Narrow hedged or espalied California natives

To espalier a plant is to train it into a plane of growth such as on a flat trellis or a wall.  This cultivation technique lends itself to privacy screens and other narrow spaces such as property line plantings adjacent to a walkway or driveway.  Frequently, the same purpose is served by narrow hedges, which tend not to need the support of a trellis or wall, so I'll try to summarize both in this blog post.  Fruit trees such as citrus, apples, pears, and quince (yum) are frequently espaliered with success and are a delight to see.  Depending upon your garden sensibilities, a fruit tree espalier might be just the thing.  I won't dwell further on those here.

California native discussion after the jump break.




Do you have a narrow space that needs a plant, but you can't decide what  native would grow well there?  I don't normally think of using California natives on an espalier, but apparently others have.

Las Pilitas notes in their pruning guide that, " You can espalier some species, but others are very susceptible to stem borers and sun burn. The worst genus to use for espalier is Ceanothus, the best are some of the deciduous species, Clematis, Lonicera, Ribes, Prunus and the evergreen Rhus, Quercus, and Prunus." However, they then say on their central and northern California lilacs page, "Ceanothus griseus horizontalis, Yankee Point, Carmel Mountain Lilac can be espaliered." which they may intend as a specific exception to the rule or perhaps an exception only if you don't live in S California - it's not clear.

Vines and vine-like natives come in for mention which leads to a discussion of "narrow shrubs". Ribes and Cornus species come in for specific mention as candidates for an espalier. The list of narrow shrubs includes Cercocarpus alnifolius (Island Mountain Mahogany), Garrya elliptica James Roof, Lonicera involucrata ledebourii (Twinberry honeysuckle), Rhamnus (Coffeeberry) species (Las Pilitas specifically mention R. californica, R. 'Tranquil Margarita' which seems to be their own selection - too bad it's noted as not available.) and R. purshiana, Spiraea douglasii (Western Spiraea). It seems logical that any of these narrow plants could be espaliered, but they may not need more than an encouraging hand with the pruners.

Jan Nelson Landscape Design has a blog post on espaliered plants.  Jan lives in the Santa Cruz Mountains, so it's not exactly my S. California climate, but she lists "California native plants that can be espaliered are garrya, fremontodendron. Carolina cherry, flowering currant, vine maple and ceanothus while the branches are young and supple."


She must have meant Catalina cherry instead of Carolina cherry.

She says, "Don’t be overwhelmed if an espalier gets out of hand during the season. Just nip the branches back to a leaf node. Use heavy jute to attach the branch to the support wire or stake. After a season the jute will rot away which keeps the branch from being girdled by the restraint."

Again from northern California, the Gardening with Natives email list has espalier commentary.  Agi Kehoe comments that, "for a 2’ deep, narrow, space, in full sun during summer, I would espalier the evergreen ground cover Ceanothus griseus horizontalis ‘Yankee Point’, spaced 8’ apart, on the fence if there is one, or on a custom-built, sturdy trellis. Gambelia (formerly Galvezia) speciosa is a similar choice."

She continues,
Garrya elliptica is another option, also spaced 8’ apart.  Google “Garrya elliptica espalier” for images.  ‘James Roof’ has longer catkins, but the ‘Evie’ is equally attractive.  These are all drought resistant in Sunnyvale and require once per month deep watering, after establishment, and monthly “dusting” with a fine spray of water, during the dry months.  Unlike boxwood, these grow much slower, require less work, and also provide habitat for wildlife, which is equally important.

and has this important advice,

Most other, free standing, upright woody shrubs would require “pounding into submission” with constant shearing to fit this narrow space, and this undesirable maintenance damages the plants and also removes the flowers. 
 
Returning closer to home, Mother Nature's Backyard features Garrya veatchii (Canyon Silktassel) as an espalier.  G. veatchii is more suitable for our S. Ca climate, according to author Connie Vadheim who notes that, "of all the California species, Garrya veatchii has the most southerly distribution, typically ranging from San Luis Obispo County to northern Baja California, Mexico. The Canyon silktassel can still be seen in the Transverse and Coastal Ranges of Southern California (including the Santa Monica and San Gabriel Mountains of Los Angeles County)."

So here's the wrap up - As with all native plant choices, choose the species that works best in your garden conditions.  There seems to be wealth of information for N. Ca. gardeners, but for us S. California gardeners we have fewer references.

Mentioned herein:

Garrya veatchii (Canyon Silktassel)
Garrya elliptica ‘James Roof’ and 'Evie'
Ceanothus species (both as bad and as good choices)
Ceanothus griseus horizontalis ‘Yankee Point’ (a possible exception to the bad)
Gambelia (formerly Galvezia) speciosa
Ribes species specifically  R. californica, R. 'Tranquil Margarita' (which seems to be their own selection - too bad it's noted as not available.) and R. purshiana
Cornus
Cercocarpus alnifolius (Island Mountain Mahogany)
Garrya elliptica James Roof
Lonicera involucrata ledebourii (Twinberry honeysuckle)
Rhamnus (Coffeeberry)
Spiraea douglasii (Western Spiraea)
Acer circinatum (vine maple)
Fremontodendron
Clematis
Lonicera
Prunus
Quercus