Shady Way Gardens Bits and Briefs JULY 2001
PALO VERDE BORERS & JOJOBA

JULY

JULY.....JULY..... JULY ..... What can be said except it's hot and probably humid.  Although the humidity is uncomfortable for people, plants are happier especially when or if summer rains occur.  These conditions make it easy to overwater some plants.  If soil is staying wet around and into the root area and surrounding soil is also wet don't water. Observe plants.  Wilted leaves, dry soil - plant needs water.  Wilted leaves, wet soil - something else is wrong.  Monsoon storms can produce damaging winds.  Fast growing and top heavy trees like Mesquites (Prosopis sp.), Willow Acacia (Acacia salicina) and Blue Wattle Acacia (Acacia saligna) can be lightly thinned out and long, heavy branches cut back to reduce wind resistance.  When pruning during all summer months be careful not to expose major limbs or trunk to sun as burning can occur.  Make sure young trees are firmly staked. 

If we have had no rain, native plants in their natural environment or without supplemental water become semi to totally dormant.  Penstemons that were so gorgeous last spring are reduced to shriveled clumps with dried seed stalks which have possible use in dry arrangements.  Brittle Bush, Bursage, Buckwheat, Fairy Duster, Wolfberry may actually look dead.  Creosote Bushes take on a yellow cast.

PALO VERDE BEETLES

During humid summer months Palo Verde Beetles (Prionus sp.) make themselves evident.  Some years there are lots some years few.  These huge (to 4") beetles emerge at night from holes mostly beneath native Palo Verde Trees.  For at least a couple of years, the larval stage of this borer has been feeding on tree roots thus weakening the root system.  Branches may die back and greatly damaged trees may blow over.  What can be done?...probably very little.  The holes under the trees are exit holes of the adult beetle whose larval stage has already done the damage.  The adults mate, lay eggs in the soil then die.  The eggs hatch and the tiny larvae make their way down into the root system of the tree.  To effect control at this point, one would have to spread large amounts of insecticides under trees on a regular basis, an environmentally questionable practice. 

JOJOBA

A wonderful native plant for desert gardens is Jojoba (pr. ho-HOH-ba) Simmondsia chinensis, a dense grayish leaved shrub to 6 or more feet tall and wide.  Slow growing when young and very drought resistant once established , this versatile plant can be used as a single specimen, kept trimmed as a hedge if necessary or left to create a natural barrier.  They have no thorns.  Female Jojoba plants produce an edible nut (fairly bitter) that has many commercial uses as it contains an oil similar to sperm whale oil.   Nuts are dark brown and ripen in July and August.  Since male and female flowers are borne on separate plants you must have both sexes if you want a nut crop.  Without fruit, flowers or their remnants it is impossible to tell male from female plants.

Female

Male

VINCA

Vinca are notorious for rotting out during hot, humid weather.  We don't think there is much you can do about this except to avoid over watering.  Dispose of dead and dying plants.  There are usually a couple of hardy individuals that seem immune to the problem and may survive.  Fungicides may or may not help.

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Web Comments george@mswn.com September 13, 2004 Shady Way Nursery 2004