Back To The Alder-Dodonea-Pittosporum-Not-Ligustrum Saga

Their sunset moment:
 photo dodon1929_zps96102913.jpg
I'm not sure when I planted the Dodoneas.  We'd asked the landscape architect for screening plants to hide the downhill neighbor's roof when the landscaping went in back in 2000.  She made the poor choice of the native White Alder, Alnus rhombifolia.   

"It is not drought tolerant, but very fast, to 30 feet in 5-6 years. Its shade is rather dense(cool) to garden under unless you work at opening up the limb structure and even then it is very competitive. In the wild places we have seen there are almost no understory plants growing near white alder."
-- Las Pilitas comments on Alnus rhombifolia

Dear Landscape Architects, don't plant a thirsty riverbed tree on a dry slope six inches from a masonry wall.  Thanks! 

Note to self:  there are licensed professional Landscape Architects out there who know zippo about plants.   

The Alders quickly became a huge problem.  Roots, height, vigor, reseeding, trunks pressing up against a masonry wall.  The LA had chosen an elephant to do a poodle's job.  The Alders were cut down about 2003, and thus began a search for an appropriate and less problematic replacement.  Plain old Ligustrum japonicum,  the plant we here call Privet, would have made a screen, and fast, too, but...  I finally decided on Dodonea as a temporary screen while I thought through a better solution.  
A wind storm uprooted this one in 2011.  (Note That Roof behind the fallen.)
 photo Dodonea_zps6c3e67d2.jpg
Our Santa Ana winds took out two of the six planted from 15 gallon containers.  When young the Dodonea viscosa root system is small and weak.  This is a problem but also a virtue--they reseed a lot, but are easy to pull out.  Even 40" (1 M) seedlings come out with a one-finger-and-thumb light tug.   
For a while, not bad:
 photo DodoneaScreen7911_zps28df8e95.jpg
The four survivors grew to a manageable size (about 18') and did a fair job of screening the neighbor's roof.  They are not particularly dense growers, and as they matured, entire branches simply died.  Scale and borers were a problem.  After about three years of grudging, marginally acceptable performance as a roof screen, the Dodoneas went into a steep decline.  Now it is time to try again for a better solution.  
Sort of better.  A 'Wrinkled Blue' Pittosporum tenuifolium on the left, 'Tasman Ruffles' on the right.  
 photo dodon1887_zps0d3d64ef.jpg
 The two different Pittosporum tenuifolium selections that replaced the wind-toppled Dodoneas have been--promising.  They have displayed several virtues.  First, when they reach full size, they will be just about the exact right size to hide the neighbor's roof without getting too tall; this without trimming or pruning.  Second, they've done fine on modest water--two one-gallon-per-hour irrigation drippers, run for ten minutes three times per week.  Third, their glossy foliage looks beautiful in morning light.  The leaves sparkle when the morning sun shines through, a beauty that far exceeds the dour Dodoneas.   So far the sole drawback is that the foliage is not yet dense enough to completely vanquish the offending roof.  

This saga I have blogged about before, several times.  Screening that roof is a problem I have a continuing mad passion to solve in precisely the right way.  The solution is not Ligustrum.  The hedge of Ligustrum planted in the back last year to screen out another neighbor's property is growing rapidly and will be a substantial 2 meter privacy screen within another year, but for hiding that roof, it's not, it's not, it's not the solution.  Yet. 

So funny and ironic that the trio of Calothamnus villosus in the front, which have formed a perfectly wonderful privacy screen of the house across the street, was a pure impulse purchase for a problem I didn't even know I had.  That bit of the garden is so much better now with the Calothamnus screen.  
There's a house behind that plant, but wouldn't you rather look at that plant?  No thought involved whatsoever:
 photo calo0187_zpsd3418aeb.jpg 
Years of agonized effort put into solving That Roof problem, and elsewhere, thoughtless impulse produces an ideal effect.  Ain't that gardening?  And life?  



  1. Most of my greatest successes were born of the thoughtless impulse.

  2. Oh, I hear your pain! It is very challenging to find the right plant for the look and privacy one wants in the first place, then adding in all the locational and environmental issues on top rules out so many. As you may have seen, at Longview Ranch we're searching for several "perfect" trees and shrubs too. I'd have that glorious Calothamnus villosus in a heartbeat if I thought it would live here!

    1. If nothing else, it's educational, though often unpleasantly so.

  3. Back in the olden days when I worked at the nursery in San Diego we were selling Ligustrum and Dodonea to a fare-thee-well to folks who wanted fast growing screens. I can't bear to look at Ligustrum , but up here in Norcal the Dodoneas are well behaved and the mow and blow guys tend to leave them be. The Alnus R. thing--what a joke. How could anyone think a riparian tree would work in your situation ?

    1. Someone who didn't care all that much, I guess. The Ligustrum I am developing more and more respect for--respect, without affection.


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