Quaking Aspen, Fall Color & Climate Change

Inspired by a website called “Dude, Autumn Happens Here, Too” (https://www.californiafallcolor.com/ ) I set off last week to see the quaking aspen groves in the Sierra. As I drove up Highway 4 and over Ebbetts Pass the aspen groves came into view. Markleeville and Monitor Pass displayed some nice color, too. As I enjoyed the fall display I wondered if they would be as beautiful for future generations or if our impact on the environment would cause these glorious trees to change in any way.

Quaking Aspen on Ebbetts Pass, Hwy 4

Quaking aspen (Populua tremuloides) is the most widespread tree species in North America. They generally grow in high altitude areas but also exist at sea level in places like the state of Washington along the Pacific coast where climate conditions are ideal. Quaking aspen provide food for foraging animals and habitat for wildlife. They also act as a fuel break retaining much more water in the environment than do most conifer species.

High mountain systems, such as the Sierra Nevada, are uniquely sensitive to anticipated global climate changes and act as “canaries in the coal mine” to provide early signals of significant climate-driven changes. Research in the Sierra Nevada by Pacific Southwest Research Station, a USDA Forest Service research organization, shows how vegetation has responded to climate in the past and indicates changes than might be coming in the future over the next decade.

Climate has a profound influence in shaping our environment and natural resources. By looking at tree ring records of living and ancient wood and pollen lake sediments present climate can be compared to historic patterns to show climate changes.

Research indicates a complex, unpredictable future for aspen in the West, where increased drought, ozone and insect outbreaks will compete with carbon dioxide fertilization and warmer soils with unknown cumulative effects. They are vulnerable in the face of climate change. Hopefully, we will not lose this wonderful tree in California.

Weather conditions play a major part in the intensity of fall color. The time of year is nearly consistent but some years the show is more dramatic than others. The best conditions for intense leaf color to develop are dry sunny days followed by cool, but not freezing nights.

Which plants put on the best show in our area? Here are some of my favorites.

California native Western redbud turns yellow or red in the fall if conditions allow. This plant is truly a four-season plant starting in spring with magenta flowers, then leafing out with apple green heart shaped leaves. Colorful seed pods give way to fall color. This small native tree or large shrub does well as a patio tree in gardens with good drainage.

Other native plants like spicebush and Western azalea turn yellow or gold in the fall. A native vine that lights up with the onset of autumn is Rogers Red California grape. If you have an arbor, wall or fence that needs covering quickly this is your plant. The green and gray leaves are transformed in autumn into great draperies of rich, scarlet leaves with clusters of summer fruit turning all shades of purple.

Edibles that turn color in the fall include blueberries, pomegranate and persimmons.

Trees and shrubs that do well in our area and provide fall color include Chinese flame tree, ginkgo, Idaho locust, Chinese pistache, crape myrtle, witch hazel, all maples, liquidambar, katsura, dogwood, locust, cherry, crabapple, oakleaf hydrangea, barberry and smoke tree.

Planting Cover Crops to Enrich Your Soil

Every drop of rain that hits bare soil is destructive. Over 3000 years ago the Chinese knew how to protect their soil from erosion and increase fertility by planting cover crops. Early Nile Valley inhabitants also practiced this method of agriculture as did first century Romans. Lupines were planted in poor soil when no animal manure was to be had. Planting a cover crop is another way to improve and retain your soil.

UCSC Farm & Garden cover crops

A cover crop is really anything that covers the soil and protects it from rain, trapping nutrients and preventing them from leaching downward. Cover crops can increase the tilth of the soil. Quick germinating grasses easily loosen the top foot of soil with their root mass. Legumes have a tap root, a bio drill, that penetrates 30″ downward while alfalfa roots can grow even deeper.

Cover crops like bell beans, vetch and fava beans are especially valuable as they increase nitrogen levels in the soil in two ways. Atmospheric nitrogen can be “fixed” and left in the soil to fertilize subsequent crops. This is in addition to the nitrogen left from the foliage of the legume. Growing a cover crop also increases beneficial soil bacteria.

