All-Season Aloes, Manfredas and Mangaves

By William Scheick, Contributing Editor

Medicinal aloe (Aloe vera), the source of a large number of health remedies, is one of the best-known plants in the world. This tropical succulent also remains enormously popular simply as an easy-care houseplant valued for its quirky windowsill beauty.

Without plenty of indirect lighting, however, such potted indoor aloes might not bloom even when they do increase in size. Many normally grow upwards to varying heights (depending on the aloe species) as well as expand sideways by producing suckering basil rosettes. Both growth patterns eventually result in a crowded pot.

That’s when some people — I’m not mentioning any names — have been tempted to plant their A. vera outdoors. That’s usually a mistake. Although A. vera is a succulent, its tropical tissues are easily destroyed when directly exposed to our summer sunlight or to winter freezes.

Most of the cute little aloes frequently available at big-box stores have the same outdoors vulnerability. As outside plants, such aloes simply can’t take too much rain, sun or cold. They can be great indoor plants, but are likely doomed as in-ground specimens.

The height and width of a mature A. vera are not the only reason some people have tried to transplant it outside. Another reason is that these people have actually seen in-ground aloes and similar-looking succulents in neighborhood yards.

So, understandably, some have imagined that their aloe should be able to make a go of it too as an outside plant. However, successful in-ground aloe species are considerably more cold-hardy and sun-tolerant than A. vera and most other houseplant aloes.

Outside aloes

Some aloes, in fact, are cold hardy to nearly 10℉, and they are worth a try as xeric landscape plants in most of Texas. The comfort zone for these aloes is somewhat beyond halfway up the state. Farther north, in-ground aloes are gambles for gardeners who like experimenting a bit with pushing plant limits.

Consider, for instance, that most of the different aloes grown by Jimmy Turner, while he served as senior director of horticulture research at the Dallas Arboretum and Botanical Garden, had suffered severe winter damage each year. “The only one that had reliably made it in my zone 8 garden was Aloe striatula,” he told me.

A. striatula is known in South Africa as “the hardy aloe” because it is usually not damaged by frost or light snow. It is, of course, an even more reliable in-ground pick for the southern half of Texas.

Buyers should beware, however, when trying to purchase it. On the Web and elsewhere, A. striatula is often mistakenly referred to as coral aloe, which is actually A. striata.

Both have foliage with dark green stripes. But coral aloe, which can be grown outdoors in south-central Texas and farther down, has cream or pink-margined leaves.

Moreover, A. striatula and A. striata are structurally different. While coral aloe looks like an agave, hardy aloe looks like a series of medicinal aloes precariously stacked on top of one another. This tallish succulent is actually used as a hedge in South Africa.

Other outdoor aloes suitable for mid-Texas and southward also depart significantly from the typical look of A. vera. The tight agave-like spiral of A. polyphylla can dramatically swirl either clockwise or counterclockwise.

Even if this aloe is apparently not easy for gardeners to keep, it is so striking that it has become a favorite subject for plant photographers.

Structurally different, too, is the aptly named grass aloe (A. cooperi). It stays under 12 inches and produces a fan of thin, white-toothed leaves with somewhat taller chandeliers of coral flowers.

Cape aloe (A. ferox), partridgebreast aloe (A. variegata), fan aloe (A. plicatilis), Sudanese red aloe (A. sinkatana), flat-flowered aloe (A. marlothii), jeweled aloe (A. distans) and hybrid Little Red Riding Hood aloe (A. ‘Rooikappie’) all have survived in Austin-area gardens.

While hybrid ‘Fire Ranch’ has apparently not quite lived up to its reputed cold hardiness in central Texas, soap aloe (A. maculata) and one of the several spot- ted aloes (A. greatheadii) evidently have performed well outdoors there and farther south.

In central Texas these aloes can suffer winter damage when temperatures linger in the 20s. The abnormal spate of low temperatures and sleet days during autumn and winter (2013-14) were especially damaging, leaving some large in-ground aloes looking fairly “smushed.” Even so, as they have in the past, the crowns of these unsightly aloes should eventually generate new foliage during the spring and summer.

Outside manfredas

For inground plantings in Texas, certain manfredas (tuberoses) are a better bet than aloes.

Manfredas may be separated from aloes by an ocean, but both plants are actually cousins. In fact, manfredas were once mistakenly identified as aloes. Today, for example, the so-called “false agave” (Manfreda virginica) is still popularly known as American aloe.

Numbering about 400 or so, aloe species vastly outnumber manfreda species. Since most of the 20 or so categorized manfredas hail from Mexico and Central America, it isn’t surprising that few will survive winter lows as far north as the Dallas-Forth Worth area.

Even those surviving as inground plants that far north in our state might not remain evergreen.

When asked about the five different manfreda species he had observed at the Dallas Arboretum and Botanical Garden, Jimmy Turner (former director of horticulture operations for the Royal Botanic Garden in Sydney, Australia) answered that all of them generally died to the ground each winter.

However, topping a Texas-tough manfreda list is the so-called spice lily (M. maculosa). It is prized especially for its foot-high fleshy green leaves splashed with purple and also for its tall spikes of white to lavender flowers. Commonly referred to as Texas tuberose, this mildly fragrant manfreda grows wild particularly in the south-central regions of our state. It also performs well farther north.

Manfredas make great companion plants for agaves and aloes. It’s understandable, then, that manfredas were not only once thought to be aloes, they were also once believed to be agaves. Agaves and manfredas are such close relatives, in fact, that they can be cross bred, producing hybrids known as mangaves.

Mangave ‘Macha Mocha,’ which is said to withstand a temperature low of 9℉, is an attractive hybrid cross between Agave celsii and Manfreda variegata. “This is a perfect perennial” for all of Texas, according to Turner.

When Turner lived in Dallas, he enjoyed a 3-foot wide ‘Macha Mocha’ mangave outside his window. “It would get really large, and in mild winters it didn’t die back," he said.

When thinking about planting these succulents, here’s a bit of over-the-fence advice: Hummingbirds do not distinguish among mangaves, manfredas and aloes. Since they find the nectar of all three to be irresistible, hummers can be quite feisty about laying claim to them. So be prepared to share.

Care suggestions

•  Plant in spring or early fall.
• Use a commercial cactus-soil mixture.
• Shelter young plants from direct sunlight.
• Locate mature plants for half-day direct sun exposure.
• Consider eaves or awnings as protection from heavy rain.
• Companion aloes, manfredas and mangaves with suitable plants to lessen the impact of summer sunlight or winter cold.
• Position these shallow-rooted succulents for excellent drainage on slight slopes or small gritty mounds.
• Keep plant crowns higher than soil level.
• Prevent leaves from touching soil.
• Hydrate established plants only when soil is dry (though water needs vary by species).
• Feed each spring with a third of the recommended strength of container-plant liquid fertilizer.
• Drape blankets on species to reduce foliar damage during freezes.
• Cover unsheltered plants with buckets during extended rainfall.
• Propagate by transplanting offsets (“pups”) or propagating seeds (if available).