Actual size and flowering may vary slightly based on season.
Mountain Aloe
Mountain Aloe is a big, tree-like aloe that grows a single stem topped by a rosette of thick, blue-green leaves up to 3 to 4 feet long. In winter it sends up a wide candelabra of flower spikes with branches held out sideways, in yellow, orange or red. Hummingbirds, bees and birds come to the flowers. It is a slow-growing specimen for a xeric garden with some shade from the western sun.
Best for: a slow, tree-like specimen in a xeric garden, winter flowers for hummingbirds, and a bold accent with some western shade.
It grows a single stem topped by a big rosette of thick, spiny leaves. It can reach 8 to 10 feet, though it usually stays smaller in Phoenix heat.
The winter flower stalk branches into up to 30 or more spikes held out almost flat. Flowers run from yellow through orange to red.
Hummingbirds visit the flowers in winter, and bees and other birds come too. Plant it where you can watch them from the house.
It suffers heat damage when summer highs top about 112°F, so give it shade from the western afternoon sun. It is rated to about 23 to 25°F.
- Closer planting8 ft apart
- Wider planting12 ft apart
Skip water for a few days to a week after planting so the roots can heal. Then water to get it rooted, never leaving the soil soggy.
Water infrequently in summer once rooted, about every 2 weeks, and let the soil dry between drinks. It needs little water the rest of the year.
It is rated to about 23 to 25°F with good drainage. On frosty nights, drape frost cloth or a sheet all the way to the ground, not plastic, and take it off in the morning.
It suffers heat damage above about 112°F. Plant it where it gets light shade or shade from the western afternoon sun, and cut dead flower stalks after bloom.
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 Mountain Aloe get?
It can grow 8 to 10 feet tall on a single stem, with a rosette 4 or more feet across. In Phoenix it usually stays smaller because of the summer heat.
How far apart should I plant it?
Plant them about 8 to 12 feet apart, center to center. The Spacing tab shows the same number.
When does it bloom?
It blooms in winter, when a wide, branched stalk carries spikes of yellow, orange or red flowers held out sideways. Cut the stalk off once the flowers are done.
Does it bring hummingbirds?
Yes. Hummingbirds visit the flowers, and bees and birds come too, so place it where you can watch the winter show.
Does it take full sun in Phoenix?
It takes full sun to part sun, but light shade or shade from the western afternoon sun is best in Phoenix. It suffers heat damage above about 112°F.
How often should I water it?
Water it infrequently in summer once it is rooted, about every 2 weeks, in soil that drains well. It needs little water the rest of the year.
How cold hardy is it?
It is rated to about 23 to 25°F with good drainage. Cover young plants with frost cloth or a sheet on colder nights.
Are the leaves spiny?
Yes. The leaves carry short, stout reddish-brown spines on the edges and faces, most of all on young plants. Keep it back from walks.
How fast does it grow?
It grows slowly, so buy a plant close to the size you want.
Mountain Aloe or Cape Aloe?
They look alike and are used the same way. Mountain Aloe's flower spikes branch out sideways, while Cape Aloe's stand upright like a candelabra.
Is it toxic to pets?
Yes. Aloe is toxic to dogs, cats and horses. Chewing the leaves can cause vomiting, diarrhea and lethargy, so keep pets from chewing it.
Mountain Aloe for sale in Arizona, delivered to you
Mountain Aloe, Aloe marlothii, is a slow, tree-like aloe from the mountains of southern Africa. It grows on a single stem and blooms in a wide candelabra in winter. Below is what to expect in a Valley yard, from size and spacing to sun, water, cold and flowers.
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.
Mountain Aloe, Aloe marlothii
Mountain Aloe grows wild in the mountains of South Africa, Botswana, Zimbabwe, Malawi, Eswatini and Mozambique. It forms a single stem topped by a large rosette of blue-green, spiny leaves.
How big does Mountain Aloe get?
It can reach 8 to 10 feet tall, with a rosette 4 or more feet wide. It grows slowly and usually stays smaller in Phoenix.
How far apart to plant Mountain Aloe
Space plants about 8 to 12 feet apart, center to center. That leaves room for each wide rosette.
When does Mountain Aloe bloom?
It blooms in winter on a wide, branched stalk with spikes held out sideways. The flowers run from yellow to orange to red and draw hummingbirds.
Mountain Aloe in Phoenix heat
Light shade or protection from the western afternoon sun is best in Phoenix. It suffers heat damage above about 112°F. Water it only now and then in summer, in soil that drains well.
Is Mountain Aloe cold hardy?
It is rated to about 23 to 25°F with good drainage. Cover young plants on the coldest nights.
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.