How to Overwinter Plants Indoors with Grow Lights and a Grow Tent
How to Overwinter Plants Indoors with Grow Lights and a Grow Tent
How to Overwinter Plants Indoors with Grow Lights and a Grow Tent
As summer comes to an end and nighttime temperatures begin to fall, many gardeners face the same question: what should you do with the plants you’ve spent all season growing?
Tender herbs, citrus trees, tropical plants, ornamentals and other container plants may thrive outdoors through spring and summer but struggle once cold weather arrives. Instead of letting those plants die back or trying to squeeze everything beside a sunny window, an indoor growing space can help extend the season and keep selected plants healthy until spring.
Why Outdoor Plants Struggle When You Bring Them Inside
Moving a plant indoors protects it from freezing temperatures, but temperature is only part of the equation.
One of the biggest changes is light. Even a bright room provides very different growing conditions from the outdoor environment. Iowa State Extension notes that even the brightest indoor locations receive only a fraction of the light intensity plants experience outdoors, which is why supplemental lighting may be needed.
Plants also encounter lower humidity, reduced air movement and different temperatures indoors. Heating vents and radiators can make the problem worse by creating localized hot, dry conditions.
Overwintering Doesn't Have to Mean Barely Keeping Plants Alive
There are different ways to overwinter plants. Some species benefit from a dormant or semi-dormant winter period, while others can continue growing indoors when their environmental needs are met.
Herbs are a great example. Basil can be grown indoors throughout the year, while rosemary, oregano, thyme, parsley, mint, chives and other herbs can also be grown or overwintered indoors. Supplemental lighting is particularly useful during winter when natural daylight is limited.
The goal, therefore, doesn't always have to be simply keeping a plant alive until spring. With adequate light and the right environment, your indoor space can become an extension of the growing season.
Why Use a Grow Tent for Overwintering Plants?
A grow tent isn't necessary for every plant. A bright window may provide enough light for some species, particularly those being maintained rather than actively grown.
For gardeners overwintering multiple plants, however, a grow tent creates a dedicated environment where lighting, airflow and humidity can be managed together. It also keeps plants and growing equipment organized in one space rather than spreading them throughout the home.
Make Better Use of Your Grow Light
The highly reflective white PEVA interior of the Active Grow Walden White Grow Tent redirects light that reaches the tent walls back toward the growing area, helping improve light utilization and distribution around the plant canopy.
This is especially useful when growing multiple plants at different heights or arranging smaller containers together under LED grow lights.
Unlike the dark interiors and reflective metallic materials commonly associated with traditional grow tents, the Walden's bright white interior also creates a clean environment for viewing and caring for plants.
Give Plants Consistent Light Through Short Winter Days
Winter doesn't just bring colder temperatures—it also means shorter days and, in many regions, long stretches of cloudy weather.
Grow lights allow you to provide a consistent photoperiod regardless of what's happening outside. For example, university extension recommendations for indoor herbs commonly suggest roughly 12–16 hours of supplemental light, depending on the plant and growing conditions.
Using an automatic timer makes it easy to maintain that schedule while still providing plants with a regular dark period.
Choosing an Active Grow Light for Overwintering
Not every overwintering plant needs the same amount of light.
Plants that simply need to remain healthy until they can return outside may require substantially less light than herbs or edible crops that you want to actively grow and harvest throughout winter.
For many indoor gardening and overwintering applications, Active Grow Sun White and Sun White Pro spectrum LED grow lights provide broad-spectrum white light designed to support healthy plant growth while maintaining a natural-looking growing environment.
Higher-light applications can be paired with more powerful Active Grow fixtures when greater intensity is required.
Why the Walden 3-Tier Works Especially Well for Winter Growing
Floor space becomes valuable when outdoor plants suddenly need somewhere to live for several months.
The Walden 3-Tier White Grow Tent turns a relatively small footprint into three growing levels. Each shelf can support plants under its own lighting, making the system particularly useful for herbs, seedlings, smaller houseplants and other compact crops.
By taking advantage of vertical growing space, the 3-Tier design also means you don't have to dedicate an entire spare room to keeping plants under grow lights.
Don't Bring Outdoor Pests Inside With Your Plants
Before moving plants into their winter growing space, inspect them carefully.
Outdoor plants can carry aphids, spider mites, whiteflies, scale, mealybugs and other pests indoors. Inspect the foliage, stems, soil, containers and even the underside and rim of pots. Washing foliage and isolating newly imported plants from established houseplants can help identify problems before they spread.
This step is especially important when several plants will eventually share the enclosed environment of a grow tent.
