Sunday, April 25, 2010
How does your garden grow? Part 8: Lilacs.
You know winter is over when you see the pretty Daffodils, but you know for sure it's spring when the Lilacs bloom. These lovely, various shades of purple and white, heavenly scented blooms are popping up all over NEW and many other parts too.
It used to be that you needed almost a winter freeze to bring the blooms of this woody shrub completely out of their buds. Not so anymore. They grow best in zones 3 - 7, but can be found pushing the boundaries of these zones. There are over 20 varieties and many can now be grown in warmer climates. I've had the pleasure of growing up with these in my yard and I have them in my yard now as an adult. I've seen them as small as a dwarf bush all the way to a 12' x 12' tree or even bigger with select varieties.
They like to grow in full sun, but I have found they can handle part shade too. Lilacs like neutral to slightly alkaline soil. You can buy test kits at your local garden center. If it the first year planting keep then well watered. After that they are very drought tolerant. On older bushes you should prune them regularly and rid them of suckers found around the base. You can plant these elsewhere to start more Lilacs if you'd like. You do not have to remove suckers, but should at least remove old wood. This will promote new growth. New growth = more blooms. It's pretty much up to you. If you aren't happy with your Lilac, usually just giving it a hair cut will improve it greatly. One more reason to prune is that if you don't and you let your Lilac tower above you--well so will your flowers. Enjoy the view from waaay down here. Or go grab a ladder. If you don't want to climb to pick them then you should prune.
Pruning is easy. The rule of thumb is to not remove more than 1/3 of the bush at a time, but if someone goes crazy with the trimmer it will more than likely come back. Maybe just not as vibrant as the year before. You should also do it as soon as the blooms have faded. You can wait, but just don't do it at the end of summer or fall. The shoots will have time to develop better this way. Also, Lilacs set their buds for next year as soon as this years flowers fade. So sooner is better. It's best to remove suckers, thick (over 2"), woody branches, and any dead or diseased branches.
Lilacs don't really have any insects that like to bother it. Mice and voles are attracted to their bark so you shouldn't mulch around them until they are well established. You can also use screen as a protectant at the base. If the summer is very humid or damp powdery mildew can be a problem. You can treat it with a fungicide. Watering from the ground and not directly onto the leaves helps. Sometimes you will get borers that like the old wood. This would be another reason to prune Lilacs. Leaf miners aren't a fatal problem. They just don't look the best. Scale can be a nuisance and can be treated with oils that can be found at garden centers.
One last thing. If your blooms aren't as awesome as they were last summer, it's okay. This happens. Maybe last summer was very stressful on your Lilac. Maybe there wasn't enough water and the temps were over 80 everyday. This will affect your blooms for the following year. Lilacs are pretty easy to maintain and will brighten someone's day if you bring them some of these flowers. Even if that someone is you. I can't resist picking them and putting them in a pretty vase on my dining room table. Oh the scent! Soon. Very soon.