Yellow clematis tangutica

(Question)

Hello there
is clematis tangutica – yellow available during Spring/Summer in Garden centers in Toronto? I never seen yellow one. Thank you very much.

(Answer)

Dear gardener, thank you very much for your question which gave me the opportunity to learn more about different clematis varieties, some varieties of which have been declared invasive species.

The Clematis tangutica is a late-flowering beauty with the common name golden clematis or sometimes orange-peel clematis, due to its thick yellow petals (really: sepals). C. tangutica is a very vigorous deciduous climber with small, bright green, coarsely toothed divided leaves. Nodding, lantern-shaped single, golden-yellow flowers that are 4cm long appear in early summer and autumn, followed by huge, silky seed heads from autumn through winter. It is easy to grow, grows easily up chain-link fences or trellises, and flowers dependably.

In direct answer to your question, after doing a search of local nurseries in Toronto, I could not find clematis tangutica listed very frequently. This could be a function of not-very-strong search engines, or that it is too early in the season for nurseries to know what they will be able to obtain in the spring (considering the issues with supply lines due to the Covid pandemic), or thirdly, that Toronto nurseries are no longer carrying this variety of clematis. I did find it for sale through some Canadian mail-order nurseries. May I suggest that you use “Clematis tangutica for sale”) as the key words in your search engine and you will get some links. It is a bit problematic for the Toronto Master Gardeners to recommend any particular nursery.

However, you should also be made aware that there is a growing trend that is identifying clematis tangutica as invasive. If you see a photo of the plant in the fall when it is in seed, with the hugest seed production, you will understand why. It self-seeds easily. The plant can also propagate vegetatively just from its stems. It used to be grown at the Toronto Botanical Gardens, but there are no photos of the plant on their website indicating that it may have been removed. So far, only Alberta has declared it an invasive species, but some US states have also listed this creeper and its synonym (or close relation?) Clematis orientalis as invasive.

An alternative clematis suggested by the Ontario Invasive Plants organization is the Jackman Clematis (Clematis x jackmanii), although it is purple and will not give you the wall of yellow that you desire. Another group of clematis is the Alpine clematis, and although their flowers are also in the purple range, the shape of their flowers is the interesting nodding lantern-shape of the clematis tangutica.

As a totally different idea for a vine that will give you yellow flowers, consider Dutchman’s Pipe (Aristolachia macrophylla) which is a perennial vine that can grow to 9 metres. It has a unique pipe-shaped, yellowish flower that blooms in late spring and summer. It has very attractive dark heart-shaped leaves.