For the Napa Valley, El Niño refers to a weather pattern in which warming sea surfaces cause heavier-than-average winter rains and wind with warmer-than-normal temperatures.The U.S. Climate Prediction Centerhas predicted 65 percent likelihood that we will feel the effects of El Niño as summer ends, with that probability rising to nearly 80 percent by the end of the year. The National Oceanic and Atmospheric Administration says that this weather pattern usually continues for nine to twelve months.
Because of the current drought, the idea of a wet winter is welcome to me. The coming rains are too late for a number of my trees and shrubs, which are either dead or have dead branches. And the high winds that accompany El Niño storms could blow any of these trees down. Clearly I need to trim dead branches and trees and make sure weak plants are staked properly.
El Niño storms often dump massive amounts of rain in a short time, creating flash floods and heavy water build-up in yards. You can find some good suggestions on how to handle storm water as well as how to collect it for future use at www.countyofnapa.org. In the search box, type “slow it spread it sink it” to find an online reference guide by that name.
Since good drainage is extremely important to plant health, my other pre-storm chores involve clearing a place for the rain water to go. These tasks include clearing weeds from the run-off ditches in my yard as well as cleaning out rain gutters and spouts.
Highly saturated soils make it hard for plants to survive. In wet soil, t is almost impossible for roots to take up all the oxygen that the plant needs, which causes the roots to decay. Deep roots are the first to rot. If the condition continues shallower roots will also be damaged. Even plants that don't appear to be flooded may have problems during extended wet weather. And you may not see the damage until next summer. One of the best defenses for your winter vegetable garden is to make sure you have well-drained soil and to plant in mounds.
After an El Niño season, everything may appear normal in your garden until summer temperatures top 90°F. After the 1997-98 El Niño season, Napa County farm advisor Dean Donaldson warned Master Gardeners about this phenomenon in the group's newsletter. “Sometimes tree growth is simply stunted,” wrote Donaldson. “Usually, however, people observe their beautiful trees and shrubs suddenly turning from green to yellow or reddish brown. Usually it is the entire tree and it happens within a few days of hot weather. Insects are attracted to those weakened trees and often get the blame. If the whole tree dies, you can blame El Niño.”
When those record-breaking El Niño rains subsided and weather warmed up, fungal and bacterial pathogens emerged on foliage. Many trees and shrubs evidenced phytophthora root and crown rot. Slime molds appeared on soil surfaces, and snails and slugs proliferated.
Anthracnose, fire blight, and powdery mildew all thrive after a mild, wet spring. When you see evidence of these diseases on plants, cut out and discard the affected material immediately. Sanitation is the number-one way to keep these diseases from spreading. Iron chlorosis may also be a problem in wet soils.
The best thing we can do for our gardens before an El Niño-influenced winter is to create good drainage. Afterward, watch for symptoms of root rot, fungus or bacterial diseases.
Garden Tour:The UC Master Gardeners of Napa County invite you to their sixth garden tour, “Down the Garden Path,” on Sunday, September 13. On this self-guided educational tour you will see seven gardens by Master Gardeners in and around the City of Napa. These gardens illustrate how Napa County Master Gardeners use University of California research-based horticultural information to develop and maintain their own gardens.
Tickets: $30 Advance/ $35 Day of Event. Purchase tickets at http://ucanr.edu/ucmgnapa. Or you can purchase tickets at the UC Master Gardener office (address below). For more information, call 707-253-4143.
Workshop: The UC Master Gardeners of Napa County will host a free workshop on “Worm Composting” on Saturday, September 26, from 9 a.m. to 11 a.m., at the Napa Valley Museum, 55 Presidents Circle, Yountville. Explore worm composting, an ideal solution for composting kitchen scraps and returning the nutrients to your soil, especially when outdoor space is limited. Co-sponsored by Napa Recycles! Free Online Registration.
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.
