Roses of the Desert
By Ralph E. Mitchell
The very first plant I received when I moved to Charlotte County almost twenty-years ago was a desert rose given to me by Master Gardener volunteers as a welcome gift. It was a plant I had heard of, but never grown before. First in a pot and then in the ground, this flowering plant never disappointed me with its unique appearance and colorful flowers. Desert roses are very popular plants, and I would recommend them as a gift for the gardener who has everything.
To begin, the desert rose is not a rose at all, but a relative of some more familiar plants including Allamanda, Plumeria, Oleander and Carissa. This drought-tolerant plant is originally from desert regions ranging from Africa to the Arabian Peninsula. Noted for thick stems and a swollen base, desert roses have smooth grayish-green branches and glossy green leaves. Growing upwards to six-feet tall, the base of desert rose is called a caudex which is often noticeably swollen giving the plant an almost bonsai-like quality. The flowers in cultivated desert roses are tubular with flared lips available in colors including red, pink and white – some forms sporting double or even triple petals and fragrance!
Desert roses are good for containers or in the landscape. Containers work well because they offer very good drainage and mobility if winter temperatures or overly rainy weather occur. Use a well-drained (cactus) potting mix and a pot wide enough to accommodate the expanding swollen stem. If planted in the landscape, select a full sun area in well-drained soil. Soil modifications may be needed to ensure a well-drained area as excess moisture will promote stem and root rots. Raised beds are one idea using loose rubble or rocks with sandy soil to build a flat, eighteen-inch mound. Using a mixture of seventy five percent sand to twenty-five percent top soil, plant the desert rose at the same depth it was in the pot being careful not to damage the roots. Don’t use organic mulch around desert roses as excess moisture retention can encourage rots. Desert roses can take a lot of rain in temperatures above eighty degrees F as long as the soil is well-drained. However, cool temperatures and moisture will initiate problems. Don’t be surprised by significant leaf loss during the winter – this is normal. Temperatures below forty-degrees F can cause branch tip damage and accordingly protection during cold weather may be needed.
While desert roses can attract scale insects and mealy bugs, one of the worst insect problems that I have seen is the oleander caterpillar. Due to its relation to oleander, desert roses can become infested with this defolating insect – sometimes suddenly. While you could use a least-toxic insecticide like Bacillus thuringiensis (Bt) for control purposes, handpicking may be easier to undertake with quicker results. Frequent monitoring is advised.
In general, desert roses do not need much in the way of pruning. If you conduct any pruning to stimulate bushiness, do it early in the growing season and use disinfected pruners. Also, wear gloves as the sap is considered toxic.
Some named cultivars to look for include ‘Singapore’ with pink flowers and ‘Grumbley’s White’ with white flowers. Local specialty growers will also have many additional cultivars and forms available. Try these “Roses of the Desert” in your yard today! For more information on all types of plants for your Florida Yard, or to ask a question, please visit https://www.facebook.com/CharlotteMGLifeline/. Ralph E. Mitchell is the Director/Horticulture Agent for the UF/IFAS Charlotte County Extension Service. He can be reached at 941-764-4344 or ralph.mitchell@charlot tecountyfl.gov.
Don’t forget that Florida-Friendly Landscaping™ is a program that our office encourages as it promotes planting the “right plant in the right place”, water conservation, common sense pest management, sensible use of fertilizers, composting, etc. that help develop a sustainable landscape. For more information on this important, over-arching program, please contact Sara Weber, FFL Education-Training Specialist, at Sara.Weber@charlottecountyfl.gov .
UF/IFAS Gardening Solutions (2020) – Desert Rose. University of Florida Extension Service, IFAS.
McLaughlin, J. & Garafalo, J. (2002) Desert Rose. The University of Florida Extension Service, IFAS, Miami-Dade County
Landre, C. (2020) Desert Rose – Adenium obesum. South-Florida-Plant-Guide.com