Cover crops are also called green manure when they are chopped up and turned into the soil in spring before going to seed. The planting of legumes like peas and beans can actually increase nutrients in your soil giving you a net gain which is needed to offset what you take out of the soil when you harvest fruits, vegetables and flowers.

Late September to the end of November is the best time to sow cover crops. You will need to irrigate lightly a couple times per week if it doesn’t rain. You can also wait to sow just before the rains start. Be careful about working overly wet soil, however, as you can ruin the structure of your soil.

fava beans

Recent research now recommends planting a mixture of grasses and legumes. Annual cereal grasses such as oats, rye and barley germinated quickly to hold and shield the soil until the legumes take hold. Bell beans, fava beans and vetch, which are the best legumes for our area, grow slowly the first 3 months then take off growing 70-80% in the last 3 months. The ratio of grass seed to legumes can vary from 10% to 30%.

There are other legumes that fix nitrogen but nowhere near as efficiently as bell beans. Crimson clover seed is more expensive, needs lots of water to sprout and competes poorly with weeds. Mustard causes competition with the fruit trees as bees will concentrate on the mustard flowers instead of the fruit tree flowers.

You don’t need to use inoculates on legume seed. Our soils have a native resident population of good bacteria that will break down the seed coat and encourage the plant roots to fix more nitrogen especially after cover cropping for a few years.

Work the soil lightly with a metal bow rake then broadcast 8-10 seeds per square foot. Weeds should be already cleared but this step doesn’t have to be perfect. Afterward the area should be raked again lightly 1-2 inches down and covered with 3-4 inches of straw. Wood chips would be fine, too. Mulch heavier if you have bird competition. Cover crops are vigorous and will come up through just about anything. Water in lightly.

 

At Home with The Mountain Gardener

When I think about my home and garden what often comes to mind is sharing. “Wouldn’t so-and-so love this plant or flower or meal, too?” Besides my adult friends I get to borrow some children occasionally to share my little piece of paradise up here in Bonny Doon. This is the story of my day at home and in the garden with 3 1/2 year old Scarlett Biles.

Scarlett Biles, The Mountain Gardener & Sherman

I called our outing “Camp Sherman’ in honor of my springer spaniel who is ever at our side. All of us, including Sherman, donned colored neckerchiefs ‘cause everyone at day camp wears one and you can sit on it in a pinch. First order of the day was to start a little photo album to remember it all so Scarlett helped me print out a picture her mother Kelly had taken of us back at her house. It’s amazing what kids these days can do with very little instruction. She’s a computer whiz.

Scarlett clowning with the hot dogs buns

Although our lunch menu was not exactly a gourmet meal to remember we had a good time making PB&J on hot dog buns to take with us for our hike. After finding a flat spot at the side of a trail that is almost in my backyard, we set up our “camp”. Sherman found a stick to chew while we looked at the butterfly, wildflower, tree and bird guides I had in my day pack. Kids love to identify what they see in nature. Scarlett found the picture of the tan oak leaf right away. We listened quietly to the birds in the forest and found them on an app on my phone. I was busy drawing when I saw that Scarlett had figured out how to play a bird call on my phone after seeing me go through the steps once. It’s so true. If you’re ever stumped on your computer ask a kid to figure it out.

Scarlett at the computer

Back at the homestead, Scarlett helped print out more pictures we took on the hike for her photo album. I added a couple of pics that I already had when the Acorn woodpeckers showed up at the feeder as well as the chipmunks. Naturally, it was time to eat again and watermelon and root beer seemed to go together. We were both sad when it was time to take her home but big sister Adelyn showed me their new tree-fort-in-progress when we got there. Suffice it to say a good time was had by all.

So, the moral of this story is that having a garden is not all about the pruning, planning and transplanting. And a gourmet meal shared with friends can be as simple as a PB&J. It’s the little things in life that count the most. Although I have plans to prune the hydrangeas hard this winter and maybe not let so many of the impatiens balfourii self sow next year it’s all part of enjoying our homes and gardens and not worrying about the little stuff unless the little stuff is 3 1/2 years old.

Fall Tasks in the Garden

Some people wait all year for fall weather to arrive. The heat of summer is over and the tourists are gone along with that pesky fog along the coast. For us up here in the Santa Cruz mountains, this is one of the best times to be outside. Here are tips for early fall in the garden.

