GWA: Citrus and Dates

After arriving in Tucson for the Garden Writers Association Symposium, I was ready to see new gardens and new plants.  I participated in a panel Saturday morning after breakfast and a wonderful keynote from Petey Mesquitey.  The panel was great.  Kirk Brown, who played the part of Merlin the wizard, moderated our session on the future of sustainability for consumers.  He placed me with Rosalind Creasy and Casey Sclar.  Ros is undoubtedly the foremost expert in edible landscaping and Casey has lead the vanguard of the sustainability movement at public gardens.  I was really flattered to be able to speak with them.  By all accounts it was a success. 

After picking up a box lunch, we set off for our first tour.  The first stop was the Benedictine Sisters Monastery.  The Sisters have several cottage industries and they cultivate citrus and dates.  The citrus trunks are painted white to help them avoid sunscald.  We all wanted to buy date products, but the dates are not yet ripe. 

The clusters of ripening fruits against the deep blue sky was enchanting.  I'd love to have a taste when they are ripe.  I know that dates are typically pollinated by hand.  I wonder if the Sisters do the pollinating.  

Boxwood Society Meets at Arboretum

It's been 10 years or so since the American Boxwood Society has met at the Arboretum.  Even though we didn't have newly refurbished meeting space available as we had hoped we would, we couldn't have picked a more beautiful day to host.  We had planned to spend a good deal of time in the National Boxwood Collection, and the weather cooperated.  Curator Lynn Batdorf provided a tour, highlighting the latest developments.  He's been working steadily on removing old layers that have rooted and grown into neighboring plants.  In the process he unearthed this wonderful prostrate form of boxwood.  It's a wonderfully irregular octopus of a boxwood that is quite old and no taller than eight inches. 

Dr. Richard Olsen was there also.  He's been working on Catalpa, and they obliged by displaying some fine fall foliage.  He was there to talk about the work he has just started to try to find resistance to boxwood blight caused by Cylindrocladium pseudonaviculatum and breed new boxwood with resistance to the disease.  He'll continue to work on Catalpa, too.  This tree is interesting because of the large burl on the trunk, and it has a witches broom on it that Richard has propagated.

Oak Detective

We've been losing many of our oaks at the Arboretum.  We've also been looking for a reason for their death.  Sure, there are the customary oak problems, Armillaria and Phytophthora on some, Hypoxylon and ambrosia beetles on others, and every other combination you might be able to think of.  We've had all the experts look at declining oaks on the property, but so far, no pattern has been established to explain what is going on. 

I happened to be out looking at something else with Kevin, and he directed me to the north side of the Azalea Collections where I met a chain saw wielding expert from the Forest Service.  He had cut down a small chestnut oak, Quercus prinus, and had collected all kinds of samples.  It looked a bit like a crime scene with evidence collection taking place. 

Chris Carley, on the right below was there and has been a key player in bringing forestry types and plant pathologists to the Arboretum to collect data that might point to a cause or causes for the loss of our oaks.  He's also been monitoring our property carefully for emerald ash borer and Asian longhorned beetle.  I'm happy to report that neither have been found so far, but Chris's work as part of the American Public Gardens Association's Sentinel Plant Network is a key part of keeping ahead of new pest and disease problems.  

Even though we haven't found a pattern to the oak deaths, careful observation and data collection will help us understand what is going on.  It might be a natural cycle of death that is part of the progression toward climax forest, or there may be underlying causes that we can diminish to help our oaks survive.