How to Water Poinsettias


How to water poinsettias

I love poinsettias and buy them every year for their beautiful red bracts, which add an unequivocal air of festive elegance to any Christmas! However, when I first started growing poinsettias, it used to lose its leaves, which, from my research, I found out was due to my watering practices.

I have done lots of trial and error and many experiments when it comes to watering poinsettias, and I have concluded that universal watering advice does not necessarily apply.

I discovered that you have to tailor the watering requirements to an individual plant as there are so many variables such as climate, size of the poinsettia, type of pot, etc.

In this post, I’ll share with you all the watering techniques, tips, and tricks that I’ve learned so that you can water poinsettia according to your conditions.

Let’s get straight to the point! Here’s my 2 sentence advice:

Poinsettias need the top inch of soil to dry out between waterings. Water them with a good soak so that water emerges from the drainage holes of the pots. Typically, watering them generously once a week meets the plant’s moisture requirements without causing root rot.

As I’m sure you know, it is important to know how often and how much to water poinsettias as they are sensitive to overwatering and underwatering.

Keep reading to learn how to establish the optimal watering frequency for your climate and the conditions in your home…

How Often to Water Poinsettias

So, for us to water our poinsettias correctly, I think we need to undertsand where and how they grow in the wild…

Poinsettia are shrubs that are native to Mexico and Central America where they grow in tropical regions with some humidity, warm temperatures, and occasional rainfall.

Poinsettia is well adapted to the conditions of their native habitat which transfers quite well to growing as house plants, but they are sensitive to both overwatering and underwatering, preferring the soil to dry out a little bit between watering rather than consistent moisture or damp soil.

So I learned that to grow poinsettias in the home we need to recreate the watering conditions and cycle of soil moisture as their native environment.

I actually asked for advice from a specialist poinsettia grower whilst I worked in a garden center, who told me what is critical is that you soak your poinsettias but wait for the top inch of the soil to dry out somewhat before watering.

So this isn’t an exact science, but the soil shouldn’t feel damp nor completely dry, but somewhere in the middle! When I started implementing this advice I found I was watering my poinsettia once a week.

But as I mentioned earlier, the top inch of your soil may dry out more quickly or take longer. Here are the main factors that I have identified that influence how often you water your poinsettia…

  • The natural humidity of the climate (humidity reduces water loss from the leaves and slow evaporation from the soil, which can mean you water the poinsettia less often).
  • The size of your pot (smaller pots dry out much quicker).
  • The material of the pot. (Clay and terracotta dry out more quickly than plastic pots as they are breathable).
  • Whether the poinsettia is in the current of air-con or forced air or any draughts (air currents can sap moisture from the leaves and increase the poinsettia’s demand for water).
  • The capacity of the soil to retain moisture.

My method for establishing the correct watering frequency is to feel the soil with my finger to detect when it has started to dry. I was told that they actually use this exact method to decide when to water when growing poinsettias commercially.

If the soil is moist, I delay watering for a day or so, but if it feels somewhat dry to a depth of one inch, this is the perfect time to water.

I personally have tested using a water meter when learning how to use poinsettias, but I found that they just are not precise enough when it comes to watering poinsettias. I used a range of them, and they often told me the soil had dried out when it was still damp to the touch.

In my experience, Poinsettias are so temperamental when it comes to watering that I advise using your finger instead to be sure.

Pro Tip: I was taught by commercial growers to always water poinsettias with lukewarm water. the poinsettias native range is warm and cold water can shock the plant which can increase the risk of the leaves dropping off and the plant dying.

Poinsettias should be watered consistently throughout the year, but note that demand for water can fluctuate if, for example, in Winter, the heating is on more frequently as this can dry out the pot quickly.

Adjust your watering frequency throughout the year if necessary, but always let the top inch of the soil dry out between watering to avoid root rot and maintain a healthy plant.

How I Increase the Humidity For My Poinsettias

I also experimented extensively with how to increase the humidity for poinsettias. The more common advice I read online was to mist the leaves. However when I lived in a cold climate I had to have the heating on everyday which dried out the air signficantly. I found that misting alone was not able to counteract the dry air in these conditions so I testedt another hack I found online.

I placed a tray of water underneath the poinsettia (and propped the pot above the waterline with pebbles to allow for good drainage). The constant evapouration from the water along with the occasional mistng kept my poinstteia in better condition to stop the leaves droppoing.

