When Frost Hits, These Are the Plants to Protect First – And The Most Effective Ways to Do It
Make sure to move these tender plants indoors a few weeks before a potential frost
October and early November are typically when gardens in zones 5-8 get their first frosty nights. This means, for many, the time to take action and protect the most delicate of your plants is already here or not far off. Ideally, this should be done a few weeks before an anticipated frost.
Before freezing temperatures arrive, prioritize tropical plants and any houseplants that spent the summer outdoors. Their time has come for them to retreat indoors for winter. They are the most at risk around your yard and will thank you for the special attention. It won’t take long to protect plants from frost and ensure they live to see another season.
Here we reveal the first plants you should protect when the frost threat is imminent. This includes bringing houseplants indoors for the winter and protecting tropical plants in your garden. A plant caddy with wheels, like this two-pack of rolling wooden plant caddies at Amazon, can help you effortlessly move container plants indoors over the coming weeks.
Think Tender Houseplants First
It might sound like a no-brainer, but those that need consideration first are your most tender plants. These are damaged when temperatures drop and are usually killed once it hits 32°F.
There are different ways that gardeners tend to protect tender plants. They can be moved indoors, wrapped and kept outdoors, or lifted and stored for winter. The latter includes dahlias, cannas, gladioli, elephant’s ear, and caladium. But these can wait for now. When you lift dahlias and others on that list, wait until after the first frost before lifting and storing them.
Instead, there is another group of tender plants that need more pressing attention – that always need to be safely indoors ahead of the cold. These include houseplants that grow outdoors in summer and tender plants you can bring indoors to overwinter. That potential list includes pelargoniums, coleus, begonias, bromeliads, succulents, Boston ferns, and pothos.
These tender specimens make top winter houseplants that can then spend the warmer months outside to soak up the sun. However, tropical houseplants can suffer cold damage when temperatures get below 50°F, so these tender plants must be brought indoors first to prevent stress or harm.
‘Houseplants that have been brought outside during the summer months should be returned indoors a few weeks before a potential frost – when the temperature starts to dip to near 50°F is a good time,’ recommends Michael Jesiolowski, Plant Clinic manager at The Morton Arboretum.
‘Check for insects and apply insecticidal soap or neem oil before they are brought in.’
You can get ready-to-use insecticidal soap at Walmart to treat pests when bringing houseplants indoors for the winter.
Gardeners should be proactive and start thinking about bringing houseplants indoors for the winter well before the first anticipated frosts. When planning a fall gardening checklist, start with your tropical houseplants, which have the highest cold threshold, followed by ferns, succulents, and cacti.
However, as we all know, the weather is unpredictable, and there can be surprise early cold snaps. In the case of a premature frost warning, put any houseplants that may still be outdoors, along with other tender plants, at the top of your hit list.
Mirela Bajic, Senior Garden Designer at House Designer, says: ‘If I only had ten minutes before a frost, tender plants come first. Pelargoniums, tender salvias, young citrus, a light frost can wreck these outright, not just knock a few leaves off.’
It is better to start thinking about bringing houseplants indoors for the winter well in advance of any frosts. Monitor the forecasts and get them moved before nighttime temperatures reach 50°F. Succulents and cacti can handle short periods under 50°F, but it is better not to take the risk and move all houseplants sooner rather than later.
Michael Jesiolowski is the Plant Clinic Manager at The Morton Arboretum. The Plant Clinic is a leading source of science-based advice about trees, plants, and landscapes, helping gardeners and landscape professionals throughout the Chicago region and the world have healthy, attractive, well-chosen plants.
Mirela Bajic is a Senior Garden Designer at House Designer, with formal horticultural training and further advanced studies in garden design and horticulture. With a particular passion for biodiversity, wildlife-friendly planting and environmentally conscious design, Mirela enjoys helping clients create outdoor spaces that feel connected to nature while remaining practical for everyday living. Her expertise spans planting design, garden layouts, seasonal planting, outdoor living spaces and sustainable landscaping.
Don’t Forget Tropical Plants
Tropical houseplants top the priority list, but any tropical or subtropical plants across the garden will also need attention when night-time temperatures are forecast to drop. Add plants such as banana trees, tree ferns, aeonium, plumeria, and bird of paradise to the priority list for overwintering plants indoors.
‘For quick protection, keep it simple. Move what you can, fleece whatever's stuck outside, bring the genuinely tender stuff in if there's room,’ advises Mirela.
When frost is predicted, the most effective materials for overwintering tender plants are frost cloth, cloches, or even bed sheets to protect plants. You can get frost covers at Amazon to place over plants.
‘Frost cloth is best, but sheets or another breathable fabric works too,’ says Rebecca McLeod, a gardening content creator and ambassador for Digz Gardening. ‘If you're using plastic, be sure that it’s not touching the plant, as that will cause damage to the foliage it touches.’
Think About Containers Too
If you are wondering what should also be prioritized, Mirela Bajic says the order should be ‘tender first, containers second, anything newly planted third’.
Plants in container gardens are more susceptible to cold as they are more exposed. You can move pots together against a house, put them in a garage or sheltered area, or cover them with frost cloth or winter pot covers (available at Amazon).
Newly planted specimens are also more vulnerable because they are not yet established. The cold affects them more than it will once they are fully rooted. To protect these plants, mulch around the roots and cover them with frost cloth.
What to Shop
If you grow tender fruit trees in pots outdoors, such as citrus, bananas, olives, or avocados, they will also need to be brought indoors for winter. Again, you should be proactive and start overwintering fruit trees in pots once night-time temperatures start dropping to around 50°F. Bring them into a greenhouse, porch, conservatory, or place them in front of a bright window.
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