From the cold, rainy day in March 2008 when we planted the 28 Magnolia denudata tree Allée in the Moss Family Temperate Woodland Garden, we knew that winter would hold special promise for this garden. Over the next 8 years, we have added many winter flowering trees, shrubs, and herbaceous plants.

Two spectacular Camellia species offer hybrids that give us the huge flowers of Camellia reticulata and the diminutive blooms of Camellia sasanqua. Camellia sasanqua ‘Brooksie Anderson' shows off lovely, small, clear pink blossoms all along its arching branches from November through January. From January through April, Camellia reticulata ‘Buddha' is covered with 6” wide deep-orchid pink flowers, some of which will mature into hard plum-sized fruits bearing three coffee bean-like seeds.

We also have Camellia sinensis (Thea sinensis), the most widely grown camellia in the world, the plant from which all true tea is derived. Don't look for bold flowers but appreciate this plant as you have a hot cup of tea on a winter morning.

In February, our most glorious Magnolia ‘Caerhay's Belle' will burst forth with 12” lipstick pink, scented blooms on naked branches. As my husband Tim says, “The great thing about ‘Caerhay's Belle' is that it blooms in February to give us a bright lift on a winter day. And the sad thing about ‘Caerhay's Belle' is that it blooms in February when the wind and rain can strip the flowers off overnight!” It tends to keep blooming for several weeks, so rainy, windy days won't rob it of all its blossoms.

Next will bloom the Allée of 28 Magnolia denudata beginning in March. The Chinese have cultivated this tree since at least 600AD and call it Yulan. Magnolia denudata, like many Asian magnolias, is a precocious bloomer, meaning that the flowers appear before the leaves, creating a very dramatic scene in late winter to early spring. If our winter is very mild, the flowers and leaves come at the same time, somewhat reducing the effect of clouds of lemon-scented white flowers.

We have had to wait a few years to see Magnolia rostrata bloom. It was planted in 2012 as a gift from the Rhododendron Species Botanical Garden. In the Spring of 2023, it rewarded visitors and volunteers with several very large fragrant flowers. It is endangered in its native Southern China and the Republic of the Union of Myanmar and seldom grown in public gardens.

Not to be missed are the early flowering and fragrant Rhododendron taronense and Rhododendron ‘Forsterianum.' Both have waxy white flowers that hold up well to rain and scent the air with dianthus and clove perfume. These plants are part of our collection of Maddenii series rhododendrons, which have been sourced and gifted by the Rhododendron Species Botanical Garden in Federal Way, Washington, where they must be grown in the Rutherford Conservatory and in cool greenhouses. Here in coastal Northern California, we can grow them outside exceptionally well.

Beginning in March, come see our Toona sinensis, Chinese Toon tree, with its brilliant flamingo-pink new growth. The green form of this tree is widely grown in Asia from the Korean peninsula, through China to Indonesia and is used for food and timber. We like our tree's amazing pink plumage in contrast to the green.

Along the perpetually wet central bed, you will find several species of Primula (primroses). Follow the stairs into the forest to see the Hellebores that the family of Stan Baird, Ph.D., donated.

Make a date to come walk through Humboldt Botanical Garden on a winter day to see the runnels awash with rainwater along the Dedekam Ornamental Terrace, then into the Lost Coast Brewery Native Plant Garden, where volunteer Curator Mark Moore has added many new native plants to the collection. Then wander up to the Moss Family Temperate Woodland Garden either from the lower Water Fall Trail or the main road. Winter is a wonderful time to visit.

Humboldt Botanical Garden is a member of the Eureka Chapter of the American Rhododendron Society.

 June and Tim Walsh are Charter members of Humboldt Botanical Garden and UCCE Master Gardeners. June is the leader of the Tuesday Wild Weeders and Grateful Deadheaders volunteers who care for this slice of heaven.

 All photos were taken by the author, June Walsh, and used with permission.

The Humboldt Master Gardener/Del Norte Help Desk is staffed by volunteers trained by the University of California to answer gardeners' questions using information based on scientific research. Click on this link to submit your garden/landscape question to our Help Desk.

