- Author: T. Eric Nightingale
Planning a drought-tolerant garden can be a challenging endeavor. Knowing which plants to use and where to plant them is difficult as information and advice can vary significantly. However, there are a few simple things you can do to make the process easier.
The first task is to become intimately acquainted with your garden. Watch the way the sun moves and where the shade falls throughout the day. It may seem obvious that how much sun a plant receives will affect how much water it uses, but not all plants labeled for low water use will thrive in full sun.
Knowing the locations in your garden that receive shade from summer heat can greatly affect the health of your plants and the maintenance required to keep them looking attractive.
Note how wind moves through your garden. Evapotranspiration, the loss of water through plant leaves, increases significantly with high, hot or dry winds. On a cloudy yet windy day the plants in your garden could dehydrate more than you expect.
Finally, get up close and personal with your soil. Check its water retention by digging a hole about a foot deep and wide and filling it with water. Hope for the water to percolate through in about an hour, signifying good drainage.
Many drought-tolerant plants, especially succulents and cacti, will rot if soil drains too slowly. Conversely, if the soil drains too readily, it can be difficult to keep even low-water plants adequately hydrated.
All of these factors will help you form a picture of how water will be utilized in, and move through, your garden. This knowledge is a useful tool when choosing new plants.
When working on creating a drought-tolerant garden there are some preconceptions it is best to discard. When many people think of a garden, the image that comes to mind is of a classic English garden. This is understandable as modern home gardening and many of its traditions originated in Europe.
But England has a different climate than Napa, and it is not realistic to expect our gardens to look like English landscapes.The plants found in English gardens are often not good candidates for a Napa Valley garden, least of all a drought-tolerant one.
Many of the best-known annual plants are thirsty in our climate, as are many popular perennials such as hydrangeas, camellias and gardenias. Tropical plants, while visually stunning, are often troublesome as well. Even if they are not labeled as requiring a lot of water, the relatively low humidity in Napa Valley can make it difficult to keep them healthy.
Changing our expectations for our gardens does not mean lowering them. A garden can use less water and remain visually pleasing, lush and colorful. In a sunny location, shrubs such as salvia and lavender can be placed among large succulents such as aloe and agave. The contrast of soft and sharp textures is pleasing to the eye. The salvia will bloom most of the summer, while many aloe, such as Aloe capitate, bloom in the winter.
Many popular groundcover-type plants have shallow roots and need frequent watering. These can be easily replaced by a clumping or vining succulent. A favorite of mine is ice plant, Delosperma cooperi, which produces a carpet of purple-pink blooms from spring through summer.
Identifying plants that work in a drought-tolerant garden is easy after some practice. Generally speaking, plants with large, glossy leaves are a poor choice. These plants will lose a lot of water to evapotranspiration and are prone to sunburn. Plants with dusty or fuzzy-looking leaves are much more adapted to hot, dry conditions.
The roots of a plant can also tell you something about its water needs. Small, shallow roots will need more frequent watering than large, deep-burrowing ones. Never hesitate to gently remove a nursery plant from its pot and inspect the roots. They are a key indicator of plant health.
An important bit of information often missing on plant labels is the term “once established in the ground.” Succulents excepted, a potted plant will usually need more water and fertilizer than the same plant in the ground. Many drought-tolerant shrubs survive by growing broad or deep root systems. It takes at least a year for new plants to develop a useful root system, during which time they will need additional water.
Knowing these facts about your garden and the plants in them, as well as altering your perception of how a garden should look, can make an enormous difference in your relationship with it. You can minimize required maintenance and reduce your stress, leaving only the pleasure of enjoying the beautiful space you have created.
Next workshop: “Home Vineyard: Part 2” on Saturday, September 14, from 9:30 to 2:00 p.m., in Calistoga. Learn techniques to maintain your new or existing home vineyard. Workshop location will be provided after registration. For more details & online Registration go to http://napamg.ucanr.edu or call 707-253-4221.
