Pruning Native Plants – Part 3
By Allison Levin
I began this series on pruning California natives with ideas about why a gardener might prune woody plants. Next, I discussed proper pruning techniques. In this entry, I’ll look at a number of woody California native plants and consider how pruning might best enhance each, utilizing the techniques discussed in my second article.
A reminder: Since pruning weakens plants, special consideration should be given to older specimens. Only prune healthy plants, start conservatively, and take notes or pictures. Observe over the subsequent year to see how the plants respond to your work. Also, remember that pruning is a seasonal practice, with different times for different plants, and is something I’ll continue to address in a future installment.
The essence of a tree
Think about – observe – what is the essential beauty of your tree (or shrub). Maybe it is the reason you planted it: a glorious flower show, colorful berries for wildlife in fall, the drama of its bark or the twists in its branches. Perhaps the essence of your tree is the calming richness of its green leaves.
A different kind of “essential beauty” can also be found in individual trees’ stories and how the environment has influenced their growth. Windswept trees may have remarkable movement in their limbs, while on another tree, the bark’s deep fissures tell the story of a long, heroic life.
These essential features can guide you as you think about how to style your tree. Other reasons, as considered before, may include problem solving of size, health, and the role of the tree in a garden.
Here are some California woody plants that are popular in native plant gardens; and some ideas on what each plant’s essence might be. I also note what kind of pruning will help highlight essential features.
- Vine Maple (Acer circinatum)
Essence: Detail of leaves on a graceful structure.
Pruning approach: Structural enhancement with thinning cuts, leaf plucking in dense areas.
- Buckeye (Aesculus californica)
Essence: Fragrant masses of flowers, bright green leaves on dramatic white limbs.
Pruning approach: Prune immediately after flower show, thinning cuts to open foliage and show off dramatic white limbs. Tip pruning for crown reduction.
- Manzanita (Arctostaphylos)
Essence: Delicate flowers, leaves, and twigs. Twisting branches and trunks. Aging, brilliant red bark.
Pruning approach: Conservative thinning and reduction cuts to show structure and detail. Or for dense look in groundcovers or shrub forms, pinch tips after flowering.
- Coyote bush (Baccharis pilularus)
Essence: Finely textured evergreen.
Pruning approach: Shear both species and dwarf varieties for unobtrusive, mounding component in Japanese style (or other) garden. (Note that shearing is a technique best suited for small-leafed plants, and should only be employed while new foliage is still emerging.)
- Spice bush (Calycanthus occidentalis) Essence: Lush foliage and strappy red flowers; ornamental seedpods remain in winter silhouette.
Pruning approach: Spicebush can be kept full and to desired size via tip pruning, or styled as small trees, with thinning cuts to create multi-trunk form.
- California lilac (Ceanothus)
Essence: Vibrant flowers and deep greenery.
Pruning approach: For hedge form or size control, lightly shear or tip prune after flower show. Ceanothus suffers from saw cuts over an inch in diameter, so structural work via small cuts should be done regularly.
- Redbud (Cercis occidentalis)
Essence: Brilliant pink flowers on intricate, twisting wood in winter; delicate cooling canopy in summer. Pruning approach: Thinning cuts to expose, enhance winter silhouette.
- (Corylus cornuta) Essence: Catkins, nuts, textured leaves. Pruning approach: thinning and reduction [also known as drop crotching] cuts for winter silhouette.
- Island ironwood (Lyonothamnus floribundus)
Essence: Wildly dramatic peeling bark, cutleaf foliage, and seasonal canopy of flowers. Pruning approach: Remove spent flowers, thinning cuts for structure and translucence.
- Beach pine (Pinus contorta), monterey pine (Pinus radiata), cypress (Cupressus), etc. Because of their potential large size, pines and other conifers are often left out of native gardens, but size can be controlled with proper pruning cuts.
Essence: Woodland fragrance, gleaming needles, iconic cones and bark.
Pruning approach: Thinning, reduction cuts, tipping pruning, and occasional releadering [replacement of old leader with finer branch when original becomes too coarse; thinning cut at tree’s apex] for size control. Because of insects and other issues, timing is especially important in conifers, and cuts should only be made during dormancy.
- Coffee berry (Rhamnus californica)
Essence: Beautiful green foliage.
Pruning approach: Thin lightly, tip prune to establish structure and control form.
- Currant and gooseberry (Ribes)
Essence: Bright flowers on winter silhouette, green element in spring and summer.
Pruning approach: Thinning cuts for winter silhouette and to keep airy. Espalier ribes, as well as many of the woody shrubs discussed above, with more extreme structural thinning and frequent tipping or pinching.
Allison Levin is a member of the CNPS Marin chapter. She is an aesthetic pruner and native plant consultant living in Sausalito and working in the greater SF Bay region.