How Long Can Plants Stay in the Garage?

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Robby

Every year at this time, I am surprised by the motley group of containers that has accumulated in my basement for safekeeping through winter. This year there are the amaryllis bulbs I’ve been growing for ten years, the shamrock (oxalis) that summered outdoors, and sheared-back pots of chives, rosemary, and sage. Even though the space is chilly and dark, they will be safe and happy through the winter there, with minimal care.

I’ve been enjoying overwintering plants in garages and other cold spaces for many years, and while I’ve had many successes, there have been failures, too. Here are a few tips for overwintering plants in a garage or basement I learned through trial and error.

Many gardeners are familiar with the temptation of buying plants a little too early in spring. After a few warm days, it’s hard to resist picking up some flowers or vegetables from the greenhouse. But it’s still too cold outside to plant them. So where do you put them? The garage often seems like the perfect place to store plants until it’s warm enough to transplant them outdoors. But how long can plants actually stay in the garage before damage occurs?

The Dangers of “Garage Syndrome”

Leaving plants in the garage for more than a few days can lead to a condition called “garage syndrome” or “kitchen cupboard syndrome” This refers to the stress and damage plants suffer when kept in a poor environment like a garage

Though not an actual disease, garage syndrome can cause real problems for plants. Within 2-3 days, plants start aborting flower buds and young leaves The longer plants sit in the garage, the more damage occurs Symptoms include

  • Flowers dropping petals or becoming misshapen
  • Leaves turning yellow or showing odd growth
  • Stems thickening abnormally
  • Stunted growth
  • Loss of leaves and flowers
  • Twisted, drooping stems

What Causes Garage Syndrome?

Several factors contribute to garage syndrome in stored plants:

  • Stagnant air – Still, stale air lacks fresh oxygen that plants need. It also allows gases like ethylene given off by cars or decaying fruit/flowers to build up.

  • Temperature extremes – Going from warm greenhouse to near-freezing garage stresses plants. Lack of day/night temperature changes also disrupts growth.

  • Low light – Garages are often dark or dim, with little natural light getting through. Plants can’t photosynthesize properly in low light.

  • Fumes – Car exhaust contains ethylene as well as other pollutants that can damage plants.

  • Cold floors – Concrete garage floors cool plant roots and cause further stress.

How to Avoid Garage Syndrome

While garages make poor storage spaces for plants, you can take steps to minimize damage:

  • Harden off plants – Before going in the garage, set plants outside in shade for a few days to transition them.

  • Give airflow – Leave garage doors open a crack so fresh air circulates. Set up fans inside too.

  • Provide light – Supplement with grow lights or set plants near windows that get sunlight.

  • Moderate temperatures – Insulate pots or avoid placing plants on cold concrete. Move plants back inside if temps drop too low.

  • Limit exposure – Only keep plants in the garage for a few days, a week at most.

  • Check plants daily – Monitor for signs of stress like wilting or yellowing leaves.

Recommended Garage Storage Times for Plants

Different plants have different tolerances for garage conditions. Here are general guidelines for maximum garage storage times:

  • Seedlings – 1-3 days. Very vulnerable to stresses.

  • Annual flowers/vegetables – 3-5 days. Less hardy than perennials.

  • Perennials – 1 week. Mature plants withstand more.

  • Succulents/cacti – 2 weeks. Their thick leaves and stems retain moisture.

  • Trees/shrubs – 1-2 weeks. Established ones adapt better.

  • Tropical plants – 1 week at most. Require very warm conditions.

  • Fruit plants – 3-7 days. Avoid exposure to ethylene gas.

  • Roses – 3-5 days. Cold easily damages buds and flowers.

These times assume good garage conditions with airflow, light and stable temperatures. Adjust accordingly if conditions are poor. When in doubt, err on the side of less time in the garage rather than more.

Extending Garage Storage Time for Plants

If keeping plants in the garage for longer periods is unavoidable, a few tactics can help minimize stress:

  • Place plants up on benches or tables, not directly on the concrete floor.

