August 2006 Los Feliz Ledger Column, "Made in the Shade"
Iris douglasiana (Douglas iris) photo by Mike Bauman. Douglas iris is a great California native for bright shade. If you wish to plant it under a native oak, do so in the late fall or winter and don't disturb the oak's roots. For more information on California oak trees, please see: California Oak Foundation website.
During heat waves—like what we’ve experienced lately—I often think about one of the cardinal rules of gardening with California native plants: "install in the fall."
It is the simple concept of working in concert with nature that is conveyed in this dictum. Sadly, though, it continues to elude many Southern California gardeners, especially those who hail from the East Coast or other wetter-in-the-spring and summer climes. They tend to hold onto the notion that spring is the time to kick the gardening into high gear.
After living here for several years now, the idea that water is scarce and temps are high from spring until late fall is finally sinking in and making me alter the way I deal with my garden.
The life and growth cycle of California native plants follows the weather patterns here, and thus functions symbiotically. They've had to adapt over the years, in order to survive in the wild.
We see an example of that with wildflowers, the way they bloom profusely in the early spring (after a nice long drink) and die back as the heat increases in the summer. Their seeds then scatter with the wind, facilitating a grand show the next spring provided there is enough winter rain.
Perennial and evergreen natives are not unlike wildflowers. Although they do not die, many of them don't do a lot of growing during the heavy heat. Generally, they like to be left alone—the way they would live in the wild. Fremontedendron is an example of a gorgeous California native that has to be planted in the fall because that is the only time it can handle irrigation. It will die if watered in the summer. An unknowing gardener will cry out that Fremontodendron and other natives with similar needs are so difficult to grow.
That is precisely why it is so important to learn about the plants we purchase for our gardens. By researching a plant’s cultural needs (what kind of soil it grows in, how much water it should get, what climate it grows in, how much sun or shade it should receive) we can help them live a long happy life and, in the process, avoid a lot of stress ourselves.
The good news for people intent on putting in plants this time of year is that there are natives that absolutely love the bright shade of the north side of a house or under an arbor or tree (just don’t plant under an oak in the summer; moisture in the dry months triggers oat root fungus) and consequently will be more amenable to being planted during the heat. These shady characters have the benefit of a cooler microclimate in which they are protected from the harsher elements just beyond the canopy.
Desert and riparian plants will also do alright if planted during the heat. Just be sure to provide them with ample protection from the direct sun.
If you choose to put natives in the ground now or in the near future, plant them in the early morning for success. Irrigate in the mornings too.