No, i did not feed them steroids.  The amazing Tree Dahlia (Dahlia imperialis) grows all by itself to 15 feet tall!  This auction is for a rare Double Lavender form (above) with big, fluffy, pom-pom shaped blooms!  Like the original single-flowered form (down below), it is an oversized plant with thick, bamboo-like stems and tropical-looking foliage.  This fast-growing plant really livens up the garden.  People are always surprised when they find out this monster is a Dahlia!

The flowers of this double form are about 5 inches across and are a lovely shade of lavender.  They lack the orange center of the original form, because of the fluffy petals and petaloid stamens.  Each bloom can be slightly different, which makes for interesting discoveries!  The blooms are lightly fragrant.  The plant tends to grow a bit shorter than the original form, topping out at about 15 feet tall.  The attractive stems grow to 4 inches thick and are hollow like bamboo.  The stems were reportedly used by the ancient Aztecs as pipes to carry drinking water!

The original single-flowered form.  This is one plant!

The Tree Dahlia is not really a tree of course, but a tuberous perennial, like other dahlias.  This species flowers late in the year, around November/December, and frost during that time may kill the flower buds.  In winter, you may cut  the plant back to the ground and new growth will shoot up in the spring.  The plant looks great when grown next to my double-white Tree Dahlia, or all by itself.

The huge stems

Tree Dahlia will flower in Zones 8 to 10, although it's known to flower in Zone 7b in warmer years.  The tubers are said to be hardy to 20-25 degrees F (-7 to -4 degrees C) if planted deep and well-mulched.  Or just move the tubers indoors for the winter.  Protection from strong winds is recommended, as the new shoots and flower sprays are fairly delicate.  Either full sun or a half-day of sun is fine.

Check availability

Tips on growing this plant