Phlox drummondii 'Intensia Cabernet' (Intensia Cabernet Annual Phlox) care

Light

Most houseplants will scorch where phlox drummondii 'intensia cabernet' thrives. Give it the windowsill you'd otherwise leave empty because everything else burned there. Full sun, 6 or more hours daily, for the heaviest flowering and most compact growth. It tolerates a little afternoon shade in very hot regions but blooms best in bright, open positions. A plant moved abruptly from low light to direct sun bleaches in 48 hours — always acclimatise over a week.

Watering

Aim for when the top 2-3 cm of soil is dry, roughly every 4-7 days for phlox drummondii 'intensia cabernet', but treat that as a starting point rather than a rule. A south-facing summer windowsill will dry the pot twice as fast as a north-facing winter room. Lift the pot; if it feels noticeably lighter than it did wet, water it. Keep evenly moist while establishing, then water moderately and let the surface dry between waterings. More heat- and drought-tolerant than seed phlox, but containers still need regular summer watering.

Soil and pot

Phlox drummondii 'Intensia Cabernet' grows best in 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. A pot with a working drainage hole is non-negotiable for this species — even free-draining mix will turn soggy in a closed planter. If you love the look of a decorative pot without a hole, use it as a cachepot around an inner nursery pot you can lift out to water.

Humidity and temperature

Phlox drummondii 'Intensia Cabernet' sits happiest at around 40-70% humidity and 16-29°C (60-85°F). Bred to tolerate heat and humidity better than traditional phlox, with strong resistance to powdery mildew. Good spacing and airflow keep foliage clean in muggy summers. If you keep the room above 16 year-round and avoid placing the plant near a cold draught, a hot radiator, or an air-conditioning vent, you have already handled the two biggest indoor stressors.

Fertilising

Feed phlox drummondii 'intensia cabernet' sparingly. Feed every 2-4 weeks with a balanced liquid fertiliser through the growing season, or use slow-release granules at planting. Steady feeding sustains the continuous flush; avoid heavy nitrogen, which favours leaves over blooms. Skip fertiliser entirely on a stressed, recently-repotted, or actively wilting plant — fertiliser salts make damage worse, not better. Wait for a round of healthy new growth before resuming a feeding rhythm.

Common problems

Below are the issues we see most often on phlox drummondii 'intensia cabernet' in the Growli community. Each is annotated with the most common cause so you know where to start.

• Powdery mildew — Less common in this mildew-tolerant series, but possible in crowded, damp, shaded sites. Improve airflow and water at the base.
• Reduced flowering — From insufficient sun or excess nitrogen. Site in full sun and use a balanced feed for non-stop bloom.
• Root rot — Caused by waterlogged soil or overwatering. Plant in free-draining medium and let the surface dry between waterings.
• Spider mites — Fine stippling and webbing in hot, dry conditions. Rinse foliage and treat with insecticidal soap or miticide if persistent.

Propagation

The Intensia series is propagated vegetatively from cuttings, which root readily in warm, humid conditions to keep the cultivar true. Species annual phlox is easily grown from seed, but cuttings preserve this selection's colour and vigour. Propagation is the cheapest, most satisfying way to expand a collection — and it doubles as insurance against losing a mature plant to an accident. Take a backup cutting once the parent is established and healthy.

Toxicity to pets

Phlox drummondii 'Intensia Cabernet' is pet-safe. ASPCA-listed as non-toxic to cats and dogs (phlox appears on the ASPCA non-toxic plant list). Eating large quantities of any plant may still cause mild, transient stomach upset, but annual phlox poses no known poisoning risk to pets. If you keep cats, dogs, or curious children in the house, weigh placement carefully — a high shelf or a hanging planter is enough for casual safety. For severe ingestion incidents, call your local vet and the ASPCA Animal Poison Control Center (in the US, 888-426-4435).

Pet-safety status is sourced from the ASPCA Toxic and Non-Toxic Plant List, which catalogues the most-asked-about plants for cats, dogs, and horses.

Phlox drummondii 'Intensia Cabernet' deep-dive guides

Every aspect of phlox drummondii 'intensia cabernet' care, each with its own calibrated guide:

• Phlox drummondii 'Intensia Cabernet' watering schedule
• Phlox drummondii 'Intensia Cabernet' light requirements
• Best soil mix for phlox drummondii 'intensia cabernet'
• Phlox drummondii 'Intensia Cabernet' fertilizing guide
• When to repot phlox drummondii 'intensia cabernet'
• How to propagate phlox drummondii 'intensia cabernet'
• Phlox drummondii 'Intensia Cabernet' growth rate & size
• Phlox drummondii 'Intensia Cabernet' cold hardiness
• Phlox drummondii 'Intensia Cabernet' temperature & humidity
• Is phlox drummondii 'intensia cabernet' toxic to cats & dogs?
• Is phlox drummondii 'intensia cabernet' toxic to cats?
• Is phlox drummondii 'intensia cabernet' toxic to dogs?
• Getting phlox drummondii 'intensia cabernet' to bloom

Featured in these plant shortlists

Phlox drummondii 'Intensia Cabernet' qualifies for 12 curated Growli shortlists — each one filtered objectively from our structured plant-care library, so the selection is consistent and checkable:

• Best pet-safe houseplants — Houseplants the ASPCA lists as non-toxic to cats and dogs — every one verified against the ASPCA toxic and non-toxic plant list.
• Best drought-tolerant houseplants — Houseplants that prefer to dry out — forgiving of forgotten watering and ideal for travel or busy weeks.
• Best flowering houseplants — Indoor plants grown for their blooms — selected from the flowering species in Growli’s plant-care library.
• Best pet-safe low-maintenance plants — Non-toxic to cats and dogs and forgiving of forgotten watering — the easiest safe choices for a busy pet household.
• Best pet-safe flowering plants — Flowering houseplants the ASPCA lists as non-toxic to cats and dogs — colour and blooms in a pet home, without the worry.
• Best pet-safe plants for bright light — Non-toxic to cats and dogs and happy in a bright, sunny spot — safe plants for your best-lit windowsill.
• Best small & tabletop houseplants — Compact houseplants that stay under about 40 cm — desk, shelf and windowsill plants that never outgrow a small space.
• Best houseplants for full sun — Houseplants that want direct sun — the species for a hot south or west-facing windowsill where shade-lovers scorch.
• Best fast-growing houseplants — Houseplants documented as fast or vigorous growers — quick to fill a pot, cover a pole or trail down a shelf.
• Best cat-safe plants — Houseplants the ASPCA lists as non-toxic to cats (and dogs) — safe greenery for a home with a curious cat.
• Best dog-safe plants — Houseplants the ASPCA lists as non-toxic to dogs (and cats) — safe greenery for a home with a curious dog.
• Best small pet-safe plants — Compact, tabletop houseplants that are also ASPCA non-toxic to cats and dogs — safe greenery for a desk or shelf.
• Browse all 29 plant shortlists — pet-safe, low-light, drought-tolerant and more

Related guides

Phlox drummondii 'Intensia Cabernet' is also commonly called Intensia Cabernet Annual Phlox or Cabernet Drummond Phlox.

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