Give Plants Time to Adjust
Moving directly from summer sunshine into an indoor environment can stress plants.
A gradual transition is generally better. Oklahoma State University Extension recommends acclimating outdoor plants to reduced light before permanently moving them indoors, while also completing the transition before damaging cold temperatures arrive.
Some leaf yellowing or dropping may still occur as plants adjust to their new environment. What matters is providing appropriate conditions for the new growth that follows.
Remember That Winter Watering Is Different
Plants growing indoors often use water differently than they did outside during summer.
Lower temperatures, reduced evaporation and changes in plant growth can all affect how quickly containers dry. Rather than maintaining your summer watering schedule, check the growing medium and water according to the needs of the individual plant.
Overwatering can become a bigger problem indoors, particularly for plants being maintained rather than actively grown. Extension guidance similarly recommends reducing watering frequency after outdoor plants transition indoors.
Don't Forget Airflow and Humidity
Light is only one part of a healthy indoor growing environment.
Air movement can help create a more consistent environment around the canopy, while tropical plants in particular may struggle with the dry conditions created by winter heating. Keeping plants away from heating vents and other extreme temperature fluctuations is important.
For growers who want greater environmental control, ventilation, circulation and humidity management can turn a basic winter growing space into a much more controlled indoor environment.
Coming Late Fall 2026: More Control with Active Grow EDGE
Active Grow’s new Edge Series is designed to make managing the growing environment inside a Walden White Grow Tent even easier. The system brings together environmental control, ventilation and air circulation, lighting control, and humidity management to help create a more consistent indoor growing environment throughout winter.
The Edge Series includes the Edge Controller, inline and oscillating fans, humidification, and lighting control, creating a coordinated system for managing your Walden growing environment.
Available late Fall 2026.
What Plants Can You Overwinter Indoors?
The list is extensive, but good candidates can include:
Herbs: rosemary, oregano, thyme, parsley, mint, chives and others
Edibles: selected peppers and other container-grown crops
Tropical plants: many tropical foliage and flowering plants
Citrus: container-grown lemon, lime and other citrus
Ornamentals: tender perennial container plants
Houseplants: plants that spend their summers outdoors
The correct winter strategy depends on the species. Some plants should continue actively growing, while others benefit from cooler temperatures and reduced growth during winter.
FAQs
Bring tender plants indoors before temperatures fall low enough to cause cold damage or frost. The exact temperature depends on the plant, but tropical plants and many warm-season crops can become stressed well before freezing. Whenever possible, transition plants gradually from full outdoor sunlight to a more protected, lower-light location before moving them completely indoors. Inspect plants carefully for pests before placing them near other indoor plants.
For plants that you want to keep actively growing, 12–16 hours of light per day is a useful general starting range, although the ideal photoperiod depends on the plant species, light intensity, and your goals. Plants being maintained in a slower-growing or semi-dormant state may require less light. Use a timer to provide a consistent schedule and give plants a regular period of darkness each day.
Yes. A grow tent can provide a dedicated, controlled space for overwintering plants indoors, particularly when natural window light is insufficient. Pairing a grow tent with LED grow lights allows you to provide consistent light while making it easier to manage airflow, humidity, temperature, and plant organization. A reflective white interior, such as the interior of the Active Grow Walden White Grow Tent, also helps redirect light toward the growing area.
Many container-grown plants can be overwintered indoors, including citrus, tropical plants, herbs, peppers, houseplants, and tender ornamentals. However, different plants require different winter conditions. Some can remain actively growing under supplemental light, while others benefit from cooler temperatures and a period of reduced growth or dormancy. Research the specific needs of each plant before deciding how much light, water, and warmth to provide.
Not always. Some plants can overwinter successfully with adequate natural window light, especially if they are entering a period of slower growth. However, supplemental grow lights can be beneficial when natural winter light is limited or when you want plants to continue actively growing. LED grow lights provide a consistent light source regardless of shorter days, cloudy weather, or the location of your indoor growing space.
Build a Winter Garden Instead of Ending Your Growing Season
The arrival of fall doesn't necessarily have to mean the end of gardening.
By bringing appropriate plants indoors before damaging cold weather arrives and providing the light and environment they need, you can protect favorite plants, continue harvesting selected edible crops and start the following spring with established plants instead of beginning again from scratch.
An Active Grow Walden White Grow Tent paired with energy-efficient Active Grow LED grow lights provides a dedicated space for doing exactly that—whether you're protecting a few favorite plants or creating an indoor garden that continues producing throughout winter.