Bring Your Green Thumb Indoors This Winter

With winter weather patterns just around the corner, most gardeners are finished with outdoor projects. Healthy house plants are a beautiful addition to any indoor living space. If you’ve not already done so, take some time to get them spruced up and ready to look their best for winter.

Unless we have an extended deep freeze and power outage (perish the thought!), the odds of indoor plants freezing to death are slim. A greater threat is damage to leaves or flowers by dry, heated indoor air. To increase relative humidity around plants, try placing them on a water-filled gravel tray and keep plants closely grouped. Water evaporating from the tray and transpiration of water from leaves will keep humidity higher around the foliage. A related growth factor is temperature. From a plant’s perspective, cooler nights are desirable, and flowering plants especially benefit from a 10 to 15 degree differential between day and night-time thermostat settings.

Different species have different light requirements as well. Try to place plants in south-facing windows for maximum light intensity and best light quality. Plants tend to prefer rooms painted a light color, since darker colors absorb light. The duration of time that house plants receive light is usually a minor issue. However, poinsettias and Christmas cactus are two examples of species that need short days in order to stimulate flowering.

Watering mistakes can be neatly divided into two categories: overwatering and under-watering. Check moisture content in the potting soil by inserting your index finger into the media. If it feels moist, don’t water. Roots normally grow to the bottom two-thirds of the container, so be sure to water deeply. As a rule of thumb, pour water in until it runs out the bottom of the pot. Wait to water again until the soil feels dry. Finally, make sure your container has drainage holes. If water cannot escape from the pot it is easy to keep roots too wet.

For plants that have outgrown their container, consider taking advantage of the remaining warm days to divide and/or re-pot any candidates. These make nice Christmas gifts for like-minded friends, and there is still time to get them settled into their new home before Santa departs on his 2014 run! When selecting a container, think larger rather than smaller. Pots should be roomy enough to accommodate plenty of new root growth and allow for an inch or so of headspace at the top. Clay pots are considered the healthiest choice by some, as their porosity helps ensure good air movement around roots.

For maximum plant happiness, good potting soil is a necessity. Potting soil serves three functions. It is a reservoir for air and water, for nutrients, and it is the plant’s base of support as its root system expands. The easiest approach is to buy potting soil pre-mixed and sacked at the garden center. More often than not, the blend will also contain fertilizer, and your only job will be to water and enjoy your new specimen.

With established plants, or if your soil did not contain fertilizer, select a reputable soluble fertilizer brand with analysis of approximately 20-20-20, mix according to label instructions, and feed monthly during spring, summer, and early autumn. Due to decreased light availability in winter, plant growth slows, and fertility needs decrease accordingly. Take care not to spill liquid fertilizer onto leaves. Fertilizers are salts and can cause injury to foliage. If you do have a spill, simply rinse the leaves with clear water. For more information about house-plant care, or if you have specific questions, contact your county Extension office.

University of Arkansas, United States Department of Agriculture and County Governments Cooperating. The Arkansas Cooperative Extension Service offers its programs to all eligible persons regardless of race, color, sex, gender identity, sexual orientation, national origin, religion, age, disability, marital or veteran status, genetic information, or any other legally protected status, and is an Affirmative Action/Equal Opportunity Employer. Neal Mays is an agriculture agent with the UA Cooperative Extension Service in Benton County. Contact him at The opinions expressed are those of the author.

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