How to Plant Native Plants in Containers for Small Spaces
Even small spaces like patios and balconies can support California native plants and bring the benefits of wildlife habitat and water conservation. And having native plants nearby gives you and your home a connection to where it is, beautiful Southern California.
If growing natives in containers use a lean soil, with less organic ingredients than most general purpose potting soils. Some “Cactus Mixes” will do. It’s also useful to blend a bit of good quality garden soil with any bagged purchased mix, to get some beneficial microbes going. But don’t use 100% garden soil, it will compact too quickly in a container and may create drainage and watering problems.
In containers, soil over-heating is a common issue, especially with native plants. Soil temps in a pot often are much more than in the ground. To reduce this issue, select containers that reflect heat, not absorb it. Light colors are usually better than dark colors and thick-walled are better than dense or thin walled. Double potting is a new technique, where you plant in one pot, then set that pot into a slightly larger one, with an inch or two layer of soil between the two pots. This insulates the soil around the roots and keeps them a bit cooler.
Lastly, avoid sitting isolated small native plant pots onto hot surfaces, like concrete patios or stonework. Clustering a few together, where the plants get the sun, but the pots and soil get some shade from one another.
I suggest over potting native plants slightly, a bit bigger container than you might use for other plants. Many low water and drought resistant plants have that quality because of their large root systems. These plants don’t have root systems that are problematic around concrete, pipes, etc., but they may be wide spreading (sage scrub plants) or deep growing (chaparral plants) and need the extra space. Larger pots are better for most natives.
Water according to the plant’s natural requirements and in the ground try to group plants with similar water needs together. Water according to Southern California’s natural rainfall patterns. Usually this will mean several irrigations in the cool, rainy (usually) months and much less during the warm dry months. Rainfall will handle a lot of this irrigation, but supplement when it’s not there.
In general, deeper but less frequent irrigation is the rule for natives. When you do irrigate the plant, do so all the way the deepest part of the root system.
Don’t rely on drip irrigation for most native plants. Natives generally do not perform well with this approach, for several reasons. Instead, water as nature does, over the top, like rainfall. Slow and deep is best, wetting the entire root system.
During the warm, dry months a frequent “refreshing sprinkle” is a great idea! This is a wonderful technique that Mike Evans at Tree of Life Nursery in San Juan Capistrano has been championing. It is basically a splash of the leaves. It’s a great activity to do at the end of a hot day, when you get home from work or your chores. And it’s good therapy for you as well! This “splash” should be over the top and just enough to wet the leaves and the area around the plant, but not enough to irrigate the soil.
Don’t worry much about water conservation – you’ll not be using very much water. Of course, some of this water will fall to the ground, but it will rather quickly evaporate and not create an over-watering issue. In the meantime, this “refreshing sprinkle” will cool the environment around the plants, and many natives will absorb some of that moisture directly into their leaves, hydrating the plant, but without overwatering it. You can do this with a garden hose and a thumb (for the best therapy too – haha) or by setting your overhead sprinklers to come on for a minute or so in the evening. A “refreshing splash” every day or two during the hot dry summer can make a huge different to the health and appearance of native plants.
Plant natives in the fall and winter where possible, whether in containers or the ground.
Just as natives like lean soil, most also like slightly lean nutrition. A slow-release organic fertilizer applied to containers or around the entire root system of plants in the ground is a good idea. Do this at the onset of the growing season, which for most natives is mid to late Fall, then other light half-strength applications through the remainder of the cool growing season. Put away the Miracle-Gro and other synthetic fertilizers for use on native plants.