  • Group plants together to conserve warmth and humidity.

  • Water sparingly since plants grow slower.

  • Use plastic sheets or row cover to insulate and retain moisture.

  • Opt for plants in larger containers that retain more soil moisture.

  • Check soil moisture often. Garage air dehydrates pots faster.

  • Provide strong lighting like LED or sodium grow lights.

  • Increase ventilation with fans supplementing open doors.

  • Move plants back indoors or under cover at night if frost threatens.

  • Avoid plants prone to cold damage like basil, impatiens, caladiums.

  • Don’t keep freshly repotted or propagated plants in the garage.

Signs It’s Time to Remove Plants from the Garage

Monitor plants closely for signals that garage time must end:

  • Wilting, drooping, or loss of turgor pressure in leaves and stems

  • Leaf yellowing or browning

  • Leaf or flower drop

  • Flower discoloration and damage

  • Lack of new growth

  • Aborted flower buds

  • Mold or rot developing on leaves or soil

  • Pale, elongated growth indicating light starvation

At the first such signs, quickly move plants back indoors or to a sheltered outdoor spot if nights are mild. Resume normal care and most will recover from short garage stays. Severe or prolonged stress may be irreparable, though. When in doubt, err on the side of caution with garage plant storage.

Key Takeaways on Garage Storage Duration

To summarize garage plant storage:

  • Avoid keeping plants in the garage for more than a few days if possible. A week at most for hardy plants.

  • Harden off plants before garage storage and check them daily.

  • Improve garage conditions with airflow, moderate temperatures, and supplemental lighting.

  • Adjust duration according to the plant type, its hardiness, and current conditions.

  • Monitor closely for stress signals and remove plants at the first signs of trouble.

  • Take steps to reduce plant stress if longer garage storage is needed.

A few days in the garage won’t harm most established plants. But use caution, monitor closely, and don’t overdo it. When spring planting time beckons, patience is a virtue where garage plant storage is required. The healthiest plants will come from proper hardening off and soil temperatures, not the garage.

how long can plants stay in garage

Avoid Temperature Fluctuations

Reduce the guesswork about watering by covering your whole collection of pots with an old blanket or flannel sheet. Also cover the plants when you temporarily heat the space for other uses. A cloth cover will reduce temperature changes and block light that might confuse the resting plants.

how long can plants stay in garage

Clean Up Containers Before Bringing Them Inside

With plants that have grown in pots outdoors all summer, I assume the top half inch of soil has gone salty, so I scrape it off and scatter it in the yard. Then I snip off dead plant parts, give the pots a quick wipe with a damp cloth, and move them into cold storage. After a few days, I check for signs of unwanted insects, earthworms or earwigs.

how long can plants stay in garage

How long can plants stay in a garage indoors?

FAQ

Can you leave plants in the garage?

Many of the best plants for overwintering in a garage or basement have bulbous roots designed to store nutrients and moisture through a dormant period. Amaryllis, oxalis, cannas, dahlias, and tuberous begonias hold moisture in their fleshy bulbs, tubers and corms, so very little supplemental water is needed.

Will an unheated garage protect plants from frost?

The key to success with garage storage is that this area is attached to the house but not heated. The garage never goes below 32 degrees but tends to hover in the 40’s and low 50’s all winter. This keeps the plant dormant but the plants never freeze.

Can plants grow in a garage?

Some of the best edible plants that will likely thrive in your garage environment include carrots, mint, tomatoes, lettuce, mushrooms, and kale. Most of these vegetables can be grown in pots or containers, so you can move them around as necessary to ensure they are getting enough light.

Can I leave my house plants for a month?

As long as you give all your plants a nice, long drink before leaving, they should be just fine until you return. Don’t go overboard, though– too much water (1) can have as negative impact on potted plants as not enough water. Not all plants require the same amount of water.

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