Feature Article - for release the week of April 27, 2008

Dan Culbert – Extension Horticulture Agent

 A Rose for the Ages

Beyond the stresses of daily life, gardening can be a way to relax and enjoy what’s right with the world.  Because we have recently endured more than our share of challenging events, I have resolved to write something attractive for the home and garden that can help us move into a special place in your Florida Yard.

Today’s column will introduce a very nice plant that can be enjoyed by anyone, the Desert Rose.  If you take the time to select and properly care for this tropical ornamental, you will be repaid many times over with beauty for years and years to come.

The Desert Rose (Adenium obesum) is a succulent plant native to east Africa and parts of Arabia.  Because it produces beautiful blooms with little care, it is a favorite of many gardeners.  During the summer months in Florida it will produce large numbers of flowers with two inch trumpet like shapes.  Bloom can be seen in shades of pink, rose or white.

It is a member of the Dogbane (Apocynaceae) Family, which includes many other familiar topical plants such as the Allamanda, Carissa, Frangipani, Oleander, and the milkweeds.  All of these plants, including the Desert Rose, contain poisonous substances, and most will bleed a white sap when cut.

The plant itself has very fleshy stems and will mature to form a large fat bulb-like structure at the base of the plant.  It is a small to medium sized shrub and can grow to be 4-5 feet tall.  Because of it short growth habit, it often looks like a natural bonsai plant. (It is also a popular plant with bonsai enthusiasts.) 

Three elements: think Bright, Warm and Dry

Direct sunlight to bright light is a must for these plants all year long.  A southern facing porch is an ideal spot for this plant.  If grown in too much shade, the Desert Rose will not flower properly and is likely to become leggy.  In darker locations, especially in humid places like Florida, it can also develop plant diseases.

It thrives at temperatures up to 90 degrees but will not survive too many hours below 40 degrees. To protect the Desert Rose from our occasional cold temperatures, consider growing it in a pot.  That way it can be brought inside on those few days when the thermometer dips into less than tropical conditions.  During the cooler times, the plant is kept a little bit on the dry side, as it does better with a seasonal period of dormancy.

The third critical element to success with the Desert Rose is restricted soil moisture.  Remember that succulents require little water.  To achieve optimum results requires both well drained soil and careful attention to avoid overwatering.  Water should be withheld if day-time temperatures fall below 80^oF or the weather is cool and cloudy. John McLaughlin suggests  root rot problems are a combination of cool temperatures and wet soil that  promote rot.  He feels that night time temperatures (above 65ºF) to be a more realistic guide as when to water.    In South Florida, regularly scheduled watering should be done only during extended hot, dry weather, such as our late spring.  Be sure to feel the soil first to insure it is dry before adding water.  When it needs water, water it thoroughly until it drains from the bottom, then don’t water again until the soil dries out completely.

 

Pots or Planted?

Adenium can be grown in any container with proper drainage. Unglazed ceramic pots are best because they allow the soil to dry out between each watering.  For the long haul, remember that if a clay pots are used, they must be wide enough to allow for expansion of the thickened base of the stem (the caudex) to prevent the container from cracking. A free draining potting mix should always be used.

Success with direct planting of the Desert Rose into a Florida Yard should only be considered if the conditions are ideal for this plant.  Instructions for preparing a raised bed of well-drained soil are available from our office.  Be sure the spot will get lots of sun and will not sit in a wet spot before plant it in the landscape.  Desert Rose can be a great landscape item here in South Florida, but it needs full sun and needs to be part of a ‘dry garden’. 

Nutrition needed by this plant is normal for other container grown ornamentals.  Best results can be obtained by frequent applications of liquid fertilizer (half strength 20/20/20) when the plant is in active growth stages.  Withholding nutrients during periods of dormancy.  Slow release granular fertilizers are also a good choice.

 

Pests and Propagation

Attention to proper watering and plant placement will take care of most plant disease on the Desert Rose. There are few insect pests on this plant.  Scale and mealy bugs sometime occur on the leaves. According to John  McLaughlin, Red spider mites are the worst pest locally (late spring) as well as scale insects (more so in the fall), plus oleander moth caterpillars occasionally take an interest in the leaves.  Soap based insecticides should be used, as certain chemical insecticides may damage the Desert Rose – so read the label first.  Careful regular inspection of the plant can catch these critters early enough to keep them from becoming a problem.

Growing a new Desert Rose from existing plants takes a little care.  Cuttings can be made, but some references report that plants grown from cuttings may not develop the thickened bulbous base.  Seed are rarely produced by this plant, but if they produce the long seed pods, growing out the seed into plants is possible (it is also available from our office.)  Extreme hobbyists have even been able to graft superior selections onto a rootstock with impressive results.  

For additional information, visit the Solutions For Your Life website: http://solutionsforyourlife.ufl.edu and our Okeechobee web page, http://okeechobee.ifas.ufl.edu.  If you need additional information on the Desert Rose, please email us at okeechobee@ifas.ufl.edu or call us at 863-763-6469.  Local residents can stop by our office at 458 Hwy 98 North in Okeechobee, and visit our Okeechobee County Master Gardeners from 1 to 3 PM on Tuesday afternoons. .  Go Gators!

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Trade  names, where used, are given for the purpose of providing specific information. They do not constitute an endorsement or guarantee of products named, nor does it imply criticism of products not named. The Florida Cooperative Extension Service - Institute of Food and Agricultural Sciences is an equal opportunity/affirmative action employer authorized to provide research, educational information, and other services to individuals and institutions that function without regard to race, color, sex, age, handicap, or national origin.  Florida Cooperative Extension Service / IFAS / University of Florida.  Larry A.  Arrington, Dean. Last update: 05/12/2008.  This page is maintained by Dan Culbert