- Author: Flo Pucci, Master Gardener
Drought Tolerant Vs. Drought Resistant Gardens by Flo Pucci Master Gardener.
As a new homeowner in San Joaquin County and a recent graduate of the Master Gardener program, I am interested in ideas that can help me design a garden with low water requirements and low maintenance plants. However, I am constantly mystified about the large array of terms to define: "drought-tolerant," "drought resistance," "drought-adapted," "water-wise," "xeric," "native," "Mediterranean," "environmentally friendly," and “sustainable” gardens. I'm even more perplexed when professionals and retailers use terms conflictingly, even differing on what the terms mean, resulting in time and money wasted. So, I decided to unpack the meanings, techniques, and definitions behind these terms and plant materials that can aid in the pursuit of a drought-resistant garden.
Drought-tolerant. What does drought tolerance mean in connection to the land and the environment? The word "drought" means a period of prolonged exceeding aridity, mainly one that causes extensive crop damage or prevents their successful growth. Once this occurrence is understood, we know that drought causes plants, crops, and wildlife to become parched and eventually die through lack of rainfall and water. Consequently, drought-tolerant and drought-resistance terms are often used synonymously and inaccurately so. In a general sense, the word tolerant means the capacity to withstand pain or hardship and, more specifically, "the relative power of an organism to grow or thrive when subjected to a harsh environmental dynamic."
Drought-resistant. These plants can survive for long periods without water. In other words, they take drought-tolerant one step further. Plants with relatively low water requirements or plants well adapted to an arid climate are described as drought-resistant or drought-tolerant.
Water-wise. This refers to landscaping or gardening with plants that grow well in a garden that manages water efficiently. On the other hand, low water plants are those that are adapted to live through times of water scarcity without drastically changing their attractiveness. They are very resourceful at using water, avoiding heat, keeping cool, and some continue to bloom during the heat and drier time of the year. Examples of water-wise plants: Aloes, African daisies, Pink rockrose, Rosy buckwheat, Gazanias, Madrones, etc.
Xeriscape. This is another term for drought resistance or drought-tolerant landscapes or gardens. This label outlines a landscaping style that uses drought-tolerant plants to help conserve water.
According to UC Master Gardeners, the longstanding concept of xeriscaping as a garden packed with succulents and gravel has changed to low-water-lush. Lush means growing actively with rich foliage, productive, fertile, thriving, and possibly on low water cycles. A good illustration of this concept is the learning Landscape at the Robert J. Cabral Agricultural Center in Stockton.
Indeed, experts warn not to confuse California natives with naturalized plants brought here from other places by human migration and that have established themselves in their new environment like the California pepper tree, originally for South America. Some small sub-groups of these naturalized plants are considered invasive, like pampas grass, vinca, and Mexican feather grass, altering the ecosystem where there are planted. Native plants are often dormant, induced by heat and lack of moisture in the soil. Here, fire season is pervasive during the summer and fall due to the lack of rainfall which is a natural occurrence in the California landscape. Fires regenerate the vegetation growth and maintain the health and vitality of native plants communities. Coastal regions' landscapes are the exception due to coastal fog.
However, for California gardens, one needs to look for plants drought-adapted to our climate, which means plants evolve in sync with our climate's characteristic pattern of cool, wet winters and warm, dry summers. In other words, they tolerate our six months of summer dry season once established. Examples of California native plants: California fuchsia, yarrow, poppy, matilija, manzanitas, toyon, Indian mallow, lupine, and artemisia, just to mention a few.
Established vs. Non-established. This distinction is often overlooked by new gardeners to a significant detriment. An established plant has grown its root system from its former bound root nursery pot life into our garden's soil. However, most plants need to acclimate and develop a new root system to survive without additional supplemental water. As a result, new gardeners going by the label drought-tolerant may think that after the plant is in the ground, it will grow without any additional care. However, plants need a slow transition to maturity once they are in the ground. Planting during the cooler months will help conserve water, and rainfall will keep the plant hydrated. Roots must stay moist and must not be allowed to dry out for two to three months.