Q. I have a Meyer lemon tree that has been covered with fruit for months, but not all of them are turning yellow. The fruit looks to be mature size, but some are still dark green. Recently, my tree has started to bloom again. Is this normal? Can I harvest the lemons even if they have not turned yellow?

A.  One great thing about Meyer Lemon is that it can bear fruit all year round. Lemons will flower and fruit more than once per year if conditions are favorable. On the coast, Meyer Lemons often have blooms and fruit in varying stages throughout the year.

Meyer lemons are typically ready to harvest when they have turned a deep yellow or orange color and feel firm to the touch with just a slight “give.” They should also be fragrant. It's best to harvest them when they are fully ripe for the best flavor. The heaviest harvest is usually late Winter/Spring.

The reason your fruit has not turned yellow may be that we have not had enough cold weather to encourage the color change. It occurs naturally as the fruit ripens, but cold weather speeds up the process.Citrus turns color in Fall, but the color does not affect the sweetness of the fruit.

The Meyer lemon is a cross between an orange and a lemon and is known for its milder taste, so if you pick it green, it will be more acidic in taste than your typical Meyer lemon, and you may be disappointed. The fruit is usable at any stage past dark green but will have a stronger acid flavor if you pick it before it is fully ripe. Meyer lemons don't ripen any further once picked, so if it's the milder taste you want, then it's best to leave the fruit on the tree as long as possible. That said, when citrus fruit freezes, it can become pithy and lose its juiciness. Protect your tree and the ripening fruit by covering it with a blanket, heavy tarp, or row cover on those nights when it's predicted to dip below freezing.

The best place to store the fruit is on the tree. Once you pick the fruit, it does not increase in sweetness or ripen more fully. However, if you do pick the fruit, it will keep for about 4 to 6 weeks under refrigeration. Juice from lemons can be frozen for up to 4 months.

For more information on growing citrus and frost protection, check out

The University of California book, The California Backyard Orchard, or on the web  https://homeorchard.ucanr.edu/Fruits_&_Nuts/Citrus/

https://sonomamg.ucanr.edu/Food_Gardening/FRUITS/Meyer_Lemon/

https://www.redding.com/story/life/2022/11/04/what-do-if-meyer-lemons-do-not-ripen-turn-yellow-master-gardener/10589465002/

(AKA Christmas Cactus, Thanksgiving Cactus, Easter Cactus, Crab Claw Cactus, or Schlumbergera)

Holiday Cacti et al are collectively known as Schlumbergera. Charles Lemaire, a French botanist, named the genus Schlumbergera in 1858, commemorating Frédéric Schlumberger, who had a collection of cacti at his chateau in France. There are three different species and over 200 cultivars. Schlumbergera truncata blooms earlier, usually in November, and is more accurately called the Thanksgiving or Crab Claw cactus. Schlumbergera x buckleyi (sometimes referred to as S. bridgesii) blooms later, often in December or January (hence “Christmas cactus”). Finally, there is Schlumbergera gaertneri (formerly classified as Hatiora gaertneri or Rhipsalidopsis gaertneri) which blooms in the spring, around Easter, and again later in the year. [1]

This showy, low maintenance plant is an indoor star around the holiday season. It blooms in a variety of reds, pinks, salmons, fuchsias, yellow, and pale beiges, I even saw a blue one recently being advertised on-line. They are natives of the coastal mountains of southeastern Brazil. Their native habitat is in high altitude (3,000 to 5,000 feet), moist rain forests where they are epiphytic, meaning they grow either on moss-covered tree branches or in rock crevices filled with decayed leaves and other vegetation, rather than in the ground. 

If you're fortunate to have a Holiday cactus but aren't sure what kind of species it is, you can distinguish them by their leaves. Thanksgiving cactus (S. truncate) stem segments have pointed teeth (dentate), often with two large teeth at the end of the segment resembling a crab claw. Christmas cactus (S. x buckleyi) leaves are smoother, scallop-edged segments with somewhat drooping branches. And, Easter cactus (S. gaertneri) have very rounded leaves with small golden bristles at the ends. 

