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Johnson County

Research-based Information You Can Trust — Localized for your needs

Johnson County
11811 S. Sunset Drive
Suite 1500
Olathe, KS 66061

Office Hours:

Monday - Friday,
8:30 a.m. - 5 p.m.

(913) 715-7000
(913) 715-7005 fax

Map to our office

K-State Research and Extension is committed to making its services, activities and programs accessible to all participants. Reasonable accommodations for persons with disabilities may be requested by contacting Johnson County Extension at (913)715-7000. Notify staff of accommodation needs as early as possible.

Kansas State University Agricultural Experiment Station and Cooperative Extension Service

K-State Research and Extension is an equal opportunity provider and employer.

Frequently Asked Lawn and Garden Questions

House Plants

Christmas Cactus:

Some years my Christmas Cactus blooms and other years it does not. What should be done to get a Christmas Cactus to flower?


The Christmas Cactus, an epiphyte native to the jungles of South America, is a popular, flowering holiday plant. Epiphytic plants grow on other plants and use them only for support, not for nutrients. Flowering is induced by certain temperature and/or light treatment. If the temperature is held at 50 to 55 degrees, flowering will occur regardless of day length. However, the flowering usually is not uniform. Temperatures below 50 degrees prevent flowering. Flowers can also be generated by nights greater than 12 hours in length and temperatures between 59 and 69 degrees. Twenty-five consecutive, long nights are enough for flower initiation. It takes an additional nine to ten weeks for flowers to complete development and bloom.


I saw a plant called a cineraria at a garden show this spring. They did not know much about it. What can you tell me?


Cineraria is a beautiful pot plant started from seeds in the greenhouse. It can be found normally in the winter and very early spring. The daisy-like blooms are red, blue, lilac, violet, or white, often bicolor. The plant will flower for several weeks in filtered light, given plenty of water, remaining moist at all times.
Once the plant has flowered, discard it; it will not flower again. It cannot be grown as a houseplant. Enjoy it while it lasts for its cheery, bright color.


My hibiscus has been on the patio all summer covered with red blossoms. Now it is about five feet tall and takes up half the living room. I can’t let it freeze. What do I do with it now?


Your dilemma is fully understandable. If you don’t want to let it freeze and buy another in the spring, consider these two options:

  1. Treat the plant like a houseplant and let it overtake your home until spring. The plant will shed leaves and not really look all that great but will live to see another spring; or
  2. Let the plant go semi-dormant over the winter. Put the plant in the basement and water sparingly. The plant will drop its leaves but will survive.

In the spring, after danger of frost, move the plant back outdoors and prune severely. With fertilization and watering, new growth will appear. This process will probably delay flowering until mid to late summer.


The poinsettia that I have enjoyed during the holiday season is still beautiful. Is there something else that I can do with it now other than discarding it?


With good care and high light, poinsettias can be grown as attractive house plants. The brightly colored bracts will remain on the plants for many months. When the bracts begin to fade, cut them off to trigger new green growth on the plant. In the spring after the danger of frost passes, the plant can be moved outdoors. It will make a beautiful addition to a patio container. Trimming the plant back about one-half will stimulate new growth. If the plant is watered and fertilized on a regular basis during the summer months, it can reach three feet tall and wide in a single summer.

Next fall, the plant can either be left outdoors to freeze or brought back indoors. If you decide to re-bloom the plant, special care will be needed for the plant to flower. It is not easy, but it can be done. Contact Johnson County Extension, (913) 715-7000, for a copy of an informative brochure on poinsettias.

Salt buildup on pots:

I have had an African violet for a number of years. It flowers and looks great. Lately I have noticed a whitish deposit on top of the soil and around the edges of the pot. What is this and how do I get rid of it?


The unsightly deposit you are describing is a “salt buildup.” This sediment is caused from water and the breakdown of nutrients in fertilizers. If allowed to remain, it can damage the plant by drying out the roots like salt on food or walkways in the winter.

There are a couple ways to remove the deposit. One is to leach or run water through the root media to help remove the deposits. Another is to repot the plant using fresh potting mix which would also remove the salts.

Return to Frequently Asked Lawn and Garden Questions

K-State Research and Extension Johnson County Master Gardener logo

Have questions? The Garden Hotline is staffed by trained EMG volunteers and Extension staff who will assist you with questions.

Phone: (913) 715-7050

Email: garden.help@jocogov.org