- Author: Sherida Phibbs
Selecting plants is not a “one-plant-fits-all” approach. Trees, shrubs, plants, vegetables, etc., all have their own climate requirement to grow and produce at their best. Knowing your planting zone is the first key element in selecting your landscape plants and trees, knowing when to plant your vegetable crops and knowing if certain fruit trees and berries will be successful in your area.
The USDA Cold hardiness zones are based on winter minimum temperatures. The AHS (American Horticultural Society) heat zone system is based on average number of days above 86 degrees F. Since these two systems are limited, the best and most reliable system is the Sunset Zone.
We recommend using the Sunset zone system. This system bases its climate zones consisting of many factors: cold, heat, humidity, wind, proximity to the Pacific Ocean, snow cover, and the length of the growing system.
The Humboldt and Del Norte Counties consists of 6 Sunset Zones. Zone 17 is the maritime zone for both counties. Zone 1a is the Costal Range Mountains for both counties. Zone 15 is Humboldt's costal zone, 14 is the interior zone and transitional zones are 4 and 7. Del Norte's transitional zone is 7. To determine your zone visit our Website to find your location on the Sunset Map.
Most all landscapes and gardens have microclimates. These are areas in your gardens that are influenced by various factors: i.e. exposure to wind, structure walls, sloping ground, dry banks, eaves and overhead structures and trees.
Shade trees and overhead structures will provide planting areas for shade loving plants. During a frosty evening, this area will be a few degrees warmer than the air over the open ground.
Masonry and stucco south and west walls soak up solar energy during the day and then releases it at night. In our counties cooler summer days, it will help to provide the warmth that heat loving vegetables require during the day and the evening.
North walls get little direct sun. This is a perfect location for woodland plants like ferns.
East walls generally can get up to half a day of sun and is less intense than a west facing wall. Azaleas and fuchsias generally will be happy.
Eaves will provide frost protection for delicate flowers.
Sloping grounds make a perfect location to grow citrus as the air flow is warmer than the air on hilltops or in the valleys below.
Drought tolerant plants would be the best solutions for planting in dry bank areas.
Cold air pockets lay in low-lying areas. This is a benefit for tulips which needs that extra chill to encourage bloom. These cold pockets are also good locations for certain fruit trees and berries which require cold periods for production of fruit.
Get to know your garden and plan your selection of plants and plant site location. Use microclimates to your advantage to be successful with your vegetable gardens and your landscape.
Source: The Western Sunset Zone 2017 Third Edition
- Author: June Walsh
- Contributor: Humboldt Botanical Garden
The Wollemia nobilis of Australia have been saved from the raging fires of Australia by special fire crews and air dropped fire retardant in a Top Secret operation.
On the afternoon of October 26, 2019 an unseasonably warm Saturday following a run of hot days, the wind picked up over the Blue Mountains and lightning sparked what was to become the beginning of the biggest forest fire Australia has ever known. One bolt made ground near a densely grown area of the Wollemi National Park.
On January 15, 2020 the Sydney Morning Herald reported that firefighters had saved the Wollemia nobilis trees (commonly called the Wollemi Pine) of the Wollemi Mountains west of Sydney Australia. While most of the Wollemi National Park has been burnt by the fires north-west of Sydney, specialist fire crews managed to ensure the only existing stand of Wollemia nobilis survived.
"It was like a military-style operation," New South Wales Environment Minister Matt Kean told the Herald. "We just had to do everything." Fanned by strong winds and temperatures in the mid-80s the “fire tore towards the coast like a beast on holiday. It was voracious.”
"Wollemi National Park is the only place in the world where these trees are found in the wild and, with less than 200 left, we knew we needed to do everything we could to save them,” Mr. Kean said.
There are fossils of the Wollemia nobilis as well as other Araucariaceae dating from the time of the dinosaurs (245 to 65 million years ago). In 1994 a Wollemia was found in the bottom of a canyon along a stream in Eastern Australia's Blue Mountains growing among flowering trees.
There are two Wollemia nobilis in the Moss Family Temperate Woodland Garden. The first one came as a gift in 2008 from the National Arboretum in Washington DC. It had been acquired from the Sydney Botanical Garden in the first distribution of newly propagated trees. The second came to us in 2016 from a San Francisco Arborist who had received her tree in 2006 as a wedding gift. Both trees have had male cones and the first tree put on female cones in the summer of 2019.
We are grateful for the splendid Wollemia nobilis in the Humboldt Botanical Garden.
Humboldt Botanical Garden
at College of the Redwoods
7707 Tompkins Hill Rd, Eureka, CA
- Author: Tom Schrader
The Cymbidium (sym-BID-ee-um) orchids are known for their beautiful, long-lasting sprays of flowers and they do well outside.
There are two main types—standards and miniatures. Miniatures only grow where summer nights are above 70°F. Our coastal climate is not suited for miniatures unless you grow them indoors or a heated greenhouse.
The standard type of cymbidium is best for Humboldt County. They originally came from cool and bright areas in Asia, so let's talk about conditions that are required to make these orchids thrive.