Contrary to their “cactus” name, Schlumbergera need moisture and thrive in cooler temperatures making them an ideal house plant. They require humid moist conditions, a plus for most of our coastal residents. Schlumbergera can live outdoors in a shaded area and can be left outside as long as temperatures don't dip below 50 degrees. After that, it's best to bring them in.  

With proper care, these plants can live 50 years or more. Here are some pointers for growing them:

• They like to be root-bound and only require transplanting when the soil can no longer provide nutrients, about once every three years or so. 
• When repotting, the potting mix should be loose and fast draining; a good slightly acidic cactus soil mix would work well.
• They will produce new growth and leaves when they are exposed to indirect bright light and when temperatures are between 50-70 degrees (their preferred temperature range).
• They can be fertilized every two to four weeks during the growing season using a well-balanced formulation such as 10-10-5. Either liquid fertilizer or a granular slow-release formulation may be used. Be sure to follow directions on the label when applying.
• Holiday Cacti should be allowed to dry out partially though not completely between waterings. Water when the top one or two inches of soil are dry.
• Holiday Cacti are temperature and light sensitive.  To start their budding cycle, they require short days with 12-14 hours a day in total darkness (even ambient light should be avoided) and cool nighttime temperatures between 50-55 degrees. These conditions should be maintained starting about six to eight weeks ahead of their flowering period.
  

  Thanksgiving Cactus
• While in the budding cycle, water should be reduced.  Once buds start to set, regular watering can be resumed, the plant can be moved to a lighter location and temperatures can be increased to between 60-65 degrees. 
• Holiday Cacti usually remain in flower for four to six weeks and then will enter a rest period, followed by a new growth cycle. After they have bloomed, they can be pruned and shaped. 
• They are super easy to start and you can use the pruned sections to start new plants. Allow the cut ends to dry (callus) for a few days, and then insert them about 1 inch deep in moist, clean potting mix (5 cuttings in a 6-inch pot).  

I'm not sure when the tradition of giving a Holiday Cacti as a gift started but they are the gift that keeps on giving unlike wreaths and poinsettias. In 2009, a Bozeman Montana Daily Chronicle article documented a 145-year-old Christmas cactus that had been passed down through the generations. Martha Kent brought the cactus to Bozeman, most likely from Pennsylvania by wagon train when her family homesteaded in Cottonwood Canyon in 1863 or 1864.  Since then, the red-budded cactus, which blooms each year in time for the holidays, has stayed in the family. At the time of reporting, the plant had grown to be roughly 3 feet tall and 3 feet wide. Each family member has a start from the original plant.[1]  Perhaps it's time for you to start your own family tradition by giving a Holiday Cacti to your favorite plant lover. 

 

[1] P. Geisel and C. Unruh, Holiday Cacti, Publication 8114, UC Regents, 2004

[2] Amanda Ricker, Chronical Staff Writer, “145-Year-Old Christmas Cactus passed down through family” Dec. 9, 2009 

 

Resources:

P. Geisel and C. Unruh, Holiday Cacti, Publication 8114, UC Regents, 2004

Perry, Ed. “The Christmas Cactus,” The Stanislaus Sprout, Regents of the University of California, Division of Agriculture and Natural Resources, December 14, 2020

Butte County Master Gardener's Blog, “Cactus from the Rain Forest,” November 26, 2021

Image Credits:

Leaf Identification, photo by Beverly Kukuk, used with permission
Pink Holiday Cactus, photo by Beverly Kukuk, used with permission
Christmas Cactus Image by Sabine from Pixabay
Thanksgiving Cactus Image by TonioG from Pixabay
Easter Cactus Image by gwendoline63 from Pixabay

 

 

Do you wonder what seasonal gardening tasks should be done month-by-month?  Or what seasonal pests to be looking out for?  The Humboldt/Del Norte Master Gardener Help Desk Team is providing you with some tasks that will help you maintain and grow beautiful edibles and landscape plants. 

