Aloe marlothii aka Transvaal Aloe

Aloe marlothii, or mountain aloe, belongs to the Asphodelaceae family. It is native to Botswana, Mozambique, Eswatini, and South Africa. It grows in dry scrub, savanna, and rocky places. These include inland cliffs and mountain tops. It can dominate sites with bare, stony soil. Its home range has summer rain and dry winters.

This evergreen succulent grows into a tree-like plant. Garden plants reach about 8–13 feet (2.5–4 metres) tall. Their spread reaches 5–8 feet (1.5–2.5 metres). Some plants reach 20 feet (6 metres), beyond the usual range. Most have one trunk that does not branch. Some send up shoots at the base, forming small groups. Thick, silver-green to grey-green leaves form a large rosette. Dark spines line the edges and both leaf surfaces. The RHS gives five to ten years to reach maturity.

The tubular flowers can be red, orange, or yellow. They grow in spirals along branches of a tall flower stalk. These branches extend almost sideways and curve as they age. Flowering dates differ between the sources and growing sites. The RHS reports summer flowers in the UK. Chicago Botanic Garden lists November through February. Sunbirds and bees pollinate the flowers. The plant also draws birds and butterflies, according to Chicago. Its bold shape suits borders and planting as a single specimen. The RHS also lists it for greenhouses and conservatories. Chicago reports that deer tend to leave it alone.

Give mountain aloe full sun and soil that drains well. Chicago also lists partial shade as suitable. The RHS accepts loam and acidic, neutral, or alkaline soil. Established plants withstand drought. Water moderately during growth, but give little water during dormancy. For pots, use peat-free cactus compost or loam-based compost with grit. The RHS advises monthly liquid feed from May to August. It rates the plant H1C for UK conditions. Yet it reports brief survival at 21°F (−6°C) with dry roots. Chicago gives a similar cold limit for dry climates.

No pruning is needed, and the RHS reports few disease problems. Scale insects and mealybugs may still attack it. People consume the sweet nectar from its flowers. Records also describe leaf and root preparations for stomach pain and worms. These are traditional uses, not proof of safe treatment. The RHS warns that eating the plant can harm people and pets. Wear gloves and other protection when handling its spiny leaves. The reported use of nectar does not make other parts safe.