#HouseplantVacation is Over For the Season. Here's What to Do. And When.

I wrote this article originally for The National Garden Bureau, of which I’m a proud member. However, the info is so important, I asked to reprint it here for the benefit of my readers too . I hope you enjoy it and find a few tips for making the transition from garden plant to houseplant, a smooth one. You can find much more information on bringing them back outside in the spring in Tropical Plants and How to Love Them. – MW

If you’ve been using your houseplants outside this season, by the end of the summer, many of those indoor/outdoor plants are looking their very best, having enjoyed elevated levels of warmth, light, humidity, and fertilizer over a long season. Added sunshine, rain, and ventilation is just the spa vacation we all need after a winter cooped up indoors!

But the days are starting to noticeably shorten, and the temperatures are cooler in the mornings and evenings. It’s time to think about bringing them in – so how do bring those newly vibrant houseplants inside without bringing in pests, or shocking them with a different environment?

Bottom line: The longer you wait to start the process, the harder it’s going to be on your plants – and eventually on you. Here’s five easy steps to make it super successful.

1) Make the transition less painful – Start sooner than you think

For the most part, houseplants are tropical plants that cannot be left outside in cold climate gardens. Although they may be rubbing shoulders right now on your deck or in your garden with other tropical plants that you may have grown specifically for your outside garden, your houseplants are intended to beautify your indoor space.So, where you might allow some plants (such as canna and elephant ears) to go dormant as the weather gets increasingly colder and bring them into your garage for storage; or where you may send others to the compost pile; your houseplants will act as indoor décor during the long months of winter, and you want them looking their best.

Houseplants bring so much to the outside garden, and paired with other tropical plants can look even better than they are. Here a common pothos and snake plant pair with a rex begonia vine to create something beautiful for the season.

To make the transition less painful, give the plants as little change in environment as you possibly can. That means moving them inside before those indoor/outdoor differences become too great – particularly nighttime temperatures.

Though you may not notice any differences in your houseplant-to-be, and let the days get away from you, metabolic changes are happening within the plant to cope with lower temperatures. If you wait until the 11th hour on the night of your first frost and haul them indoors to a drier, warmer, lower-light position, they will most likely react by dropping a lot of leaves.

This isn’t the best way to begin an indoor romance. Or stay in love with the houseplants you bought this season.

Watch your outdoor night-time temperatures. Before they are consistently in the low-sixties, do some ‘furniture rearranging’ outside with your other plants, add a few fall fillers from your local garden center, and quietly remove and protect the houseplants that will function as houseplants for the next few months indoors.

Houseplants can be used in so many cool ways in the garden during the growing season. Here, a white and green ‘Saturn’ snake plant adds an interesting texture to a terrific container display. This will be removed from the pots before it gets too cold and repotted indoors to grace a tabletop.

2) Bathe, Inspect and Evaluate

About two weeks before the temperatures start shifting in your region, it’s important to give your plants a physical. I like to give the plant a hose bath:

washing off dust and debris,
thoroughly soaking the growing medium, and
perhaps most importantly, inspecting each leaf and treating the plant for visible pests.

Treating a plant under drought stress or in direct sunlight is never a good idea.

Check each leaf of your plants carefully front and back for the telltale signs of pests. If not the pest itself, then leaf damage or indeed black mold which lives on the honeydew excreted by sucking insects.

Assess. Assess. Assess. Do you love it enough?

This check-up allows you to re-evaluate your romance with this plant. Do you want to commit the time, space, and energy to maintain this particular plant as a houseplant?

No guilt. Our feelings about a plant and whether it still works indoors can change based on the overall health of the plant, our life circumstances, and even summer furniture acquisitions. We have a much better winter when we pay attention now to the little feelings that tell us a relationship is over.

If you’ve allowed pests to become a major problem on the plant, this could be one of those red flags. And this is why we start two weeks before the plants are coming inside.

3) Treat, and Then Treat Again

Pests can travel into the house on ornaments and on pots, not just leaves. Make sure you check and treat all surfaces.

Hitchhiking pests such as aphids, spider mites, mealy bugs, and scale can rapidly become a problem in a warm indoor environment without insect predators, as the population has the ability to go through several life cycles. Inspecting and treating the plant using an IPM (Integrated Pest Management) approach, and doing so again two weeks later, gives you the best chance of keeping pest populations low indoors.For the most part, healthy plants mean low pest populations, and you’ve just spent a summer giving them the healthiest conditions you can. But this doesn’t mean that a few pests don’t lurk in the shadows.

