Plumeria are tropical plants with fragrant flowers, grown for their sweetly scented blooms. But as you find your local climate turning cool for fall and winter, it’s time to start making considerations over the long-term care of your plumeria.
Plumeria plants, also known as frangipani, or the Hawaiian lei flower, are not at all frost tolerant, and hate temperatures below 60F, but can survive anything above 50F. In this article, I want to take a moment to share Plumeria 101’s tips and tricks for successfully overwintering a Plumeria, whether it’s in a pot or the ground.
Plumeria During Winter
Plumeria are needy plants. They require regular fertilizing, and close attention to prevent pests and diseases, like spider mites, mealy bugs, and blacktip fungus. But in winter this can get even harder because, in cultivation outside their natural habitat in the tropics, they need some serious care to prevent root rot, stem rot, frost damage, and branch dieback, all of which can either kill the small trees entirely or prevent them from blooming regularly the following year.
Winterizing plumeria is critical to ensure a healthy plant next spring. Winterizing is the process of not just moving, but properly preparing your tender plants for winter.
For some perennial frost-tender plants, like dahlias, or pelargoniums, winterizing is as simple as cutting them to the ground and placing them in a warm dry place from late fall to early spring, but for tender shrubs and tender trees like plumeria, the winter months are cold and unpleasant, and they are unlikely to survive outdoors without serious attention.
Plumeria Winter Requirements
Plumeria Temperature Tolerance
Plumerias need to be kept above 50F at all times, if the temperatures drop below this they will not recover from the frost damage. Ideally, they should be above 60F or even 75F where possible. For plumerias grown indoors, over-wintering is easy. Simply cut back any old or damaged, dead or diseased growth, remove fallen leaves from around the base of the plant, and stop watering for several months. When the day lengths start to shorten in winter, they will become inactive, and stop growing. They will automatically begin growing again in spring.
Do not keep them next to a radiator or central heating system as they can burn and the leaf scorch or dried-out branches won’t recover in spring. Ideally, they should be kept in a warm room in direct sunlight.
However, if you grow your plumeria tree’s outside, either in the ground or in pots, there are a few things we’ll cover later to keep them safe over winter. For most of the US, late October or early November is roughly the time you should be thinking about starting to winterize your plumeria plants. As soon as there is any risk of frost, they should be indoors.
Plumeria Moisture Tolerance
Even during their active growth, plumeria need an ample amount of sun, and good air circulation to prevent them from standing in too much water, but keeping their root ball dry over winter is essential for maintaining good soil structure and nutrients for next year’s tender growth to be supported when the new shoots appear in spring.
Never water a plumeria when the soil is at all damp, and for outdoor plumeria, especially grown in the ground, make sure not to mulch your plumeria plants for winter, as this can lead to damp roots and they can’t tolerate wet feet at all. Instead, consider a frost cloth. Frost cloths keep plants warm in winter and can keep excess moisture off the tender new growth which will help prevent fungal growths or infection.
When the weather warms again, simply remove the cloth to restart growth.
Plumeria Winter Care
Plumeria, or frangipani, are triggered into winter dormancy by cold weather and short days as fall and the winter season approaches. In most climates, your frangipani trees should be grown indoors, or in patio containers, with free-draining soil, and bright but indirect sun. this means you can take them inside for the entire winter.
Remember, the trigger for the following care guide is not daytime temperatures. It’s when nighttime temperatures drop below 60F. If you wait for the daytime temperature to be that low, it will already be too late.
Bring Plumeria Indoors For Winter
If you are growing plumeria outdoors, and lucky enough to be in the warmer parts of the country it’s still best practice to overwinter plumeria indoors.
Potted plants are easy enough to move indoors, but mature plants might be problematic with the weight of the pot. If your plumeria is getting too big to handle, there are a few tricks to get it back to size, without damaging its healthy growth, but these are best done in the new growing season, as winter pruning will only trigger new tender growth.
How to Overwinter Plumeria Plants
Winter pruning trees or shrubs promote new growth, but no new flowers. Pruning in March will promote new foliage, with no new fragrant flowers, while pruning in late summer creates new foliage, and more fragrant flowers the following year.
When winterizing your plumeria it is important to cut back any dead, diseased, or damaged growth, which would otherwise cause rot during its dormancy. A dormant plumeria cannot recover from illnesses and is much more likely to carry fungal infections to other parts of the plant during the cooler months, so remove any diseased growth before you bring your plumeria indoors, or into the greenhouse.
Check for pests that you might be moving into contact with other plants too. Remove them by hand, or use an organic pesticide like neem oil to help control their population and eradicate pest problems before you overwinter frangipani.
While sunny spots are great to keep the temperature of plumeria warm and promote a more natural response to the changing day lengths of fall and winter, you can in fact overwinter them in the dark, which can oddly promote early flowering as the extreme difference in day length in late March triggers early flowers.
Overwintering Plumeria Outdoors
For plumeria that can’t be moved, either because they are too large, or planted in the ground, you’ll need a few things in your store cupboard every year to help get them through the cooler temperatures.