The UC Master Gardeners are volunteers who provide UC research-based information on home gardening and answer your questions. To find out more about upcoming programs or to ask a garden question, visit the Master Gardener website (http://napamg.ucanr.edu) or call (707) 253-4221 between 9 a.m. and noon on Mondays, Wednesdays or Fridays.
The multiplication of plants, known as propagation, is an entertaining and rewarding part of gardening. Many people are familiar with growing and multiplying plants using seeds. This method is useful but can be time consuming and, depending on the plant, difficult.
Luckily, many plants can be reproduced from a cutting, a process known as asexual reproduction. With a cutting, you are certain to reproduce the plant exactly, whereas sexual reproduction is a roll of the genetic dice.
If you have never propagated from cuttings before, I recommend starting with succulents. Succulent cuttings need little encouragement to root and regrow. I have often found a broken piece of a succulent that has fallen into some hidden place, grown roots and re-established itself. But like their parent plants, they are sensitive to over-watering and fungal infections. There are, however, things you can do to minimize complications and help your cuttings grow.
First choose a place to make your cut. If the plant is leafy, choose a spot with only one or two leaves above the incision site. These leaves will feed the plant through photosynthesis, but will also release water vapor. When necessary, remove excess leaves from the cutting.
If you are propagating something other than a succulent, look for new growth. This part of the plant is more adaptable than an older or woody area and will root more easily. You may need to wait for another season, when the plant begins fresh growth. Convincing a woody cutting to root can take weeks or even months.
Use a sharp, sterile knife to make the cut. A dull blade can damage cells at the site, causing rot. An unclean knife can introduce fungi and bacteria and transmit diseases.
When propagating succulents, set the cutting aside for a day or more to let the wound callous. This will prevent any moisture, fungus or bacteria present from entering the cutting. If your incision site is narrow, consider making your cut at a sharp angle. This produces a larger wound, but also creates a larger root-growing area.
Prepare a small pot with well-drained soil. Some people prefer to use perlite, vermiculite or a mix of the two. I have the best luck with cactus soil mixed with a little extra perlite. This provides a stable and well-draining environment for the cuttings. Be gentle when placing your cuttings. Pressing them roughly into the medium will damage the wound site and invite the entry of unwelcome microscopic visitors.
You may wonder how this little snippet is supposed to grow. The answer is: plant hormones. Each plant leaf releases a specific hormone that flows downward, instructing the plant to grow new roots. In turn, each root sends a different hormone upward, demanding new leaves. When you take a cutting, you upset this balance. Hormones from the roots are literally cut off, leaving only those coming from the remaining leaves. It is this imbalance that causes cuttings to sprout roots.
You can increase this imbalance, and your chance of success, with rooting hormone. Available at nurseries and garden stores, rooting hormones are synthetic versions of those found within the plant. If you purchase powdered rooting hormone, dip the wound site in it before placing the cutting in the growing medium. If you purchase a liquid type, dilute it as directed and pour it into the growing medium after you have placed the cutting. I use the liquid form and add a little every time I water my cuttings.
Now comes the time for patience. Minimal watering and bright, indirect sun will be all your cutting needs to do its work. Resist the urge to check for roots. When roots first grow, they are only one cell thick and very fragile. You will not be able to see them, and fussing with your cuttings will break them.
Watch your new plants for signs of over- or under-watering and infection. If you suspect a fungal infection, reduce watering and spray the cutting with Neem oil. Rooting time varies, but I usually check mine after about two weeks. Using a thin tool, I push aside some of the growing medium and look for roots.
In the end, cuttings are like children. All you can do is give them the tools to succeed and hope for the best. If you are lucky you will soon have some beautiful new additions to your garden.
Do you want to become a UC Master Gardener of Napa County volunteer?
To obtain an application you must attend an information meeting. For meeting dates, location and times, or to learn more about the program and volunteer commitment, visit the UC Master Gardener of Napa County website.
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. U. C. Master Gardeners of Napa County ( http://ucanr.edu/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.
This year has been one of the hottest on record, and next year is likely to be even hotter. As the temperature rises, gardening can become increasingly challenging. There are a few easy things you can do to help your garden beat the heat this summer.
