Actual size and flowering may vary slightly based on season.
Sturt's Cassia
Sturt's Cassia is an Australian evergreen shrub with dull green leaves that have a soft, velvety look. From late winter into early spring it carries masses of yellow pea-like flowers, and bees visit them. It grows at a moderate pace to about 6 to 8 feet tall and nearly as wide, and it needs little water once rooted. Use it as a winter accent, an informal hedge or a background screen.
Best for: winter color, informal hedges and background screens, and low-water desert yards with full sun and soil that drains.
Masses of yellow pea-like flowers cover the plant from late winter into early spring, when little else is blooming. Bees visit the flowers, so plant it where you can see it from the house.
It grows about 6 to 8 feet tall with a nearly equal spread. That fills in a loose hedge along a wall or the back of a bed. Plant it about 6 to 8 feet apart and let it keep its natural rounded shape.
Once it is rooted, a deep soak about once or twice a month in summer is enough, with little or no water in winter. Extra water only makes it grow bigger and leggier.
Roots can rot in soil that stays wet, and nights colder than about 22°F can damage it. Shearing ruins the shape and cuts the bloom, so prune lightly right after flowering, which also removes the seed pods.
- Informal hedge or mass planting6 ft apart
- Single shrub in a bed8 ft apart
Water every 3 to 4 days for the first two weeks. Then stretch it to every 6 to 7 days, then every 7 to 10 days, and every 10 to 14 days by about week 8.
Once rooted, give it a deep soak about once or twice a month in summer and little or none in winter. Too much water makes it leggy and yellow and can rot the roots.
Cut it back moderately right after it blooms to remove the seed pods and control height. Pruning later in the year removes next spring's flowers, and shearing ruins the shape.
Once it is rooted, it needs little or no fertilizer. Extra feeding and water only push leggy growth.
It handles cold to about 21 to 22°F. On a colder night, cover young plants with frost cloth that reaches the ground and take it off in the morning.
Drainage test first. Dig the hole and fill it with water. If water is still sitting in the hole a day later, you likely hit caliche, clay or hard soil, so fix the drainage before planting. If it drains very fast, the soil is sandy. Standing water around roots is a common reason new plants fail.
Weed cloth. Cut it away from the planting hole and where the roots will spread. Remove any plastic sheeting completely, since it keeps water and air out of the soil.
Rock or decomposed granite with no soil underneath. Bring in soil close in texture to your native soil, mix it with the soil below, and build up enough depth for roots before planting.
If you can break through. Use a breaker bar, pick, or jackhammer. Dig through the caliche and break out the solid chunks. Backfill with the soil you dug out, with no compost or manure in the hole. Confirm drainage before planting.
If you cannot break through. Dig narrow holes through the hard layer beside the root ball, not under it, and refill them with the same soil, not gravel. If it still will not drain, plant on a low mound of the same soil.
Root ball. Check the outside edges for any roots circling around. Loosen or cut those so they grow outward. Do not break up the center of the root ball.
Depth. The top of the root ball should sit at or just slightly above the surrounding soil level. Planting too deep can lead to rot and kill the plant.
Drip emitters. At planting, put the emitters on the root ball, on different sides of the plant. After about 2 months, move them to the outer edge of the root ball. Over the first year, add emitters farther out toward the edge of the branches as roots grow. Once a plant is rooted, never water only at the trunk.
Is Sturt's Cassia the same as Senna sturtii or Cassia sturtii?
Yes. It was sold as Cassia sturtii and is now grouped as a form of Senna artemisioides, the same plant family as Feathery Cassia. Nurseries still sell it under the cassia name.
How big does Sturt's Cassia get?
It grows to about 6 to 8 feet tall with a nearly equal spread. You can keep it around 4 to 6 feet by cutting it back right after it blooms.
How fast does Sturt's Cassia grow?
It grows at a moderate pace, and faster with more water. Water it deeply but not often once rooted, so it does not get too big and leggy.
How far apart should I plant Sturt's Cassia?
Plant it about 6 to 8 feet apart, center to center. Use 6 feet for an informal hedge or a mass planting and 8 feet for a single shrub in a bed.
When does Sturt's Cassia bloom?
It blooms from late winter into early spring with yellow pea-like flowers, and bees visit them. Save any pruning until the bloom is done.
How is it different from Feathery Cassia?
Feathery Cassia has fine, needle-like gray leaves. Sturt's Cassia has wider, dull green leaflets with a soft, velvety look. Both bloom yellow in late winter on little water, so choose by the leaf look you prefer.
What are the pods, and can it reseed?
Green seed pods follow the flowers and turn brown in late spring and early summer. Pods left on the plant can drop seed that sprouts, so trim them off right after bloom.
When should I prune Sturt's Cassia?
Prune it right after it finishes blooming, in late spring, by cutting the branches back moderately. That removes the pods and controls height. Do not shear it, because frequent shearing cuts next year's flowers.
How often should I water Sturt's Cassia?
Once rooted, give it a deep soak about once or twice a month in summer and little or none in winter. Let the soil dry between soaks, since too much water can rot the roots.
How cold hardy is Sturt's Cassia?
It handles cold to about 21 to 22°F, and colder nights can damage it. Cover young plants with frost cloth on the coldest nights.
What soil does Sturt's Cassia need?
It needs soil that drains well, and roots rot where soil stays wet. Rocky or sandy desert soil is ideal, and heavier soil works if you water deeply and less often.
Sturt's Cassia for sale in Arizona, delivered to you
Sturt's Cassia, sold as Senna sturtii or Cassia sturtii, is an Australian shrub grown for its late winter bloom. It stays evergreen, has dull green, velvety leaves and needs little water once rooted. This page covers its size, spacing, bloom, seed pods, pruning, watering and cold, and how it compares with Feathery Cassia.
Sourced from trusted Arizona growers and delivered directly to your door, job site, or property. We deliver across the Valley and to nearby towns, and quote delivery anywhere else in Arizona.
How big does Sturt's Cassia get in Phoenix?
It grows to about 6 to 8 feet tall with a nearly equal spread. A moderate cut right after bloom keeps it around 4 to 6 feet.
When does Sturt's Cassia bloom?
It blooms from late winter into early spring with masses of yellow pea-like flowers. Green pods follow and turn brown by early summer.
How far apart do you plant Sturt's Cassia?
Plant them about 6 to 8 feet apart, center to center. Use the closer spacing for an informal hedge or a mass planting.
How often do you water Sturt's Cassia in Arizona?
Once it is rooted, give it a deep soak about once or twice a month in summer and little or none in winter. It needs soil that drains well.
When should you prune Sturt's Cassia?
Prune right after it blooms, in late spring, and do not shear it. A moderate cut then removes the pods and keeps next year's flowers.
How cold hardy is Sturt's Cassia?
It handles cold to about 21 to 22°F. On the coldest nights, cover young plants with frost cloth.
What is the difference between Sturt's Cassia and Feathery Cassia?
Feathery Cassia has fine, needle-like gray leaves. Sturt's Cassia has wider, dull green, velvety leaflets. Both bloom yellow in late winter on little water.
We deliver across the Valley, from Phoenix, Scottsdale and Mesa out to San Tan Valley, Maricopa and Casa Grande, and up to Prescott, Sedona, Payson and Globe. See delivery areas and rates.