Garden Q&A – Establishing Native Plant Gardens
CNPS Garden Q&A with Barbara Eisenstein, Native plant garden writer and consultant
Native plant garden writer and consultant
I’m new to growing native plants. What are the differences between growing common, non-native garden selections and native plants?
Some assume that because native plants grow in the wild without care they’ll be easy to grow in our gardens. Yet gardeners new to natives sometimes complain of losses in their early attempts with these plants, especially in comparison to common ornamentals.
To understand this paradox, consider where your garden plants come from and how they are grown. The goal of the commercial nursery is to produce a large number of healthy plants that are ready for sale as quickly as possible. Most nurseries propagate plants — both native and non-native — by cuttings. Once rooted, the object is to get them ready for market by growing them rapidly while controlling for pests. This is usually done in greenhouses or under shade cloth to provide ideal exposure, appropriate irrigation, and fertilizers and pesticides as needed.
Next, you buy this pampered young thing and transplant it into a new environment in which little is controlled. Hopefully it will get some regular water while it settles into its new home, but the soil conditions, exposure, heat, wind, and pests are no longer managed. Furthermore, the new caretaker may be unfamiliar with the plant and not know whether it is calling out for water or drowning in it.
This means we must balance between giving them enough water in summer to keep them alive and encourage some growth, but not so much that they rot out.
Plants native to our region have been selected over eons by nature to survive in our unique Mediterranean climate. Many are wonderfully adapted to withstand months of heat and drought. And therein lies the rub. These plants are often susceptible to pathogenic microorganisms that thrive in moist, warm soils. They accept the warm moisture in nurseries because the potting medium is free of pathogens. Once placed in our garden, disease-causing fungi and bacteria become active in warm, wet soil, and native plants adapted to hot and dry soil may succumb to disease.
The obvious answer, then, is to keep them dry during the summer. But alas, our new native plants are pampered, young things. They have been accustomed to an abundance of water through their short lives and are not ready for the real world. After a few years in the ground, once their roots have grown into the surrounding soil and they have acquired enough bulk to take them through the dry season, they will be healthiest in dry summer conditions. First, however, they need to become established. This means we must balance between giving them enough water in summer to keep them alive and encourage some growth, but not so much that they rot out. And it is this balancing act that is somewhat difficult.
To help these plants become established, planting in late fall to winter is best. This way, they do not have to survive extreme heat and drought right after being relocated. For the first year or two, you may need to water them a couple of times a month, but be sure to water them deeply and then allow the soil to dry out a bit. Try to water before the plants become drought-stressed. As they grow, you should water less frequently but thoroughly to encourage strong, deep roots.
Native plants are different than common, non-native ornamentals. However, with time and experience, most gardeners find that they really are not difficult to grow and require fewer inputs and less maintenance. We have excellent reasons to use native plants in our gardens. Not only can many of these thrive with little to no supplemental water, fertilizers, or pesticides, native plants have evolved with native insects and other animals, and therefore provide the best habitat. A native plant garden offers food and shelter for birds, lizards, and butterflies, along with solace for many, including the harried urbanite.
Hello! I have a north-facing, small apartment balcony in San Mateo. Which native plants would be good for container gardening for the upcoming winter season??
Great question! Take a look at our Patio and Container Gardens article here: https://www.cnps.org/gardening/patio-and-container-gardens-5423
You can also visit Calscape.org to learn about plants native to your region: https://calscape.org/
We also recommend getting in touch with your local chapter and their horticulture experts as they will have helpful, region specific advice. Find your local chapter here: https://www.cnps.org/chapters/map
There is so much content online about why and how to plant native plants, but so little support during the establishment time of the plants. Can anyone provide any direction on where one would go with questions? For example I have planted five 15 gallon Ceanothus Ray Hartman this year in full sun, good drainage, with only hand watering, San Diego area. Three are doing great, but two are starting to look a lighter green color and leaves are curling slightly. Most literature is advising against watering, however this is the first year. Who can I ask for advice on what to do in this situation? Is there a service that CNPS offers in these kind of situations?