Typically, the first sign of a plant's heat stress is wilting. No need to panic; immediate watering usually results in a quick rebound. If the plant continues to suffer, however, you will begin to see brown areas and dropped leaves. At that point, the plant may be permanently damaged and require extra care.
Provide the stressed plant with water and shade if possible. Pay special attention to container plants, as they not only get hotter but can be more difficult to rehydrate. Very dry container soil may resist absorbing water at first. You may need to water repeatedly to rehydrate it.
Regarding in-ground plantings, your soil will partially determine how well your plants stay hydrated. Sandy soil drains quickly, whereas clay soil (common in Napa County) retains water, possibly too much for your plants.
The optimal soil type is somewhere in between, rich in humus. Amending your soil with compost or manure will help change its structure to one that is healthier for your garden.
When planning for hot weather, consider that a plant does not have to be in direct sunlight to suffer from heat. A plant may become stressed if the air or soil around it reaches extreme temperatures.
Wind can also be a problem. Despite what common sense or personal experience may tell us, wind will not help your garden stay cooler on a hot day. While a breeze may bring relief to the gardener, it draws moisture from plant leaves, increasing their rate of dehydration.
The key to preventing such problems is proper watering. Where possible, install drip irrigation. The slow, steady application of water will reduce the likelihood of water stress. Drip irrigation also encourages plants to grow deeper roots, allowing them to find water that might otherwise be inaccessible.
Most plants also benefit from mulch. A thick mulch around the plant helps keep soil cool and slows evaporation. Even container plants benefit.
I do a lot of container gardening, and I water my containers by hand. When I know the day will be hot, I prepare my plants with an extreme soaking. During extremely hot periods, I rarely worry about overwatering anything except cacti and succulents. However, that's not impossible, so check your container soil regularly.
Be aware that hard surfaces absorb heat, raising temperatures around them as the day progresses. Light-colored containers reflect sunlight, potentially increasing the amount directed at your plants. These features can be used to your advantage in shady areas or during cool seasons but can turn deadly during the summer.
I recommend treating plant labels with a skeptical eye. Many times I have planted something that the label indicated was suitable for full sun, only to watch it shrivel to a crisp in the Napa heat.
Fertilizer can dehydrate a plant, making it more vulnerable to high temperatures. Before fertilizing, be sure the plant is well hydrated and showing no signs of heat stress. I typically wait to apply fertilizer until the cool of the evening.
If you experience significant challenges in a certain part of your garden, consider using drought-tolerant, low-maintenance plants such as succulents, cacti and California natives.
Salvias are one of my personal favorites. I have heard them referred to as "the only truly drought-tolerate plants" (other than cacti and succulents, of course). Once established, which may take about a year, they will have deep roots that help them access extra water when needed. The family is diverse, and nurseries offer salvias with a variety of growth habits and flower colors.
Finally, don't forget about self-care. Gardening can be strenuous, and you can become dehydrated more quickly than you expect. Start garden work early in the day, and never forget to water yourself!
Free Guided Tree Walk: Meander through the park as guides talk about its history and share information on 41 different trees. Wear comfortable shoes. Water and restrooms are available. All are handicap accessible. The book Trees to Know in Napa Valley will be available for $15, cash or check only. Tours depart from Fuller Park, 560 Jefferson Street, Napa. ONLINE REGISTRATION or call 707-253-4221. Walk-ins are welcome but you will be guaranteed a complimentary map if you register at least 48 hours in advance.
Do you want to become a UC Master Gardener of Napa County? To apply, you must attend an information meeting. For meeting dates, locations and times, or to learn more about the program and volunteer commitment, visit the UC Master Gardener of Napa County website.
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. U. C. Master Gardeners of Napa County (http://ucanr.edu/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.
- Author: Gayle Nelson
Article by Iris Craig, UC Master Gardener of Napa County, Class of 2016.
Napa has a well-kept secret: the demonstration garden at Connolly Ranch maintained by the U.C. Master Gardeners of Napa County. Master Gardener volunteers are there almost every Thursday morning pulling weeds, trimming plants and caring for the succulent and container gardens. The camaraderie among the volunteer gardeners and Connolly Ranch staff is delightful and keeps us coming back.
