Many of the flowers and plants we grow in Alberta are annuals here. But many of those plants are technically perennials, in other parts of the world. They just really can’t hack those 10-14 days of -30ºC to -40ºC that we get in February. It's only a few days in Central Alberta anyway. They get many more -40 days up north.

We buy these gorgeous flowers in the spring, tuck them into our pots and hanging baskets and flower beds, and then sadly send them to the compost bin come September or October. But we don’t have to. Many of the flowers we mourn when the frost hits (like it has the last couple of days here) are tender perennials. So they would survive through the winter just fine in warmer regions of the continent. Heck, even warmer parts of Canada, like the west coast (best coast). With its growing zones of 7-8-9. It's Canada’s gardening mecca.

I’m not bitter or envious at all over here in chilly zone 3. Definitely not. Why do you ask?

Many of these tender perennials are plants that we could overwinter indoors and set them back outside next spring, bigger and better than ever.

First, it's essential to know which plants are tender perennials and which are annuals. Annuals are designed to grow hard and flower profusely for only one season. They are not going to reward you next year if you bring them in for the winter. Plants like petunias, calibrachoa, and pansies won’t bloom as beautifully next year, so there’s no point in overwintering them.

Plants to Overwinter Indoors

There are a surprising amount of plants you can overwinter indoors. Here is a list of plants that I know you can bring inside for the winter: geraniums, coleus, begonias, impatiens, fuchsias, dracaena, hibiscus, hot peppers, herbs, and most succulents.

I’m sure there are plenty more that you can bring in, but those are the ones I’m most familiar with. A quick google search about your plant should tell you whether it's perennial or annual. If it's a perennial, you should be good to bring it in. This year, I’ve brought my Lemongrass indoors because I rooted them from the grocery store pieces, so I don’t want to let them die. We’ll see how it goes.

Taking Cuttings vs. Overwintering the Whole Plant

There are two main ways to overwinter your tender perennials. You can bring the whole plant indoors, or you can take cuttings to start new clone plants. It depends on the amount of space and how many bright sunny windows you have.

Got lots of south-facing windows and lots of space? Maybe you want to bring the whole pot in.

What are the benefits of overwintering the whole plant? Your plant will keep getting bigger and bigger every year. We used to do this with dracaenas. I don’t know what variety, we never paid attention. But, we’d bring them inside in their pot every fall. Eventually, they got so big that they wouldn’t fit in our house anymore.

We ended up donating them to a local college, and they lived in their science building for many more years. I’m sure they were nearly 15 feet tall by the time they finally died. I assume they died from lack of nutrients, as I don’t think they ever got repotted after leaving our house.

So, if you’ve got the space, and you’d love to have some large statement plants on your patio in years to come, this is a fun way to grow the biggest version of a plant in your neighbourhood. You do have to take a little more care to get them ready for coming inside. I’ll cover that later.

If you have significantly less space, the other common way is to take cuttings from your plants. Most plants can be propagated by cuttings. Propagating involves cutting a little slip of a plant, 4-5 inches of stem from a healthy young branch of the plant, and rooting it for next year. Check the underside of leaves and the stems for pests and remove them if you find them.

Taking cuttings is the best bet if you have a smaller place or less window space. I have done this with geraniums and silver nickel vine this year. I took 2-4 slips from each geranium, trimmed off most of the leaves and have placed them in pots of soil, near a sunny window. The other benefit of this method is that you’re less likely to bring unwanted pests indoors. Which I’m about to get too.

Dealing with Pests

Outdoor potted plants are likely to have some critters living with them. We don’t notice pests on outdoor plants as quickly as we do on indoor plants. Things like aphids and gnats and mealybugs and scale may have established themselves in your outdoor plants.

You may also have ants building a cozy home in the bottom of your pots, entering through the drainage holes, and slugs hiding out under the cool, damp base of containers. There’s probably spiders building safe, dry homes under the rim of your pots, too.

Here’s the thing to keep in mind, PESTS AREN’T BAD.

Bugs are critical to our environment. Yes, they can potentially cause damage to your plants, but we don’t want to rid the world of them, or we’ll rid the world of us too. BUT, you’ll want to deal with them as best you can before you bring your whole potted plants inside.

How to Address Pest Infestations on Outside Plants

First, give all the pots a thorough cleaning. Wipe down all the sides, under the rim, and the bottom of the pot. If it's a bigger pot, you may even want to give it a spray off with the hose before you wipe down with a cloth, brush, or sponge. Check under the rim and the bottom of the pot for pests. Then clean the drip tray too.