The challenge with both of these is that they increase humidity, so as soon as temperatures begin to rise in spring and the risk of frost has passed, they need to be removed immediately. Check your plants regularly in the warmer afternoons to make sure there are no signs of fungus on the stems or leaves beneath the cloths or insulation.
To use the pipe insulation, simply wrap it around young tender growth to protect it from the worst of the weather. For woody stems that have fully matured, they will probably be ok with the protection of the fleece alone, as the bark prevents full penetration of the cold frost to the live parts of the plant inside the stem.
The fleece needs to be double layered to ensure full protection, so wrap the fleece around the entire plant, and tie it securely around the trunk. The other benefit of this is that it provides a canopy to protect the plant from falling rain and snow, which will keep the roots as dry as possible outdoors during winter.
Overwintering Plumeria in the Greenhouse
If like me, your plumerias are kept in standard greenhouses, there are some excellent products you can buy to keep your greenhouses warm in winter. They vary greatly in price, so it’s completely up to you which you go for, but depending on where you are in the country, the more energy-efficient models are advised, as they will need to run at higher temperatures for longer periods of time.
Keeping your greenhouse warm in winter will not only allow you to keep plumeria plants happy outdoors during winter dormancy but has the added benefit of letting you grow winter crops more successfully, like greenhouse cabbages or komatsuna for salads, which will go from seed to crops even in the coldest months if you keep the greenhouse well heated.
Greenhouse Heater for Plumeria During Winter
Electric heaters are the most energy-efficient way to heat your greenhouse, as well as having more reliable controls. These traditional style heaters from Bio Green, have a long lead, that should easily reach the main socket from the greenhouse in most gardens, meaning you can turn them on and off without walking all the way to the greenhouse.
Their primary control is the thermostat, which can be kept low for most pants, or tweak up a few notches to suit plumeria’s temperature requirements.
Remember, even in the depths of its winter dormancy, plumeria still need some heat.
Propane might not sound that efficient, but one refill can last a greenhouse up to a month, and by setting this heater on its lowest setting you can get almost the entire frosty part of winter covered with one tank. You do need to turn propane canisters off manually so they’re not burning all day and night though.
No greenhouse really needs 24/7 heating unless you’re right up in Alaska, but then you’re probably not trying to grow plumeria outdoors anyway.
For larger greenhouses, it can be challenging to heat the entire area, but even though greenhouses are typically quite good at holding their heat overnight, sometimes setting something more powerful up is the only way to your space safe.
This contractor’s heater, usually used for construction sites might not be the most efficient heater on the market, but it will certainly keep the temperatures nice and high. The only downside is that while it has an automatic shut-off, to prevent it from overheating, it’s not programmable, so you’ll need to go out through the snow and turn it on manually every night, and off again in the morning.
Bringing Plumeria Out Of Dormancy
To bring a plumeria out of dormancy in Spring, there’s really not much you need to do, but to promote vigorous new growth, and improve the overall plant health, this is a great time to trim roots.
Pruning plumeria roots every 2-3 years prevents root rot, as well as reinvigorates the entire plant. Old roots can get lazy, and stop taking on as many nutrients due to their thicker skins and larger area. Young sinuous roots have a greater surface area, and can therefore take up more water and more nutrients to promote new foliage, and better flowers.
In spring, after trimming your plumeria roots, place them back in full sun outdoors and gently pinch out young tips as they emerge, which will promote branching off, and a bushier flower coverage, which will flower for longer in the year too.
Moving Plumeria Back Outside After Winter
When you’re confident that the temperatures are reliably above 70F, as the weather warms, start watering the plant once a week and add fertilizers when new foliage appears.
Start partially acclimatizing your potted plants, especially young plants, to the outdoor conditions, by leaving them out for a few hours in full sun during the afternoon for a week. After a week, leave them out overnight and that’s it! a healthy plumeria, ready to flower again right through summer in its sunny location.
Plumeria Winter Care FAQs
When should I winterize my plumeria?
As soon as temperatures drop below 60C plumeria should be protected from frost. The plants go dormant as soon as the day length changes in late fall, so should ideally be brought indoors to overwinter away from the danger of frost.
Do plumerias lose their leaves in winter?
There is nothing wrong with your plumeria if it loses its leaves in winter. A really healthy mature plant will hold onto its leaves a little longer, some even hold them until spring, but they provide no value to the plant and are completely dormant. Plumeria leaves last for a single season, so do not worry if your plant loses its leaves in the fall, simply increase fertilizing next year to improve foliage health.
Do plumerias go dormant in winter?
Plumeria plants go dormant in winter. They are triggered by falling temperatures and shorter sunlight hours. They are tropical plants and they have long winters to adapt to in most climates where they are grown in cultivation, so protect dormant plants from cooler temperatures, and do not water them at all during the winter.
Plumeria are tropical plants. They like tropical weather, and most of us simply can’t provide them with that, but with a little bit of help, and clever gardening, we can make sure they feel at home in our garden.
Overwintering plumeria is really quite straightforward, so shouldn’t put you off starting a plumeria collection yourself. Even if you don’t have a spare room or a greenhouse, they can be kept indoors, or in the garage and require almost no care during their dormant period every year.