Blue Potato Vine; aka,
Climbing Chilean Potato Tree
"The paths reached tendrils to my hair
From every vine & tree.
There was no refuge anywhere
Until I came to thee."
-Josephine Preston Peabody
(1874-1922)
(1874-1922)
The Blue Potato Vine (Solanum crispum glasnerium) scarcely looks like a potato, but is indeed a cousin to the kitchen potato (S. tuberosum).
Calling it a Potato Vine still strikes me as odd; as well to call it Eggplant Vine since it's equally related to S. melongena, or Deadly Nightshade Vine since it's related to S. dulcamara.
It's not quite exactly a vine, either, hence its alternative & rather whimsical-sounding name "Potato Tree."
It is often described as a "wall shrub," which best captures its nature. It gets round & bushy, so has to be annually trimmed back to the wall to retain a semblance of vining appearance. It's best to prune it closer to the trellis every spring, taking care not to harm saved bits since these may be brittle. It grows rapidly & blooms profusely after such a trim.
As a Wall Shrub, it's hard to beat, thickly covered over with clusters of the brightest blue & orange little blooms, with rapid growth to the considerable height of ten to fifteen feet in a single year.It is nearly evergreen in warmer climates than ours though best described as "semi-deciduous" around here. If the main woody vine is trained well, it thickens up with lovely twists & turns, so it can look interesting in winter even if it behaves deciduously in chillier zones.
Ours made it through its first winter without going entirely dormant, so was in fact fully evergreen & even produced new fresh leaves. As it is growing so near a window & the trellis is attached to the house, with full morning to noon sunlight, it is not too likely to experience any cold stress even if we occasionally have much colder winters in years to come.
Knowing it was going to get quite large & requires a sturdy trellis, Granny Artemis built it a splendid nine foot tall trellis & stained the wood a cedar color. She designed the trellis so well, it looks like it came from the Rich People's Garden Shop.
Our freshly planted potato vine looked a little whimsical reaching only to the second rung of such a big trellis, but not to worry, we well knew it would grow & soon enough a nine-foot trellis would seem minimal to sustain it. Sure enough, in the following spring (2003) it shot right to the top of the trellis & then some!
Even its first year, as such a young vine, it was gorgeous, already covered over with blooms. The "Glasneria" variety is bluest of all, & hugely deserving of its Award of Garden Merit given by the Royal Botanical Society. The second photo shows it in May 2002 when we'd only had it a little while & it had only climbed a couple rungs of the trellis.The third photo from June 2003 shows a segment of the already huge shrub. In a single year it completely filled the trellis. The purple-black leaves in the background is from the Black Swan Beech.
The Blue Potatoe Vine has at the same time grown outward from the wall to as much as a five-foot overhang, which I've had to trim repeatedly; although, because it is overhanging a sump-pump cap, it's nice to have that obscured, so I let it grow further from the wall than is usual.
Pruning incites increasingly vigorous new growth & floweriness. I've several times put up a ladder in order to bind parts of the wall-shrub to the trellis. It's hard to say if it's in the main climbing the trellis on its own, or if it functions as a "vine" mostly because I'm training it to espalier.
The bright blue blooms begin in May & continue clear to September or even October (until the first heavy frost). In warmer areas it likes a bit of shade, but ours has full morning to noon sun since we're on the low end of its temperature tolerances, & we knew that good light & placement up next to the house would be best for it here.
In late August & September, it becomes covered over with yellow-orange berries, soft as tomatos, but hideously bitter tasting & mildly toxic. The berries can be seen on the Blue Potato Vine Page of the Berries Gallery.
Gardeners' reports on its hardiness for zone 8 or chillier are often contradictory. Some claim they found it to be fragile in Zone 8, & others are just as adamant that theirs did spectacularly well even in areas colder than ours. Peoples' varied experiences probably has a lot to do with how well it was situated for its winter experience. If it gets through its first two years fine, it will just be hardier & hardier. Our own experience is that it is perfect for Zone 8, though our having it against the house is possibly part of the reason for its success.