#008 - Growing Shade

Understanding Light Conditions in Your Garden

Growing Shade: Understanding Light Conditions in Your Garden

If you’ve ever opened a plant book, you probably know the terms “Full Sun, Part Sun, Part Shade, and Full Shade.” But did you know that these seemingly simple terms actually have a very precise meaning? Full shade does not mean no sunlight. Full sun does not mean constant sun exposure. These labels are highly specific, but they also depend heavily on context, location, season, and microclimates.

Here’s a basic breakdown of light levels:

• Full Sun: 6 or more hours of direct sun per day

• Part Sun: 4 to 6 hours, often with some midday to afternoon sun (when sun is more intense)

• Part Shade: 4 to 6 hours, mostly in the morning (when the sun is less intense)

• Full Shade: Less than 4 hours of direct sun per day

But definitions only get you so far. You also need to understand the orientation, topography, and microclimate of your site. In Los Angeles, for example, a north-facing garden might still receive intense indirect light that affects planting choices if it is in the center of a yard with no canopies or walls. The slope of your land, nearby buildings, reflective surfaces, and even the maturity of existing trees all influence what actually counts as "shade" or "sun."

My own garden is a good example. It’s on a northwest aspect in Frogtown, at the base of the hills of Elysian Park. The sun sets behind those hills about an hour earlier than it does across the rest of the city, which changes how much afternoon light we actually receive. Add in six mature fruit trees — lemon, tangerine, persimmon, and three guava — and the garden becomes a shifting map of full sun, dappled light, and deep shade. It’s a complex condition that doesn’t exist in many locations: one area is in deep shade all summer when the trees are fully leafed out but receives full sun in winter after the deciduous canopy drops. On top of that, there are areas in full shade year-round under the mature tangerine and lemon trees, and others in full sun, amplified by reflected light from our windows and white walls.

This presented a serious challenge. I admit, I had analysis paralysis. I didn’t plant anything for almost three years. I observed. I paid attention to light patterns and seasonal changes. You can buy a shade meter if you want to get technical, but honest observation and note taking works just as well. I finally designed and planted the garden myself in the winter of 2023, and since then, it has become an experimental lab. Although there have already been many successes and failures, right now I’m currently testing how much sun Satureja douglasii (Yerba Buena) can handle and whether Carex spissa (San Diego Sedge) will survive in full shade.

But as you might guess, it’s never as simple as sunlight when it comes to plants. Moisture also complicates everything. More water can sometimes help plants tolerate more sun. A shade-loving plant might thrive in full sun if it gets enough irrigation and some breeze to cool the leaves. Others, however, may rot with excess moisture or still scorch despite supplemental irrigation. It all depends on the plant, the site, and how they’re paired. Large, tougher plants can create shade for smaller, more delicate plants. You can also use a friendly boulder, carefully placed, to give respite to an adjacent plant during some of the hottest parts of the day.

Remember, the intensity of sunlight in Southern California is brutal. I’ve watched plants burn to a black crisp in a single day during heat waves. And it’s not just the direct rays. Reflected heat from windows, concrete, stucco, or metal can double the damage. Even a perfectly sited plant can fail if it sits next to a glass guardrail that acts like a magnifying glass focusing sunlight into an intense beam that will burn right through the foliage.

That’s why planting season matters. Ideally, In Southern California, everything should go in the ground between November and March. The temperatures are cooler, the sun is lower in the sky, and the shorter days reduce plant stress. Plants get a chance to establish before the onslaught of summer. We write this into our project specs, but construction schedules rarely honor it, often to the detriment of projects. I have had to replace plants more than three times during a July install in a particularly complicated condition of intense sun and shade.

There also tends to be a visual difference in designing sunny versus shade plantings. Shade gardens rely more on foliage color, texture, and shape than on flowers. Many shade-tolerant plants will never bloom in deep shade. That’s not a failure, it’s just how they behave. If you want color, reach for vibrant foliage: Begonias, Heucheras, and Loropetalum come to mind. Multiple layers of diverse foliage forms and varying shades of green help create depth and interest in a garden where flowers are not constantly the center of attention.

In deep shade, blooms are a bonus, but foliage is the foundation. When flowers fade or never show up at all, it's the texture, form, and contrast of leaves that create visual richness.

Shade gardens should be designed like renaissance paintings, with drama, depth, tone, repetition, and surprise. And because shade gardens often evolve slowly, building with foliage gives you lasting structure.

Here’s how to think about it:

Leaf Shape:
Contrast is key. Pair bold, architectural leaves (like Aspidistra, Fatsia, or Farfugium) with fine-textured ferns (Woodwardia or Polystichum) and delicate groundcovers like Satureja douglasii or Dichondra repens. Rounded leaves soften edges, while lanceolate or serrated foliage adds movement and rhythm.

Color Variation:
Green is not just green. Cool blue-greens, deep emeralds, silvery tones, and even burgundy or bronze foliage can bring a quiet drama to dark corners. Plants like Acanthus mollis (deep, glossy forest green), Agave ‘Blue Flame’ (matte blue green), or colorful species like Heuchera ‘Grape Expectations’ (deep, iridescent, multi-toned purple) break up visual monotony.

