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Plant Focus

Quercus douglasii is an endemic California oak tree, affectionately called “the blue oak”.

A New Quercetum!

General view of the new quercetum - click on images to enlarge

It is our vision that when the years roll on and you reach your eighties that you do not downsize nor retire but that you have projects. To realize this we took back from our tenant farmer an area of land to add to our garden. We decided to plant out a collection of oaks. Our soil is very alkaline, with a pH of 7.6 to 7.8. It is good, fertile, heavy soil—not clay, and it lies on a layer of limestone. It is not known how compatible many species of oak may be with different soil types.  For example, will the American oaks grow on our soil?  Some of the soil in America is neutral to acid and they have a continental climate—cold in winter and hot in summer. We have a maritime climate with many cloudy days in winter, which may be a factor. Thus this is a scientific experiment.

We started with planting at the end of March 2017 48 oaks, some of which are scrub oaks or dwarf shrubby oaks. A few other trees were included to provide variety.

A list of trees planted is below. After planting, we experienced dry weather and all trees were kept well watered.

Lammas growth on Quercus acutsissima (left) and Quercus chrysolepis (right) 

They have settled down well and many species have shown good Lammas (late summer) growth.  Nonetheless, it will be two or three years before one can really tell if the project is a success.

List of Quercus

Q. acutissima
Q. agrifolia
Q. aliena
Q. aucheri
Q. berberidifolia
Q. ×bushii
Q. cerris
Q. chenii
Q. chrysolepis
Q. coccifera
Q. dolicholepis
Q. durata
Q. ellipsoidalis
Q. gambelii
Q. frainetto*
Q. gilva
Q. hartwissiana
Q. ×hispanica 
Q. ithaburensis
Q. kelloggii
Q. libani
Q. lobata
Q. mongolica
Q. muehlenbergii
Q. oglethorpensis
Q. petraea
Q. polymorpha

Q. pubescens
Q. robur 
Q. robur ‘Purpurea’
Q. rotundifolia
Q. ×runcinata
Q. rysophylla
Q. sadleriana

Q. serrata
Q. suber
Q. trojana
Q. turbinella
Q. vacciniifolia
Q. variabilis
Q. ×warei
*This was planted about 15 years ago and is a nice specimen Quercus pubescens

Other Plants

Abies cephalonica
Betula utilis
var. jacquemontii  ‘Doorenbos’
Calycanthus ×raulstonii 'Hartlage Wine'
Calycanthus chinensis

Cladrastis lutea
Corylopsis spicata
 ‘Norman Hadden’
Euonymus latifolius
Euonymus tingens
Fagus sylvatica ‘Dawyck Purple’
Liriodendron tulipifera
Notholithocarpus densiflorus 
var. echinoides
Magnolia macrophylla

Magnolia sieboldii
Magnolia ‘Susan’
Pinus sp. (from Mexico)
Sequoia sempervirens


All photos ©James Harris