How to prep your indoor plants for winter so they don't die
With winter on the way, it's time to prep our precious indoor plants for the colder months to make sure they get through happy and thriving, not dead or barely surviving. I remember my first 'winter with plants' when I had enough of a collection of valuable plants to worry about them making it through. Following these tips, I would have had nothing to worry about. Okay. True. Less to worry about (I worry a lot).
Soon 'Winter is Coming' won't conjure up pictures of dragons, wolves and White Walkers. But until that day, I'm going to milk that Game of Thrones reference just a bit longer. Because winter is coming. And for the plant addicted, winter can be a tad scary.
Summer is just SO easy. Root rot what? Often the biggest issue is just keeping up with watering the thirstiest chaps in the jungle, without going overboard and ending up with fungus gnats. Overwatering seems impossible.
Come winter, root rot becomes a serious reality and the #1 killer of houseplants over winter. Overwatering is SO easy to do in winter. And overwatering can mean a swift death sentence compared to underwatering. Plus our plants can fool us into overwatering them if we don't know better.
But water's not the only winter worry. Find out how to get your house plant jungle prepped for winter, and what to do (and not to do), to get them through the colder months.
#1. Aziz, light !
(that reference is for you Fifth Element fans)
If you're lucky like me, and get lots of light at your place, winter is wonderful. Instead of paranoid opening and closing of curtains and blinds to make sure no-one gets cooked as the sun moves around the house, now you can chill.
Winter sun - even direct - is weaker than our intense summer sun. Some plants you would normally never dare place in the path of direct sun, can thrive over winter with a little sunbathing.
Great for a bit of sun stress (of the good kind), to colour up your plants too. Keep your Ficus Elastica Ruby red, and give your Tineke a soft blush. Keep Syngonium pink, and Pink Bubbles from reverting. An absolute necessity for your String-of and Chain-of everythings to get them through winter. My String of Pearls HAVE to move to the windowsill for hours of direct winter sun a day to get enough direct rays not to die off over winter at my place.
Most of our indoor plants need more light over winter, so even if direct sun is a no go, move your jungle closer to sources of light. Remember winter also means shorter days, so that means fewer daylight hours, so shift your plants in the best position to make the most of what they can get.
If you're worried it's all a bit low light to keep your jungle going, even with shifting them to new locations for winter, grab yourself a little grow light for a few hours of extra light every day.
#2. Bye bye dust bunnies
With more daylight hours and much brighter light in summer, a light coating of dust isn't too bad. Enough light can get through for plants to get by. But come winter, those dusty leaves can cause health issues, and when dealing with less light and drier air, clean leaves that can breathe and photosynthesize become even more important.
Grab a soft, damp cloth (I use a microfibre cloth but make sure you get one that hasn't been treated with anything), chuck something on Netflix to binge watch, and get wiping. It's very therapeutic. I use the Plant Runner Neem Oil Leaf Shine for mine, but have heard a lemon juice and water mixture also works well. The Plant Runner Leaf Shine isn't a silicon type of leaf shine that clogs your plant's pores or leaves an artificial glossy shine, and a little goes a long way.
If you're not in the mood for a leaf-by-leaf wet wipe, chuck everyone in the shower for a good rinse, or work those hand muscles and get the spray mister out and banish those dust bunnies. Remember even with a good shower rinse, dust can be pretty stubborn, so you will likely still need to wipe at least the newer leaves (who do a lot of the heavy lifting for photosynthesis).
Speaking of cleaning, what are your windows looking like? Dust, dirt and mineral deposits can build up on glass, letting less light in to reach our precious plants. They might need a good spring clean too as part of your winter prep while you're in the cleaning mood (and if you feel like cleaning mine too, yes please, I never seem to be in this magical thing called 'cleaning mood').
#3. Warm and toasty (but not too warm)
Most of the indoor plants we love come from climates that stay warm, bright and humid all year round, with a 12 month growing season. Put them in a typical kiwi house over winter and they may be missing home pretty fast.
If your place gets below about 10 to 15 degrees indoors on the regular over winter, consider an oil heater or similar in the room your plants are in, set to come on when the temperature drops, to help your plants get through winter. Mine gets set to 15 as some of my jungle are less tolerant of those overnight lows.
Plants who thrived on windowsills during summer usually need to be moved further away from the glass over winter nights as that can be one of the coldest places in a home. Also shift plants away from the path of cold drafts, and warm drafts too such as the path of air con units, and set back further than you might think away from heaters and fireplaces which can scorch delicate leaves.
#4. A dry cry for help
Beware some heat sources. Many dry the air. The trusty HRV, DVS and air con units are all common culprits for this. Even a toasty fireplace is bad news for our humidity-loving indoor plants.
Weird as it sounds, another danger from dry air is root rot. That's because our plants are fooling us. Dry tips, crispy edges, all signs point to thirst, right? But don't fall for it!