Use an IPM Approach

IPM is an industry-utilized system of using the least toxic solution first when combatting pest populations. It’s a preferred approach industry-wide that recognizes the weaknesses and strengths in all treatments.When inspecting and treating plants coming indoors, begin by using a mixture of manual removal, horticultural soap, and horticultural oil. Horticultural soap is very effective on soft-bodied insects such as aphids, whereas horticultural oil works well on hard-bodied insects like scale by smothering them. Repeated treatments are necessary as there are several stages to a scale insect’s life cycle, and eggs may be protected by the bodies of adult insects.

Start with horticultural soap to try and remove the majority of insects using your fingers, rinsing with a hose afterwards – this is why it’s most practical to take care of these treatments while the plants are still outdoors. Then, spray with horticultural oil, using your hands to make sure it coats all parts of the plant, including the front and back of the leaves. Remove any leaves that are yellowed and/or heavily infested with insects, instead of trying to treat them. Do not forget to inspect the sides, bottom, edges, and rim of the pot too.

Remove Houseplant pests with horticultural soap

Giving a plant a bath with horticultural soap and a hose is fantastically freeing, as you don’t need to worry about indoor surfaces and can spray with abandon!

Say Goodbye

If the infestation is severe and the plant is of low value, after two treatments, it’s compost pile time. Plan on looking for that plant next spring if possible, and lose the guilt. Every time a plant dies, it’s an opportunity to change things up a little next year.However, if the plant is of high value, after two treatments you may want to resort to spot treatment with the appropriate chemical matched to the insect and their stage of development, and perhaps use a systemic granulated insecticide added to the soil to kill the remainder of the pests.

4) Find The Perfect Place & Don’t Forget Your Saucers!

Once you’ve committed to another beautiful winter indoors, you’ll need to decide where it’s going.Luckily, most houseplants have a range of light levels and temperatures they can handle. Take time to research your plant and know both what it wants, and what you can get away with. Sometimes you can get away with a lot, like putting a sansevieria in a low-light bathroom.

Sometimes, a poor position will kill it – such as giving a maiden hair fern just the right amount of light near an east-facing window…and directly over a heating vent. Know a plant’s rules before you bend them.

For your larger, floor-bound, or ceramic pot-housed plants, be kind to your back, and your floors. Use a furniture dolly and a helper to get them inside, and cheap furniture sliders to move them into place.If you’ve been gardening for many years, chances are you’ve ruined more than one indoor surface with an overwatered plant. We never think we have overwatered a plant until we come back and find it sitting on swollen, warped floors. Even if you are the most careful person in the world, it’s always going to happen. Save yourself the stress, invest in plastic saucers to go underneath the pretty saucers that you have.

Water issues are not just about drips. Condensation can build up between the saucer and the floor and cause mildew and disfigurement of the surface. Small spacers placed between the surface and the saucer will keep airflow from allowing this to happen.

5) Give Yourself a Schedule. It’s a Long Winter

It’s longer than you think when there are plants under your care.When we neglect a plant and its appearance starts to reflect that neglect, a curious thing starts to happen in our psyche: The worse it looks, the less we feel like dealing with it. This never ends well. Worst case: It dies. Best case: We end up with a plant that we can’t wait to throw outside (probably too early) and that will struggle for the first half of the growing season to get healthy.

Don’t build bad karma – give your plants what they need on a regular basis. Strong houseplants that are not picky high-maintenance partners need two main things from you during the winter months when sunlight is low and growth is slow: regular water, and regular pest inspections.Once you get on a schedule for a beautiful, home-enhancing tropical plant, it’s not much to ask. Save your fertilization for active growth in the spring, when you bring them back outside again.

Make sure you set up a schedule for watering your houseplants as soon as they get back in the house, even if it means a weekly bath instead. Pictured: various air plants.

Do a little research on your houseplants to see if they like it on the dry side or on the moist side (usually on the plant tag), and use that information as a guide only. Your house is different than other houses, and some areas of your house are warmer than others which will stimulate growth and subsequent water needs.

In general, plants are in their dormant season and do not need as much water as they do when they are growing outdoors. Watch your plants carefully and see how they are responding.

Creative ways to add Houseplants to your home

Figuring out where your houseplants are going to do best in your house is always challenging at the end of the growing season, but who knows the cool combinations you might come up with. Plants aren’t static – our décor shouldn’t be either!

A Full Year of Beauty – Brought to You By Your Houseplants

The season doesn’t have to end with the summer. Use those precious houseplants to create a versatile, beautiful living space indoors and out. The plants will be healthier, you’ll find yourself inspired to get creative with placement, and you’ll naturally edit the plants that don’t make you joyful.It’s a win-win – for the plants, and for you!