How to Grow Lilacs, it is easier than you think.
You need to know how to grow Lilacs if you want to add this favorite Spring shrub to your cottage garden. I have also shared how to Propagate Lilacs from Suckers and Rooting Lilacs from cuttings, in other posts.
Why Grow Lilacs
Spring just would not be Spring in our neck of the woods without the sweet scent of Lilacs wafting around the neighborhood. Scent is an added element to our gardens that bring us such sweet delight. Lilacs thrive on neglect and provide such a great way to welcome the coming of Summer.
Most of the Lilacs here were planted back in the 40’s when this neighborhood was established and they have thrived. The variety of colors is wonderful along with their being both single and double (also named French Lilacs) type.
Singles & double Lilacs
This photo below is an example of a Single Lilac flower (you can see the individual flowers clearly).
Next is an example of a Double or French (it is harder to tell the individual blossoms apart, they are so jammed together). It reminds me of the fur of a French Poodle.
Neglect is Good
All of the Lilacs in my photos are planted in areas that get little or no watering in summer . They live off of what they get through the winter and Spring. We rarely get summer rains. Many of the lilacs are quite neglected as they are on properties that are not lived in.
I live in Zone 8, on the colder end. In winter we can get down into the teens with plenty of rain and snow but on average winter lows are in the low 30’s. In the summer time our temps range in the upper 80’s with a few 90’s tossed in here and there. Keep in mind those are the averages, we do get weird years where we have some hotter days for longer periods of time.
The Lilacs in my neighborhood bloom within a week of each other and though the blooms on each bush only last a few weeks the succession lasts for about 5 weeks. So if you wish to get a longer bloom time be sure to plant varieties that bloom at early, mid and late season.
Pick Lilacs for your Zone
For healthy lilacs plant a variety suited to your Zone…these heirlooms (Syringa Vulgaris) grow best in Zones 3 – 8 (I have seen some old lilacs flourishing lower down the mountain so this is a bench mark and not a hard and fast rule)
If you live in a warmer zone that does not get the winter chill needed for the heirloom lilacs to bloom there are some newer Hybrids just for warmer zones.. here is a link to some.
I have read these are good in Zone 9 but I have not tested them, I do believe they grow these in Descanso Gardens in Southern California but I have yet to verify by visiting.
There are hybrids bred for compactness for the smaller garden called Dwarf Lilacs. Some claim they are superior to the heirlooms as they don’t take as long to bloom and maintain a more tidy appearance in the garden, they even have cute names like Miss Kim, Tiny Dancer and Tinkerbell Lilac. I have yet to try either so I cannot say whether they really are superior or not.
If you start your lilac from cuttings be aware that you won’t get blooms for about 3 years and they can take up to 5 years. So the buying a potted Lilac may be the ticket for you if you are impatient.
1. Choose a sunny spot (6 hours of sun) if you are in a very hot summer area they may like some afternoon shade
2. Well drained soil (lilacs do not like wet feet)
3. Neutral PH to slightly alkaline soil
4. Spread out the roots when planting your container grown lilac in the ground so dig your hole a lot larger than the diameter of the container it is in, some say to plant it deeper than it was in the container by 2 inches and some say level to the ground around it. You decide on that one.
1. Do not over fertilize. Spread some compost around the base in late Winter/early Spring and you can add some after they have bloomed or later in summer. If you over feed them you will get lots of green growth but no sweet smelling flowers! (we have snow on the ground in late winter/early spring so nothing is added to them at that time in our neighborhood)
2. The first year keep it watered through the summer, no more than an inch a week, to get your Lilac established then after that be light handed on the water.
3. After your lilac has finished blooming trim or prune to shape it. Don’t wait, if you prune off the new growth that comes soon after the bloom you will sacrifice next years flowers. It is not necessary but to me a good idea to prune back to eye level. What is the point of blooms way over your head and these heirloom lilacs can easily get to 20 feet tall.
When pruning cut out any dead or weak canes, cut out 2/3rds of the suckers coming up at the base, leave 1/3 for future blooming stems. You can actually dig them up and pot them to make more lilacs if you wish, they actually mature faster than taking cuttings and rooting them. Some say to have only about 10 canes per bush for best health but not sure how correct that is.
What if your Lilac refuses to bloom?
This may sound strange but it has worked for so many on different flowering shrubs and fruit trees. Visiting a local nursery I spotted one of the workers whacking the potted lilacs with a rubber hose. I had to ask what in the wide world he was doing and he explained he was promoting blooms.
I thought he was pulling my leg but then he explained that by beating the plant (not enough to break through the bark) it makes it think it is dying, goes into survival mode and in turn flowers.
On larger trees and shrubs you can use a wood stick or 2 x 4 lumber, again not hitting hard enough to do damage to the trunk but hard enough to wake it up. As he was explaining it to me I remembered my uncle had told me to do that to some tomato vines I have that were not producing though they had all the right conditions. Obviously a tomato plant has a much more tender base and I did not use a 2 x 4 but I did use a bamboo cane to give it a good beating and it worked. From then on it bloomed, set fruit and was productive.
If your Lilac is not blooming try and give it a good beating about the base and see what happens! You might be pleasantly surprised.
Here is to a sweet smelling garden!
Are you a fellow flower lover? My favorite garden book of the moment: Floret Farm’s Cut Flower Garden
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All About Lilacs