Check that soil. Go down as deep and close to the roots as you can (honestly, get a soil moisture meter, total winter water game changer to avoid root rot). Don't be surprised if you find that soil's plenty wet still. Those signs that look like thirsty roots, are more likely a cry of attention for humidity. If you'd fallen for it and watered, you could easily lose your plant to root rot, when all they needed was humidity.
Used to high humidity all year-round in their natural climate, many indoor plants can really suffer over winter. Invest in a couple of humidifiers (those H2O portable cordless humidifiers are a game changer).
Misting and pebble trays barely make any difference, if at all, over winter (or summer for that matter). Shifting plants into the bathroom? Same problem. Barely enough humidity for long enough to make much difference (plus many bathrooms are designed to dry fast, and stay cooler and drier than the rest of your home).
Smaller humidifier models like those H2O humidifiers (like the one above), are very localised, so only make the air more humid directly around your plants, without risking a damp house. Some plants need higher humidity all year round but even the most hardy indoor plants can benefit from a humidity boost to get through dry winter days.
#5. Water can be a death sentence
This one might be a no brainer for you, but in my books it's best never to assume what someone does and doesn't know. Like washing hung out to dry in summer vs winter, everything stays wetter longer in winter, including your plant's soil.
Plants need less water in winter. Sometimes a thirsty, twice-weekly water-lover can drop their demands down to every 2 to 3 weeks or less over winter. Keep watering at summer levels and that might be the end of your relationship.
Watering too often is WAY more serious than not enough. Winter and root rot go together. And root rot can mean a sudden death sentence. Don't risk it. Some plants DO go dormant or die off over winter (I'm looking at you Miss Caladium), so don't need water at all over winter. Cacti would be another one you might want to give watering a miss over winter. Succulents I'd drop down to every 3 to 4 weeks depending on your conditions. ZZ maybe once a month, again depending on conditions.
In general though, read up on your individual plant's needs, and check that soil down at root level before you water, and you should get through the winter water worries sweet as.
If you don't have something that checks moisture levels down at root level - like a Sustee (that's the thing in the plant above), or a cheapy Water Meter or those clever little Soil Sensors - then at least grab a thin wood dowel (like a kebab stick) and stick it on down there. Take it out after a minute and see if the tip has changed colour or not. If it's dry, water away.
For Sustee it's really easy. Wait till window changes colour from blue to white. Only water when white. Those Soil Sensors also change colour. You press the sensor and a different colour lights up depending on the moisture level from wet, moist to dry. Whatever you choose, a moisture sensor of some kind takes a los of stress out of watering in winter.
#6. No wet feet
It's even more important to let plants fully drain in winter after watering, before putting them back in their cover pot. No wet feet! Even for ones I'm chill about bottom-watering in summer, or watering in their cover pot and tipping excess out later when I remember, I get paranoid about over winter.
For my African Violets I set a timer when I bottom water. For anyone else I change from a mix of bottom or top watering in summer, to only top watering in winter, to remove the risk of over-saturating the soil and drowning roots.
Don't underestimate the harm poor soil can do in winter also. If your plants are not ones that like staying wet, a substrate that has high water retention is all very well and good in summer, but could be a death sentence in winter. Consider repotting before winter into a light, airy, free-draining mix instead.
Keep in mind that repotting, or potting up, is a big deal for plants to cope with, so I'd only recommend it if really necessary to fix poor soil that stays waterlogged too long. I love the Bioleaf Potting Mix which is a super free-draining pre-mix of orchid bark, fern fibre, pumice, worm castings and more, already done for you, or you can DIY your own potting mix using these separate substrates and make your own.
Either way, use this guide for what to do and not do when repotting so your plants don't die to help your plants recover without complications.
#7. Dead growth? Or no growth? You choose
As so many of our indoor plant faves come from environments that stay warm and humid all year round, they don't die off or go dormant over winter in their natural home. They are used to a 12 month growing season, where they simply speed up or slow down, but grow all year-round.
However winter can be struggle street for them in NZ, so don't make it any harder on them than it has to be. Many will put growth on go-slow - but not stop altogether over winter - so to get them prepped for winter growth (and spring growth around the corner), give them a tidy up. Get rid of those dry, crispy bits, and chop off old or dying leaves.
That old growth won't magically regenerate over winter. Instead your plant may put precious energy in to dying leaves, when that winter energy is best used for winter growth, and getting ready for spring. Don't make your plant choose between one or the other!
Roots that grow the moment you look away in summer, can get stubborn in winter, but there's no reason you can't chop and prop your way through winter if you spoil your babies with a bit of extra heat, light and humidity. That way they'll be ready for potting up come spring when the serious growth kicks in.
Get those String of Turtle strands (lush Turtle goals above), and baby PPP safely tucked up in a Grow Pod for extra light and humidity to survive over winter. You can also pop those wishlist babies on a heat mat to get root growth humming. Without enough warmth, cuttings may rot and die, rather than root.