This is a teaching garden, designed to showcase research-based gardening practices and provide a place for the public to learn. The Napa County Master Gardeners inspired by similar gardens in Fresno County and Santa Clara County, began looking for a suitable site in 2000. It needed to be of adequate size with water, parking and accessibility, and of course it had to be affordable.
At the time, Connolly Ranch was being managed by the Land Trust of Napa County. Connolly Ranch and Master Gardeners have a similar mission, focused on education and connecting local people to the environment. Master Gardeners focus on adult gardeners' education, while Connolly Ranch aims to connect kids and their families to nature. We were offered a sloping site in the Ranch adjacent to the garden area.
In the summer of 2002, we began preparing the site for the future demonstration garden. Cleanup was the first task: hand-pulling weeds and hauling away years of accumulated debris. A tractor leveled the site and then created terraces. Master Gardener volunteers built a retaining wall and raised beds. We later added a shaded teaching and meeting location and a kiosk for posting information about the garden and upcoming events.
Master Gardeners and local businesses, including Van Winden's Garden Center in Napa and Mid City Nursery in American Canyon, donated plants and trees. A non-working fountain was repurposed as a succulent garden, and old tires were made into planters.
With enthusiasm, creativity and hard work, Master Gardeners made the many improvements that you see today. We constructed two storage sheds and a covered patio with benches and tables as well as a bulletin board built with the help of some Eagle Scouts.
We have designed and planted a bird, bee and hummingbird garden; a fire-wise garden; a succulent garden; a butterfly garden; an herb garden; a Mediterranean garden; and seasonal and container vegetable gardens. There are espaliered fruit trees and a rose garden. The roses are trained high to foil deer.
Each season, volunteers conduct field tests of vegetables and flowers to determine which varieties grow best in Napa County. Their progress is documented and made available through the Master Gardeners of Napa County website and publications. Last year, we planted corn, squash and beans by the Iroquois method. The Iroquois determined that this trio, which they called “the three sisters,” helped each other thrive. The beans feed the soil and climb up the corn stalks, while the large squash leaves shade the ground and keep weeds under control. Produce from the garden is donated to the Napa Food Bank.
The demonstration garden provides training for Master Gardeners on topics such as how to build and maintain a composting worm bin, how to espalier fruit trees and how to identify weeds. The Master Gardeners are often on hand during public events at Connolly Ranch to answer questions about gardening and provide educational garden activities for the whole family.
Master Gardeners volunteer more than 900 hours yearly in their garden to keep the it looking great and to educate the public.
The demonstration garden as part of Connolly Ranch is open to the public on the first Wednesday of every month and for special Connolly Ranch events throughout the year. See the Connolly Ranch website for details on days and times at http://connollyranch.org Connolly Ranch is located at 3141 Browns Valley Road in Napa. The parking access is off Thompson Ave. To get the Master Gardener Demonstration Garden inside the Ranch, from the parking lot walk past the greenhouse, the Beckstoffer chicken house and the big barn all on your left. Then enter the garden gate to the children's garden area and veer to the left down the path. You will see the entrance to the Master Gardener Demonstration Garden area.
Right before you enter, look to the right to see a California native plant garden dedicated to one of our members, and the hillside of white Matilija poppies, take a deep breath and enjoy the scents, then walk through the gate to our little Eden.
Workshop: U. C. Master Gardeners of Napa County will host a workshop on “Rose Pruning” on Saturday, January 7, from 10 a.m. to 12 noon, at University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Certified Rosarian Lynne Andresen and other Master Gardener rose enthusiasts will demonstrate and explain proper pruning techniques and review rose types, common rose disorders and routine maintenance. Online registration (credit card only); Mail-in registration (check only or drop off cash payment).
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. U. C. Master Gardeners of Napa County ( http://ucanr.edu/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.
What is the difference between cacti and succulents? All cacti are succulents but not all succulents are cacti. Named for the Latin succulentus, meaning juice or sap, succulents are defined by their liquid storage ability and belong to many different botanical families.
