By Susan Krzywicki, originally published in Let’s Talk Plants! November 2015, No. 254. Republished November 2023.
Under The Pine Trees
Many San Diego gardens showcase lovely pine trees – the really lucky among us have the fabulous Torrey Pine, Pinus torreyana. With its windblown structure and deep green color, it is romantic and iconic.
Read more about the Torrey Pine here:
But there are other pines and conifers (non-native as well as native) that are grown here in gardens. And what to cultivate under them is an age-old question.
Native plants provide a great solution. The way to approach this is from a plant community perspective: find out what grows naturally in your location, then decide on an aesthetic strategy that gives you a long-lasting solution.
Here is a website that can help you do just that; type in your address or zip code and find a very specific list of plants for your location. Go to calscape.org and click on “Enter a California address" or click the map to see plants native to that location at the middle top of the page.
Most pines are denizens of acid-soiled forests, rich in humus, but the Torrey seems to be left over from the Ice Age, sitting on coastal bluffs. This Coastal Sage Scrub region is the home of Sagebrush, Artemisia californica, Ceanothus, Ceanothus spp., Manzanita, Arctostaphylos spp., and Sages, Salvia spp. It extends along the ocean inward to the point where we no longer receive marine influence. Most of the rest of our county is the Chaparral plant community. Common Chaparral plants would include some larger shrubs such as mountain mahogany, Cercocarpus spp., toyon, Heteromeles arbutifolia, and lemonade berry, Rhus integrifolia. These all make good companion choices.
Design strategies for an attractive landscape
Because of the year-round needle drop and dense established root structures, consider:
· Plants with large, smooth leaves, or those with open-branching structures so the needles fall through and become mulch. Consider planting a ring of shrubs just outside the drip line that will minimize the pile-up of needles.
· Decomposed granite (DG) paths under the canopy and/or a circle around the tree, so you can rake the needles easily.
· Large pots filled with shade-loving plants. If you’ve created a DG area, you could use pots on casters. Run drip emitters to the pots.
Plant choices that work in the dry shade and beyond
To create a garden under the canopy itself:
· Bush Anemone (Carpenteria californica)
· California Wild Rose (Rosa californica)
· California strawberry (Fragaria californica)
· Coral bells or alum root (Heuchera micrantha)
· Currants and gooseberries (Ribes spp.)
· Douglas Iris (Iris douglasiana)
· Oregon Grape (Berberis aquifolium)
· Sword fern (Polystichum munitum)
· Yarrow (Achillea millefolium) *2023 Editor’s note: Yarrow is the 2024 Herb of the Year™ as designated by the International Herb Association
· Yerba Buena (Satureja douglasii)
Use these choices at the drip line and beyond
· Bush monkeyflower (Mimulus aurantiacus)
· California fuchsia (Epilobium canum)
· Ceanothus (Ceanothus spp.)
· Deer grass (Muhlenbergia rigens)
· Manzanita (Arctostaphylos spp.)
· Penstemon (Penstemon spp.)
· Purple needlegrass (Nassella pulchra)
· Salvia (Salvia spp.)
· San Luis Obispo coyote mint (Monardella villosa obispoensis)
· Sulfur flower (Eriogonum umbellatum ‘Shasta Daisy’)