California's ongoing water situation has produced many suggestions for dealing with drought conditions. One pertinent idea is permeable hardscapes. Permeable means that a material allows liquids or gases to pass through it.Hardscapes are the non-living or man-made sections of an outdoor area such as driveways, walkways and patios.
Traditionally a lot of the hardscapes in our yards have been made of non-permeable materials, such as concrete. Non-porous materials in a city or town environment encourage the runoff of possibly polluted waters and the overflow of the storm sewers which at times may cause flooding. Additionally because the water is unable to penetrate the surface the soil dries out and moisture is unavailable to hydrate nearby plantings,increasing the need for irrigation in the dry season.
Permeable materials allow the water to slowly percolate through. The filtering of the water by the permeable material,as well as chemical interactions with soil and soil organisms, removes a large portion of the pollutants and allows the water to return to the aquifers much refreshed. The soil is also able to store the water for the use of nearby plants so you do not have to supplement their water needs as much.
If we had cemented the area I probably would not have gone to the labor and expense of removing it. At one point we did take out a section of concrete from another area in our yard, and it was a lot of heavy work. Rather than send the concrete to the land fill, I was able to recycle it into a retaining wall. Reused concrete chunks are sometimes called “urbanite”.
I decided to check out permeable hardscapes to see what the costs were and just what materials were available out there. The selection of cement pavers, decomposed granite, gravel, mulch and so on is legion. You can also use a product called pervious concrete, which looks and acts like concrete in the landscape but allows water to pass through.
The pavers, permeable concrete, and similar products need a good base and mostly professional installation. The flagstone I liked but car traffic would probably crack the slabs. I thought of decomposed granite (DG) but the installation I found was labor intensive. I love the cobbles I have in other areas of my yard but their uneven surfaces would not work at this location.
The side yard had been filled with pea gravel for a dog run at one time. Over the years the gravel had been joined by silt and soil to create a hard packed material and it had become a haven for difficult to remove weeds. I decided just to refresh with that same material. Pea gravel is permeable. When the gravel is loose, it is easy to remove the occasional weed with a stirrup type hoe, and if you have pets the removal of pet feces is simple.
I dug the area down about 4 inches and removed the gravel/soil to another location. It made a fine walking surface around my raised beds.We then computed the amount of pea gravel needed and had it delivered. Because the location was right on the street the delivery truck was able to dump it right where it needed to be. This was super convenient as now all I had to do was spread it around with no wheel barrow involvement at all. After a few hours of hard, sweaty labor the area looked refreshed and new.
Both the cost and labor commitment fulfilled all my expectations. It looks great and more importantly it is permeable. The only downside is that the pea gravel tends to spread and needs frequent sweeping to return it to the designated area. Overall, though, I am happy with the entire project.
If you are choosing hardscapes for your yard, it is worth the time to check out permeable material options. You can beautify your landscape and conserve some of our precious water at the same time.
Garden Tour: The UC Master Gardeners of Napa County invite you to attend their sixth garden tour, “Down the Garden Path,” on Sunday, September 13. On this self-guided educational tour, you will see seven gardens by Master Gardeners in and around the City of Napa. These gardens illustrate how Napa County Master Gardeners use University of California research-based horticultural information to develop and maintain their own gardens. Tickets: $30 advance / $35 day of event. Purchase tickets here: http://ucanr.edu/ucmgnapa Or you can purchase tickets at the Master Gardener office (address below). For more information, call 707-253-4143.
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. UC 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.
About 40 years ago I attended a lecture on best practices for tree pruning. Strybing Arboretum auditorium was filled because the speaker was a well-known arborist. When pruning side limbs, he said, the cut should be as flush with the trunk as possible. This allowed gravity to assist the tree in quickly closing the wound. I still recall the arborist’s name, but as subsequent research proved his advice incorrect, I won’t mention it.
Experiments by a university professor, whose name I won’t mention because I don’t quite remember it, showed that trees possess cells that form a barrier to decay just beyond the junction of a side branch and the trunk. You can see this little raised ridge, known as a collar.