Layering:
Think in vertical sections. Use low, creeping groundcovers like Fragaria vesca, mid-height mounds of Heuchera or clusters of Iris douglasiana, and taller anchors like Heteromeles or Frangula. Layering not only makes a space feel lush, it protects the soil, prevents weeds, reduces evaporation, and mimics natural woodland ecology.

Light and Shadow:
In a shady garden, light becomes precious and theatrical. Position light or variegated leaves (like spiky blue grey Dudleyas or the dramatically variegated Fatsia 'Spider's Web') where they’ll catch dappled light and glow. Use dark-foliaged plants to recede and create visual depth. If you combine both, you will create a dramatic garden with bright exclamations and deep hidden secrets.

Don’t forget seasonal change
Evergreen structure is essential in dry shade gardens, but deciduous species like Ribes sanguineum var. glutinosum, Cercis canadensis, or the Persimmon tree I mentioned add movement and color shifts that mark the seasons and create temporary dramatic hits of bold colors. Plants don’t even need to be deciduous to undergo color change – the foliage of Mahonia aquifolium will go deep reddish-purple in the winter, followed up by bright yellow flower spikes in the early spring. This all goes to show that the structure you build in a shade garden doesn’t have to be static, it can evolve and change over the duration of a year.

*WARNING*

Now that we’ve made it through the ins and outs of planting for shade conditions, please don’t go ahead and assume that all of this applies to interior plants. They are another story altogether. You can’t just grab a typical “full sun” plant and stick it in front of a window and expect it to thrive. With indoor gardens, you get into things like bright indirect light, filtered light, artificial light, and a host of other factors. That might be a future Hot Plant Tip – you’ll just have to wait and see!

The shade of it all

There are all kinds of shade plants, and we often get really creative with shady gardens because they allow us to plant things we couldn’t plant elsewhere in Southern California. There are tons of books and online resources out there that can help you develop your shade plant palette, but I thought I’d leave you with some of my favorite Southern California Dry Shade plants. These are plants that will do well in a low-water-use garden or project, and many of them are used to plant under big shady oaks, where heavy irrigation would otherwise cause problems for these well-established and drought-tolerant trees.

Perennials and Groundcovers:

• Salvia spathacea (Hummingbird Sage): Known for its vibrant magenta flowers and aromatic foliage, this plant thrives in dry shade and attracts pollinators. I personally have had nothing but problems with Salvia spathacea, with my plants suffering from powdery mildew and dying very rapidly despite multiple applications of copper fungicide.

• Heuchera maxima (Island Alum Root or Coral Bells): With its large, lobed leaves and delicate cream-colored flowers, it's ideal for under-oak plantings. The native Heuchera can be ephemeral – coming and going as it pleases, so make sure it gets mixed in with lots of other vegetation that can cover for it while it slumbers.

• Fragaria vesca (Woodland Strawberry): This groundcover spreads quickly via runners, offering tiny edible red fruits that delight guests.

• Satureja douglasii (Yerba Buena): A low-growing, delicate groundcover that performs well in protect shaded areas. Its leaves smell like mint, and the tiny white flowers are present for a substantial portion of the year

• Symphoricarpos mollis (Snowberry): A low-growing rambling shrub with rounded leaves and white berries, which can tolerate the deepest of shade. Native birds eat the berries to survive the winter.

Shrubs:

• Ribes viburnifolium (Catalina Currant): An evergreen shrub with fragrant foliage and red berries, it can fill in major gaps in your garden quickly and effectively.

• Heteromeles arbutifolia (Toyon): Also known as Christmas Berry, it provides white flowers and red berries (or yellow if you opt for the ‘Davis Gold’ variety, attracting birds. Don’t plant this under an oak – it’ll become a tree itself over time, but this is a great plant to plant nearby an oak, without having to worry about over-irrigating.

• Carpenteria californica (Bush Anemone): A beautiful shrub with white, fragrant flowers, thriving in shaded conditions. It can be short lived, so you might be heading back to the nursery sooner than you expected.

• Frangula (Rhamnus) californica (Coffeeberry): They grow with the oaks and kinda look like an oak. The root systems are similar to oaks and commonly share resources with oaks. They grow small red berries in the fall, and there are many different cultivars with varying forms and sizes, so finding the Coffeeberry that fits your garden-specific needs should be no problem

Grasses:

• Elymus condensatus (Giant Rye): One of the few grasses that grows under oaks. Although Giant Rye will grow in full sun, particularly with regular water, it will grow well in full shade with no extra water in most of California. It’s perfect for those of you that want a grassy prairie look that runs right under the canopy of your oak.

It’s rare to find shade in a climate like Southern California where our golden sun gets all the glory, but when you do find a dappled nook, you must take the opportunity to go all in with bold design moves and create something intimate and enticing. The takeaway is simple: there are no one-size-fits-all rules. Know your site. Watch how the sun moves. Think seasonally. And remember that every garden is a chance to learn something new about plants AND about yourself.