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Most of the plants we keep in our homes hail from the tropics, so not only do they not know what season it is, they don’t even know what seasons are.
In most tropical rainforests there are two seasons: hot and wet, and hot and really wet.
Sometimes there’s extra wind.
Do plants actually know what season it is?
No! They follow certain patterns; for example, peace lilies tend to bloom in spring and autumn BUT in the wild, they just flower whenever they’re ready, and can do so year-round.
In our homes, certain conditions can induce them to flower which correspond with the seasons.
It’s also worth noting that we can use seasonality to manipulate our plants, for example giving plants such as Christmas Cactus and orchids a period of darkness in winter can stimulate blooming when spring comes.
There’s also a theory that letting Hoya dry out a little more than usual just before they’re due to form peduncles (around April) can cause a bumper crop of flowers. I tried it this year (I basically missed a watering – so rather than watering every three-ish weeks, I waited six) and it seems to have worked!
They’re not out yet but there are multiple peduncles on every vine:
So if we’re saying that plants not only can’t tell what season it is but also don’t have any concept of seasonality (at least, the four we get in the UK), how come they conform to a typical growing season/dormancy period cycle?
Basically, whilst they don’t know what season it is, they do know how hot/humid/bright it is. That’s why if we have a particularly warm March, the growing season can get underway very early, and then have a bit of a stutter in April when it goes all wintery again.
This year (2023) it was pretty cold and grey right up until the end of May, so everything’s starting pretty late.
That being said, it’s been pretty warm (at least, it has been in my south-facing living room window) so though it took a while for them to get going, my plants are all thriving at the moment.
They get less light in winter
Light is super important to plants. I know that sounds obvious, but it’s your saving grace in winter. But also hard to find.
Light definitely helps with growth, BUT you’re unlikely to get enough light for growth in winter anyway. It’s still worth maximising your plant’s light because the bit of energy your plants can create can help keep their strength up a bit.
The weaker and more sickly your plants look, the more appealing they are to pests, and dealing with house plant pests in winter is NOT fun. They’re more persistent and can do more damage.
Grow lights are a great option in winter. I like hanging ones like this Bestva – they’re not the most aesthetically pleasing BUT they’re the most bang for your buck when you’re trying to balance cost, power, and, most importantly, the number of plants you can cram under it.
Those cheap Amazon ones are fine, but the general rule of thumb is that a light that only needs a USB power connection is never gonna be strong enough to make that much of a difference.
If you don’t have grow lights, then just try to move any plants that live in dark spots into a brighter one over winter.
I spread my plants all over the house in summer, but in winter they all huddle together for warmth (is it a pain if they get pests? Yes, but they’re also less likely to get them).
In summer I tend to concentrate on watering and feeding more than dusting, but in winter they don’t need watering that often, so my plant care is more geared towards keeping the leaves clean.
Clean leaves can absorb more light and dust is a spider mite magnet, so don’t overlook this.
The temperature is lower
Plants grow slower when it’s colder – whether that’s because it’s winter or just a chilly day in Spring. Temperature isn’t as cut and dry as hot=good, cold=bad – as I mentioned, some plants bloom better if they’ve had a period of cold weather.
Last winter was particularly bad for my plants because energy prices were high and I’m not bankrupting myself for my plants. They were all fine, but I had to be extra careful when it came to, for example, watering them.
Watering with water straight from the tap isn’t that big of a deal in summer but it can cause plants to go into shock in winter. Leave your tap water to come up to room temperature, or add a bit of warm in so it’s tepid.
I also water less in winter. Obviously with a lower frequency because they take longer to dry out, but also less in one go. Water stored in soil can bring down the temperature around the roots for a long time, and make the plant more vulnerable to shock (and the consequent pests).
you can opt to shower your plants off with tepid water BUT make sure you take the time to dry the leaves after. Warm water on the leaves in a cold room will cause black marks pretty quickly.
The air is usually drier
This isn’t really a good or a bad thing.
On one hand, the lower humidity can cause any growth that does appear to be a bit crispy. However, since winter growth is often weak and spindly anyway it’s not really a big deal.
On the other hand, if you have the humidity too high, then you’re creating an atmosphere that’s great for mould growth. Mould on plant soil isn’t a big deal, but it can be harmful to humans because it can also lead to black mould on walls etc.
Another reason I water less in one go in winter is it reduces the moisture in the air.
In winter we have quite high humidity, so we use a dehumidifier. The plants aren’t bothered and we can water them with the water it collects.
Try to keep your humidity balanced or on the lower end (60% or below. It’s more important that your plants are warm and a humid warm is harder to heat.
Your plants may never notice the seasons
For those of you that live in new, super-insulated homes, or that have to keep the heat high for whatever reason, your plants may never notice it’s winter – especially if you have good light/lots of grow lights.
If the differences between the seasons don’t really impact your home environment then there’s no reason why you can’t have abundant house plant growth year-round.