Pruning just beyond this collar leaves the protective cells intact. It is true that a callus of bark would quickly form over a flush cut, but rot would permeate the trunk. Some trees became like a glove, with a healthy-appearing exterior but a decaying interior.
In my time as a landscape contractor, I used a variety of procedures that improved on previous methods but were later superseded.
At one time, conventional wisdom held that the planting holes for shrubs and trees should be twice as wide and twice as deep as the root ball. Later, the thinking was revised to twice as wide but only as deep as the root ball. Then the recommendation changed again: to twice as wide but square. The most recent advice I have read suggests digging a saucer-like planting hole that is two inches less deep than the root ball is high.
These revisions happened when people realized that the roots mainly grow in the top 18 inches of soil. Roots require oxygen, and there is little available below that depth. Gardeners and landscapers also realized that disturbing the soil beneath the plant caused the plant to sink later. A certain way to kill almost all shrubs and trees is to plant them with the crown beneath the soil. The square hole was intended to counteract the tendency of plants grown in round containers to keep circling their roots.
Another commonsense practice is to shear a plant before transplanting it. The thinking was that roots damaged by transplanting would have less demand placed on them. But now we know that this thinking is incorrect.
The top most stem of the tree or shrub generates a hormone known as auxin. This hormone inhibits lower side stems or branches, thus keeping the main stem dominant. As auxin flows down the connective tissue, the phloem, it diminishes sugar flow to leaves that, being in shade perhaps, are using more sugar than they are producing. But the major effect is that, upon reaching the roots, auxin greatly promotes root growth.
The roots also generate a hormone, cytokinin, which has the opposite effect. Cytokinin inhibits root growth but promotes shoot and leaf growth. Consequently, the best preparation for transplanting is to shear the plant but leave the main stem intact. The auxin from the main stem promotes root growth, which generates cytokinin, which promotes top growth. These hormones provide the best chance for plants to quickly flourish in their new location.
As we understand more of the inner workings of a healthy plant, we are better able to supply the care it needs. And the more we know, the more we realize how staggeringly complex nature is.
Workshop: Napa County Master Gardeners present a workshop on “Edible Landscape Design” on Saturday, October 5, from 10 a.m. to noon. Location is American Canyon Library,
300 Crawford Way in American Canyon. Design your garden to be both beautiful and edible. Learn what to consider and how to integrate edible plants into your ornamental garden. Bring a detailed plan of your garden to work on with guidance from U.C. Master Gardeners. Learn about books to help you with your design from Napa County Library as part of the Eat, Move, Read program. Seating is limited. Register online at http://ucanr.edu/ucmgnapa or call 707-253-4147.
Garden Tour: Napa County Master Gardeners will host a self-guided garden tour, “Down the Garden Path,” on Sunday, September 22, from 10 a.m. to 4 p.m. Visit seven unique gardens in and around downtown Napa, all maintained by Master Gardeners. Tickets: $25 advance/$30 day of event. For more information and to purchase tickets, visit http://ucanr.edu/ucmgnapa or call 707-253-4147. Find us on Facebook under UC Master Gardeners of Napa County.
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. Napa County Master Gardeners ( 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?
Order your spring-blooming bulbs now to have the best selection. The bulb growers will ship your bulbs in time for proper planting in our area. Local nurseries also stock bulbs to coincide with the best planting time for our area.
Select the largest bulbs available; mature bulbs produce more flowers. Choose heavy, dense bulbs with no decay or mold. Pre-packaged bulbs frequently cost less, but they are likely to produce smaller blooms.
Plant your bulbs in the fall when temperatures remain consistently cool and the soil temperature has cooled to below 60 degrees. If you plant too early, when the soil is still warm, you are likely to end up with lots of top growth and fewer flowers.
