Many gardening aficionados enjoy giving their indoor plants some exposure to sunlight by bringing them outside. Yet, when the weather starts to cool down, it’s essential to bring them back inside.
If your plants are hardy, you can safely bring them outdoors to enjoy the winter weather. Just be sure to ease back in slowly so as not to shock them with too much change at once.
Temperature
Houseplants typically come from warm climates and cannot survive temperatures below 50 degrees.
Once night temperatures exceed 50degF, gradually move houseplants outside into protected shady areas. A covered porch usually provides protection from light frost; however, garage or sun room are better options in cold climates.
Some houseplants can tolerate mild winter temperatures if their roots are protected with mulch, hay or other similar materials. Some tropical varieties, like palm varieties and succulents, even thrive in cooler temperatures.
Before putting your plant outside, it is important to consider its particular needs. Some plants, like begonias, will succumb to cold temperatures while others like cacti and some palm varieties can tolerate low temperatures if given enough water and sunlight.
Lis Friemoth, a gardening expert who offers concierge and horticultural services, advises that if you are taking your houseplants outside, it is essential to keep them well watered until temperatures begin to rise again. She suggests using a hose to spray down the soil with water and re-watering every few days as weather improves.
She recommends wrapping your plants in blankets, newspapers or towels to protect them from freezing overnight before bringing them out again. Doing this can help avoid damage to their leaves and stems due to exposure to cold temperatures.
A cold night can wreak havoc on your plants’ growth and development of healthy buds. They may take longer to respond, leading them to drop leaves or turn yellow.
Most houseplants, particularly those in bloom, cannot survive temperatures below 10 degrees Celsius and may succumb if temperatures drop even further.
Plants are composed of a complex chemical mix and the temperature they experience directly affects their growth or movement. Chemical reactions tend to take more time at lower temperatures, so when temperatures increase again, those same reactions will take place more quickly.
Light
Most houseplants, even the more tropical varieties, cannot withstand temperatures below about 50 degrees Fahrenheit. Therefore, if you’re thinking of leaving your plants outdoors in winter, wait until nighttime temperatures consistently remain above this number and there is no promise of frost for at least one month.
Step one is gradually transitioning your plants outdoors onto your porch or patio. It’s wise to leave them in partial shade for a few days until they get used to outdoor conditions, as direct sun can do serious damage.
Once your plants become accustomed to outdoor life, gradually increase their exposure to full sun. If unsure how much light each day your plant requires, consult the National Centers for Environmental Information or Old Farmer’s Almanac to see how many hours of natural illumination you typically receive in your region.
It’s also wise to move plants away from drafty areas and cold windows. Since indoor humidity levels tend to be higher, you’ll want to ensure that your plants don’t get stuck in a pocket of air between windows and curtains or next to a radiator in direct sunlight.
Finally, be sure to water your plants less often during the winter. Watering too frequently during this period can lead to root rot and mold growth, making your houseplants unattractive.
If you’re worried that cold temperatures could harm your plants, Roundtree Nursery & Supply offered WBTV a selection of indoor plants suitable for outdoor use. These include citrus trees (Lemon and Orange trees), ferns, ivy and other shrubs that can be easily trimmed or reshaped to fit into an outdoor space.
For some plants, wrapping them in plastic or using pegs to cover their growing tips is a beneficial practice during the season. This helps prevent them from losing leaves and keeping them alive; however, be aware that this may reduce their sensitivity to environmental changes.
Soil
Although temperatures are beginning to warm up, it’s still not too early for planting outdoors. Even though it may appear warm outside, soil temperatures can still drop below freezing–plants that aren’t winter-proof may need to be moved indoors when temperatures dip below zero.
Soil is a porous medium composed of minerals, living and dead organisms (organic materials), air, and water. These elements interact in remarkable ways, making soil one of the world’s most diverse and valuable natural resources.
The precise proportions of soil components can affect its physical and chemical characteristics, which in turn influence plant growth. Ideal soil has the right acidity level, regulates temperatures appropriately, retains and drains water efficiently, and supplies essential nutrients like nitrogen, phosphorus, and potassium to plants.
No soil is perfect, but loam – a combination of sand, silt and clay – tends to work well for most plants. On average it contains around 40% sand, 30% silt and 20% clay but exact proportions will depend on what type of soil you have.
Sharon Yiesla, plant knowledge specialist at the Morton Arboretum in Lisle, notes that well-drained soil provides space for plant roots to expand and is less likely to freeze. But this doesn’t guarantee it won’t happen, she cautions.
To guarantee your soil doesn’t get too cold, a reliable way to measure its temperature is with an instant-read thermometer with a probe that can be pushed as deep into the ground as possible. Be sure to avoid direct sunlight and take readings at different times during the day since sunlight may affect readings.
When soil temperatures drop too low, it can actually kill plants. That is because when water between soil particles freezes and forms sharp-edged ice crystals that cut plant cells and eventually cause their demise.
Protecting your plants requires keeping their soil warm. You can do this by bringing them inside when temperatures drop or placing a heating mat or other insulating material on top of soil where you plan to plant. Alternatively, frost cloth may help trap heat within soil.
Water
Many homeowners will begin bringing their houseplants outside when temperatures warm enough for some sun. Before you do so, however, make sure the plants are secure in their new environment.
When it comes to houseplants, the answer depends on a few factors. Most are native to tropical-like regions and will die if temperatures fall below 50degF (10degC). Once nighttime temperatures start rising consistently above 55degF (15degC), you can begin gradually moving your indoor plants outdoors.
In order to prevent shock, first place your plant in a protected location such as a porch or patio that gets slightly less sunlight than usual. After moving it from indoors to outdoors, let it adjust for around two weeks in this new environment.
Once temperatures stabilize and there’s no risk of frost, you can begin bringing your houseplants indoors again. According to Lis Friemoth, a gardening expert who offers concierge services, wait 2-4 weeks after the last frost has passed before moving them indoors again.
Your plants may need some time to adjust to the cold, so be patient with them as they adjust. While some might be able to tolerate some damage temporarily, others will need longer for recovery.
Before you bring your plants indoors again, ensure they don’t receive too much water or fertilizer. Doing so could cause them to dry out, leading to wilting.
Additionally, you should add a small amount of mulch to prevent soil drying out and retain moisture. Doing this will shield your plants from pests which may be particularly prevalent during this time of year.
Once your plants have returned inside, wait until you’re ready to feed them again in order to protect their roots and leaves. If a drink is necessary, be sure to water gently so that none of its leaves become damaged.
