Gadenin日本語Get the appTake the sleeve or foil off first
Almost every poinsettia comes home wrapped in a printed sleeve or a sheet of foil crimped round the pot. It looks like packaging but it functions as a sealed bag: water poured in cannot get out, so it collects invisibly in the bottom and the lowest inch of compost stays saturated. Within two weeks the roots begin to rot and the leaves start dropping, and the owner concludes the plant needed more water.
Remove it on the day you get the plant. If you want the look, cut the base out of the sleeve so it becomes a collar, or stand the pot inside a decorative outer pot that you can lift it out of. The plastic nursery pot underneath already has drainage holes, and they need to work.
If you keep it in a cachepot, lift the plant out to water, let it drain for ten minutes, then put it back. Watering it while it sits in the outer pot means you never see the water pooling in the bottom.
Water when the surface has dried
A poinsettia in a warm room is a thirstier plant than most winter houseplants, and the compost it is sold in is light and peaty and dries from the top. The right moment is when the top half inch is dry to the touch and the surface has gone a shade paler, but the pot still has some weight to it.
In a room at 64 to 70F (18 to 21C), that usually works out at every four to seven days. In a cooler room, or on a shaded windowsill, it can be ten days or more. Do not fix an interval and stick to it. Check with a finger every two or three days and water when the plant asks.
| Condition | Typical interval | What to watch |
|---|---|---|
| Warm room, 68 to 72F (20 to 22C) | Every four to five days | Dries fast, wilts if you go too long |
| Cool room, 59 to 64F (15 to 18C) | Every seven to ten days | Easy to overwater at this temperature |
| Near a radiator or heating vent | Every three or four days | Leaf edges brown from dry air, not thirst |
| Summer, after cutting back | Every three or four days | Growing hard, uses far more than in winter |
| Autumn, during the dark treatment | Every five to seven days | Check it before covering, not after |
How to water it properly
Small sips wet only the top and leave the root ball dry in the middle, which is a slow way to lose a plant. When you water, water thoroughly.
- Use tepid water Cold water straight from the tap shocks the roots of a tropical plant in a warm room and can trigger leaf drop on its own. Let it stand in the room for an hour, or mix in a little warm water until it feels neither cold nor warm to your wrist.
- Water until it runs from the bottom Pour slowly onto the compost, not over the crown, and keep going until water comes out of the drainage holes. That tells you the whole root ball is wetted rather than just the top.
- Let it drain, then empty the saucer Give it ten to fifteen minutes in a sink or on a draining board, then tip away everything that has collected underneath. Water standing in a saucer overnight is the commonest single cause of root rot in this plant.
- If the compost has shrunk from the pot sides Water poured on will run straight down the gap and out without wetting anything. Stand the pot in an inch or two of tepid water for twenty minutes so it takes up water from below, then drain it fully.
Reading a wilted poinsettia
A wilting poinsettia looks the same whether it is bone dry or waterlogged, and the two need opposite treatment, so always feel the compost before you reach for the watering can.
| What you see | If the compost is dry | If the compost is wet |
|---|---|---|
| Whole plant limp and drooping | Thirsty. Water thoroughly and it recovers in hours | Root rot. Stop watering and let it dry right out |
| Lower leaves yellowing and falling | Went too dry once too often | Overwatered. The usual cause by far |
| Leaves fall while still green | Rare from dryness | Waterlogged roots, or a cold draft |
| Brown crisp leaf edges | Dry air from heating, not thirst | Damaged roots cannot supply the leaves |
| Gray mold on fallen leaves | Unlikely | Too wet and too still. Improve airflow |
A plant that wilts from dryness usually stands up again within three or four hours of a thorough watering. If it is still limp the next morning with wet compost, the problem is the roots.
Feeding, and what to record
Do not feed while the bracts are colored. The plant is not growing, it has all the nutrients it needs from the nursery, and feeding at this stage does nothing except build up salts in a pot that is already struggling. Start feeding in late spring once you have cut the plant back and new shoots are coming, then give a balanced liquid feed at half strength every two weeks through summer, stopping when the dark treatment begins in autumn.
Keep a simple watering note for the first month you own the plant: the date you watered and how the compost felt when you checked. After four or five entries you will know your own room's interval, which is worth more than any general figure. Note the date you took the sleeve off too, because it marks the point from which the plant was actually draining.