Adenium Soil Requirements
Adenium obesum, commonly known as the Desert Rose, is a flowering succulent related to the oleander and the plumeria. As a succulent, it thrives in extremely well drained and coarse planting mediums and will easily succumb to root rot when planted in regular garden soil or potting mix. Often grown in containers when small, adenium roots grow quite large in relation to the plant top.
Coarse Sand, Gravel & Grit
Since adenium is native to the soil of sub-Saharan Africa and the Arabian peninsula it prefers lightweight, sandy and coarse soil. Add organic coarsening agents to the planting bed up to one third of the volume of planting soil. Use clean sharp sand, poultry grit, gravel or even horticultural charcoal or lava rock to make the planting soil free draining.
Succulent Potting Mix
Use a commercial succulent or cactus potting mix as the basis for the planting medium for your adenium. It can be amended with a few other ingredients to make it even more free draining but will provide a good foundation for growing the moisture sensitive plants.
Perlite or sponge rock is a lightweight, coarse planting material that aids water drainage and remains lightweight even when used in large volume. Add perlite grains to the adenium planting soil to compose up to 1/3 of the overall planting soil soil volume. This addition will help to ensure that the adenium roots are never sitting in waterlogged soil and that tender young roots can easily penetrate the planting medium.
Adenium Obesum Nutrient Requirements
Desert roses are slow growers. To produce the maximum growth in early years, water them weekly when they are actively growing so they don’t dehydrate and fertilize with a high-nitrogen fertilizer. Slow-release fertilizers that are coated with sulfur will release their nutrients in about eight weeks; if they are coated with polymer, they will release their nutrients in about 12 weeks. A balanced fertilizer contains nitrogen, phosphorus and potassium. It does need high nitrogen to flower. During the growing season, feed desert rose bonsai monthly with a water-soluble, slow-release 13-13-13 fertilizer.
- USDA Plant Data Base Profile: Adenium
- University of Florida IFAS Extension: Adenium Obesum
- Arizona-Sonora Desert Museum: Adenium Culture: Producing Large Specimens Quickly
- Missouri Botanical Garden: Adenium Obesum
- Broward Bonsai Society: Desert Rose, Karoo Rose, Impala Lily, Sabi Star
- Lowes: Fertilizer Buying Guide