Was your plant in a huge pot with a bunch of other plants for the summer? You may want to consider repotting it into a smaller pot for the winter. This will also allow you to give it some fresh soil.

Once your pots are clean, check the plant itself for pests, look at the underside of every leaf.

Yes, every single leaf.

Check the stems, particularly where smaller limbs branch out from the main stem.

Start dealing with any pest infestation you find, however you prefer. If it's small, you may be able just to use rubbing alcohol and q-tips to kill the bugs. If it's big, you might want to try the dish soap method or Safers insecticidal spray (I assume there are other brands, but Safers is what I’m familiar with).

How to Bring Your Whole Plant Indoors for Winter

There’s a big difference between outdoor growing conditions and indoor growing conditions. What follows is the recommendation that all the big gardening sites and books make.

This process should take about 5 days before your plants are fully acclimatized to indoor living. And then, ideally, you’ll want to keep them quarantined indoors for another 2 weeks, away from all your houseplants, to make sure all pests are dealt with and don’t spread to your other plants.

Day 1: Get Shady & Clean

Move the plants you want to bring indoors to a shady spot in your yard. They need to adjust from bright light to lower light levels, so group them all together somewhere that they’ll be in the shade all day.

Start your cleaning, repotting, and inspect pests. Prune back any plants that need it, quite a bit. You can safely take off up to 1/3rd of the total volume. Cut off any browning or dying leave, trim brown tips off of things like dracaena.

Prep a place indoors that you can quarantine your outdoor buddies away from your houseplants. Ideally, it should be easy access to the door, so you can bring them outside.

Got a garage? Perfect!

But, you’ll want to do indoor quarantine somewhere else, because your garage likely doesn’t have enough light to keep your plants happy for 2 weeks, unless you’ve got large windows in it.

Day 2: Garage Sleepover

Bring all your plants indoors for the night. If you have a garage, and some garden carts, or steal your kid’s wagon, set your plants on the cart, pull them in at night.

Day 3: Back Outside in the Shade

Take your plants back out in the morning, to the shady spot, put them back inside in the evening, just before dark.

Days 4-7: Lather, Rinse, Repeat

Repeat this process. Put them back in the garage or house in the evening just before the sun goes down. Repeat this process every day for 3-4 more days. Shorten their outside time by an hour or two every day, until they’re not going out at all anymore.

Now you’re safe to bring your outdoor plants inside to your quarantine space.

Days 7-14: Daily Inspections for Stowaways

Check your plants daily and keep your eyes peeled for pests. Treat as needed. Once your plants have been quarantined for 14 days, and you don’t see any new signs of pests, you can move them to a more permanent winter location, ideally near a south window.

Full Disclosure: I do not do this whole process... I still have successful plants, but they’d probably be even better off, and I’d have fewer pest infestations than if I did this.

Tips For Keeping Your Plants Happy Over Winter

Don’t fertilize
Don’t water too often (check the soil with your finger, but don’t water until it feels dry to a depth of an inch or to your first knuckle.

How to Taking Cuttings for Propagation

If you decided to take cuttings instead, you can root cuttings in two ways:

You can put the stem cuttings in water, and let them grow roots, then plant them into pots.
You can put your cuttings straight into fresh potting soil.

I used 4-inch square nursery pots for my geraniums, and I put a cutting in each corner of the pot. The thing about taking cuttings and putting them directly in the soil is that you need to make sure the soil stays damp until they root. So don’t let the soil dry out, but don’t make it saturated wet either, because that will just cause rot.

I’m rooting my silver nickel vine cuttings both ways. I have 3 cuttings in a pot with soil, and I have a few rooting just in water. I don’t know how the roots are doing in the soil ones. I haven’t checked yet. The ones in water are starting to grow tiny roots.

If you’re doing the water propagation method, be prepared for it to take awhile. Like, a few weeks. Change the water for fresh stuff every few days.

I took the geranium cuttings on October 7. I brought my lemongrass indoors, too, a few days before that. The lemongrass was all in individual pots around the yard, so I dug out all 4 plants and stuffed them all in one pot together. This is probably not ideal, because it means it’ll be nearly impossible to separate them next year, but I’m ok with that.

Anyway, if you haven’t done this yet and in Central Alberta, I’d recommend getting at it ASAP. We had -4 last night, and it started snowing today. So if you want to save them, get started on it today if you can.

If you’ve gotten frost and the leaves on your plant are all brown and wilty already, it might be too late. But, you could try cutting back the dead foliage and moving the pot it inside anyway. The roots may still be viable, and they may come back if you bring them inside.

How to Save Your Favourite Outdoor Plants: Bring Them Inside!