What you hear is true on the one hand. Poinsettias can’t stand waterlogging. But on the other hand, watering is not difficult if you know these basic rules:
Watering poinsettias - in a nutshell
- Only water when the soil has dried out.
- Water moderately
- For each watering:
a) Water a normal-sized poinsettia (in a pot about 13cm) 100 ml of water, roughly as much as you’d fit in a champagne glass.
b) Water mini poinsettias (in a pot of about 6 cm) with about 20 to 30 ml of water, roughly as much as you’d fit in half a shot glass.
- Water with room temperature water
- Remove any remaining water from the saucer or container after 15 minutes to prevent waterlogging.
The ideal time to water
The best time to water is when the soil has just dried. If you put your finger into dried soil, it will feel warm and dry and the soil will not stick to your finger. If you lift the pot, it will feel light.
Also, the potting soil changes colour: it becomes lighter, looking more light brown than dark brown, when it is time to water.
How much water does a poinsettia need?
Water poinsettias moderately. The soil should be thoroughly moist after watering, but not soaking wet.
The experts at Stars for Europe recommend 100 ml of water per watering for normal-sized poinsettias in 12 or 13 cm pots. This is roughly the amount that fits in a champagne glass (100 ml up to the level mark). Pour 20 to 30 ml of water into each mini poinsettia.
Usually, a small shot glass has a volume of about 20 millilitres. Pharmacies also often sell small pipette bottles with a volume of 20 millilitres.
XXL poinsettias in larger pots need more water. Watering 10 to 20 percent of the pot volume is considered optimal.
How often do you have to water a poinsettia?
It depends. Above radiators in dry air in a bright location, you may need to water every day. In other places it is enough to water twice a week. Mini poinsettias need water more often than large ones because of the small pot volume.
It’s important to be observant and find the right watering schedule for your conditions.
If your poinsettia needs constant replenishment, you can increase the amount of watering.
Remember: Watering in advance does not work. This would cause the notorious waterlogging we are about to discuss.
The problem of waterlogging
If the soil is completely soaked and waterlogged, water will settle in the coarse pores of the substrate. It will take away the air the roots need to breathe. The result is yellow, limp leaves – and an uncertain fate for the poinsettia.
To prevent this from happening, remove any water that has run into the saucer or container no later than 15 minutes after watering. And reduce the amount of watering if there is always too much water left!
If the water runs into the saucer when you water and the dried root ball is supplied with liquid from this reservoir, that’s okay as long as you remove the rest after a quarter of an hour.
The nurseries that produce poinsettias do it similarly. They use the principle of accumulating water and flood the cultivation tables. After a short time, the water runs off again.
Water preferably room temperature
Tropical houseplants that need warmth react badly to cold water. This is no different with poinsettias than with orchids or African violets. It is best to refill the watering can immediately so that the contents are at the right temperature before the next use.
Soft water makes poinsettias shine
It can’t be said that the poinsettia is a great friend of chalky water in the long run. But where do you get soft water?
Soft water can be collected from water butts or melted snow (bring to room temperature before watering!). Filters remove limescale and chlorine; when boiling, the limescale remains as scale in the boiling water (let the water cool down before watering).
Watering or dipping - which is better?
Both have advantages and disadvantages. The advantage of watering is that you have control over the amount of water. In addition, the poinsettia can stay in its place.
On the other hand, watering only works if there is a container around the poinsettia. If you wrap the root balls in moss, it is easier to remove the plants from the decoration so that the moss and root balls can refresh themselves in a bowl of water. Let them drain well before returning them to their place!
Submerging the root balls of poinsettias is practical for the smaller pot sizes because their small volume of soil stores little liquid anyway.
Dipping a poinsettia - how does it work?
• Take the poinsettia out of its container and place it in a deep bowl or bucket of room temperature water. Do this so that the root ball is just below the surface of the water. As the water flows into the potting soil, it bubbles.
• Wait until almost no more bubbles rise, because then the soil is sufficiently saturated.
• Let the poinsettia drain so that excess water runs out of the coarse pores.
• Put the poinsettia back in its place.
• Empty the remaining water from the saucer or container after 15 minutes to avoid waterlogging.
The dipping method is often the only way to sustainably moisten severely dried out potting soil again.
What to do with limp, green poinsettia leaves?
If a poinsettia’s leaves droop, the soil is too dry.
The roots do not have enough water to send to the leaves. First individual plant cells die, then the whole poinsettia.
If the soil dries out so much that it separates from the edge of the pot, it is doubtful whether the plant can still be saved by watering.
Tip: Take good care of mini poinsettias! Because the pot volume is small, the soil dries out quickly. This applies to all mini plants 😉
Do not water if leaves are limp and yellow!
Limp, yellow leaves occur when a poinsettia gets too much water, not too little. They are the most obvious symptom of the notorious waterlogging. More watering would make things worse. Is there water in the pot? Pour it away and only water again when the soil has dried out!
Do I need to fertilise my poinsettia?
No. Poinsettias are supplied with fertiliser. They have enough for four to six weeks, which is sufficient for the Advent and Christmas season.
If you plan to plant your poinsettias over the summer, start fertilising at the end of February. Until April, half a dose of a normal houseplant fertiliser is sufficient every four to six weeks. When growth starts, fertilise poinsettias just like your other houseplants.