Dahlia imperialis

Dahlia imperialis, the giant tree dahlia, is native to Mexico and Guatemala where it can grow up to 30 feet tall! In cultivation it more commonly reaches 10-20 feet. It is a very late bloomer with 3-4 inch wide, single, lavender flowers. This imposing oddity is hardy in coastal BC if grown in warm microclimates protected from winter rain such as up against the foundation of the house. Or grow it in a large pot and place as a specimen in the garden. It likely will not flower if grown outdoors year round though the imposing size is a great subtropical garden feature. If in a pot it can be brought into a greenhouse, sun room, or bright window where it will usually flower in the winter.

The Tree Dahlia is the tallest member of the Dahlia genus and is native to high elevations in Mexico and Central America. Because of its upland habitat, this species is surprisingly cold hardy and flourishes in many temperate climates. Rapidly reaching heights of up to 20 feet in one season, you can literally watch the canes grow throughout the day. The Tree Dahlia has tubers and will die down during the winter making over-wintering similar to other Dahlias. Cold hardy to zones 7b and above.

If you've heard of "tree dahlias" these are the plants being referenced. Maturing to a huge 8-18 feet in a single season, Dahlia Imperialis looks like nothing you've ever seen before. Six inch pink flowers are held in loose groups that are 2-3 feet across. Plant where growing season are very long (or extend the season by starting indoors) - these dahlias need 7-8 months to blooms. Some gardeners grow for the bamboo-like stems and use for landscape effect. Happy in mild West Coast locations where they grow with wild abandon. Why Grow Dinnerplate Dahlias? Few flowers offer the color and form diversity of dahlias Dahlias are garden showgirls; this variety easily reaches the eaves of a ranch home. Stake plants to support super tall stems and flowers; see Dahlia Planting Guide for tips Dahlia tubers can be saved, divided and shared. Click on the Dahlia Planting Guide button, right, for details and growing tips.

This rather imposing tree dahlia reaches roof height (12-15 ft a season). The pink flowers are always a gamble, though. It blooms after Thanksgiving and only in mild years will it not frost before bloom. Half sun, normal water. Stake it.

Tree Dahlia. I mean it - TREE Dahlia. This holdover from the Pleistocene reaches 20' tall with good rich soil making impressive Bamboo-like clumps with very thick stems. The flowers are the size of garbage can lids - no I'm kidding but they should be. Average size and pale lavender.

A real traffic stopper! This magnificent species Dahlia from Central America grows like a weed here in California. So why is it so hard to find? To at least 8' tall, it can reach 20' when happy. In areas with cold Winters, some gardeners include this monstrous beauty just for its foliage! The tall canes are bamboo like, with lush leaves. The flowers, though, the flowers!! Each lavender pink bloom can span up to 6” & the massive flowering panicles can be 3' across - and mind you that is per stalk! Large plants can produce an abundance of flowers both alarming & astounding when you stand underneath them in full bloom & see them all looking down at you. Wonder! Cut back to 6” after it has finished blooming. Cold hardy and tough as nails.