Poinsettia
Euphorbia pulcherrima
The color sits in the bracts, not the flowers — kept warm and clear of cold glass it is a perennial, not a Christmas throwaway.
- Type
- Houseplant · Perennial
- Botanical family
- Mixed / other
- Foliage color
- Green
- Flower color
- Red
- Sunlight
- Bright indirect light, with no direct sun on it.
- Watering
- Water once the top 2 cm of the potting mix are dry.
- Feeding
- A balanced liquid feed monthly from spring through autumn.
- Frost tolerant
- No
- Flowering
- November
- Pruning
- Cut it hard back to 10–15 cm in spring.
- Mar–Mar Senescence
- Mar–Nov Bud Break
- Nov–Dec Flowering
- Jan–Mar Flowering
- Plant spacing
- 17.7 in
- In-row spacing
- 17.7 in
- Between rows
- 22 in
- Square-foot density
- Not suited to SFG
- Root system
- Fibrous, and content in a pot
- Working depth
- 6–14 in
- Can reach
- 24 in down where the soil allows
- Spread
- 9–18 in across, about 0.5–1× the width of the plant
- Shallowest pot
- 8 in of soil
It spends its life in a pot, so the pot is the whole root run. Move it up one size when roots show at the drainage holes, and remember that it can never go looking for water it has not been given.
The habit is Poinsettia’s own; the figures are what that habit usually comes to at this size, not a measurement of this species. Roots follow the soil either way: a compacted pan, a high water table or heavy clay stops them well short of any of it, and deep open ground lets them go further.
- Cats and dogs
- Recorded toxic
Recorded as toxic to cats and dogs by ASPCA.
- Fungus gnats Fungus gnats breeding in soggy potting mix
- Whitefly Whitefly, which finds poinsettia more often than not
- Gray mold (botrytis) Botrytis gray mold taking hold in cold, damp air
- Root & crown rot Root rot where overwatering or poor drainage leaves the pot sodden
- Leaf drop after cold drafts or a swing in temperature
Beneficial predators that hunt this plant's pests — grow their favourite flowers nearby to recruit them. companion plant
- Dragonflies & damselflies Odonata
Aerial hunters that take mosquitoes, midges and small flies on the wing all day, and whose larvae spend a year or more clearing the same insects from the water. A pond with planted margins and no fish is the way to have them.
- Beneficial nematodes Steinernema & Heterorhabditis spp.Hunts Fungus gnats
Microscopic worms watered onto damp soil that hunt down soil-dwelling grubs and release a bacterium that kills them within days. Timing is the whole thing: warm, damp soil and a small target grub, which means late summer for most of what they are used against.
- Big-eyed bug Geocoris spp.Hunts Whitefly
A stubby 3 mm bug with enormous wrap-around eyes, working the soil surface and the low foliage for aphids, mites, thrips and insect eggs. It is the main natural check on chinch bugs in a lawn and it is killed outright by insecticide.
- Centipedes ChilopodaHunts Fungus gnats
Flat, fast, one pair of legs to a segment — and a predator, unlike the slow round millipede it is constantly confused with. It hunts slugs, cutworms, springtails and woodlice by night under mulch and stones. Learn the difference and leave this one alone.
- Green lacewing Chrysoperla carneaHunts Whitefly
Its bristly larvae — "aphid lions" — impale aphids, mealybugs, thrips, and mite colonies, eating hundreds a week. Adults feed on nectar and pollen from small open flowers and overwinter in hollow stems left standing.
- Ladybird (lady beetle) CoccinellidaeHunts Whitefly
The gardener’s favorite ally: adults and their alligator-shaped larvae each eat thousands of aphids, plus scale, mealybugs, and other soft-bodied sap-suckers. Grow flat, open flowers for the adults and never spray a colony that ladybird larvae are already working.
- Minute pirate bug Orius spp.Hunts Whitefly
A pinhead-sized true bug that is the best natural check on thrips, and happily spears aphids, mites, and insect eggs too. It needs pollen when prey is scarce, so keep something flowering nearby.
- Parasitic wasps Braconidae & TrichogrammaHunts Whitefly
Tiny, stingless wasps that lay eggs in or on caterpillars, aphids, and moth eggs — the white cocoons riding a hornworm are their calling card, so leave that caterpillar be. Umbel flowers with shallow nectar keep the adults fuelled.
- Predatory mites Phytoseiulus & AmblyseiusHunts Fungus gnats
Fast orange mites that hunt spider mites egg-by-egg, and cousins that clear thrips and fungus-gnat larvae. Sold as a biological control for greenhouses; outdoors they follow humidity — mist and mulch, don’t dust with sulfur.
- Rove beetle StaphylinidaeHunts Fungus gnats
Slim, quick beetles with short wing cases that hunt in soil and litter, taking root-fly eggs and larvae, fungus-gnat larvae, and mites. Mulch and undisturbed ground keep them resident year-round.
- Spiders AraneaeHunts Whitefly
Webs, ambushes, and night patrols make spiders the garden’s steadiest generalist predators, taking whatever flies or crawls past. Mulch, ground cover, and undisturbed corners keep the population dense.
Green-leaved houseplants, like this one.
The Cottage Garden Companion — the gardener's herbarium at cottagegardencompanion.com