Hi Sori. Here is a response from Barbara Eisenstein
Response to question on Ceanothus ‘Ray Hartman’:
Establishing native plants can be challenging, especially for the new gardener. I addressed this issue in my book. Wild Suburbia – Learning to Garden with Native Plants. Check out the chapter, Keep Your Garden Alive. You can also contact the nursery from which you got the plants or the landscape professional who put them in. Tree of Life Nursery in San Juan Capistrano is another source of good information. You might try bringing pictures of the declining and healthy plants. Be sure to take close ups of the leaves and step back to get good clear pictures of the entire plant. If no one at Tree of Life can help, they may be able to refer someone to you.
Now, let me now try to give you a few suggestions based on your comment. First, it is important to know that 15 gallon plants are harder to establish than smaller ones. These have been in containers for a longer time and so the transition from controlled nursery conditions to your garden can be more difficult. If you do decide to replant, I suggest starting with 1 gallon plants, or at most, 5 gallon. Ray Hartman ceanothus is a very fast growing plant so you will not have to wait long for them to get large.
Here are a few things you might check out in your garden. Feel around the base of the plants to make sure that there aren’t any significant air pockets in the soil surrounding the root ball. This can happen due to improper planting, but also, sometimes the organic matter in the potting soil decomposes, leaving these pockets. Usually you will notice that these plants show drought stress more often than others. Once you firmly (using your hands) press soil into these pockets and water thoroughly these plants often bounce back.
Another thing to check is to make sure that ants have not taken up residence at the base of the new plants. You will see them busily marching up and down the plant. They do damage in themselves, but more importantly they harvest pests like scale and aphids. If you have ants around the base you might want to try an ant bait like Advion. I treated a manzanita by sprinkling diatomaceous earth around the base of the plant, keeping the powder off the stem of the plant. If this does not stop the ants, you may want to try mixing a little borax in with the diatomaceous earth.
With regard to watering, my book has tips on how to do it and how to know when to do it. Hand watering, especially for new plants, is best. Mike Evan of Tree of Life has an excellent youtube video on this: https://www.youtube.com/watch?v=Q3-4AGQF6II. CNPS also has great information on gardening with native plants, including watering (https://www.cnps.org/gardening).
Most importantly, you really need to check the soil – by hand! – to know whether your plants are suffering from too much or too little water, or whether the problem is something else entirely. Drought stressed plants, especially young ones – usually show wilting in the new growth. If this does not firm up and the soil is dry when the sun has gone down, then the plant needs water. If the soil is damp or the stems firm up once the hottest part of the day passes, then just watch your plants in the days to come for more evidence of drought stress.
Young plants (and older ones, if it is hot enough) can be stressed by heat, even if well watered because they cannot take up enough water to keep up with transpiration. This was not an especially hot summer, so this may not have been a problem. If hot weather is predicted, try to shade the plant during the heat of the day with shade cloth or even a white sheet.
Let me conclude by repeating that 15 gallon plants are a challenge to establish. You mention that some of these plants are still doing well. Ray Hartman ceanothus have relatively large green leaves. Mine often drop these leaves after blooming, when the summer heat arrives. They don’t look great through the summer, but perk up and leaf out once the weather moderates in winter. With new plants it is best to try to keep them growing during the establishment period. However, depending on how many leaves are dropping and what the plants look like in other ways, it is possible that they are fine. Check for pests, air pockets in the root ball, and adequate watering and then hope for the best. Hope this helps, and good luck with your new garden.
Link to Wild Suburbia: https://heydaybooks.com/book/wild-suburbia/
Link to Tree of Life Nursery http://californianativeplants.com/
Thank you Barbara for taking the time to write such useful, and practical information. If this plant dies, I will definitely plant a smaller size.