The Washington PostDemocracy Dies in Darkness

Houseplants awaken in spring. Here’s how to care for them.

(iStock)

Like humans, houseplants have light-driven internal clocks that affect their behavior. In winter, when the days are shorter, many plants enter a period of slow or no growth. More light in spring triggers active growth, which means it’s time to tweak your plant-care routines.

Your houseplant-care needs will depend on where you’re living during this transition from winter to spring, says Sarah Humke, research and development manager at Wild Interiors. Floridians, for example, might see more plant growth as early as March, while those in northern states may not see changes until late April or early May.

No matter where you are, though, your plants will let you know when they’re ready for a change. “When you start to see smaller leaves growing from the soil or off the shoots, that’s your trigger” to switch your care routine, says Clydette Alsup-Egbers, an associate professor of horticulture at Missouri State University.

Here are five ways to switch up your plant-care routine for spring, according to gardening and plant experts.

Tweak your watering schedule. When houseplants start to grow more, you’ll probably need to water them more than you did in winter. But there’s no hard-and-fast rule about how often or how much to water them; instead, it depends on the conditions of your home.

The right way to care for one of nature's most neglected creatures: The houseplant

If you’re running heat or central air, your plants may need more water, because your humidity will be lower. Plants in a more humid environment — whether that’s a steamy bathroom or a home in a soupier climate — might need less water.

A plant’s location also factors into watering. Plants in south- and west-facing windows get more light and may be thirstier than those under grow lights or in north-facing windows.

Soil is the best indicator for when to water, so check your plants regularly, especially during the transition from winter to spring. “Stick your finger into the soil about an inch,” Alsup-Egbers says. “If it’s dry, water, but if it’s moist, don’t.” If water comes out of the drainage holes at the bottom of the pot, you may be watering too much.

Start fertilizing. Your plants also need more nutrients when they start sending up new shoots and leaves. Starting in late April or early May, Humke suggests using a houseplant-specific fertilizer and diluting it to half-strength. The more a plant is growing, the more fertilizer it will need, so you may need to ramp up to a full-strength solution by summer.

Carl Johnson, a gardener at the United States Botanic Garden, suggests fertilizing each time you water while the plant is actively growing. Most houseplants don’t need to be fertilized in winter.

Give your plants an outdoor vacation. To kick-start your houseplants’ growth, consider moving them outdoors during the warmer months. “After spending all winter in a dry desert, plants love being out in the heat and humidity, because they’re used to tropical environments,” Humke says. The elements can be beneficial, too. Wind, Alsup-Egbers says, can make plants’ stems stronger, and the rain can wash dust off the leaves.

It’s best to wait until overnight temperatures reach the mid-50s or low 60s before taking your houseplants outside for the season. Or make sure there’s no more than a 10-to-15-degree difference in temperature between indoors and outdoors. For example, if you set your house to 75 degrees in winter, wait until the overnight outdoor temperature reaches 65. “Too big of a temperature transition could shock and damage the plant,” Humke says.

Too much direct sunlight can burn plants, so keep them in a shady area. If you move them outside, plants should stay there for the whole summer, Johnson says, because too many changes could cause stress-induced harm to the plant. If you’d rather not move a plant outside, consider relocating it to a sunnier window for spring. (Avoid places near air-conditioning vents, because cold air can strip plants of moisture.)

Do some spring cleaning. Johnson suggests removing dead or damaged leaves from the soil and the plant, because this will improve your plant’s appearance and help it to grow.

Also consider dusting the leaves. “Plants that have been inside all winter tend to get dusty, which can inhibit photosynthesis,” Johnson says. Moisten two soft cloths or sponges with room-temperature water, then gently pull the leaves through them. If the plant is large or extremely dusty, Alsup-Egbers says you can give it a tepid shower in your bathroom.

Repot if needed. As a plant grows, it may need a roomier home. If the plant is much larger than the height of the pot, or if you can see a lot of the roots when you take the plant out to look at it, then it’s time to repot, Alsup-Egbers says. Upgrade to a pot that’s an inch or two larger in diameter, then fill it with potting mix, add the plant and give it a drink.

Ashley Abramson is a freelance writer in Wisconsin.

Loading...