Redbor Kale (red curly kale) care

Light

Most houseplants will scorch where redbor kale thrives. Give it the windowsill you'd otherwise leave empty because everything else burned there. Full sun, 6 or more hours daily, for strong colour and dense, sturdy plants. The purple-red pigmentation is richest in bright light and cold conditions; shade dulls the colour. A plant moved abruptly from low light to direct sun bleaches in 48 hours — always acclimatise over a week.

Watering

For redbor kale in the ground or in a bed, aim for when the top 2-3 cm of soil is dry, every 4-7 days. Soak the root zone rather than misting the foliage; deep, less-frequent watering trains roots downward and produces a more drought-resilient plant by mid-season. Aim for about 2-3 cm of water weekly and keep moisture even. Drought toughens and embitters the curled leaves and weakens plants against pests.

Soil and pot

Redbor Kale grows best in rich, firm, well-drained loam. Fertile, organic-rich and moisture-retentive with a firm root run for tall, top-heavy plants. Slightly acidic to neutral pH 6.0-7.5; lime toward neutral to suppress clubroot. 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

Redbor Kale sits happiest at around Outdoor ambient humidity and 7-24°C (45-75°F). Grown outdoors with no special humidity needs; space generously so the dense curled foliage dries and aphids do not lodge in the frills. If you keep the room above 7 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 redbor kale sparingly. A hungry crop. Enrich the bed with compost or aged manure before planting and side-dress or liquid-feed with a nitrogen-rich fertiliser every 3-4 weeks; steady feeding sustains the dense curly leaf production. 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 redbor kale in the Growli community. Each is annotated with the most common cause so you know where to start.

• Cabbage caterpillars — Cabbage white and looper larvae shred leaves and hide deep in the curls. Use insect-mesh covers, inspect the frilly leaves closely, and hand-pick or treat with Bt.
• Cabbage aphid — Grey waxy aphids colonise the dense curls and growing point, where they are hard to dislodge. Use a strong water jet, insecticidal soap and natural predators; check often.
• Wind rock — Tall plants on loose soil rock in wind, loosening roots and stunting growth. Plant firmly and deeply, earth up the stem, and stake exposed plants.
• Clubroot and whitefly — Swollen distorted roots in infected soil, plus clouds of brassica whitefly under leaves. Rotate brassicas, lime to near-neutral pH, and disturb whitefly with regular handling.

Propagation

Grown from seed (an F1 hybrid, so saved seed will not come true). Sow 1 cm deep in modules or a seedbed and transplant at 4-6 weeks, spacing 45 cm apart and planting firmly; not propagated from cuttings. 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

Redbor Kale is mildly toxic to pets. Garden kale (Brassica oleracea) is not individually listed by the ASPCA and is generally non-toxic to dogs, but it contains N-propyl disulfide and thiocyanate/isothiocyanate compounds that can trigger Heinz-body hemolytic anemia in cats and GI irritation with repeated or large feeding. Treat as unsafe for cats in quantity and check with a vet before feeding. 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.

Redbor Kale deep-dive guides

Every aspect of redbor kale care, each with its own calibrated guide:

• Redbor Kale watering schedule
• Redbor Kale light requirements
• Best soil mix for redbor kale
• Redbor Kale fertilizing guide
• When to repot redbor kale
• How to propagate redbor kale
• Redbor Kale growth rate & size
• Redbor Kale cold hardiness
• Redbor Kale temperature & humidity
• Is redbor kale toxic to cats & dogs?
• Is redbor kale toxic to cats?
• Is redbor kale toxic to dogs?

Related guides

Redbor Kale is also known as Redbor kale, red curly kale, and ornamental red kale.

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