If your bulbs arrive before you are ready to plant, open the packages to give the bulbs good air circulation. Store them in a cool, dark, dry place.
Despite what your grandmother may have told you, it is not necessary to pre-chill bulbs in our area. Tests done by Sunset Magazine and the U.C. Master Gardeners showed that there was little difference in the performance of pre-chilled and non-chilled bulbs.
Choose a location for spring-flowering bulbs that receives at least five to six hours of sunlight. You can even plant under deciduous trees as the trees generally do not leaf out until after the bulbs have bloomed.
It is critical to plant bulbs where the soil drains well. Bulbs hate to have “wet feet” and will let you know by rotting instead of blooming.
Plant all bulbs with the pointy end up and the root scars down. Follow directions on planting depth for that type of bulb. The general rule is to plant most types of bulbs three times as deep as the bulb is wide.
Bulbs need water while they are actively growing. Even though you cannot see them after planting, remember to irrigate until winter rains begin.
Soil preparation depends on whether you are planting for repeat bloom. Bulbs contain all of the nutrients they need for the coming season’s growth and bloom. But if you want bulbs to repeat in successive seasons, amend your soil with compost and other nutrients. Do not put fertilizer in the planting hole as bulbs are susceptible to root burn. Instead, dig bulb fertilizer into the soil under the root zone or broadcast fertilizer over the beds after planting.
For repeat blooming, leave the bulbs in the soil after flowering and allow the leaves to turn brown so that the bulbs build back their reserves for the following season. Daffodils, native iris, muscari and scilla are the most reliable repeat bloomers in our area.
I have a love affair with tulips but have finally admitted that they do not repeat well in my garden. I also have very active gopher and rodent populations, and they consider tulip bulbs a culinary delight.
My solution is to treat my tulips as annuals. I grow them in strategically placed two-foot diameter pots that I also use for summer annuals. When the annuals are giving up the ghost in fall, I remove them from the pots and plant tulips in the same soil. There is no need to enrich the soil at this point as the bulbs contain all of the nourishment they need for a single season. When the tulips have finished their spectacular demonstration, I remove the bulbs, renew the soil in the pots, add compost and fertilizer and plant flowering annuals. This way, I have an almost continuous display of blooms in the same pots with minimal effort.
Because the critters do not seem to like daffodils, I have had success in naturalizing daffodils for repeat bloom in several locations in my garden. Daffodils do not require the cooler winter temperatures that tulips demand so are much better suited for repeat blooming in the Napa Valley.
Whether you choose to naturalize daffodils in your yard, grow tulips as annuals in pots or experiment with varieties of bulbs you have never tried, now is the time to plan your spring bulb garden. A small amount of effort this fall should provide you with a magical floral display next spring.
Workshop: Napa County Master Gardeners will present a workshop on “Planting Spring Bulbs” on Saturday, September 14, from 9:30 a.m. to 11:30 a.m., at University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Plant bulbs now for a colorful display in early spring and find hidden beauty in your garden. Learn about different kinds of bulbs, how to plant them and what they need to thrive. Online registration (credit card only) Mail in registration (cash or check only).
Garden Tour: Napa County Master Gardeners will host a self-guided garden tour, “Down the Garden Path,” on Sunday, September 22, from 10 a.m. to 4 p.m. Visit seven unique gardens in and around downtown Napa, all maintained by Master Gardeners. Tickets: $25 advance/$30 day of event. For more information and to purchase tickets, visit http://ucanr.edu/ucmgnapa or call 707-253-4147. Find us on Facebook under UC Master Gardeners of Napa County.
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. Napa County Master Gardeners ( 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?
Having a shady spot to rest in your garden should be one of your goals as gardeners....a place to sit back and enjoy the fruits of your labors. If you have lived with your garden for a while, you will know your favorite places. Investigate these areas as possible sitting areas.
A woodland setting on a hot summer day offers a protective canopy of tall trees. These shady retreats may not always be as showy as sunny borders, but they offer interesting scenes, with a layering of understory trees or shrubs and a mix of herbaceous plants at your feet.
