A potted lilac on a garden center bench may be ready for the ground when the local planting window opens. Timing, depth and spacing help the shrub settle in after planting. Planting time changes with lilac type and local climate.
When Is the Best Time to Plant Lilacs?
Use local guidance to choose between fall and spring planting.
In Iowa, early fall before the ground freezes is the recommended time, which gives the roots cool soil to settle into before winter. In Utah, spring is a good time to plant. Late lilac is a spring planting as well.
The state selector right under this section takes you to the page for your state.
From the almanac
Lilacs in your state
The dates on this page depend on where you live. Your state's page carries its frost dates, its USDA zones and the year laid out month by month.
Northeast
Southeast
- Alabama
- Arkansas
- Delaware
- Florida
- Georgia
- Kentucky
- Louisiana
- Maryland
- Mississippi
- North Carolina
- South Carolina
- Tennessee
- Virginia
- West Virginia
Midwest
Southwest
West
Pacific Northwest
Canada
How to Plant a Lilac Bush
A careful planting order protects the roots at each stage.
- Pick a sunny, well-drained spot, so the roots never sit in standing water after a heavy rain.
- Mark each planting spot by the job the shrub will do, so full-grown plants have room and do not crowd one another.
- Dig a hole wider than the root ball and no deeper, then set the shrub at the same level it grew in its pot.
- Loosen any roots circling the root ball with your fingers, so they grow outward into the new soil instead of around themselves.
- Backfill with the soil you dug out and firm it gently, so air pockets collapse and the roots touch soil on every side.
- Water right away, so the soil settles around the roots. In Wisconsin, the advice is to keep watering two to three times per week for the first month while the roots take hold.
Spacing depends on what the lilac is meant to do. In Iowa, space specimen shrubs 10 to 15 feet apart. A hedge there goes in 5 to 8 feet apart. In Minnesota, a shrub border is spaced about 8 feet apart. In Montana, a six- to eight-foot hedge asks for two to three feet on center, and a very tall, informal hedge can stretch to six feet.
Planting Time by Lilac Type
Different lilac types can require different planting windows and spacing. A shrub grown for a hedge is spaced differently from one standing alone.
| Lilac Type | What changes | Why it matters |
|---|---|---|
| Common lilac | Grows into a large shrub, so it gets wide spacing | A full-grown shrub needs space around it to spread without crowding its neighbors |
| Late lilac | Planted in spring, with the room its mature size needs | It is a tall shrub too, so it still needs space around it |
| Lilac grown from seed | Seeds are sown in March or as soon as they ripen, in a cold frame | Warm, then cold stratification before sowing improves germination |
Some unrelated plants also share the name. In Texas, Vitex grows best in full sun with good drainage. In western Oregon, California lilac belongs only in un-irrigated spots in the garden. Check the plant tag first, because a spring or fall rule for common lilac does not carry over to these. For a shrub that matches common lilac, plan the window and the space it needs before you buy.
Lilac Planting Mistakes to Avoid
Planting Too Close to the House
In Montana, lilac roots can damage foundations over time, and a shrub tucked against a wall is hard to move once grown. In Montana, the advice is to keep lilacs at least five feet from buildings. Measure from the wall to the center of the planting hole before you dig.
Planting in Wet Soil
A spot where water lingers after rain leaves the roots sitting in soggy ground, and the shrub suffers there. If your yard is low or holds water, choose a slightly higher, better-drained place or build up the planting area before you set the shrub in.
Skipping Fall Water
In Wisconsin, a lilac planted in fall can dry out over winter when rain stays away. In Wisconsin, the advice is to keep watering weekly until the ground freezes in late fall if no rain has fallen. Check the soil near the roots before each watering.
When to Plant Lilacs in Your State
Planting windows vary, so use your state page to match the season to your area. The months differ from one state to the next, and each state has its own page.
- Use the state selector to reach your state’s page, then read its lilac months before you buy a shrub.
- Check that page while the soil is workable and before you buy the shrub.
Common Questions
Can You Plant a Lilac in Summer?
Use the planting window recommended on your state page rather than assuming summer is suitable. In Iowa, early fall is recommended; in Utah, spring is a good time.
What Soil pH Do Lilacs Prefer?
In Washington, lilacs prefer a soil pH of 7.0 to 7.5. In Washington, that is much more alkaline than the soil occurs naturally in the northwest. A simple soil test tells you where your yard stands before you plant.
When Should You Fertilize a New Lilac?
In Washington, the advice is to apply a fertilizer high in phosphorus in early spring.