Food and Entertaining

History Adventuring: The eucalyptus trees of Phoenix, Arizona, and other areas.

Depending on the species, many eucalyptus trees, such as this one growing in a Casa Grande park, bring focus and some shade to residential, commercial and public areas.

If you have a small yard and you're looking for a tree that gives shade and a plant that can get by on a little water, you might consider one of the various species of eucalyptus.

Picking the right tree to grow in our low desert environment can be difficult.There are a lot of questions that people ask when they decide on a tree.

We can only make good decisions if we understand the strengths and weaknesses of each tree.Can we make informed decisions after that?I want to talk about a group of trees that are sometimes praised, sometimes snubbed and occasionally used in our landscapes: the eucalyptus.

There are trees in the warm desert regions of Southern Arizona.They are frost and heat tolerant.Those mentioned need full sun exposure.Most use relatively little water and some can go for a long time without an irrigation.They are intriguing candidates for low-water-use landscapes.Many are tolerant of over wet conditions and can be planted in a lawn.Good shade and color are provided by most.Sometimes flowers are used to provide the color, but more often it is through the bark of the tree.Not all trees make good trees for home yards because of their size or growth habits.

If a tree stays in a pot too long, it can become root bound.I warn you that this is a word of warning.Sometimes root binding develops in the root system of plants that sit in a container too long.As the roots grow out from the trunk of the tree, they can either hit the inside of a container or bounce back into the root ball at a sharp angle.The tree is at risk of being blown over in a wind storm because of root binding.Plants that have not spent a lot of time in a container can be used to grow the best trees.

Some eucalyptus trees are too large or messy for home yard conditions, and some lose branches during windstorms.Many are good neighbors and can be planted with confidence around our homes.Let's get to know them better.There are six different eucalyptus trees that are well adapted for home yard planting, and a couple that have not.

Over the years, it has been a mainstay in many yards.It is acceptable for limited spaces even though it needs a little more room to grow.It's known as the Coolibah tree.It grows at a moderate rate up to 35 feet tall and spreads to the same width.It has silvery-gray leaves.Most forms of this species are grey in color, but some have a white bark.It has no problem with iron deficiency.It was described as a nice, quiet, graceful, open-canopied tree.

The Ghost Gum is a good choice for warm temperatures.Some forms have more than one trunk.It is a tall tree, growing up to 60 feet tall, but in our area it is usually less than that.The bark is snow white and grows at a moderate to fast rate.It is 15 to 30 feet wide.The faster it grows, the more water it receives.The leaves are gray to green in color.They are pointed at the tip and are 1 to 112 inches wide.The purple tint in the leaves can be caused by the frost.It likes soils that drain well.

The bark of the Salmon Gum is smooth and pink.It has green leaves.It can grow up to 100 feet tall.Because of its slow growth, it almost always stays smaller for a longer period of time, good news for people with small yards.It doesn't have all the peeling bark that other species do.It is a great tree because it doesn't grow fast and only gives off a small amount of litter.

Red Ironbark is the common name of E. sideroxylon.The tree is somewhat frost tender, down to only 20- to 25-degrees F., but its blue green leaves and dark colored bark make it truly spectacular.Depending on the variety and amount of water it gets, it is a medium tree that grows from 20 to 8 feet tall.It has flowers that are red to pink.Young plants need to be watered at least once per week in warm weather to ensure rapid growth.It doesn't like wet feet so it's not a good choice for lawns.It needs a fast draining soil in order to prevent iron deficiency symptoms.

The Swamp Malee is a small tree that grows from 6 to 20 feet tall.It is perfect for smaller yards.Don't let the name scare you.It does well in the desert.It has small leaves and iron deficiency symptoms are rare.It will tolerate both wet and dry conditions for a short time.It has a smooth bark and gray-green leaves.It's hardy to about 15 to 20 degrees F. making it immune to freeze damage in our warm climate.

E. torquata has beautiful red and yellow flowers that make good cut flowers in a vase.Most of the year, some varieties bloom on and off.It's called the Coral Gum.It is 20 feet tall and wide.It grows at a moderate rate and has a slender trunk.Its bark is dark brown.A heavy flower and seed production season can cause some branches to fall.It seems to be tree free of problems.

The two species that are not recommended for home yards are frequently selected and planted.E. camuldulensis does better in parks and large open areas than in most home yards.It's also called the Red Gum.The Silver Dollar Gum is prone to chlorosis in soils that don't drain well.Pick another tree unless you want to try something.

Many ucas trees are problem free and make good shade trees.Pick one of the recommended varieties that fit your needs when selecting a specimen tree.

You can reach one of the Master Gardener volunteers at the Cooperative Extension office.204.

Rick is the director of the University of Arizona's Cooperative Extension in Pinal County.gibsonrd@ag.arizona.edu is where he can be reached.