Late fall is not a good time for major pruning so if you have some shrubs that need a tune-up do it soon.  Wounds heal slowly later in the fall, leaving them more susceptible to disease. As a general rule, don’t prune when leaves are falling or forming. Wait to prune most trees until late in the dormant season or in late spring after leaves and needles form. To avoid sap flow on birches and maples, prune after leaves mature. Fruit tree summer pruning should have already been done when growth ceased.

Refresh perennials, such as butterfly bush, salvia and yarrow by cutting a third to half of their growth later in the fall.

Rake leaves- compost or put in your green can. If large leaves are left in place they will mat down and set up fungal problems come spring.

Remove dead and diseased leaves from under camellias, rhododendrons and roses.

 

Bearded iris

Now through October, divide summer blooming perennials that are overgrown and not flowering well. Alstroemeria, agapanthus, coreopsis, iris, daylily, yarrow, rudbeckia, calla lily, aster and penstemon fall into this category. You can also divide spring blooming perennials like candytuft, columbine, astilbe, bergenia and bleeding heart although they don’t always bloom the first spring afterwards due to the energy they use re-establishing themselves. If you’re on a roll out in the garden, though, go for it now. You never know what other projects you may be working on next spring.

Start perennial flowers seeds now so that they will be mature enough to bloom next year.

Fertilize shrubs lightly one last time with an all-purpose organic fertilizer or layer of compost. Use compost only on California natives.

broccoli with sweet alyssum

Plant cool season veggie starts like broccoli, cabbage, cauliflower, chard, lettuce, spinach, brussels sprouts, onions and leeks in soil enriched with 4-6″ of compost as summer vegetable crops will have used up much of your soil’s nutrients.You can sow seeds of beets, carrots, radishes, spinach, arugula, mustard and peas directly in the ground. Planting early ensures your plants get a good start before cold weather sets in and growth mostly stops until spring. You’ll be able to start harvesting in just a couple months if you start now that the weather has started to cool.

If you aren’t going to grow vegetables in the garden this fall consider planting a cover crop like bell beans, fava beans and vetch after you’ve harvested your summer vegetables. Next month I’ll talk about how to go about doing this and how this benefits your soil.

Cut back berry vines that have produced fruit. Canes of the current season should be trained in their place.

Spider mites and thrips are especially prolific during the late summer. If some of the leaves on your plants are pale with stippling, spray the undersides of infected leaves with organics like insecticidal soap switching off with neem oil as they build up a resistance to one of the pesticides. Plan to spray with a horticultural oil in the winter to kill overwintering eggs.

Autumnal Equinox in the Garden

The autumnal equinox happens on Saturday, September 22nd this year. It’s the official start of fall when the sun crosses the celestial equator and moves southward. The earth’s axis of rotation is perpendicular to the line connecting the centers of the earth and the sun on this day. Many people believe that the earth experiences 12 hours each of day and night on the equinox. However, this is not exactly the case.

During the equinox, the length is nearly equal but not entirely because the day is slightly longer in places that are further away from the equator ( like where we live ). Also the sun takes longer to rise and set in these locations as it does not set straight down but in a horizontal direction.

ceanothus ‘Heart’s Desire’

With the changing of the season, take advantage of fall planting weather by looking at what’s covering your ground. Be it the small lawn for the kids to play on, ground cover to keep the weeds at bay or erosion control to keep the hillside intact, this is an excellent time to plan for winter.

Let’s start with the lawn. If you still need a space for recreation, this is a good time to reseed those bare spots. Also to keep the lawn healthy by removing underlying thatch with a thatching rake. Then aerate the lawn by poking holes in the sod and fertilize with a complete lawn fertilizer like an organic all-purpose. Your lawn needs the phosphorus in the fall to encourage deep, strong roots for the winter.

If the kids are grown and no one is using that lawn, why not rip out the water guzzling grass and replace it with a walk-on groundcover? There are many to choose from like dymondia, lippia, potentilla, duchesnea strawberry or any of the kinds of thyme.

Living ground covers add beauty to the garden while holding the soil in place and preventing erosion. They contribute to soil health by encouraging microorganisms. A garden wouldn’t thrive as well without groundcovers.