 

 

 

PLANNING AND GARDEN JOURNAL 

• Refer to your gardening journal for your list of fall tasks.
• Make note of how well your annuals performed.
• Add photos to help for next year.
• Order fruit trees for next year, many nurseries have online preordering.
• Time to start planning and preparing new gardening space for early spring planting.
• Start paperwhite narcissus indoors for a December bloom.
• Plant bare root deciduous trees, shrubs, and vines (e.g., caneberries, fruit and nuts, grapes, and roses). Plant California natives. Select species and cultivars well-adapted to your local site.

 LANDFILL DIVERSION

• Composting

o   What are Hot and Cold Methods? Link

o   Visit our website for more information. Link

o   Vermiculture – Worm Composting Link

• Grass cycling – See below under “Lawn” section
• Rake up leaves on lawns. Use fallen non-diseased leaves as mulch or add to compost bin as carbon material.
• Pull nonperforming annuals, chop up insect/disease free plants and add to compost pile.
• Right Plant Right Place – Select the plant for the mature size, climate conditions, sun requirements, and irrigation needs.

WATCH OUT FOR INVASIVES

• Invasive Weeds of Humboldt County 3^rd Edition Link
• Invasive Plant Checklist for California Landscaping Link
• Green Gardening Brochure Link
• CAL-IPC Humboldt Website Link
• Remove seed heads from invasives.

VEGETABLE GARDENS

• Planting times gleaned from The Humboldt Kitchen Gardener by Eddie Tanner

• Time to sow seeds for coastal areas in October:
• Lettuce, Spinach, Cilantro, Dill – Greenhouse or coldframe
• Radishes, Asian Greens, Arugula – March through late October
• Peas – Greenhouse or coldframe September through October
• Garlic – September through October
• Oats, Rye – September through October
• Time to sow seed for inland areas:
• Lettuce, Spinach, Cilantro, Dill – mid-August through mid-October,
• Lettuce, Spinach, Cilantro, Dill – from mid-October to late February Greenhouse or coldframe
• Radishes, Asian Greens, Arugula – late July through early October
• Peas – Greenhouse or coldframe mid-September through late October
• Garlic – mid-September through late October
• Wheat – September through mid-October
• Plant cover crops in vacant space in your vegetable garden. UC Davis Cover Crop Database
• Additional vegetable gardening information can be found on Humboldt/Del Norte Master Gardener website link

 

BERRIES AND MISCELLANEOUS FRUITS

 

FRUIT AND NUT TREES – Gleaned from UCANR The Home Orchard Publication

• Note: not all fruit/nut trees listed may be suitable to plant for your area. Make sure to select the tree and variety that will do best for your location.
• Apricots
• If not sufficient rainfall - Irrigate every one to three weeks to a depth of 18 to 24 inches.
• Cherry
• If not sufficient rainfall - Irrigate every one to three weeks to a depth of 18 to 24 inches.
• Fig
• If not sufficient rainfall - Irrigate every one to three weeks to a depth of 18 to 24 inches.
• Peach/Nectarine
• If not sufficient rainfall - Irrigate every one to three weeks to a depth of 18 to 24 inches.
• Pecan
• If not sufficient rainfall - Irrigate every one to three weeks to a depth of 18 to 24 inches.
• Persimmon
• If not sufficient rainfall - Irrigate every one to three weeks to a depth of 18 to 24 inches.
• Pistachio
• Remove mummies and fallen nuts
• Plums/Pluots/etc
• If not sufficient rainfall - Irrigate every one to three weeks to a depth of 18 to 24 inches.
• Pome Fruit – Apple/Pear/Quince
• If not sufficient rainfall - Irrigate every one to three weeks to a depth of 18 to 24 inches.
• Control codling moth. IMP Link
• Harvest season – times vary for climate and varieties
• Pomegranate
• If not sufficient rainfall - Irrigate every one to three weeks to a depth of 18 to 24 inches.
• Harvest season – times vary for climate and varieties
• Walnuts
• If not sufficient rainfall - Irrigate every one to three weeks to a depth of 18 to 24 inches.
• Harvest season – times vary for climate and varieties 

• Add to your gardening library – UCANR Publication The Home Orchard Link Use Promocode PRHUM12 for a 10% discount.
• Additional fruit and nut tree information can be found on Humboldt/Del Norte Master Gardener website Link 

