Drought Tolerant and Dependable - Senna artemisioides - Silver Foliage too!

I love the silver foliage of Senna artemisioides! It is well known that this gorgeous foliage color is an evolved adaptation to withstand solar radiation and slow down transpiration. It is wonderful how silver is the perfect color to make all plant combinations sing! It combines well with everything. This "little black dress of plants", is the magic ingredient to make semi-arid gardens look like they make sense. Any flower color works with silver. Even with no flowers, some silver-foliaged punctuation among other green plants creates excitement and rhythm. It also visually cools the garden. Here is a garden photo from blogger Noelle Johnson www.azplantlady.com that illustrates what good blender silver foliage is in the landscape.

Noelle Johnson

Senna artemisioides is the plant in the rear of the foreground with cheery yellow flowers. The species name, "artemisioides" reminds us that this plant looks similar to Artemisia. Below is a closeup of the flowers and feathery foliage, which is the inspiration for its common name, Feathery Cassia. What looks like leaves are actually another drought adaptation, and are actually flattened leaf petioles. Once in awhile, you will see a remnant of a leaf. This plant blooms in late winter/early spring for several weeks. Later, it can throw out a few blooms if it is not too hot. It is always an early treat to see it blooming, and I never water it. I have it planted in well-drained sandy loam soil in full sun. This plant really does well with heat, so feel free to place it next to a sidewalk or wall. 

Pretty against a blue wall                                                                                                                           S. Reeve

The plant originally comes from the MacDonnell Ranges just west of Alice Springs in the Northern Territory of central Australia. Flowers are followed by flattened green seed pods that look like flat edamame. They look like pea pods because they are a legume, and also a member of the Fabaceae Family. Senna is also a member of the Fabaceae sub-family, Faboideae characterized by having bilaterally symmetrical (zygomorphic) five-petaled flowers with fused or connate stamens. These pods eventually dry brown. If you find them unattractive you can trim them back after flowering and you can also take the opportunity to keep this shrub under its 6-8 foot height and width. It trims easily and remains neat in the landscape. This plant blooms on old wood, so do not wait to prune it. Combine this plant with any selection of silver-foliaged Leucophyllum frutescens or blue-flowering Eremophila hygrophana for perfectly matched, and oh so satisfying, complementary colors. Add a grouping of Agave gemniflora, a Cercidium x 'Desert Museum" and a local boulder and you have a great combination! 

Senna artemisioides                                                                                                                                 S. Reeve

Here is a closeup of the fragrant five-petaled flowers, and the needle-like phyllodes that are 2-4 cm long or around 2 inches. The flowers of Senna like other members of the Fabaceae are frequently visited by native bumblebees. This plant is reportedly hardy to the low 20's and is deer resistant. It is best to grow this plant slowly. Do not fertilize. Water deeply and infrequently, or in my case, not at all. Overwatering can lead to root rot. Fertilizer and water will cause an unattractive droopy growth habit when the flowers are blooming. Naturally, the growth habit is rounded and attractive. Seeds can be collected and sown for propagation. Soak overnight in boiling water. Love this plant for its ease of care and naturally beautiful habit and because the bees love it too.