One of my favorites is Elfin thyme. It doesn’t need mowing, edging or fertilizing or much irrigation. You can walk on it and it stays green all winter, shading into bronze tones when the weather cools. It even blooms in midsummer for several weeks. Note that bees are attracted to it as with all of the ground covers in the thyme family at this time.

kurapia

Another favorite that I have in my own garden is kurapia. It’s deep rooted, doesn’t require much water, is compact and low maintenance. It’s been bred to have sterile seeds. This is a good groundcover if pollination of nearby fruit trees is needed or you want to encourage bees to your garden for pollination. If bees are an issue kurapia can be mowed to cut off the blooms.

There are also Ca. native and prairie meadow grasses that you can walk on. They need little irrigation and even less mowing. Some can be planted from seed, others from plugs or sod. Good choices include Idaho, California and red fescue, carex pansa, June grass and Hall’s bentgrass.

grevillea lanigera ‘Mt Tamboritha’

If you don’t need to walk on your groundcover, low-growing native shrubs that are good groundcovers are baccharis, ceanothus maritimus, ‘Anchor Bay or ‘Heart’s Desire’, manzanita, creeping snowberry, creeping mahonia, salvia ‘Bee’s Bliss’ and ribes viburnifolium. Mediterranean ground covers like cistus salviifolius, grevillea lanigera, rosemany prostratus, rubus pentalabous are also good low-water choices.

It’s time to enjoy fall weather and cover that ground before winter.

All About Mums

Can it be? Already I’m seeing my dogwood and crape myrtle showing signs of fall color. Pictures on Instagram and Facebook from other gardeners show early color on sumac and lilac. I know fall is in the air when the pink amaryllis belladonna bloom and I’m ready.

Garden mums

Mums are in their prime as early as September. We tend to think of chrysanthemums at Thanksgiving as temporary filler plants for fall containers and borders but mums are perennials and can play a bigger role in your garden if you let them. Established mums can tolerate quite a bit of neglect and still keep blooming every year.

Chrysanthemums were first cultivated in China as far back as the 15th century. Over 500 cultivars had been recored by the year 1630. In Japan records go back all the way back to the 8th century relating to mums.

The botanical name for the garden chrysanthemum has been changed to dendranthemum grandiflorum but I never hear anyone use this name. It doesn’t exactly roll off the tongue.

Yellow or white chrysanthemum flowers of the species. C. morifolium are boiled to make tea in some parts of Asia. In Korea, a rice wine is flavored with chrysanthemum flowers. Chrysanthemum leaves are steamed or boiled and used as greens in Chinese cuisine.

Another variety of chrysanthemum- cinerariaefolium- is important as a natural source of insecticide. The pyrethrins extracted attack the nervous system of all insects. Harmful to fish it should be used with caution but it’s not persistent in the environment and is biodegradable.

Grown for years to flower only in late summer and fall, they are short day plants, setting buds when they receive light for 10 hours and darkness for the other 14 hours of the day. This is why mums bloom in the spring on leggy stems if they are not cut back. And this is how growers manipulate their blooming, adjusting the dark and light periods with shades in the greenhouse so buds will form in any month. They’re nearly constantly available in grocery stores and florists in every season.

At this time of year when garden mums abound pick a plant with lots of buds. They bloom only once and won’t set more flowers until next year. Those buds, though, last a long time if you don’t let them dry out. Although mums are somewhat drought tolerant once established you should water deeply once or twice a week depending on the weather.

The specific type of plant doesn’t matter since they all have long term growth potential. If you particularly like one color or form of chrysanthemum, plant it now to enjoy again next year. You never know what the growers might decide to grow next season.

Choose a well-drained, sunny spot to plant them. Like many members of the aster family, mums won’t tolerate soggy ground. After blooming, trim off the old flowers and cut back plants to within a 4 or 5 inches of the ground. If you started with 4 inch pots, trim back by half.

Next spring pinch them back when they are 8 inches tall. Keep pinching until July, then allow plants to start forming buds for the traditional fall show.

A word of caution: all parts of chrysanthemum plants are potentially toxic to dogs, cats, humans and other mammals and a skin irritant for some people.

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