Southwest Regional Reports

Get to Know the Genus Eucalyptus—Grow the Best Variety for You

These plants come in hundreds of shapes and sizes, ensuring there’s a perfect one for your space

The impressive features of eucalyptus plants are hard to beat. Varieties can have striking bark, gorgeous flowers, or interesting habits.

I feel bad for the genus Eucalyptus (Eucalyptus spp. and cvs., Zones 8–11). So misunderstood and generally shunned in polite plant society, just because of the misdeeds of a few family members who got a bit aggressive. A little like dogs, really—the bad behavior of a few lumbering giants instilling undue fear of all claiming to be a “dog.” Doesn’t make sense, does it?

Learn more: Plants That Can Anchor a Landscape

It’s true enough that the massive eucalypts of yore were classic examples of “wrong plant, wrong place.” The antics of the bulky Tasmanian blue gum tree (E. globulus) account for the lion’s share of the bad rap. They have aggressive roots, colonizing seedlings, falling limbs, and the ability to spread fire, and—let’s be honest—they drink too much!

It’s time to move on, don’t you think? There are at least 800 species of eucalypts out there, mostly native to Australia. Like dogs, they come in hundreds of shapes and sizes, some big and boisterous eucalyptus trees, some small and timid, and some “just right.” The ones that follow are among my favorites so far, and most hail from the drier regions of western Australia, with tolerance of significant heat and frost. I’ve grown them all in my Tucson garden, usually in lean and xeric conditions. Eucalyptus plants are not just beautiful but also have temperaments that I’ve come to appreciate in smaller garden settings.

Recommended Eucalyptus Varieties

Strickland’s gum bark close up

Strickland’s gum

(E. stricklandii)

Zones: 8–11

Size: 15 to 30 feet tall and wide

Conditions: Full sun; well-drained, average soil

The lustrous, deep green leaves on this species of eucalyptus tree’s pendulous branches produce abundant large, yellow flowers throughout the crown. Strickland’s gum begins to form a canopy fairly fast, and selecting/pruning a good arrangement of scaffold branches early on is a good idea. As the sturdy, upright trunk expands, gray-brown, plated bark peels away to reveal beautiful, smooth, cinnamon-toned patches beneath.

 

E. woodwardii with bees

Lemon flowered gum

(E. woodwardii)

Zones: 8–10

Size: 25 feet tall and 10 to 15 feet wide

Conditions: Full sun; well-drained, average soil

The upright leader of this tree supports pendulous branches in youth, maturing into an irregular open crown with weeping branches. Leaves, buds, and young stems are dusted a silvery gray. Large, golden-yellow flowers laden with nectar are a feast for honeybees and other pollinators, and they occur along the draping branches down where you can enjoy them. The bark slowly sheds in gray-and-rust-colored ribbons.

 

Coral gum plant with flowers

Coral gum

(E. torquata)

Zones: 8–11

Size: 25 tall and 15 to 20 feet wide

Conditions: Full sun; well-drained, average soil

This eucalyptus grows quickly to perfect patio proportions, with deep green leaves uniformly spaced in a rounded crown. Seedlings can flower at just 5 feet tall, and flowers seem to appear almost any time of year on different trees, in shades of pink, coral, or rose red. Hummingbirds frequent the blooms, which provide them with plentiful nectar. The abundant blossoms are among the showiest of the smaller eucalypts, and flowering lasts for many weeks.

 

Gimlet gum

Gimlet gum

(E. salubris)

Zones: 9–11

Size: 30 feet tall and wide

Conditions: Full sun; well-drained, average soil

Slender, mid-green leaves and a quick growing habit set this eucalyptus apart. This tree tends to develop a multi-stem appearance, and one might want to encourage this, as the fluted trunks are one of its best features as it matures. The bark varies with the season from olive green to a lustrous satiny copper. It truly shines when contrasted with silvery-leaved shrubs. Cloudlike tufts of foliage are held aloft in a rounded canopy. Small, white flowers are an incidental feature.

 

Little ghost gum

Little ghost gum

(E. victrix)

Zones: 9–10

Size: 20 to 30 feet tall and 10 to 15 feet wide (smaller in drier conditions)

Conditions: Full sun; average, well-drained to damp soil

The common name of this plant gives you a pretty good idea of what it looks like. Little ghost gum sports pendulous branches of silver blue-green leaves that sway from an open canopy. The multiple and contorted trunks are ghostly white and glow against darker backgrounds or walls. It’s amazing when used as a focal point, or enchanting in small groups. Either way, this plant begs for evening uplighting. Little ghost gum is a treasure even without its seasonal small, white flowers.

 

Bookleaf mallee stems

Bookleaf mallee

(E. kruseana)

Zones: 9–11

Size: 8 to 15 feet tall and wide

Conditions: Full sun; well-drained, average soil

With a sculpted character unlike all the others, this eucalyptus species grows into a large shrub or small tree and is a true standout. The rounded, silver-dollar leaves are tightly stacked in orderly alternating rows—not unlike the pages of a book—presenting a most unusual geometric look. These silvery, bottlebrush-style branches sometimes show great symmetry, and sometimes dip and twist away on their own random trajectories. Either way, the color is a wonderful contrast to greener, leafier plants that play by the rules. Soft, yellow flowers appear in tightly packed bunches among the blue-gray leaves.

 

 

Discuss this and any other gardening topic in our Southwest gardening forum.

Find more information on Southwest gardening here.

 

More plants for the Southwest

Shopping-List Plants for the Southwest

Plants That Take Sun and Shade for the Southwest

Trees That Create Light Shade for the Southwest

 


Dan Johnson lives and gardens in Denver, Colorado, and in Tucson, Arizona. He is an associate director of horticulture for the Denver Botanic Gardens.

Photos: Dan Johnson

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