Why is my poinsettia not turning red? Experts point out the common poinsettia care mistake

Poinsettia not turning red? Plant experts explain the potential reasons

Poinsettia on window sill
(Image credit: Barbara Eddowes/ Getty)

Wondering why your poinsettia is not turning red? Poinsettias are a festive classic, a plant famous for its beautiful red bracts that go very well with Christmas decor. And although poinsettias are often bought as annuals, they actually are perennials and will turn red again with the correct care. 

One of the best Christmas plants, poinsettia needs a more specialist approach than most plants to get the characteristic red color. You may have heard about the need to keep poinsettias in the dark during the night. If you're doing this but still aren't seeing any red on your poinsettia, it may be that the plant's other key requirements aren't being met.

Poinsettia leaves close-up

(Image credit: Annie Japaud/ Getty)

It is true that poinsettias require 12 hours of darkness from October onwards in order to develop their red bracts (they're not flowers, by the way). But many fans of indoor garden ideas forget the other crucial half of the balance – the light requirements during the day. Emilly Barbosa Fernandes, a small space gardener from California and a consultant at HouseGrail, explains that if poinsettias won't turn red 'you are not letting them absorb the light. They need at least 8 hours of indirect sunlight daily.'

If your poinsettia is in full sun, it will need six hours of direct exposure, according to Lindsey Hyland, expert gardener and Founder of Urban Organic Yield.  'If you've been watering the plant well and its potting soil is moist, then it may simply be getting too much water and fertilizer and not enough light,' Lindsey says. 

Remember: poinsettias come from Mexico where they are used to plenty of bright light during the day. If you're keeping yours in a dark cupboard and then it sits in a dark corner all day, its light needs will not be met. 

Poinsettia in basket

(Image credit: Johner Images/ Getty)

What if I forget to put my poinsettia in the dark?

This is another common mistake  – placing your poinsettia in the dark inconsistently. Lindsey explains that if 'the darkness is no longer interrupting the process of pigmenting,' you won't get the desired red bracts – even if you've missed a night or two. Be patient and don't forget to put your poinsettia in the dark every single night. 'It will take a little bit for the colors to show up but you should see some change within a week or two.'

It also can be easier to cover the plant with a cardboard box or even a bag for the night if you don't have a suitable cupboard to put it in for the night. Just make sure that no light gets in at all, whatever you're using, and your poinsettia should soon be taking center stage in your indoor plant ideas

Anna writes about interior design and gardening. Her work has appeared in Homes & Gardens, Livingetc, and many other publications. She is an experienced outdoor and indoor gardener and has a passion for growing roses and Japanese maples in her outside space.