Wednesday, July 3, 2013

Sandra's Garden: The Last One

Species name: Syringa vulgaris

Common name: lilac

Location: Sandra's garden

Lilacs are some of the most easily recognizable shrubs used commonly for ornamental purposes. They have large heart-shaped leaves (although, not all plants that have "lilac" as a common name have heart-shaped leaves...), purple to white flowers, and the flowers have *THAT SMELL* that you smell it once and you never forget it. To me, it smells exactly like Myrtle Beach in South Carolina because that's the first place I was ever made aware of the smell; I remember walking to the beach from the camp ground past what must have been lilac bushes and a pond with baby ducks and snapping turtles that would eat the ducks. Thankfully I never actually witnessed a duck being eaten or else it might have scarred me for life. But I feel like I remember there being pens that people would keep baby ducks in so the turtles couldn't get them. Maybe I'm just making things up...this was back when I was 5 or 6 years old. I can barely remember last week!

And back to lilacs. They are native to Europe, from Croatia east to Moldova and south to Albania and Bulgaria. They had been introduced to the rest of Europe centuries ago and lilacs are now considered naturalized to most countries throughout the continent. The earliest settlers to North America brought lilacs as ornamental species, and so they have also existed in North America for many, many years. They are also considered naturalized here (it's even the state flower of New Hampshire), and have very little chance of becoming invasive since so few of their seeds are fertile. Normally you'd think a plant wouldn't do very well in the wild if the majority of the seeds being produced wouldn't be able to grow a new seedling, but this is relatively common in ornamental species (especially shrubs) because of their history of domestication: it was recently discovered that lilacs are actually hybrids of two drastically different species. When you hybridize two species that are closely related sometimes you don't even notice a reduction in fitness (or a reduction in the number of viable seeds being produced, which is a reflection of the potential number of offspring a single shrub could produce, called "fitness"). When you hybridize two species that aren't closely related then usually this reduction in fitness is quite drastic, if the hybrid takes at all. This hybrid shrub was likely a natural hybrid when it was first produced, and was since propagated over time.

Pruning lilacs is an art form to make sure it keeps flowering. If you just whack off the entire shrub at ground level (strangely enough, a "hard prune" is recommended by most garden centres for lilacs at least once every three or so years), you'll get a very "spotty" flowering on your shrub; these plants flower best on old growth. If you're cutting it off all the time, you're eliminating the possibility of getting really showy lilac flowers in the spring. The other side to this story is that lilacs can grow quickly if in optimal conditions, and so they can get to be an enormous size if left unchecked for too long. Dead-heading branches where flowers have been after flowering but before developing seeds can remove the branch's ability to extend further while at the same time promoting flower growth in later years. Win-win! Something to keep in mind too is that lilacs flower best every other year. So if you get one bad year, don't fret! A good one is probably on its way the next year.

If you like the idea of a lilac but absolutely cannot risk having a non-native plant escaping from your yard into a natural area, you could always plant a "doubled" cultivar. These cultivars have been selectively bred to have their stamens (or the "boy parts" of the flower that produce pollen) replaced with petals, so there are eight petals in each flower instead of four. If a flower doesn't produce pollen it cannot produce seeds, so this is a great way of planting a lilac for the smell without worrying about the plant getting away from you.