The best sitting areas have both sun and shade. But if you have to choose one or the other, generally a sunny location is better. There are ways to provide shade if the sun becomes too bright: an arbor, an umbrella or an awning, for example.
Note where the sun falls in your garden. The south side of the house is in the path of the sun for most of the day and is the warmest. The west side gets the afternoon sun and is the next warmest, followed by the east side which receives morning sun. The north side of the house is the coldest because it is shaded most of the day.
Small gardens, usually partially shaded by buildings, need cheerful places where sunlight streams through the foliage and pools on garden furniture, flowers and paths. Study how the light falls in your garden and devise as many opportunities as you can to make the garden sparkle. Variations of shade and sun throughout the day create different visual effects during day and evening hours.
The “show” changes as light moves and fades. Paving and ground covers provide a surface for catching the play of light in the garden. To bring light into an entrance garden shaded by trees, remove the lower branches and thin the canopies, allowing sunlight to dapple the garden below. Cream or white variegated leaves lighten up shady parts of a garden. Chartreuse or gold foliage also has a warming effect in shade. White or blue flowers can brighten up a shady area.
Dappled shade is prettier than dark shade and usually sufficient protection from heat and glare. Select trees with open branches and delicate leaves and trim any dense vines. If a patio is shaded by walls, try to create a view from the patio that is bathed in light, where you can watch sunlight playing across the garden.
Trees and shrubs that are adapted to dense shade are valuable in the garden. Plants including Fatsia japonica, the hollies and mahonias are notable for their foliage, while others such as camellias are grown for their spectacular color. When planning your shade garden, think about layers: ground covers, small shrubs, and larger bushes. Think about colors and textures and your space.
Sunset’s Western Garden Book offers many suggestions for shade plants. A favorite of mine is Ajuga reptans (carpet bugle), which spreads by runners. There are several varieties with varied leaf colorings but all send up blue flower spikes in spring and early summer. Daphne odora ‘marginata’ (winter daphne) will take partial shade, provides a heavenly scent and is an evergreen. Hostas provide elegant foliage and a huge range of color. Lamium maculatum is a vigorous ground cover reaching six inches in height, with heart-shaped gray-green leaves with silvery markings. Pittosporum tobria ‘variegata’ is a dense, rounded shrub five to ten feet tall, with creamy white, fragrant orange blossoms in early spring. Vinca minor (dwarf periwinkle) makes a spreading mat of shiny, dark green leaves with blue flowers. There are many varieties available.
Visit a local nursery and browse through the shade plants. Be sure to note the plant’s mature size, usually indicated on the plant tag.
Let your garden reflect your environmental concerns as well as your aesthetic sense. It should be in harmony with nature, a place where you can enjoy the sounds of birds, insects and animal life and appreciate the patterns of light that change throughout the day. A shady oasis that provides the possibility of peaceful enjoyment can be a restorative place for you.
Workshop: Napa County Master Gardeners will conduct a composting workshop in partnership with the City and County of Napa and NRWS/NCRWS. The workshop is Saturday, September 7, at 9 a.m. at the Yountville Community Center. Learn how to turn yard waste and kitchen scraps into wonderfully rich, free compost for your garden. Discover the basics of backyard composting, worm composting, and grasscycling. Register here: http://compost.naparecycles.org/index.html.
Garden Tour: Napa County Master Gardeners will host a self-guided garden tour, “Down the Garden Path,” on Sunday, September 22, from 10 a.m. to 4 p.m. Visit seven unique gardens in Napa, all maintained by Master Gardeners. Tickets: $25 advance/$30 day of event. For more information and to purchase tickets, visit http://ucanr.edu/ucmgnapa or call707-253-4147. Find us on Facebook under UC Master Gardeners of Napa County.
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. Napa County Master Gardeners ( 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?