Mediterranean. When referring to Mediterranean plants, this classification denotes regions globally that share similar climate characteristics of dry and hot summer and cold and rainy winters. These locations are California, Central Chile, the Mediterranean Basin, the Cape regions of South Africa, and Southwestern and South Australia.
Mediterranean plants primarily consist of arboreal and shrubby evergreen sclerophyllous plants, characterized by complex, leathery evergreens foliage, specifically adapted to prevent moisture loss and oils to evaporate with adaptation to high levels of aridity.
According to some experts, the phrase "summer-dry" is more inclusive because it names the five regions with similar climate characteristics instead of the Mediterranean. Therefore, plants from any sub-tropical region that share similar climate conditions can grow and thrive in California, particularly in the Central Valley. Examples include olive, pistachio, myrtle, juniper, citrus, hydrangeas, bougainvillea, clematis, aromatics, lavender, rosemary, and yarrow.
Drought is a fact of life in the western states. That is why water conservation should be a lifestyle priority in these regions. While local native plants are best suited to most sites, other good choices include drought-resistant plants from different parts of the world. Many of these plants share characteristics that help them survive intense heat and low rainfall periods. Furthermore, plants with low water requirements not only beautify the landscape once established, but also offer many other benefits. Woody perennial herbs such as rosemary, sage, and thyme, all from the Mediterranean region, can be used in cooking and combine well with blooming perennials such as blue-flowering catmint.
In brief, here are some basic guidelines for a practical and drought-resistant garden.
1) Improve your soil by incorporating organic matter.
2) Plant in the right place; group plants with similar water, sun, and shade exposure needs.
3) Reduce the lawn amount around the yard. It requires too much water to stay green.
4) Control weeds.
5) Upgrade irrigation systems by connecting smart controllers to a weather station or drip emitter.
6) Water deeply but infrequently to encourage roots to grow downwards.
7) Mulch to conserve soil moisture.
Water-wise gardens take a bit more to plan than a typical garden, but over time, they look beautiful and offer significant savings in labor cost and, above all, water.
For more information, please check the following sites.
https://sjmastergardeners.ucanr.edu/Water_Conservation_/Low_water_landscapes_/
https://sonomamg.ucanr.edu/projects/Water-wise_Gardening/
https://sjmastergardeners.ucanr.edu/Gardening_with_CA_Natives/
https://cagardenweb.ucanr.edu/Drought_/Drought_Gardening_Tips_/
https://mgsantaclara.ucanr.edu/garden-help/succulents-care/
https://ucanr.edu/sites/sacmg/files/183230.pdf
https://sjmastergardeners.ucanr.edu/Water_Conservation_/Irrigation_/
Growing Knowledge
Constance Starner, Master Gardener
California Plants: A Guide to Our Iconic Flora, by Matt Ritter (2018)
We are so fortunate to live in one of the most biodiverse areas in the world. California's major biomes include the temperate rainforests of the Pacific Northwest, the Great Basin sagebrush steppes, and the Mojave and Sonoran deserts, as well as the Mediterranean climate in the western part of the state. We have woodlands, shrublands, grasslands, and wetlands. And of our more than 7,000 native plants, over than one-third of them are found nowhere else.
It would take years of study to feel truly knowledgeable about our vast plant life here, but Matt Ritter has published some clear, helpful guides for those of us who want to learn to identify and understand plants without being overwhelmed by vast amounts of information. Why is it important to identify plants and learn their names to appreciate them? One reason is that when our knowledge and understanding of plants increases, our enjoyment of them increases. We are able to see them in more detail as individuals with known characteristics, rather than a diffuse sea of green, rather like being able to recognize the face of a friend of family member in an anonymous crowd.
