Southern Live Oak, Tumbleweed, Feather Grass

acorn from a Valley or white oak (Quercus lobata)

A gleaming oak tree from the Southeast and an iconic weed from Russia are thriving in Balboa Park.  The park entrance is located on the east side of Balboa Boulevard, between Burbank and Victory Boulevards, in Van Nuys.

The tree in question is southern live oak (Quercus virginiana).  After you enter the park, find the first parking lot on your left.  There are a number of southern live oaks growing between the parking lot and the south edge of the lake.
Southern live oak has a glimmering, other worldly radiance that immediately captures your attention.  It is the same radiance given off by moderately sized magnolia cultivars such as ‘Little Gem,’ compact Carolina laurel cherries (Prunus caroliniana) such as ‘Bright ‘n Tight,’ and Victorian box trees (Pittosporum undulatum).
At Balboa Park, the glossy Southern live oaks present a compelling contrast to the native California sycamores (Platanus racemosa), with their sere foliage, planted close by.  Once upon a time, California sycamores dominated the Valley’s landscape together with coast live oak (Quercus agrifolia) and California black walnut (Juglans californica) trees.  These three natives are still growing wild in our area and are especially visible along Beverly Glen and Coldwater Canyon Boulevards between Ventura Boulevard and Mulholland Drive.
Getting back to Southern live oak, it has a reputation for being the most attractive, landscape worthy oak of its kind.  Live oaks are an alternative name for evergreen oaks, to distinguish them from deciduous oaks such as Valley or white oak (Quercus lobata), the only deciduous oak species that is native to the San Fernando Valley.  Southern live oak can even grow in a lawn, a claim that no California oak, to the best of my knowledge, can make.
I also spotted some healthy tumbleweeds in an open, still undeveloped area of Balboa Park.  Tumbleweed (Kali tragus), emblematic of the wide open and desolate Western frontier, is actually native to Russia.  In the 1870’s, bags of flax seed that were shipped to South Dakota contained tumbleweed seeds and, soon enough, tumbleweeds were doing somersaults all the way to California.  Once it dies, tumbleweed is detached from the ground and is transported long distances by the wind, dropping its seeds as it goes.
For years I have observed the trees on Victory Blvd. that grow on the north side of the street between Odessa and Valjean in the Lake Balboa district.  They actually border the Van Nuys public golf course. Their leaves turn the most magnificent crimson in the late fall (this time of year) and their blossoms are white and fully cover the tree in the spring.  I’m sure that they are a flowering fruit tree – perhaps a pear or a plum or maybe a special cherry – but I haven’t been able to identify the exact variety.  It looks like a very hearty and healthy tree.  Could you please tell me what kind of tree this is?  Is it available locally?
Dale Bridges, Lake Balboa
The trees to which you refer are Bradford ornamental pears (Pyrus calleryana ‘Bradford’).  Your admiration of their fall foliage and spring flowers is understandable.  These trees make an indelible impression on one and all . . . from a distance, that is.  The main problem with Bradford pears is structural.  If you get close to a tree, you will notice that as many as a dozen branches emanate from a single point and, due to the laws of physics, some of these branches will eventually break off.  After a storm, it is not unusual to see Bradford pear trees split in two.  Only vigorous annual pruning, which would significantly alter the natural shape of the tree, can keep a Bradford pear in intact.  Another issue pertains to roots.  On Victory Boulevard, Bradford pear roots have significantly elevated the sidewalk and they would create havoc in a garden, too, competing for water and nutrients with other plants before cracking an adjacent patio, pool deck, or driveway.  You would have to do an Internet search to find this tree since it is not available in the local nursery trade.

Italian stone pine (Pinus pinea)

Speaking of trees I would not plant, be careful with Italian stone pines, which make their appearance in nurseries at this time of the year.  As young plants, they have this soft and cuddly presence that makes them hard to resist.  However, their billowy look is a consequence of juvenility.  Once they mature, sharper conventional pine needles usurp the softer foliage of their juvenile stage.  Mature Italian stone pines are recognizable by their domes, which are slighting curved to flat at the top.  Unless they are ruthlessly thinned out, they are likely to fall over.  Italian stone pines tend to lean and, once they do, it is only a matter of time until they crash to earth.  So don’t park your car – or build your house! – under an Italian stone pine (Pinus pinea).

Mexican feather grass (Nassella tenuissima)

Mexican feather grass is the new bane of western gardens.  Awful stuff.  When I went by the new student gym on CSUN’s (Cal State Northridge) campus I was horrified to see it was used exclusively in a huge area on the west side of the building. What was someone thinking? Around the corner from me here in Woodland Hills about a dozen plants were installed 3 years ago in a planting on the outside area of a short wall at a shopping center. It is now spreading throughout the area, even without much water.

Carolyn Arthur, Plant Nursery Professional, Woodland Hills
Mexican feather grass (Stipa or Nassella tenuissima) makes an initially favorable impression.  Its cushiony, kinetic tresses turn from green to gold as they flower and proliferate, self-sowing in the garden bed.  When clumps of feather grass start to look tired and worn, you cut them to the ground.  Some clumps regrow and others die but, thanks to a continuous supply of new sprouts, your feather grass increases from year to year.  Feather grass is especially popular in parkway plantings.  You are correct in sounding a word of caution, though, regarding its capacity to spread.
Tip of the Week:  My recommendation for colorful fall foliage is Chinese tallow tree (Sapium sebiferum).  Heart shaped leaves turn burgundy and gold.  This is a small to medium sized tree with manageable roots.  They are planted as street trees on Ventura Boulevard in Sherman Oaks, east of Woodman Avenue.

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