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Indoor Geraniums-Part I: The Pelargonium

© Diana Pederson

Geraniums (really Pelargoniums) are among our favorite outdoor bedding plants in the summer. Most people don't realize that they make wonderful indoor plants, too. They will flower all winter in a south-facing window or under lights. They thrive in our dry winter indoor air if we give them just a little care.

Mine flower all winter under cool-white shoplights in my basement. They are watered no more than once a week and the temperature never rises above 70 degrees. I give them 12 hours of light daily. Be sure their soil is well drained. They rot very quickly in wet soil. Zonals also grow well in a south-facing window.

During the winter, I just clean off the dead leaves and fading blossoms. I do not fertilize them until spring because I don't want to encourage strong growth or they might outgrow the area I have for them under the lights.

Zonal geraniums (Pelargoniums) are tropical plants native to South Africa, New Zealand, and Australia. Geranium is actually the name of one plant group within the Geranium family. A true geranium is a hardy perennial. Take a look at these pictures and observe the leaves. They are true geraniums: example 1, example 2, example 3. Notice how these pictures are different from a true pelargonium. Unfortunately, the misnomer has existed for so long that everyone except for the real purists just call them geraniums. If you would like a further explanation, take a look at last week's article.

Pelargoniums have brightly colored flower heads consisting of multiple individual flowers. They are found in a wide range of colors including reds, oranges, pinks, lavenders and white. Their foliage may be solid green, green with a darker green ring, or even multicolored with golds, browns, whites, and greens.

Some Zonals are only a few inches tall. If they are five inches tall or less, they are called miniatures but if they are between 5 and 8 inches tall, we call them dwarfs. The flower head is held above the foliage. These smaller plants are available at mail order nurseries such as Logees and Glasshouse Works. You will find many varieties at your better local nurseries.

Some seed raised Zonals have been introduced but these do not survive the winter for me. I wait until the end of the season and look for cutting Zonals on sale for less than $1. These plants do not produce seeds that are true to their varieties. They tend to be better quality plants. They have to be propagated by taking "cuttings" to maintain variety characteristics. These become my indoor winter garden and mother plants for the next season. This way I have named varieties which I could not afford at local going rate of $3 per plant earlier in the season. You may find similar bargains in your local area.