Marion County Extension 210 N. Iowa St. Knoxville, IA 50138 641.842.2014 [email protected] February, 2019 Volume 17, Issue 2 The Green Scene Save a tree! Send your email address to [email protected] to receive this publication via e-mail. Brighten Winter with a Clivia Plant By Richard Jauon Flowers are one of the best antidotes to the icy winds of winter, and growing a houseplant that buds and blooms inside while all is dormant outside is particularly satisfying. This winter, as an alternative to the brightly blooming azaleas, chrysanthemums or traditional holiday plants, consider growing a clivia plant. What is a clivia? Clivia or kaffir lily (Clivia spp.) is a herbaceous flowering plant native to South Africa. Plants have long, arching, strap-like leaves (similar to an amaryllis) and produce dense clusters of trumpet-shaped flowers atop 18 to 24 inch stems. The flowers of Clivia minia- ta are typically orange with yellow eyes or centers. However, there are also several rare and expensive yellow-flowering cultivars. While clivias are not winter hardy in Iowa, they are excellent, low maintenance houseplants. How do I get a clivia to bloom? Clivias need a rest period of six to 12 weeks in fall and winter to initiate flower bud development. Temperatures dur- ing this time should be 40 to 55 degrees Fahrenheit. A guest bedroom, porch or a partially heated garage (temperatures must remain above 35 F) may be suitable plant locations. Water sparingly (about once a month). When flower stalks appear, move plants to a slightly warmer location and begin to water more frequently. Clivias typ- ically bloom for several weeks in late winter/early spring. When plants have finished flowering, remove the flower stalks near their base. What should I do with my clivia after flowering? After flowering, move the plant outdoors in mid to late May. Initially place the plant in a protected location in com- plete shade. Then gradually expose the plant to short periods of sunlight. After the plant has been hardened for sev- eral days, place the plant in partial shade (two to three hours of sunlight) and leave it there through the summer. Wa- ter the plant when the soil surface becomes dry to the touch. Fertilize every two to four weeks with a dilute fertilizer solution. Bring the plant back indoors before the first fall frost. If you decide to leave the clivia indoors in spring and summer, place the plant in bright, indirect light near a south or west window. Watering and fertilization practices are the same as for plants placed outdoors. How often do I need to repot my clivia? Clivias prefer to be potbound. Repot plants when the soil ball begins to rise above the pot or the pot breaks (clay pot). When repotting is necessary, carefully remove the plant from its pot and place it in a new pot that is no more than 2 inches wider in diameter. Spring and summer are the best times to repot a clivia. What are the most common problems on clivia? Over-watering and mealybugs are the most common problems with clivia. Over-watering (watering too frequently) may result in root rots. In spring and summer, water plants when the soil surface becomes dry to the touch. Mealy- bugs are small, white, oval insects. They appear as small, white, cottony masses on stems, the undersides of leaves, at leaf axils (where the leaf attaches to the stem) and other locations. Mealybugs are piercing-sucking in- sects that feed on plant sap. They are difficult to control. Thoroughly check plants when purchasing clivias and other indoor plants. Avoid mealybug infested plants. Mealybugs on lightly infested plants can be controlled by dabbing the insects with an alcohol-soaked cotton swab or with frequent applications of an insecticide soap. African Violets By Richard Jauron African violets are one of America’s most popular houseplants. They belong to the Saintpaulia family and are not related to the hardy violets found in outdoor gardens. Under the proper growing conditions, they will bloom almost continuously indoors. My African violets aren’t blooming well. Why? The African violets may not be receiving adequate light. The proper amount of light is essential for good bloom. Generally, windows with north or east exposures are best for African violets. However, if these exposures are not possible, they also perform well under fluorescent lights. Place the fluorescent lights 6 to 8 inches above the plants. The lights should be lit for 12 to 16 hours per day. Excessive fertilization could also be responsible for the poor bloom. African violets need to be fertilized to promote bloom. However, excessive fertilization leads to vigorous veg- etative growth and poor flowering. Using a complete, water soluble fertilizer, apply a dilute fertilizer solution once every two weeks in spring, summer and fall. Fertilization usually isn’t necessary during the winter months. What is the proper way to water an African violet? Proper watering is essential for African violets. Crown and root rots may occur if plants are watered too frequently and their roots are kept too wet. Allow the surface of the potting soil to dry to the touch between waterings in spring, summer and fall. Reduce the frequency of watering slightly during the winter months. The temperature of the water should be room temperature or slightly above. African violets can be watered from the top or bottom. Watering from the bottom is done by placing African violets in saucers or trays of water and allowing the plants to soak up mois- ture for 20 to 30 minutes. When watering plants from the bottom, it’s advisable to water plants from the top several times a year to prevent the accumulation of salts in the potting soil. When applying water to the surface of the pot- ting soil, avoid getting water on the foliage or in the crowns of plants. Continue to apply water until water begins to flow out the bottom of the pots. Discard the excess water. Wick watering is another option. This is a continuous wa- tering system with a water reservoir at the base of the plant and an absorbent wick that connects the potting soil and the water reservoir. How can I propagate an African violet? African violets are easily propagated by leaf-petiole cuttings. Select a firm, healthy leaf and cut it off with a razor blade or sharp knife. Leave 1 to 1½ inches of the leaf stem (petiole) attached to the leaf blade. Fill a pot with perlite or coarse sand. Moisten the rooting medium. Using a pencil, make a hole at a 45 degree angle in the perlite or coarse sand. Insert the petiole of the leaf cutting into the hole in the rooting medium. Firm the rooting medium around the petiole of the leaf cutting. After all cuttings are inserted, water the perlite or coarse sand and allow it to drain for a few minutes. Next, cover the cuttings with a clear plastic bag. Secure the plastic bag to the pot with tape or a rubber band. (The enclosed environment drasti- cally reduces the loss of water from the leaf-petiole cuttings and prevents them from wilting and dying before they have a chance to root.) Set the pot in a brightly lit loca- tion out of direct sunlight. Roots usually form in three to four weeks. The leaves of new plants usually appear in six to eight weeks. Several plants may form at the base of each petiole. Separate the plants by carefully pulling or cutting them apart. Pot up plants individually into containers using a well-drained potting mix. Spring 2019 Workshops Here is a list of the spring workshops with dates and times. More details will come in the March Green Scene! March 26th 6:30pm—Seed Exchange April 9th 6:30pm—Herb Gardening May 14th 6:00pm—Fairy Gardens “The Green Scene” is a tip sheet developed by the Marion County Extension Office to inform people of horticulture events, problems, and interesting ideas. Let us know if you want to be added to our mailing list. Some issues are also available at www.extension.iastate.edu/marion/. This material has been prepared by Lauren Petersen, Agriculture Program Assistant. If you have questions, please contact the office at (641) 842-2014. Iowa State University Extension and Outreach does not discriminate on the basis of age, disability, ethnicity, gender identity, genetic in- formation, marital status, national origin, pregnancy, race, color, religion, sex, sexual orientation, socioeconomic status, or status as a U.S. veteran, or other protected classes. Direct inquiries to the Diversity Advisor, 515-294-1482, [email protected] .