INDOOR PLANTS

• Check for sufficient light, as there is less available window light. Plants with high light requirements may need to be moved to a different window or benefit under an auxiliary light. Use full spectrum lights for plants.
• For those houseplants that you have outside, it is time to bring them inside before your evening temperatures start dropping below 50 °F. Make sure to look them over closely as you do not want to bring in insects, slugs, and snails. Take the garden hose and give it a good rinse off. Remove damaged leaves.
• Plants start to slow growth and that is the time to start reducing the frequency of water. Water only when the soil is dry to the touch.
• Feed your plants one time this month. Do not feed succulents.
• Lower humidity due to heated homes. Group plants together. Misting does not help.  Caution when setting plants on top of tray filled with pebbles and water, as it can lead to waterlogged soil (make sure water is well below the pebbles).
• Additional indoor plant information can be found on Humboldt/Del Norte Master Gardener website link 

LANDSCAPE – ANNUALS, PERENNIALS, GRASSES, FERNS

• Plant early spring bulbs.
• Apply mulch to help retain heat and moisture.
• Divide overcrowded lilies.
• For seed saving, let the annuals go to seed, as well as for providing food for wildlife.
• For the colder areas, now until early October is the time to plant new perennials, grasses, and ferns. For USDA zones 7-9 plant September through mid-November.
• Herbaceous peonies – divide and plant September through October.
• Remove seedheads from invasive grasses.
• Weed flower beds.
• In highly visible areas groom while leaving less visible areas less groomed for nesting beneficial insects. In those lesser visible areas leave patches of bare soil for ground nesters.
• Deadhead perennials.
• As the heavy rains start, stop fertilizing. Use organic mulch to slowly add nutrients into the soil.  

LANDSCAPE SHRUBS AND TREES

Once you sense autumn weather it is time to plant woody plants. Planting in the fall allows for root growth before spring. UC IPM planting woody plants Link Plant bare root deciduous trees, shrubs and vines. 

• Shrubs
• Clear away fallen leave that are touching stems adjacent to the ground.
• Do not prune during the fall season.
• Do not fertilize this month.
• Irrigate only if rain is not sufficient. 

• Trees
• Assess tree health. If you see any problems contact the Master Gardener Help Desk.
• Irrigate only if rain is not sufficient.
• Do not fertilize this month.
• Roses
• Clean up fallen leaves. Do not add diseased leaves to compost.
• Remove leaves that have not dropped to clear away diseased leaves and to help the plant into dormancy.
• Time to transplant and plant new plants.
• Stop deadheading to promote dormancy.
• For new plants or transplanted roses irrigate if rain is not sufficient.

LAWNS

• Good time to aerate which helps with air and water to move easier. Aerating helps to create stronger grass roots. Water a few times before aerating. Aerating Link
• Mow as needed. Consider grasscycling. Mowing Your Lawn and Grasscycling Publication 8006 Link
• Rake leaves on lawn. Use non diseased leaves as mulch or add to compost bin.
• Check and repair sprinklers as needed.
• Newly installed lawn may need watering if not sufficient rain. Established lawns normally don't need irrigation.
• If you haven't been watering regularly, give at least one deep watering this month.
• Fertilize - Check schedule for types of grass.  Link to UC IPM When to Fertilize
• The Guide to Healthy Lawns UC IPM Link 

LANDSCAPE IRRIGATION

• Adjust watering schedules according to the weather and plants' changing need for water. Check systems for leaks and broken emitters and perform maintenance as needed. Consider upgrading the irrigation system to improve its water efficiency.
• Towards the end of the growing season, some plants may benefit by reducing the frequency of irrigation to help plants harden off to prepare for fall and winter. 

IPM – Integrative Pest Management

• Abiotic Disorders – Prevent or manage damage caused by aeration deficit, herbicide, salinity, soil pH, sunburn, wind and too much or little water.

