Perennial phlox
Phlox paniculata
An ornamental plant, planted September to May.
In September: nothing to do. It can be planted now.
Add perennial phlox to my plot
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Perennial phlox, month by month
Bar: the usual months. Sprout: this month.
| Sowing, planting or job | Sep | Oct | Nov | Dec | 2027Jan | Feb | Mar | Apr | May | Jun | Jul | Aug |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Plant a pot-grown perennial phlox. | usual | usual | usual | none | none | none | usual | usual | usual | none | none | none |
| Plant a bare-root perennial phlox. | none | none | none | usual | usual | usual | none | none | none | none | none | none |
| Cut back the perennial phlox. | none | none | usual | none | none | usual | usual | none | none | none | none | none |
| Lift and divide the perennial phlox. | none | none | none | none | none | none | usual | none | none | none | none | none |
| Cut the perennial phlox stems back by a third to a half. | none | none | none | none | none | none | none | none | usual | none | none | none |
| Deadhead the perennial phlox. | none | none | none | none | none | none | none | none | none | usual | usual | usual |
What to do, and when
The usual months for a UK garden. Your own plan gives the week.
Planting
Plant a pot-grown perennial phlox March to May, and September to November, 60cm apart. Strong sources: RHS and Gardeners’ World.
Plant a bare-root perennial phlox December to February, 60cm apart. Strong source: RHS.
Cut back the perennial phlox
Cut the old stems down to the base.
Usually February to March, and November. Strong source: RHS.
Lift and divide the perennial phlox
Every 3 to 4 years, not every year.
Usually March. Strong source: RHS.
Cut the perennial phlox stems back by a third to a half
Gardeners call this the Chelsea chop.
Usually May. Strong source: RHS.
Deadhead the perennial phlox
Usually June to August. Moderate source: Sarah Raven.
What the source words mean
Strong: the RHS page for this plant is among them.Moderate: another trusted UK source, or the RHS on its group.
Add perennial phlox to my plot
Every line above names the page it comes from. Where we found no good source for a job, we left it out. Where the name “Perennial phlox” comes from.