Cell Phone Tree Video

 Several weeks ago I was asked by an L.A. Times reporter to discuss, on video, camouflaged cell phone towers; the result is the video below:

Shade Trees of the Arboretum Tour Map

Here is a map of the shade trees we covered on Saturday August 4th. 

Keep an Eye Out for Summer Limb Drop

As the afternoons here get hotter and more humid it is the well irrigated trees that can become a threat. Summer limb drop affects trees like the Floss silk tree, The Italian stone pine, and other susceptible varieties. Here is a news interview I did on the subject several years ago after some children were injured by a falling pine tree :

A Handful of Climate Appropriate Trees

The following trees have been picked because they are relatively climate appropriate. Keep in mind that 'climate appropriate' means more than just low water use. Many east coast and european trees require not only water but also cold winters in order to remain healthy. Also, many tropical trees are frost sensitive here and have problems with frost either killing or damaging them. To find a specimen of these trees here at the Arboretum just click on the icon for that tree in the map above. For more information on each tree just click on the link associated with its name and it will take you to the Cal Poly Selectree Database entry for that tree if it exists. 

Afrocarpus falcatus

Geijera parviflora

Melaleuca linariifolia

Lagerstroemia indica

Citrus and other Fruit Trees

Ceiba speciosa (Chorisia speciosa)

Moringa hildebrandtii

Brachychiton rupestris

Callistemon viminalis 'Red Cascade'

Eucalyptus torquata

Corymbia (Eucalyptus) citriodora

Cedrus atlantica

Draceana draco

Olea europaea ssp africanus

Sequoia sempervirens

Quercus polymorpha

Quercus  rhysophylla

Platanus mexicana

Wanderings In The Arboretum Collection: Nuxia floribunda

This medium sized tree sits prominently on the north edge of the Bauer lawn and is in full bloom right now. It’s pom-pom like clusters of fluffy white blooms have a not unpleasant slight sweet scent, adding to the already pleasant shade it throws on the bench located underneath its canopy on its south side. It’s shape makes it quite a pleasant looking tree, having a classic umbrella appearance.

Nuxia floribunda on the north edge of the Bauer lawn. 

It is native to South Africa, Mozambique and Zimbabwe where it can be found in forests between 900 and 4,000 feet. Although it used to be in the Buddleia family it has recently been placed in the mint order in the relatively obscure Stilbaceae family. This particular specimen derives from plant material obtained from the Kirstenbosch Botanic Garden in South Africa. It has been widely planted in South Africa as an ornamental, and its bark and roots have medicinal value. 

Nuxia floribunda's sweet smelling, frothy white flowers are quite attractive. 

Nuxia's gnarled base add to its appeal. 

Inexpensive 3D Trap Aids in the Detection of PSHB

There is finally some good news coming out of efforts to control the Polyhphagous Shot Hole Borer (PSHB). With over 200 common landscape and native trees being attacked by this pest, and over 36 host trees it can breed in, the term 'apocalyptic' is hardly an exagerated one for this pest. Up until the last 6 months things were looking kind of grim, with only regular trunk spraying of contact insecticides being an effective control. Because of the huge list of hosts and trees under attack and non-hetrogenous nature of the ornamental trees (good scientific experiments require multiple samples of uniform subjects, something hard to find with the mature trees the beetle attacks), progress in controlling the beetle has been slow. However the use of 3D printing has allowed custom traps specific for this beetle to manufactured en mass for deployment in the field. These custom traps will allow researchers to better determine the effectiveness of prospective treatments in the field. Also, at least one parasite specific for PSHB may have been discovered in Taiwan. Stay tuned!

I'll Be Speaking in Altadena Next Week

Pasadena Now » Experts Discuss Altadena’s Urban Forest: Past, Present & Future | Pasadena California, Hotels,CA Real Estate,Restaurants,City Guide... - Pasadena.com

A Brush Cherry Apart

 This has always been intriguing to me -a variegated Syzygium australe. It appeared as a 'sport' on an otherwise green S. australe here and has remained stable (not reverting back to its green appearance) ever since.

Syzygium australe