• Ants - Manage around landscape and building foundations, such as using insecticide baits and trunk barriers. UC IPM Link
• Aphids - On small plants, spray a strong stream of water or apply insecticidal oils and soaps. Look for and conserve natural enemies such as predaceous bugs, lacewings, lady beetles, and syrphids. UC IPM Link
• Bacterial blasts, blight, and canker – Inspect apple, citrus and especially Prunus spp (e.g., stone fruit). Remove entire affected branches in the summer. UC IPM Link
• Black sooty mold – Black and oily leaves indicate an infestation of scale or aphids. UC IPM Link
• Citrus - Monitor for damage and pests such as leaf miner. UC IPM Link
• Carpenter Bees – Paint or varnish and seal wood in which they nest. UC IPM Link
• Carpenterworm – Project trees from injury and provide proper cultural care, especially appropriate irrigation. UC IPM Link
• Clean up mummies and old fruit and nuts in and under trees to avoid harboring pests. UC IPM Link
• Codling moth of apple and pear - Bag fruit. Promptly remove infested and dropped fruit. Apply insecticides only if precisely timed. UC IPM Link
• Coast redwood dieback – Check for drought-stress related maladies such as abiotic disorders, bark beetles, fungal diseases, and spider mites. UC IPM Link
• Compost - Turn and keep it moist. UC IPM Link  
• Crane flies – common in Humboldt causing damage to lawns. UC IPM Link
• Frost – Protect sensitive plants from cold injury when freezing or frost are predicted. UC IPM Link
• Fungus gnats - Generally from overwatering house plants.  UC IPM Link
• Mulch – Apply organic mulch where thin or soil is bare beneath trees and shrubs. UC IPM Link
• Pine bark beetles, pitch moths, western gall rust, and wood borers – If pines need branch removal, prune during October through January UC IPM Link
• Powdery mildew – distinguished by gray cover of powdery mildew can be seen on some plants as evenings become cooler and overapplication of nitrogen fertilizer. UC IPM Link
• Rainfall – Prevent water ponding around trunks and foundations. Improve drainage. Install downspout diverters to direct runoff into landscape soils but avoid waterlogging soil. UC IPM Link
• Root rot - Favored by excessive water and poor drainage. Avoid overirrigation and waterlogged soil. UC IPM Link
• Slugs – August through September is their prime egg producing time. They are light tan round eggs and can be found under a log or mulch. Good idea to remove and toss them away from your garden to be dinner for spiders and black ground beetles. Or just smash those little beasts. UC IPM Pest Link
• Wasps and yellow jackets are both a friend and foe. They can be vicious while being a beneficial insect predator. They are most active during the warmest part of the day. UC IPM Pest Link

• Weeds – Manage weeds using nonchemical methods such as cultivation, handweeding or mowing.  UC IPM Link

EXCELLENT ADDITIONAL RESOURCES

*Get a 10% discount for UCANR books purchased online at UCANR's Book Store. Use promocode PRHUM12.

• Humboldt/Del Norte Master Gardener Website Link
• Humboldt/Del Norte Master Gardener Help Desk Link
• University of California Agriculture and Natural Resources Integrative Pest Management Link
• * University of California Agriculture and Natural Resources Publication - The Home Orchard Link
• * University of California Agriculture and Natural Resources Publication – Pests of the Garden and Small Farm Link
• * University of California Agriculture and Natural Resources Publication – Abiotic Disorders of Landscape Plants Link
• * University of California Agriculture and Natural Resources Publication – Pests of Trees and Shrubs Link
• * University of California Agriculture and Natural Resources Publication – Master Gardener Handbook Link
• * University of California Agriculture and Natural Resources Publication – Healthy Roses Link
• Month-By-Month Gardening Pacific Northwest, by Christina Pfeiffer with Mary Robson, ISBN-10‏:‎ 1591866669 

• The Humboldt Kitchen Gardener, by Eddie Tanner, ISBN: 978-0-615-20900-5 (Out of print, look for used copies)
• Insects of the Pacific Northwest, by Peter and Judy Haggard, ISBN 10: 0881926892 (Out of print, look for used copies)
• Pacific Northwest Insects by Merrill A. Peterson ISBN-10:0914516183

 

 Image by Melk Hagelslad from Pixabay