Poinsettias are well known for being holiday plants (they’re not actually flowers – more on that in a second). But if you’re thinking of keeping your poinsettia beyond December or making it part of your garden then you need to know what works and what doesn’t.
Poinsettias can actually be pretty particular about their neighbors. So I’m going to go through the plants you should avoid to make sure your Poinsettias are happy.
Understanding Poinsettia
What most people call the “flower” is actually a group of colorful leaves called bracts. The real flowers are those tiny yellow buds in the center. Poinsettias are actually tropical plants native to Mexico, which explains why they can be so finicky about their growing conditions.
Poinsettias need specific conditions to thrive. They prefer slightly acidic soil, good drainage and protection from harsh conditions. When you plant a poinsettia next to incompatible plants you’re basically setting up a competition for resources where somebody’s going to lose.
The wrong companions can compete for nutrients, create unfavorable soil conditions, block crucial sunlight or even attract pests that will damage your poinsettia. Since these plants can cost anywhere from $10 to $40 for a decent-sized one it’s worth knowing what to avoid planting with them.
So before you start planning your garden or indoor plant arrangement let’s look at which plants make terrible neighbors for poinsettias.
13 Plants Not to Plant with Poinsettia
1. Mint
If there’s one plant that’s the neighborhood bully of the garden world, it’s mint. Mint’s roots will compete with your poinsettia for nutrients and space.
Mint also spreads through underground runners that can quickly invade the root space of your poinsettia. Plus mint requires more frequent watering than poinsettias, which can lead to root rot.
2. Rosemary
While rosemary has a lovely scent it’s a Mediterranean plant that loves dry, well-drained soil. Poinsettias prefer slightly more moisture.
The fundamental difference in watering needs means one plant will always suffer. Rosemary can also grow quite large and woody, eventually shading out your poinsettia.
3. Cacti and Succulents
This might seem obvious but I’ve seen plenty of holiday arrangements combining poinsettias with succulents – it looks pretty for about two weeks, then disaster strikes. Cacti and succulents need minimal water and high light and poinsettias need moderate moisture and filtered light.
The soil composition these plants need is dramatically different too. Succulents require extremely fast draining soil with minimal organic matter, while poinsettias need richer soil that retains some moisture.
4. Ferns
Ferns are humidity lovers that need consistently moist conditions. When planted near poinsettias they’ll either suffer from too little moisture or more likely the poinsettia will suffer from too much.
Most ferns also prefer deeper shade than poinsettias can tolerate. Your poinsettia needs those bright bracts to photosynthesize efficiently. Too much shade from overhanging ferns will result in leggy, weak growth.
5. Begonias
While both begonias and poinsettias can be beautiful flowering plants they compete directly for the same nutrients. Begonias are heavy feeders that will quickly deplete the soil of nitrogen and other nutrients that poinsettias need.
On top of that many begonia varieties are susceptible to powdery mildew which can easily spread to your poinsettia in humid conditions. I lost two poinsettias this way before figuring out the connection.
6. English Ivy
English ivy is another aggressive grower that will compete with poinsettias for nutrients and water. Its climbing nature can also physically overwhelm poinsettias, shading them out or even using them as climbing support, which damages their stems.
Ivy also creates ground cover that can prevent proper air circulation around the base of your poinsettia, potentially leading to fungal issues.
7. Gardenias
Gardenias might seem like they’d make good companions since they’re both flowering plants that enjoy slightly acidic soil. However, gardenias need much more acidity (pH 5.0-6.0) than poinsettias (which prefer 5.8-6.5).
Gardenias are also extremely heavy feeders and will compete aggressively for nutrients. Their dense growth habit can shade out poinsettias and they attract similar pests like whiteflies, creating a pest magnet situation.
8. Azaleas
Like gardenias azaleas require much more acidic soil than poinsettias can tolerate. When I planted a poinsettia near my established azalea bed, the poinsettia developed yellow leaves – a classic sign of chlorosis from soil that’s too acidic.
Azaleas also create significant shade once established and their shallow root systems will compete directly with poinsettias for water and nutrients.
9. Tomatoes
While it might not seem like an obvious combination some gardeners try incorporating poinsettias into vegetable gardens for color. Not a good idea. Tomatoes are prone to various fungal diseases that can easily spread to poinsettias.
Both plants are in the same susceptibility category for whiteflies, spider mites and aphids. This means planting them together creates a pest buffet. Snd tomatoes need much more frequent watering and feeding than poinsettias as well.
10. Lavender
Lavender requires excellent drainage and relatively dry conditions to thrive – pretty much the opposite of what poinsettias prefer. When planted together either your lavender will suffer from too much moisture, or more commonly, your poinsettia will wilt from underwatering.
The soil composition needs are also dramatically different. Lavender prefers lean, almost sandy soil, while poinsettias need richer garden soil with organic matter.
11. Boston Fern
Boston ferns create very humid microclimates around themselves, which can lead to fungal issues for nearby poinsettias. Their soil and watering needs are also quite different – ferns need consistent moisture while poinsettias prefer a slight dry period between waterings.
Additionally Boston ferns shed tiny leaflets constantly, which can accumulate around your poinsettia’s base and create a perfect environment for pests and diseases.
12. Philodendrons
Philodendrons grow quickly and can easily overshadow poinsettias. Their large leaves block crucial light that poinsettias need for bract coloration and general health.
Philodendrons also prefer more humidity than is ideal for poinsettias in most home environments. When I tried this combination my poinsettia developed brown edges on its leaves within weeks – a sure sign of environmental stress.
13. Peace Lilies
Peace lilies are tropical understory plants that prefer significantly more shade than poinsettias can tolerate. They also require much more consistent moisture.
When grown together either your peace lily will suffer from too much light and too little water or your poinsettia will develop root rot from overwatering and decline from insufficient light. Neither scenario ends well!
Good Companion Plants for Poinsettias
- Christmas cactus – Similar light and temperature requirements
- Cyclamen – Compatible watering needs and similar bloom time
- Kalanchoe – Similar light requirements without competing aggressively
- Snake plants – Tolerant of similar conditions and don’t compete
- Pothos – Can be trained away from poinsettias and has similar watering needs
Tips for Successful Companion Planting
- Always group plants with similar water requirements together
- Consider light needs – poinsettias need bright, indirect light
- Use separate containers when in doubt to avoid root competition
- Monitor for shared pests like whiteflies, spider mites, and mealybugs
- Remember that poinsettias are sensitive to cold drafts and temperature fluctuations
- Maintain at least 6-8 inches between poinsettias and other plants to ensure good air circulation
One trick that’s worked well for me is using decorative container groupings rather than planting directly together. This way I can move plants individually as needed and give them exactly the care they need without compromise.
Final Thoughts
Poinsettias can be great additions to your home or garden. But they’re definitely not the most easy going plants when it comes to neighbors.
It’s a good idea to keep in mind that poinsettias are tropical plants that have specific needs. Those needs – moderate moisture, bright indirect light, and protection from cold – mean any companion that competes for these resources or creates conditions that work against them is going to cause problems.
The good news is that with proper care and appropriate companions poinsettias can actually grow for years, not just for a single holiday season.
It doesn’t matter if you’re creating a holiday arrangement or bringing poinsettias into your permanent plant collection, paying attention to plant compatibility will save you money, frustrationnand heartache.