The cactus plant is defined by small, spherical, pillow-like structures called areoles from which spines, branches, leaves, hairs and even flowers emerge. Many succulents look similar to cactus, but if they do not have these cushiony areoles, then they are not in the cactus family (Cactaceae).
Succulents are native to most parts of the world whereas cacti occur naturally only from Alaska to Chile. In Maine, Vermont and New Hampshire, a native cactus has never been found. Surprisingly, Canada boasts several native cacti that have evolved to survive the harsh winters.
In Napa Valley's Mediterranean climate, succulents are a good choice for an easily maintained, slower-paced garden. Most require little water. However, low care does not mean no care.
Check your succulents regularly to catch and treat stressed plants quickly. An actively growing succulent may need water anywhere from once a week to once a month depending on the type and size of the plant, its location, the container and the weather.
The larger the plant and the plumper and fatter the leaves, the less water the plant needs. Keep the soil as moist as a wrung-out sponge. Use a drip system or water by hand, but moisten the soil and not the plant. Water can cause “sunburn” spots on the leaves.
If you forget to water, succulents usually adjust; if you over water, no worries. Unless waterlogged, they do fine. When in doubt, don't water.
Although they do not do well in full shade, succulents need only three to four hours of sunlight daily. Protect them from the onslaught of the midday sun. Early-morning and late-afternoon sun is best, with filtered exposure at noon. The plants need much less sun in winter, but be sure to protect them from frost. The succulent's plump leaves freeze easily.
With their shallow root systems, succulents do well in pots or in the ground. Nurseries sell container mixes for cactus, but you can make your own with two parts potting soil to one part perlite and one part coarse sand. Remove the plant from its nursery pot and spread the roots out on top of a small mound of soil. Add more soil but keep the roots shallow; press down softly to anchor the plant.
At the time of planting, add one teaspoon of slow-release fertilizer per gallon of soil. In spring, feed plants with a low-nitrogen liquid fertilizer diluted to half strength; be sure to moisten the soil first. Do not over-fertilize or the plant may develop softened foliage that is susceptible to rot.
Like all plants, succulents need occasional dividing, deadheading and pruning. They experience a growth spurt when moved to a larger pot. Some succulents are winter growers and look unwell in summer. Resist the impulse to overwater them during this period.
For most succulents, early summer is a good time to propagate. Allow new cuttings to dry or “callus” before planting them. Putting them in soil immediately encourages the cuttings to draw too much moisture and possibly rot.
Succulents are not plagued by many pests. Aphids, spider mites and mealy bugs are the most common. A judicious squirt of water from a spray bottle or hose removes these invaders easily. A cotton swab soaked in isopropyl alcohol and dabbed directly on the pest will also work. Avoid getting alcohol on the plant as it might damage the leaves. For more information on dealing with the pests that plague succulents, visitwww.ipm.ucdavis.edu.
Recently I attended a local flower show, and all the amazing ideas for using succulents really got my creative juices flowing. One display was of miniature fairy gardens complete with rock paths and little houses. My mind immediately started creating a tiny landscape of chubby, scalloped, speckled, spikey, fleshy, prickled succulents. The possibilities are endless and only limited by my imagination.
Workshops: U. C. Master Gardeners of Napa County will conduct a workshop on “Succulent Gifts” on Sunday, November 8, from 2 p.m. to 4 p.m., at the Yountville Community Center, 6516 Washington Street, Yountville. Bring your own love of succulents to this workshop dedicated to making gifts for the holidays or for yourself. Master Gardeners will concentrate on the right kind of soil and care for succulents, discuss the myriad succulent types, and help you make a succulent garden or two to give as gifts. Please bring succulent cuttings if you would like to share. Call 707-944-8712 to register or visit the Parks and Recreation web site.
“Succulent Gifts” workshop will be repeated on Saturday, November 14, from 9:30 a.m. to 11:30 a.m. at the University of California Cooperative Extension Office, 1710 Soscol Avenue, Napa.
Online registration (credit card only)Mail-in registration (cash or check only)
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. U. C. Master Gardeners of Napa County ( http://ucanr.org/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.