January 15, 2003
Woodbury Bulletin
Betsy Halden

Irresistible houseplants

Some plants are hard to resist. Many of us, at some time or other, have succumbed to the temptation to purchase a beautiful hibiscus plant, full of colorful buds and flowers. Hibiscus may remind of us of trips to warm-climate locations where five to ten foot hibiscus trees grow in every yard, just as lilacs do in Minnesota. Hibiscus flowers are gorgeous, between three and five inches across, and are available in a wide range of colors.

Tropical hibiscus are not difficult to grow as houseplants. They do need room and will grow to six feet tall if you let them. Three feet is a more manageable height. By pruning them to keep them in bounds, you will encourage flower drop. Each flower lasts only one day, but new flower buds keep forming to replace the ones that fall. Under proper growing conditions, once flowering begins it will continue for several months.

The best houseplant hibiscus is the Chinese hibiscus, Hibiscus rosa-rosa-sinensis. It needs a bright location but only a few hours of direct sun each day. Being a tropical plant it prefers room temperatures in the 60’s at night and 70’s during the day when it is actively growing. It can take temperatures in the 50’s during the weeks it is resting.

In general, you can repot hibiscus in the spring. Cut it back so each branch is just 5 to 6 inches long. Once new growth appears start feeding it every month with a water soluble fertilizer. Keep the soil evenly moist. Soon flowers will begin to form and continue to develop into fall and winter.

Eventually new growth and flower production will stop, signaling the beginning of the plant’s important rest period. Under warm ideal greenhouse conditions, hibiscus may never slow its growth. But inside our houses the plant will probably rest during the shortest, coldest days of the year. That means if your hibiscus is not growing now in January, it is probably resting.

During the rest period allow the soil to become drier than usual before watering, and do not use fertilizer. After 6 to 8 weeks of rest, prune back all of the branches quite hard and repot the plant if necessary. Once new growth begins, resume regular feeding and watering and try to provide temperatures in the 60’s at night. Remember, this is a tropical plant. The closer you get to providing tropical growing conditions, the better your plant will grow. It is also important to keep the hibiscus out of cold drafts. Avoid placing it in a bright and sunny foyer, where every time the door is opened, cold air charges through the entry.

The cyclamen is another irresistible flowering plant widely available this time of year. But the cyclamen can be challenging to grow successfully as a houseplant. The hardest part in growing a cyclamen is providing cool enough temperatures along with adequate light. The cyclamen grows best in bright light, but it needs day time temperatures in the 50’s and night temperatures into the 40’s. This is very difficult to do in Minnesota homes during the winter. If you have a room that you can keep cool. a cyclamen might grow well for you.

If kept cold enough, cyclamen blooms should last about two months, but if kept too warm the bloom time is greatly shortened. For this reason, the cyclamen is not a plant every houseplant gardener can grow successfully. If you are a houseplant gardener who wants easy-care-with-blooms plants, you may want to grow holiday cactus, Kalanchoe, and hibiscus.

Betsy Halden is a resident of Woodbury. She consulted Cornell Cooperative Extension and the University of Minnesota Extension Service materials when preparing this column. You can reach Betsy Halden at eahalden@comcast.net.