Dip new cuttings in rooting hormone (I mainly use the Clonex brand), to protect from root rot and speed-up development of those first roots. Get a dome or a counter-top grow house (the Elho grow houses come in medium and small), or a glass tank like an Exo Terra terrarium to keep that precious heat and humidity in. Grab yourself a grow light and you can prop and grow all year-round.
Right now I have an Exo Terra terrarium set-up myself. Inside I have an Egmont heat pad I currently switch on in the morning and off at night (but in winter will probably leave on 24/7), an H2O Mini humidifier, plus 2 Grow Bars on top with the timer set to 8 hours a day.
Simple but super effective, so I can propagate through winter and I also put my heat and humidity loving babies in there who need a little TLC to survive winter. Right now that includes a one-leaf, corm-grown Alocasia Dragonscale, baby Philodendron Pink Princess and a Manjula Pothos baby in there, along with heaps of cuttings.
PS: Who says you can't keep growing delish, fresh herbs and veges right through winter too. Chefs unite. These epic Hydro Smart Gardens are the bomb. Pizza with fresh basil anyone? Speaking of food, what about feeding your plants in winter? ...
#9. To feed or not to feed? That is the question
Many house plant hobbyists deprive their plants of food over winter. All good if your plants legit go dormant and stop growing altogether. Except many of our jungle are used to growing all year-round in habitats that stay warm, humid and bright.
So for many it's go slow, not stop, when temperatures drop. Unless you've got a no-go grower, let nature decide how much you feed. Simply because watering drops so significantly, so does how much you feed along with it.
No way I want deficiencies building up over winter impacting all that lovely spring growth, so I do the 'weakly weekly' method which simply means feeding lightly, every time you water, all year round. I let my plant's reduced water needs dictate the amount of fertiliser they need.
What you can skip if you like, is the growth boosters. The way I think of them is like your car's accelerator. Fertiliser is the fuel in the tank, and growth boosters are like putting your foot down on the accelerator. Whether natural or synthetic, products like the fantastic Groconut or cult-favourite HB-101, get growth humming. If you want to give your plants 'a rest' as such, winter's the time to ease up on the growth boosters, and cut back to just your trusty plant fertiliser instead to get them through.
Keep in mind if you do keep giving growth boosters over winter, definitely keep up the fertiliser, or the growth booster will deplete your plant's stores of nutrients faster than usual to fuel that fabulous growth, and you could end up with deficiencies come spring. Ouch.
There's a more detailed article that looks at the reasons behind Should you fertilise indoor plants in winter? which is well worth a read, which also explains more about the 'weakly weekly' method.
#10. Pest alert
Unfunnily enough, creating an ideal environment over winter for our indoor plants, can also be heaven for bugs to thrive through winter too. If you have any outdoorsy types who come inside over winter, make sure they don't bring any unwanted guests along with them into the warmth! Quarantine your outdoor plants separately for at least 4 weeks (that's about the shortest period to covers the lifecycle of most pests), before they get too cosy with their always-indoor buddies. I prefer to keep mine separate.
Also keep inspecting your indoor babies for pests the same as you would over summer. I'm a big fan of using nature to protect from bugs so they don't get established in the first place, so a silicon supplement (nature's bug protectant), is a goodie. I use the Dyna-Gro one called Pro-TeKt (I know, good name huh).
#11. Don't flush feed
Some fertilisers recommend flush feeding, where you do a flush of plain water first, then feed with fertiliser second. That makes me worry straight off the bat , because that can be a sign of a lower quality fertiliser that has a higher risk of fertiliser burn.
At any time of year I'd avoid any food with a higher risk of fertiliser burn anyway. If you need to use up the fertiliser you have, and don't want your plants to go without, then instead of flush feeding over winter, I'd feed about a quarter the dose of fertiliser, and wouldn't flush feed full stop.
Even in summer I don't flush with plain water before I fertilise. With a good food there's no need. Roots are like tiny sponges. There's only so much water they can absorb before they become saturated. If you flush first, feed second, they've already sucked up all that lovely water, without any essential nutrients with it, and the nutrients could simply be washed away.
#12. Step away from that soil
Repotting a plant is like surgery is for us. It's a major, sometimes with some serious recovery care required. The best time to repot most plants is from spring to autumn, when a plant's all about that growth. Roots often have a growth spurt late autumn leading in to winter, so you can repot later in the year than you might think.
Worst time to repot? Yep, winter. Of course if you HAVE to repot, like really hand-on-heart have to, pop your plant in recovery afterwards. That means warmth. A heat mat is pretty much a must for recovery from winter repotting in my books. Or, you know, just don't do it! This guide to repotting has a great section on recovery.
There you have it. 12 winter prep tips and tricks to get your precious indoor plants through winter safe and sound. If you found this helpful, please do give it a share. Shout outs much appreciated!
by Anna @lovethatleaf