Matt Ritter grew up in Mendocino County where he first became interested in trees and other plants. He is currently a botany professor in the Biological Sciences Department at Cal Poly, San Luis Obispo, and the author of these two books, along with other books and articles. He also has a webinar, “California Plants” available on YouTube. In all of his writings, Ritter's love of plants shines through, helping to instill a sense of wonder and awe in his readers.
A Californian's Guide to the Trees among Us explores 150 trees commonly seen in California, primarily in urban and suburban settings, including introduced as well as native trees.
Each tree species is discussed over several pages, with botanical information such as the place of origin, the way it reproduces, the growth characteristic, and even the basis for its scientific name. We learn, for example, that the deodar cedar originated in the Himalayas in the Pinaceae family, that it is monoecious, evergreen with needle-like alternate leaves, and that it grows to 80 feet or more in height. Breaking down the scientific name, Cedrus is Latin for cedar and deodara is Hindi, meaning “tree of the gods.” Each of the 150 species is discussed in a similar fashion. The book also includes a guide to the color and time of year of trees' flowers, and the appendices detail information about changing plant names, the locations of the trees photographed, a glossary, and references for further reading.
Ritter draws upon science, natural history, drawing, photography, and prose in his descriptions of trees. He evokes the connection between humans and trees, commenting, “In cities, trees are often poignantly contrasted with stark buildings, sidewalks, streets, and gutters, silently reminding us of lost connections with nature and our longing for a time prior to our taming and civilization.”
This is a fascinating as well as informative guide that will be invaluable to anyone who wants to appreciate and observe the trees in our urban forests more closely. I have enjoyed using the digital version on city walks to better understand the trees I'm seeing along the way.
Each of the selected plants is discussed on a single page that includes the plant family, common and scientific names with a pronunciation guide, photographs, and a range map showing where the species generally occurs. There is also information about its natural history and some interesting stories about the plants, such as the way they were used by Native Americans. The entry on black oak (Quercus kelloggii)--pronounced KWAIR-kuss kel-LOG-ee-eye--tells us basic botanical information about the tree and that “Black oak acorns are the most flavorful and were coveted and traded by Native American tribes. The species was named by Smithsonian botanist John Newberry in 1859 in honor of Albert Kellogg, a Northern California botanist, physician, and a founder of the California Academy of Sciences.”
This is a guide that allows the reader to either search for targeted information or to peruse for general interest, always coming away with a sense of valuing and knowing the plants more completely. As former California Governor Jerry Brown says in his foreword, “Matt Ritter teaches us how to identify and enjoy each species, and to better understand how our future is linked to that of all of all other living things: our soil, our microbiota, and our wonderful and indomitable native plants.”
Anyone interested in learning more about the iconic plants in California will find these two guides both useful and full of fascinating information.
- Author: Morris Lacey, Master Gardener
The Help Desk
Morris Lacey, Master Gardener
In 2018, my wife and I purchased a 4-in-1 plum tree. You know the kind: all the rage for plum lovers because the fruit ripens per variety over a longer period than a single varietal tree. We chose a spot in our backyard and planted it where it would be bathed in sunshine. It took off growing and we were confident it would excel in short order.
As a 2019 MG graduate, I remember one of the final exam questions dealt with a hotline call regarding a multi-varietal tree which the gardener complained the grafted branches were diminished and appeared to be dying. The tree was rather mature and there was no visual damage from pests. What could possibly have been going on? While most of my classmates and I got points for our answer, we were left in suspense as to what caused the reduced growth of the branches and what actions the gardener should take to improve the situation (as sometimes that happens with phone calls and pictures).
I did put some time in on the MG Helpline after graduation and remember seeing one call recorded with similar parameters. Again, it was a mature multi-varietal tree losing a grafted branch under its canopy with no noted infestation or disease. This spurred me to take a hard look at our 4-in-1 plum and observe what was happening to it. Could this future outcome be prevented with our tree?
