I can’t even imagine the holidays without poinsettia (Euphorbia pulcherrima).
Even if I don’t have any in my own home, they will be everywhere in the stores, hotels, and houses of my friends.
One of my Jewish friends always fills her living room with white poinsettias in blue pots for Hanukkah.
My mom has red ones surrounding the base of her 14-foot Christmas tree. These colorful plants have become an essential part of our winter celebrations.
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But did you know that you don’t have to purchase new poinsettias from the store every year and instead you can propagate them yourself, at home?
Poinsettias are monoecious, which means each flower contains the male and female parts required to complete pollination and set seed. So you only need one specimen to gather seeds.
If you need a refresher about how to grow and care for poinsettia, check out our guide.
In this article, we’re going to cover how to start poinsettia plants from seed.
Here’s what I’ll cover:
How to Start Poinsettia from Seed
Most poinsettias are propagated vegetatively via methods like stem cuttings, but you can absolutely grow them from seed as well.
It can be difficult to find seeds, and even if you do, they might not be viable.
For that reason, it’s better to harvest them from the plants yourself, if you can. We’ll walk you through that process, but first we need to make sure we’re on the same page about our terminology.
Poinsettia Anatomy
We typically refer to the colorful leaves on these plants as the flowers, but that’s not technically true.
The red, cream, green, white, pink, or coral “petals” are actually modified leaves known as bracts.
The true flowers are located at the center of the bracts and they don’t have any petals. If you look closely in the center of the bracts, you’ll see upright growths called cyathia – and there are lots of them.
Each single cyathium has a cluster of male flowers that hold the pollen plus a single female flower that sits above them on a pedicel and receives the pollen.
The female flower has a large base that contains the ovaries and multiple curved styles and the male flowers have five upright anthers.
At the base of the cyathium, there are also two yellow lumps split down the middle that look kind of like an open mouth. Inside this “mouth” are bulbous glands that exude a sticky sweet nectar that attracts pollinators.
The plant can pollinate itself with the help of pollinators or wind moving the pollen from the stamen to the stigma on the same, or different, flowers. Pollinators also help cross-pollinate the plants by carrying the pollen from one poinsettia to another.
The only difference is that there is more genetic variation in seeds produced from cross-pollination than from self-pollination.
Once the flowers are pollinated, each will develop a zygote that will mature into a schizocarp that holds the seeds.
When it is ripe, the schizocarp will burst open and expel the seeds. After that, the plant will drop its leaves.
Pollination and Preparation
If you are growing your plants inside, there aren’t any pollinators – or wind – to move the pollen from the male stamens to the female stigma.
You’ll need to do the work to pollinate the flowers manually.
To hand-pollinate, take a toothpick and wipe it on the stamens of one flower and then transfer the collected pollen on to the stigma of another.
Remember, it doesn’t matter if you have more than one poinsettia plant because they are self-fertile. But you can certainly cross-pollinate flowers from different plants if you want.
Cross-pollination will create more genetic diversity, which is usually a good thing in the long term. But if you want to try to keep some of the characteristics of the plant you have, self-pollination might be the way to go.
A few months after you pollinated the flowers, the bracts will have fallen off and you’ll see green pods filled with dark brown or black seeds.
Wait for the pods to turn dry and at that point you can pluck them off the plant and rub them between your hands to release the seeds.
You can also rub the pods while they are still on the plant. If they don’t open readily and release the seeds, they aren’t yet mature.
When you have released the seeds, put them in a plastic bag or glass container filled with moist sand.
Place this bag or container in the refrigerator and leave it there for about three months. This is known as cold stratification and it is necessary to encourage the seeds to germinate.
If you purchase seeds, unless the seller clearly states that they’ve already been cold-stratified, you’ll need to do it yourself.
Keep the sand moist and watch for any signs of mold or mildew.
If you see any, you can spritz the inside of the bag or container with a 10 percent bleach solution (nine parts water to one part bleach).
After a few months in the fridge, it’s time to sow! This is best done in the late winter and early spring.
Sowing Seeds
In the late winter or early spring, fill a seed tray or individual pots with a seed starting medium like Tank’s Pro-Lite, which you can find in 16-quart bags at Arbico Organics.
Tank’s Pro-Lite Potting Mix
Sow the seeds about four inches apart and an inch deep. Moisten the medium and place the tray on a heating mat that will keep the soil temperature about 70°F.
The seeds don’t need light to germinate, but once the seedlings emerge from the soil, you’ll need to give them plenty of sunshine.
Typically, the seeds should germinate in under three weeks, but they can sometimes take a week or so longer. If after four weeks there is no sign of sprouts, I’d recommend you to start again with fresh, new seeds.
After germination provide at least six hours of bright, indirect light, or the seedlings will become leggy and spindly. You also want to ensure good air circulation around them because the young seedlings are prone to fungal issues.
If you’d like, you can spray the seedlings preventatively with a copper fungicide.
This will kill most of the pathogens that might target your poinsettia seedlings but isn’t damaging to the young plants.
I always keep Bonide Liquid Copper as part of my gardening toolkit because it’s a multipurpose fungicide, useful for dealing with a variety of problems.
Bonide Liquid Copper Fungicide
You can find 32-ounce ready-to-use spray or 16-ounce concentrate at Arbico Organics.
Now your job is to keep the seedlings happy and alive with evenly moist soil and plenty of sunshine until there are at least four leaves and the weather outside is appropriate for planting – if you’re in Zones 9 to 11 and want to grow your poinsettia outdoors.
If you intend to keep your new specimens as houseplants, then you can transplant them into larger, more permanent containers anytime after they have four or more leaves.
Transplanting
If you plan to move the seedlings outside, wait until the nighttime temperatures are above 60°F. Poinsettia doesn’t do well in temperatures below that.
Before you transplant, you’ll need to harden off the plants over the course of a week.
That involves moving them outside for an hour on the first day and adding an extra hour every day for a week.
To plant in the ground, dig a hole that is large enough to accommodate the seedling and its roots. You don’t need to dig a huge hole, but a few extra inches to give the roots somewhere to stretch into won’t hurt.
There is no need to add any amendments unless the soil is predominantly clay. In that case, work in lots of well-rotted compost or manure.
Gently lift out a seedling from the tray. You might need to use a small shovel or large spoon to help tease it out. Put the seedling in the hole and backfill around it with soil. Water gently.
Learn more about transplanting poinsettias in our guide.
If you’re intending to keep your new poinsettias as houseplants, you can repot them into appropriately sized containers.
Start with a clean pot partially filled with standard potting soil. Set the seedling inside and fill in around the roots with more potting soil. Water the soil well.
Let them grow, and enjoy your colorful new friends!
Start Something New
I always feel such a sense of accomplishment when I start a plant from seed, especially something like a poinsettia.
And while growing these plants from seed requires quite a lot of patience, there’s nothing more rewarding than enjoying the holiday season with a poinsettia you nurtured right from the very beginning.
So tell me about your growing adventures. Are you trying to breed something special? Or maybe you’re hoping to grow gifts for the family this year? Fill us in on your propagation plans in the comments section below.
And for more information about poinsettias, have a read of these guides next:
