it is easy to grow. It is drought-resistant once established and has no pests or diseases after the first couple of years.

There are several white varieties also and some are fragrant. Lady Banks takes a while to cover a pergola but it will cover a very large one if given enough time. I planted four on my pergola (two white and two yellow ones.) The yellow are doing best and they are now covering over half the pergola. I put reed fencing flat on the top of the pergola under the climber, as I have seen done in Greece to provide shade while waiting for the vine to take over. Eventually I will hire help to stand on ladders and pull down the reed fencing. Meanwhile I have dappled shade.

Lady Banks rose does need to be tied down. For the first three years prune it little or not at all so it can get going but do feed it and tie it to the support. After three years, then prune lightly after bloom to create a second wave of bloom. Then prune harder in June every year to make it grow new wood which will bloom the following year. Do not prune in fall or winter or you get no flowers in spring. Last year all of my Lady Banks roses bloomed twice, in fall as well as in spring. They were in bloom for many months.

Another idea is grape vines. I cannot think of a more charming shade than that provided by a grape vine. I don’t know whether one should consider this and easy choice since it will always need some winter pruning. My recommendation is to plant ‘California Concord’. This grows well here and has pretty fruit. Occasionally birds or wasps may be attracted to the fruit. They can pierce holes in the fruit and then bees or flies may follow if the holes made by birds or wasps make the fruit drip. I think perhaps Concord grapes are less attractive to wasps than some other varieties since the skin of Concord varieties is very thick, but this is just an opinion not based on any hard facts. If the fruit is attacked then I would pick off the bunches wherever they cause problems, and leave other bunches until ripe simply because they are beautiful. Another idea is to plant a fruitless grapevine, such as Vitis californica that turns red in fall. All grape vines of course drop their leaves in winter and perhaps your client will not want a deciduous vine.

If your client decides to grow grapes, he will have to pick the fruit, eat some and give some away or make jelly or juice from it. I know a coastal property—a large garden where the owners have planted ‘California Concord’ on a low pergola high enough to walk under but lower than mine, so it’s easy to reach the fruit and it’s simply lovely seeing it overhead. They have long tables underneath, similar to mine long trestle table but in more than one section. The effect is charming and shade is dappled which is what your client wants.

There is also a tuberous-rooted vine from Africa for which the common name is evergreen grape(Rhoicissus capensis). Though it is not a true grape it has small fruits that look a little like grapes and it has leaves a little like grape vine leaves but rounder. I like this very much on a pergola in a frost-free zone. For dappled shade one would need to keep it cut back so it doesn’t mound up on top. One plant should be planted on every other post to allow for coverage. Vine grows about 15 feet tall and is slow growing but long lived. There is a pergola in La Jolla where it has been growing for 50 years or maybe 75 years.

Another possibility because it naturally lies flat is Mexican flame vine (Pyrostegia venusta). In full sun this evergreen vine blooms from fall to spring with sheets of flaming orange-gold flowers in a stunning display. Stems would also flow off the sides of a pergola, like a curtain providing additional shade from the afternoon sun and a very attractive hanging display. I considered planting this spectacular climber on my own pergola since I like it so much. The great advantage is that it lies flat which roses do not unless tied down and heavily pruned.

Finally I would suggest blood red trumpet vine (Distictis buccinatoria) or Royal trumpet vine (D. ‘Rivers’) since these are long-lived, easy-to-grow, vigorous, bloom in waves in warm weather year-round and can be pruned after bloom to control them and keep them flat. By pruning you can maintain just the amount of shade you want and not let the vine get too thick or overwhelming. Prune these vines in winter to control them and keep them from overgrowing or building up too thick. An outdoor restaurant in San Diego has blood red trumpet vine growing over netting to prevent flowers from falling onto diners sitting beneath the overhead trellis. It has been there many years and due to pruning provides dappled shade.