English ivy is a common vine we all know well as a houseplant or as an aggressive climber in the shady woodland garden. But ivy does something strange that turns it into an interesting, beautiful shrub for the garden.
When an ivy vine reaches the end of its structure or the top of a tree and it has nowhere further to climb, it matures.
When ivy matures it changes genetically. The leaves lose their lobed points and become rounded. The vine stops being a vine and the topmost part of the plant becomes shrubby and dense.
If you take a cutting from the shrubby mature part of the ivy, it will keep its altered genetic characteristics -- you get another mature shrub form of the plant.
But if you plant the seeds from the mature flowering ivy, you get an immature vine, and you are back to having rampant vining English ivy.
|Immature vining ivy leaf on left / Adult rounded form on right|
I first saw the adult form of ivy at Wave Hill Garden in the Bronx in 2013. I wrote about it here. It was a tidy, elegant, round shrub, flowering in late October. The flowers were yellow-greenish and really interesting; not colorful, but alive with late season bees. The foliage was glossy green -- deepest, darkest, light-grabbing, mysterious green.
|Shrub ivy -- the adult form -- at Wave Hill in late October, 2013.|
This April I found adult ivy -- Hedera helix 'Arborea' -- at Broken Arrow nursery, and brought home two plants to put in the two empty spots along the front walk where the deceased heath plants had been.
These are sometimes also called 'Poetica Arborea' or Poet's Ivy. Pliny in his Natural History mentioned that poets used the adult ivy with its light colored berries for their wreaths. You can look it up.
Louis the Plant Geek has a great write up about Poet's Ivy here. He mentions the need for fantastic winter drainage and some problems getting adult ivy through a cold, wet New England winter.
|Louis Raymond's photo|
Even so, I'm excited about this. I've wanted an adult ivy ever since I saw them at Wave Hill. And I despaired at what to replace the tidy round heaths with, until I found these and thought how perfect the round shrubby shape and dark evergreen foliage would be against the brick garage wall.
The strip in front of the garage gets warm south sun and has pretty good drainage I think. I hope the spot will provide plenty of wreaths for when poets visit my garden.