Getting your plants ready for fall

Ease your houseplants into shorter days and cooler temperatures with our fall plant care guide. 

Winter will be the most difficult time for your houseplants unless you are lucky enough to live in tropical and subtropical climates. By late spring, your houseplants may look worse for wear, weathered by months of weak sunlight and dry air. Your plants will pull through the darkest days if you adjust your care regimen now.

What happens to plants during fall?  

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Like animals, plant can sense and respond to changes in their environment. The way they pick up on environmental cues may be different - they can't smell, hear, touch, or see like us - but they too can detect new physical conditions. 

Plants can sense when fall has arrived through their leaves. Once the leaves detect a decrease in the number of sunlight hours, this triggers a range of chemical responses in cells throughout the plant. While your houseplants may not be turning brown and shedding its leaves like the trees outside, shoots stop producing leaves and cell division ceases. This pause in growth is called dormancy.

Why do plants rely on the length of the day rather than temperature as a signal for dormancy? Temperature can be an unreliable indicator for the arrival of winter. Because it can plummet very quickly, it would give little time for the slow-acting plant physiology to respond. By contrast, the days shorten over fall and winter in a regular and predictable manner.

September gardening tasks  

Start bringing houseplants indoors after the summer

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If you left your houseplants outdoors for the summer, you'll have a lush bouquet of foliage by fall. If night-time temperatures are dropping, start bringing more delicate plants inside your home, conservatory, or greenhouse.

The first plants to bring indoors will be tropical rainforest species and tender succulents. Monstera, begonia, tradescantia are some examples of plant that suffer in temperatures of less than 55 degrees Fahrenheit (12.7 degrees celsius). 

Some species may be left outside for a little longer depending on your local climate. If you are experiencing a September heatwave with warm, sunny days and slightly chilly night-time conditions, you can leave some desert succulents and cacti out. These plants love sunshine and heat but they can withstand large temperature swings that are typical of their native desert climates. 

Inspect plants for pests before you bring them back inside: aphids, earwigs, fungus gnats, mealy bugs, sale, spider, mites, thrips, and whiteflies may quickly infest your home if you bring them in. Make sure to check the underside of leaves. Treat with an organic insecticide if you spot anything. Scrub pots and rinse with water, particularly the underside of rims where insects might hide.  

Stop feeding your plant

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Unless you live in a tropical or sub-tropical climate region, stop fertilizing your plants in fall and water. Don't worry - your houseplants will not starve. Your plants respond to cooler temperatures and shorter daylight hours by becoming dormant. They are not producing new growth so do not need the extra nutrients. As long as you have kept to a regular fertilizing regime over the spring and summer, your plant will be fine. Begin fertilizing again in very late winter or spring. 

There are exceptions to this rule. Some plants that flower in winter will need feeding during the autumn and winter, such as the Cyclamen.

Cut back watering 

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Fall is the time to cut back your watering schedule. As the weather cools, soil in containers will dry out much more slowly. In the still air of your home or greenhouse, less moisture will be wicked away from soil and foliage. In addition, it is the end of the growing season.

Of course, how much water your plant needs in the fall will vary between species. Check the soil moisture with your finger to check when you really need to water your plant.

Maintain high humidity

HUUM https://unsplash.com/photos/Ruso6EXMC5U

Indoor spaces are usually driest during the cooler months thanks to central heating. Dry indoor air is detrimental to most tropical species like monstera, pilea, and anthurium. You may need to provide additional air moisture around your plant by placing it on a pebble tray, misting with a bottle spray more often, or investing in a humidifier and placing it near your plants. 

Maintain enough light

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In the fall, the sun is lower in the sky and hours of daylight get shorter. This will change indoor light levels. A plant that survives in a north-facing window during the summer may not receive enough light there in the winter. You should move sun-loving species to south facing windows and reserve north-facing windows only for the most shade-loving species like Sansevieria, aspidistra, and dracena.