But the method that, in my opinion works the best is to use a humidifier. This was best at simulating the higher humidity environment to which poinsettias are accustommed and it was notably more effective at countering dry air from indoor heating!

How to tell if you are overwatering or underwatering poinsettia

If your poinsettia is over water or underwater, the leaves turn yellow and start to droop, therefore it can be quite difficult to make the distinction between an overwatered, or underwatered plant just by appearance. (I have both under and over watered poinsettias over the years!)

However, what I have observed is that poinsettias suffering from drought stress tend to have somewhat more shriveled, wilted, or curled leaves, which can drop off in reaction to drought compared to plants suffering from too much watering.

Of course, the easiest way we can definitively tell the cause of leaves turning yellow is to feel the soil. If the soil has dried out completely, then give your poinsettia a really good soak.

The secret is to place the plant pot in a basin of water for around 10 minutes to allow the water to properly infiltrate the soil so the roots can uptake the much-needed water.

If your poinsettia appears to be overwatered and the soil is too moist, scale back the water so that the top inch dries out.

Overwatered poinsettias are more difficult to revive than underwatered plants due to the increased risk of root rot, which causes a poinsettia to die back.

(Read my article on how to revive a dying poinsettia plant).

How Much to Water Poinsettias

Knowing how much water to use when watering poinsettias is essential for their care.

As we’ve discussed earlier, the variability of the climate and conditions in the home can all influence how often to water poinsettia, but the amount of water should stay the same regardless of conditions.

I recommend watering poinsettias with a generous soak so that excess water trickles out from the base of the pot.

This ensures that the water has infiltrated the soil sufficiently so that the roots of the poinsettia can uptake the water they require.

A really good soaking also encourages the roots to grow and establish in the soil for a healthy, more resilient poinsettia.

Pro Tip: Pick up your poinsettia pot after you have watered it to make sure the soil is absorbing the water properly. Sometimes, I’ve found that water can trickle off the surface and not infiltrate properly, so the water does not reach the roots. If your pot should be heavy after watering. If it’s suspiciously light, give it a soak in a basin for 10 minutes or so to allow the soil to draw up the moisture properly.

Watering too lightly results in only the top inch or so of moistening the soil and the water does not infiltrate to the roots of the plant where it is needed which can even lead to drought stress.

Watering with a good soak then allowing the soil to dry recreates the cycle of rainfall, followed by a period of dryer weather in its native habitat to which the poinsettia is adapted.

Water Poinsettias in pots with Drainage Holes in their Base

I thought I should include a section on pots as I have seen many beginner gardeners make this mistake: Poinsettias don’t tolerate their roots being in damp soil, so your pot must have drainage holes in the base to allow excess water to escape.

As we discussed, watering so that water emerges from the base of the pot is the best way to ensure that you have watered your poinsettia with enough water.

However, I should highlight that if your poinsettia is in a pot without drainage holes in the base, water will pool around the roots, and the poinsettia will die of root rot.

Too much water can still pool around the roots and keep the soil damp if…

  • Saucers and trays are underneath pots. People often use saucers or trays to prevent water from spilling in their homes after a bout of watering. You must empty the pot regularly; otherwise, the standing water prevents the soil from drying out sufficiently for the poinsettia, and the plant dies back.
  • Roots and compacted soil in the drainage holes. If you notice water draining slowly from your poinsettia then check to see if the drainage holes are clear so that water can escape properly to prevent root rot.
  • Decorative outer pots. I always see poinsettias commonly sold in plastic pots with drainage holes, but they are presented in decorative outer pots for sale around Christmas time. The outer pot can prevent water from escaping properly and the soil stays saturated which causes root rot so either empty the outer pot of water regularly or use a saucer or tray and plant poinsettia in a pot with drainage holes.

(Read my article, why is my poinsettia dropping leaves?)

Do you have any more questions or insights about watering poinsettias?? If so, please leave a comment below! I’d love to hear from you!

Key Takeaways:

  • Always wait for the top inch of soil to dry out before watering poinsettias to meet the watering requirements and avoid root rot. Water poinsettias with a generous soak so that water trickles from the base of the pot.
  • Typically, watering once per week is suitable. Adjust the frequency of watering to suit your conditions.
  • Poinsettias should be planted in pots with drainage holes in the base to allow excess water to escape and to avoid root rot.
  • The symptoms of an overwatered and underwatered poinsettia are the leaves turning yellow and drooping. Underwatered poinsettias also drop leaves.

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