Each month, a gardener from Tohono Chul Gardens provides Oro Valley readers with information on native plant life. The mission of Tohono Chul Park is to enrich people's lives by connecting them with the wonders of nature, art and culture in the Sonoran Desert region and inspiring wise stewardship of the natural world.

By Leith Young

“Mighty as an oak”, “The lofty oak from a small acorn grows”, and

“The creation of a thousand forests is in one acorn”.   One could go on

and on with quotes about oak trees. Their beauty, strength and

determination to grow has inspired many people to deeply appreciate

and love these magnificent trees.


As tough as oaks are in withstanding the elements, it’s kind of a different

story when it comes to growing Oaks in Tucson. Yes, the Southern Live Oak or Quercus virginiana can grow when extra water is provided, but most of the native oaks don’t like the Tucson soil and struggle with the summer heat.


The Mexican Blue Oak or Quercus oblongifolia does not suffer from these problems. It is native to Southern Arizona, Southern New Mexico, West Texas and northern parts of Mexico from 3,000 to 6,000 feet in elevation.  It is the first oak you see when you gain some elevation in the Catalina Mountains and can often be found growing alongside saguaros. As you climb a little higher in elevation it becomes the dominant species in the lower open oak woodlands. It can grow from between 15 to 30 feet in height and wide depending on moisture availability.  It maintains its leathery, bluish-green leaves all winter, with flowers appearing in spring when the old leaves are being shed and new leaf growth starts. The growth rate is moderate with two or more growth spurts a year.


Mexican Blue Oak can take full sun in Tucson. Ideally, it should be planted on the north side of your house or wall to keep the root zone cool. If this is not an option place a thick layer of mulch around it. A newly planted tree will probably need water every other day, but once established it will be fine on a once-a-week watering in the summer. They take on a wonderful shape all on their own, so try to limit your pruning to only crossing or rubbing branches. Staking should not be necessary and pest are usually not a problem.


We strongly encourage you to try a Mexican Blue Oak in your yard so you and generations to come will enjoy the beauty and shade that this tree will provide. And remember, “A large oak tree is just a little nut that refused to give up!”

 
From Tohono Chul
RThe Oak Tree

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