all photos: istockphoto.com

By Barbara Arnold

 

With the first day of winter fast approaching, many avid gardeners are turning their attention indoors to their houseplants and searching for the correct methods to care for them. What is the best way to keep these plants alive in the harsh environments of our Ohio homes? Here are some quick tips to help ease the transition to indoor plants and indoor gardening.

In the fall, the growth of houseplants slows down. They are still green and alive, but are not actively growing. Even during this inactive time, which extends through fall, winter, and early spring, these plants continue to require light and some water. The plant will start growing again next spring, when the day length is longer and the temperatures are higher.

Start by knowing the name of your houseplant. This not the name you have given it, like Harold or Phoebe, but the actual plant name: Philodendron ‘Xanadu’ or Sansevieria, for example. Once you know the proper name you can correctly determine the plant’s needs. It is very frustrating to look up the wrong plant name and find that all the information is incorrect for the plant you have. 

Light
Light is the most important aspect of successful plant culture; this holds true for indoor as well as outdoor plants. The effects of low light on a plant include leaf yellowing and leaf dropping. The plant will also grow long and leggy, indicating it is growing toward the light.

Which window is best for your houseplant? Here are some simple notes to follow concerning all unobstructed windows that are not blocked by other houses, trees, etc.
* A south facing window is best for sun-loving plants.
* An east or west facing window works best for plants that require part-sun, part-shade; this equals about 80 percent of the light the plant would receive from a south facing window.
* A north facing window works for shade-loving plants; this equals about 40 percent of the light from a south facing window.

Watering
Remember: You are the only way this houseplant is going to get any water, but most houseplants are killed by overwatering. As houseplants are not actively growing but rather maintaining, the need for water is considerably less for indoor plants than it was for your outdoor plants during the summer. Watering daily isn’t necessary. Simply touch the soil to discover your houseplant’s level of moisture.  Water only when it is dry—not bone dry, but dry. Don’t let the plant sit in a saucer filled with water because the soil needs the dry-out time.

Humidity
The air in our homes in winter is really dry, with the average humidity falling between 20 and 30 percent. Comparatively, the average relative humidity for the Sahara Desert is 25 percent. Houseplants thrive in a relative humidity of 60 percent; however, high humidity in our homes does create other problems like window condensation, rotting wood, mold, and pest problems. 

There are a few ways to add humidity around houseplants that aren’t damaging to the rest of the house. Use a mister bottle with water, misting both the top and underside of the leaves. Fill a saucer with pebbles and a bit of water then set the pot on top of the pebbles. As the water evaporates the humidity is added to the air surrounding the plant first before it is dispersed through the rest of the room. Group plants together—more soil means more water. Consider placing plants in the bathroom. They can shower alone or with you, as long as you don’t let the potting soil wash down the drain.

Temperature
Keep plants away from drafts, fireplaces, stoves, and heating and cooling vents.  There are some plants for which temperature is more critical, such as anything in flower. Drafts can damage flowers. Of course, there are other plants that don’t mind the shocking cold breeze coming through the opened front door. 

Fertilizing
Fertilizing is not really important in the fall and winter, as the plant is not actively growing. Over-fertilizing can cause a build-up of salts, appearing as a white crust on the rim of pots. Browning roots and leaf tips are another indication of over-fertilizing. Start to fertilize plants when they are actively growing in the spring and throughout the summer months.

Keep your plants healthy with the right amount of light and water—a healthy plant is easier to care for than a sick one. If you find a problem, isolate the plant before it spreads to its neighbors. A quick prune to tidy up the plant will help with leaf loss due to less light in winter. A parting tip: Repot plants in the spring before they start to grow, leaving room for new roots and water. You would be amazed by what new potting soil can do for a house plant.

 

Barbara Arnold is horticulture designer at Franklin Park Conservatory.