Our tree had bloomed and produced fruit each year since being planted. In 2021, all the fruit ripened at the same time. Interestingly, two of the grafted scions appeared to be losing ground while the other two were raging. Was I setting us up for failure? What could we do to change the future?
We remembered our training: pruning can impact apical dominance and force growth to other branches. In our 4-in-1 plum, the root stock was one of the varietals and formed the largest branch, and a second varietal graft was as big as the main stock. The other two grafted branches were less than half the diameter of the other branches.
Proof is in the pudding! We pruned to give the smaller branches apical dominance and the result this year has been growth – both in height and branch-width. We are continuing to prune for apical dominance and ensure each of the varietals compete in par with each other for nutrition. It is very rewarding to see the smaller grafted branches gaining on the larger ones. We also thin the fruit, so the branches are not damaged by the weight of the fruit.
I am not completely sure the other two hotline calls I mentioned would have responded to pruning as mature trees, but I am certain our efforts on our tree will result in 4 varietals fruiting amply each year if we pay attention to managing the growth of each and balancing their growth as equally as possible.
- Author: Regina Brennan, Master Gardener
Herb Study: Miner's Lettuce (Winter Purslane)
Regina Brennan, Master Gardener
Miner's lettuce gets its name from the workers who traveled to California during the Gold Rush. Needing a source of vitamin C, gold miners learned from the Native Americans that this wild growing green would prevent scurvy and other vitamin C-related issues. Miner's lettuce is native to the western coastal and mountain regions of North America and was spread to Europe in the late 1700s when it was brought back from an expedition to the new world. It grows wild in California from Sacramento to the San Joaquin Valley. It appears most often in the spring. Today, because of the availability of fruits and vegetables, scurvy is not as problematic as it was in the Gold Rush days. And, alas, this once valued wild green has been relegated to the status of yet another spring weed. It is, however, a good source of food for animals, providing a grazing source for cattle and flocking birds.
With no knowledge of the hidden health treasure of this wild green, I have been pulling it from my garden every year, along with the other abundant spring weeds, relegating it to the status of organic trash, and sending it off in the green cart picked up weekly. Yes, I compost, no I do not compost weeds.
Just as the gold miners were shown the health benefits of this abundant wild green, I learned of it when a neighbor brought me a bowl of soup she had made. The soup was tasty, but it had a very large glob of greens that had to be eaten with a fork. I asked her what the greens were, and if she had grown them. She proceeded to tell me that another neighbor had given them to her and that he called it miner's lettuce. My gardener's curiosity was peaked, and I discovered that his cover crop of delicious greens was identical to the annoying weed I had been treating with less than respect.
According to several online sources, Miner's lettuce is a native winter annual broadleaf plant in the Montiaceae family. The flowers, leaves, stems, and roots are edible. Young leaves can be consumed raw or cooked. The plant can grow up to 12 inches, but is generally smaller. It is similar to spinach and is best suited for both raw and cooked applications, such as steaming, boiling, stir-frying, or sautéing. To avoid the glob effect, I would suggest cutting the leaves and stems into smaller pieces before cooking. The leaves will keep three to four days when stored in a sealed container with a damp paper towel in the crisper drawer of the refrigerator.
What does Miner's lettuce look like? It is a small, herbaceous, slightly succulent plant. It is light green in color, and has round, disk-like leaves, which surround its smooth, tender stem. The stem passes directly through the round leaf, and this makes identification easy. After the plant has bloomed, there is a small white or pinkish color flower growing on top of its rounded leaves. Young leaves are tastiest, as older leaves can turn bitter in the summer in a hot dry location. According to a study in the journal of the American Dietetic Association, 100 grams of miner's lettuce contains a third of your daily requirement of vitamin C, 22 percent of vitamin A, and 10 percent of iron.
Who would have guessed that such a wild plant, aka weed, has such an interesting history? I hope that shedding some light on this humble plant will encourage you to look in your garden to see if you are lucky enough to find a nutritious green that is worthy of serving your family for dinner. Bon appétit!
