Hi there. I garden in zone 5b in Whitby. I have a gentle south-facing slope with clay soil. I removed a ‘Sensation’ lilac sucker last year, and planted in my front yard garden. However, I’d like to move it to my backyard where it’ll have more space to grow, and I think it will do better. My backyard is gently south facing and has clay soil, however, I can amend it. The plant is not more than 3 inches tall and I was wondering, approximately how long will it take to bloom?
Thank you for contacting the Toronto Master Gardeners with your question regarding your plans to relocate your Lilac shrub sucker. Lilacs are a real joy of spring and their smell is glorious.
Since it is only 3 inches tall, your sucker may not be ready to be transplanted. The advice is to let a sucker grow where it resides for a full year to develop its own roots, before you transplant it. Early spring, while the parent plant is still dormant, is the time to sever the sucker from its parent plant. However, it seems that transplants may not bloom for the first 5 to 7 years.
When you buy a lilac bush in a nursery, they are usually about 3 feet tall, and are flowering. According to Michael Dirr’s “Manual of Woody Landscape Plants,” lilacs are considered to grow at a medium rate which would be between 13 and 24 inches a year.
From what I can find, you can also start a new lilac bush from a cutting, but if you want a flowering shrub, there is a bit of a process. The Cornell Cooperative Extension recommends that you graft the cutting onto an existing root stock from an older plant. They do say, however, that this is a lengthy process that usually takes months in a greenhouse where the grafted plant is under cover so that it does not dry up.
When you do transplant the sucker, make sure that you water it well. It will need a great deal of water to establish new root systems in its first year. I would advise watering it deeply twice a week – slowly pour out one pail of water each time. It may take a month or more of doing this, but I think new leaves will appear.
You mentioned your clay soil. Lilacs prefer well drained soil, so I am glad that you said you could amend the soil where you plan to relocate it. They also seem to like composted soil, but not fertilizer.
Toronto Master Gardeners have a couple of Garden guides that you may find of interest.
“Blooming Deciduous Trees and Shrubs” https://www.torontomastergardeners.ca/blooming-deciduous-trees-and-shrubs/
“Ornamental Shrubs for Various Light Conditions: A Toronto Master Gardeners Guide”. https://www.torontomastergardeners.ca/gardeningguides/ornamental-shrubs-for-sun-a-toronto-master-gardeners-guide/