Multiply Your Phlox Plants By Dividing Them Every 4 Years – Horticulturists Show How
Reviewed By COLIN SKELLY
Colin is a Horticulturist and Horticultural Consultant with experience in a range of practical and managerial roles across heritage, commercial and public horticulture. He holds the Royal Horticultural Society’s Master of Horticulture award and has a particular interest in horticultural ecology and naturalistic planting for habitat and climate resilience.
IN THIS GUIDE
Fragrant phlox are wonderfully versatile flowering plants that you can use for patio pots, rear borders, mass plantings, and much more, depending on the particular variety and its height and habit.
In view of phlox’s many merits, you will surely want another plant.
Fortunately, there’s an easy and surefire way to multiply your phloxes: plant division.
| Difficulty | Medium |
| Equipment Required | Gardening gloves, garden mattock or hand-pick, shovel or spade, sharp knife, watering can |
| When To Divide | Spring or Autumn |
In fact, as these plants grow and mature, they form congested clumps so dividing them around every four years will also help spread their blooms out across your garden.
When To Divide Phlox
Phlox should be divided in spring or autumn, with the middle of these seasons being best.
As a general rule, in spring re-plant divided sections in open ground, and in autumn, in pots.
“Phlox will spread out as a circle, eventually leaving a bare hole in the middle,” says Master Horticulturist Colin Skelly.
“To keep Phlox vigorous and prevent it from becoming too big or spreading where you don’t want it, dig up the entire clump and replant the wanted section in the desired position.
“I replant in the ground in autumn or spring, as autumns are now mild enough to allow root growth before the worst winter weather. Any additional plants that you want to keep can be planted into pots.”
You can divide phlox plants by following the steps below:
1) Prepare Pots Or Re-Planting Holes
Prepare pots or holes for re-planting divided plants and till the soil if planting in open ground.
A well-balanced loam with a slightly acidic to neutral pH is ideal.
Pots should have drainage holes and soil should drain very well.
Pre-water the planting area or pots.
2) Water And Loosen The Ground
You may want to wear gardening gloves at this point.
To be able to lift the plant with minimal stress to it, soak the soil around it and work it loose.
Do so by jabbing the ground with a garden mattock or hand-pick, or even a gardening fork.
Be sure to stay away from the roots.
Depending on the size of the particular plant of this very diverse genus, you should start anything from 10-30cm away from the main stem.
Pull away the soil as it is loosened so as to expose the roots.
3) Dig Up The Plant
Depending on the size of the plant and its root system, go around the plant with a shovel or a spade, pushing downward and prising up the plant from below the roots.
Gently grasp the plant around its centre, gently jiggle it to work it loose, and with an assist from the shovel or spade, lift it up, roots, soil and all.
4) Vertically Divide The Plant
Divide the plant vertically into two to four equal sections.
The number of sections you make depends on the size of the plant and its root system.
Separate the stems, first pull apart the upper roots near the crown as well as you can.
After you’ve done this, cleanly cut downwards through the remaining roots with the knife.
5) Re-Plant The Divided Sections
The new clumps should be re-planted promptly.
Re-plant in the holes or pots you have readied, being sure to keep the soil line of the new sections the same as it was in the parent plant.
To stay on the safe side, keep the soil level barely to the top of the main root.
Backfill and firm up the soil, and give the newly-planted sections a good watering.