Light is important as they need lots of it, but cool temperatures. Give cymbidiums the maximum amount of light possible. Full sun is tolerated in cool areas, such as coastal California. The leaves should be a medium to golden green color, not dark green.
Temperature is another critical factor for flowering. Optimum temperatures are 45-50°F at night and 65-75°F during the day. When the plants are in bud, temperatures must be as constant as possible, between 55-75°F. I leave mine outside all year long as most cymbidiums can tolerate light frosts and survive.
Water and moisture are important too. They generally produce all their vegetative growth during spring and summer (growth season) and need the most water those months. You should water heavily during the growth season to keep the potting material evenly moist. After late summer, just keep them barely moist as our outdoor humidity is enough.
Fertilizing at the right time helps cymbidiums flower. Use a high nitrogen mixture (30-10-10) in spring and summer and apply every two weeks. In the fall use a high phosphorus fertilizer (10-30-20) to help form bloom spikes. In the winter fertilize about once a month.
Potting and re-potting is where more work is involved as cymbidiums can grow quite large. Divide or re-pot after the plant has quit flowering. If you are dividing a large cymbidium, you may need to use a large carving knife or even a Sawzall to separate the pseudobulbs. If planting into a pot, select one that allows for at least two to three years of pseudobulb growth before crowding the pot. Place the active growing pseudobulb(s) farthest from the side of the pot. Pick a water-retentive potting mix—medium-grade fir bark with peat moss and perlite is a common mix.
So, let's plant these orchids and enjoy their beautiful flowers every spring and summer. Visit our own Humboldt Orchid Society for more information about growing orchids.
Reference: American Orchid Society
- Author: June Walsh
Cardamine californica blossoms from January to May. Each flower is about 1/2 inch in diameter with four white to pale pink petals. The flower closes its petals in late afternoon as the sun goes down and nods before a rain. It grows by rhizomes. Its young leaves are edible but not necessarily tasty, more like bitter horseradish which becomes more pronounced with maturity.
After flowering and setting seed it becomes dormant in the summer, until the rains return. You can hand pollinate to increase seed set.
At Humboldt Botanical Garden it grows in the Moss Family Temperate Woodland Garden under spruce and fir, and among Iris douglasiana and trillium ovatum, all of which are naturally occurring on the site.
Cardamine hirsute; a weed! It is originally from Europe, the Caucuses and North Africa. It is an invasive weed in our Humboldt County gardens.
Though it is an annual which generally flowers in fall through winter, here in Coastal Humboldt it flowers and shoots its seeds ALL year. It is a member of the Brassica family and can be eaten as a bitter herb. It has many common names; pop weeds, bitter cress, hairy bitter cress and some unmentionable names.
Like many Brassicas it has seeds that burst explosively, casting the seeds far from the parent. If you want to rid your garden of these evil-doer invaders you need to remove the weed before it goes to seed (ha, fat chance!). Remove the pulled plants to the garbage, as the plant's seeds will continue to ripen after being pulled and our home compost bins are generally not hot enough to kill seeds.
Some sources suggest using Cardamine hirsuta as a winter cover crop! Late summer mulching is suggested to prevent germination. This gardener has not found much that is very effective but patience and diligence...don't turn you're back!
June Walsh is co-curator of the Moss Family Temperate Woodland Garden
and a UC Cooperative Extension Master Gardener
Source-The Jepson Herbarium, UC Berkely
- Author: Sherida Phibbs
Sherida states “I enjoy planning and creating projects and events for Master Gardeners who then can showcase their skills and knowledge for our community. Being a Master Gardener Coordinator gives me the opportunity to make a difference for my fellow Master Gardeners and my community”.
Newly Revised Website
We have been busy as bees launching our UC Master Gardeners of Humboldt and Del Norte Counties Website. Our website will be useful for both the new gardener and the advanced gardener. Web pages include various topics with organized resource links. In response to our community's interest in growing your own Victory Garden, make sure you visit our Edible Garden page for how to get started with vegetable gardening, climate zones, vegetable planting calendars, vegetable specific growing and pest information. Our website is an ongoing work in progress as we continue to add additional content and resources for you.
Advise to Grow By - Ask a Master Gardener Help Desk
Our Help desk is a free public service available to the home gardener in the Humboldt and Del Norte Counties. Our team of Master Gardeners can assist you with questions about home horticulture and pest management. To assist you with your inquiry complete and submit a Help Desk Ticket online. Your question will be submitted to our Help Desk Team.
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If you haven't found us on Facebook you will want to. Our new beginnings include social media presence as we share with you pictures of our Master Gardeners' gardens, updates to our website, events and other interesting topics. Make sure to like and follow us to stay connected.
Newsletters and Announcements
Spring 2020 is our first newsletter edition. Our way of staying connected with you is through our newsletter and announcements. Sign up for newsletter
Our team of Master Gardeners are currently working on developing virtual webinars that you will be able to attend in the comfort of your own home. Our first virtual webinar series is "Right Plant Right Place" which will include growing your own vegetable gardens as well as your home landscape. Stay connected through Facebook and our Newsletter for announcements and registering for our Virtual Webinars when they become available./h3>/h3>/h3>/h3>/span>