dawn redwood (Metasequoia glytostroboides)
Fall is the best time of year to plant trees. The ground is still warm from the summer, stimulating roots to grow even as top growth (shoots and leaves) comes to a halt.
In fact, most root growth of trees takes place this time of year.
In Southern California, it is vitally important that roots establish themselves well in advance of spring, which may arrive to the accompaniment of scorching hot temperatures.
Winter planting can be problematic if there is rain, since wet soil is easily compacted. Also, many of our evergreen trees have subtropical or tropical habitats and may acclimate to their surroundings with some difficulty when planted in winter. Bare root deciduous fruit trees and roses, however, are best planted in winter following leaf drop.
A new book on California trees has been published just in time for fall planting.
“Trees of the California Landscape” (University of California Press), by Charles Hatch, deserves a place in the library of anyone who has a love for trees. Not only will you deepen your knowledge of your favorite tree species, but you will learn about many newly introduced or less common species that deserve wider use.
This book includes pictures and descriptions of more than 400 trees. I immediately turned to the oaks, universally acknowledged for their unsurpassed majestic qualities. No matter where you travel in the world, you will encounter oak trees.
There are deciduous and evergreen oaks for every climate and many have life spans that reach hundreds of years.
I learned that there are oak trees that do not look like oaks but would be eminently suitable for our local climate and soil.
Japanese live oak (Quercus myrsinifolia), a species I had never seen before, is pictured in the book. Its silky green foliage resembles that of a “Raywood” ash and, unlike most oaks, its bark is smooth. It is evergreen, cold tolerant, can be planted in lawns and develops slowly until reaching a mature height of 30 to 50 feet, eventually serving as a shade tree.
The Mexican blue oak (Quercus oblongifolia), so-called because of its leaf color, is a drought-tolerant species native to the Southwest. It is a small evergreen oak, growing to 30 feet tall with simple, wavy leaves shaped like those of a macadamia nut tree.
Paperbark maple (Acer griseum) is recommended as a stunning, small ornamental tree for partial sun. It is a symmetrical, well-formed specimen with peeling red bark and, when it loses its leaves, makes a stunning accent in a winter landscape.
Weeping cherry (Prunus x subhirtella ‘Pendula’) grows to only 12 feet and its drooping branches are covered with pink blossoms each spring.
An exotic tree that many may not know about is the dawn redwood (Metasequoia glyptostroboides), which was first discovered in 1945, in China. This deciduous redwood can live for more than a millennium. You will need a good-sized yard to give it room since it eventually skies to a height of 90 feet.
“Trees of the California Landscape” includes information I have yet to encounter anywhere else, including some distinctive tree lists. Here, you will find more than ten trees in a list of those with variegated foliage, more than 20 trees with pink flowers, more than 40 trees with white or gray bark, and more than 50 multi-trunked species.
There is a plethora of information on the many different ecosystems of California and the trees that are native to each.
Detailed planting specifications are included. It is recommended that the planting hole be three times the diameter of the root ball, with the crown of the tree (where trunk meets root ball) resting 2 inches above the surrounding soil. Two stakes, one on either side of the root ball, should be tied to the trunk when planting a 15-gallon tree. For 5-gallon trees, one stake is sufficient.
Tip of the Week
Hatch, author of “Trees of the California Landscape,” mentions the practice of leaving a bare circle of soil around lawn trees to prevent weedeater and lawnmower damage to the trunk. However, he advises covering this circle with mulch. Otherwise, water that ponds on the bare soil will encourage tree roots to grow there, on the soil surface, instead of downward where they belong.
