Actual size and flowering may vary slightly based on season.
Outback Cassia
Outback Cassia is a compact Australian shrub with glossy green leaves on red stems, growing about 3 to 5 feet tall and wide. In spring it is covered with bright yellow flowers, followed by reddish-bronze seed pods. It grows fast into a naturally rounded shape and needs little water once rooted. Its smaller size suits beds, borders, low hedges and raised planters.
Best for: beds and borders, low informal hedges, raised planters and mass plantings where a full-size cassia would be too big.
At about 3 to 5 feet tall and wide, it is smaller than most cassias. It fits beds, borders and raised planters where a bigger cassia would crowd.
Planted 4 to 6 feet apart, it forms a low, rounded evergreen hedge. The glossy green leaves and red stems give it color even when it is not in bloom.
Bright yellow flowers cover the plant in spring, and bees visit them. Reddish-bronze seed pods follow the flowers.
Roots can rot in soil that drains poorly, so avoid wet spots. Frequent shearing cuts down the spring bloom, so trim it right after flowering instead.
- Low hedge row4 ft apart
- Bed or border6 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 less in winter. Too much water makes it leggy and yellow and can rot the roots.
Prune lightly right after it blooms to cut off the seed pods. Pruning later in the year removes next spring's flowers, and frequent shearing cuts the bloom.
Once it is rooted, it needs little or no fertilizer and little extra water. Too much water makes it grow leggy.
It handles cold to about 20°F. On a rare colder night, cover it 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.
How big does Outback Cassia get?
It grows about 3 to 5 feet tall and wide, with a naturally rounded shape, which is smaller than most cassias. Use it in beds, borders and raised planters where bigger cassias would crowd.
How far apart should I plant Outback Cassia?
Plant it about 4 to 6 feet apart, center to center. Use 4 feet for a low hedge row and 6 feet in a bed or border.
When does Outback Cassia bloom?
It blooms in spring, sometimes starting in late winter, when bright yellow flowers cover the plant and bees visit them. Save pruning for right after the bloom.
What color are the seed pods?
They start reddish-bronze after the flowers and turn dark brown by late spring and summer. Trim them off right after bloom if you prefer a tidier look.
How fast does it grow?
It grows fast, and how fast depends a lot on how much water it gets. Water sparingly once rooted if you want it to stay compact.
When should I prune Outback Cassia?
Prune right after it blooms, trimming to shape and removing the pods at the same time. A harder renewal cut after bloom also works, as long as you leave some leaves.
Can I use it as a hedge?
Yes, as a low informal hedge. Frequent shearing cuts down the spring flowers, so shape it right after bloom.
How often should I water Outback Cassia?
Once rooted, give it a deep soak about once or twice a month in summer. It is drought tolerant, and too much water makes it grow leggy, so let the soil dry between soaks.
How cold hardy is Outback Cassia?
It is rated hardy to about 20°F, and it loves hot, dry weather. Cover young plants with frost cloth on the coldest nights.
How is it different from Feathery Cassia?
Outback Cassia is smaller, about 3 to 5 feet, with glossy green leaves and red stems. Feathery Cassia grows 6 to 8 feet with fine silver-gray leaves. Choose Outback where space is tight.
Outback Cassia for sale in Arizona, delivered to you
Outback Cassia is a smaller Australian cassia, about 3 to 5 feet tall and wide, with glossy green leaves and red stems. It blooms bright yellow in spring and grows fast on little water. This page covers its size, spacing, bloom, seed pods, pruning and watering, and how it compares with the larger cassias.
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How big does Outback Cassia get in Arizona?
It grows about 3 to 5 feet tall and wide with a rounded shape. It is one of the smaller cassias, so it fits beds, borders and raised planters.
How far apart do you plant Outback Cassia?
Plant them about 4 to 6 feet apart, center to center. That spacing works for a low hedge or a mass planting.
When does Outback Cassia bloom?
It blooms in spring with bright yellow flowers. Reddish-bronze seed pods follow, then turn dark brown by summer.
How often do you water Outback Cassia in Phoenix?
Once it is rooted, a deep soak about once or twice a month in summer is enough. The soil must drain well, since roots can rot in wet ground.
When should you prune Outback Cassia?
Prune right after it blooms to shape it and remove the pods. Pruning later in the year cuts off the next spring's flowers.
What is the difference between Outback Cassia and Feathery Cassia?
Outback Cassia stays about 3 to 5 feet with glossy green leaves on red stems. Feathery Cassia reaches 6 to 8 feet with silver-gray, needle-like leaves. Both bloom yellow and need 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.