Repotting guide

When & how to repot Phlox drummondii 'Intensia Cabernet' (Phlox drummondii 'Intensia Cabernet')

Also called Intensia Cabernet Annual Phlox, Cabernet Drummond Phlox.

More about phlox drummondii 'intensia cabernet'

About Phlox drummondii 'Intensia Cabernet'

Phlox drummondii 'Intensia Cabernet' · also called Intensia Cabernet Annual Phlox, Cabernet Drummond Phlox · flowering

'Intensia Cabernet' is a vigorous annual phlox bearing masses of rich wine-red blooms over a tidy mounding habit from spring to frost. More heat- and humidity-tolerant than older phlox, it self-cleans, resists mildew well and flowers without deadheading. Pet-safe and pollinator-friendly, it suits containers, borders and baskets in full sun.

Mature size: 25-40 cm tall and 30-40 cm wide

Watch for — Root rot: Caused by waterlogged soil or overwatering. Plant in free-draining medium and let the surface dry between waterings.

How to tell phlox drummondii 'intensia cabernet' needs repotting

Repotting on a calendar is less reliable than reading the plant. For phlox drummondii 'intensia cabernet', watch for these signs:

Roots spiralling thickly out of the drainage holes or pushing the whole plant up out of the pot.
The pot is so packed that water runs straight through in seconds and barely wets the soil.
It has split a plastic pot, or the rootball is a solid mass with almost no soil left when you slide it out.
Growth and (for phlox drummondii 'intensia cabernet') flowering have clearly stalled despite good light and feeding — but remember this plant likes being snug, so a little crowding alone is not a reason to repot.

For the underlying biology of a pot-bound root system and why it stalls a plant, see our guide to spotting and fixing a root-bound plant.

How often to repot phlox drummondii 'intensia cabernet'

Only every 2–4 years, when genuinely crowded. Phlox drummondii 'Intensia Cabernet' is one of the plants that genuinely prefers a snug pot — it grows and flowers better with its roots a little restricted, so resist the urge to repot it on schedule. Mounding, well-branched and spreading, forming a dense cushion smothered in flower clusters. Self-cleaning and continuously flowering without deadheading..

What size pot to step phlox drummondii 'intensia cabernet' up to

Go up only one pot size — roughly 2–3 cm (about an inch) wider in diameter, no more. Phlox drummondii 'Intensia Cabernet' positively prefers a snug pot: it flowers and grows better when the roots are a little restricted. The single biggest repotting mistake here is over-potting — dropping phlox drummondii 'intensia cabernet' into a pot two or three sizes up. All that surplus soil holds water the small root system cannot use, stays cold and wet, and rots the roots within weeks. When in doubt, choose the smaller pot.

Not sure of the exact diameter? Our pot size calculator takes the current pot and root spread and tells you the right next size — it deliberately recommends a single step up, never a big jump.

The best time of year to repot phlox drummondii 'intensia cabernet'

Early spring, just as new growth restarts, is the ideal window for phlox drummondii 'intensia cabernet'. The plant is moving into its strongest growth phase and re-roots into fresh soil quickly. Avoid repotting in winter dormancy or, for flowering plants, while it is in bud or bloom — recovery is slowest then and you risk dropping the flowers.

Step-by-step: repotting phlox drummondii 'intensia cabernet'

Confirm it actually needs it. Slide phlox drummondii 'intensia cabernet' out and check the roots. Only continue if it is genuinely packed — this plant prefers a snug pot, so if there is still soil and room, put it straight back.
Pick a pot only one size up. Choose a pot just 2–3 cm wider with good drainage. Resist anything bigger; over-potting is the main killer here.
Ease it out gently. Water lightly the day before, then tip phlox drummondii 'intensia cabernet' out, supporting the base. Tease the outer roots free only enough to stop them circling.
Repot at the same depth. Add a layer of fresh fertile, free-draining loam or potting mix, set the plant so the soil line sits exactly where it did before, and backfill around the sides, firming lightly.
Settle it in. Water once to settle the soil, then let it sit. Hold off on more water until the top of the soil dries — fresh soil around a small root system stays wet for a while.

Aftercare

Because the new soil holds more water than the old crammed rootball did, ease right back on watering — let the top of the soil dry before you water phlox drummondii 'intensia cabernet' again, or you will rot the roots in the very pot you just moved it to. Keep it out of harsh direct sun for a fortnight. Do not fertilise for about 4 weeks — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for phlox drummondii 'intensia cabernet'

Phlox drummondii 'Intensia Cabernet' wants fertile, free-draining loam or potting mix. Prefers moderately rich, well-drained soil with a neutral to slightly acidic pH. Improve heavy ground with compost and grit; good drainage helps avoid root rot and foliar disease. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting phlox drummondii 'intensia cabernet' — frequently asked questions

How often should you repot phlox drummondii 'intensia cabernet'?

Only every 2–4 years, when genuinely crowded for phlox drummondii 'intensia cabernet'. Only repot phlox drummondii 'intensia cabernet' every 2–4 years, and only when it is genuinely root-bound — it flowers and grows best slightly crowded. Step up just one pot size in spring using fertile, free-draining loam or potting mix. The key mistake is over-potting: a too-big pot stays wet and rots the roots.

What size pot does phlox drummondii 'intensia cabernet' need?

When is the best time of year to repot phlox drummondii 'intensia cabernet'?

Does phlox drummondii 'intensia cabernet' like to be root-bound?

Yes — phlox drummondii 'intensia cabernet' genuinely flowers and grows best when slightly pot-bound, so do not rush to repot it. The mistake to avoid is over-potting into a much larger pot: the excess soil stays wet, the roots cannot use it, and the plant rots. Only repot every few years and only one snug size up.

Should you fertilise phlox drummondii 'intensia cabernet' after repotting?

Not immediately. Wait about 4 weeks after repotting phlox drummondii 'intensia cabernet'. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.