Fall Color in Your Backyard

Quaking aspen

Soon I?ll be hiking in the Sierra among the native dogwood and hoping I?m not too late to see fall foliage. Last year I enjoyed the display of Quaking Aspen near Ebbetts Pass on Highway 4. Did you know that a massive grove of 47,000 aspen in Utah is one of the largest organisms on the planet? They all share the same genetic material and a single root system. There is a contender for this renown in Oregon where a honey mushroom measuring 2.4 miles across lives in the Blue Mountains. Interesting stuff.

Bloodgood Japanese Maple

Around here I?m just starting to see some trees and shrubs put on their coat of many colors. In my own yard, I have a Bloodgood Japanese maple that has been in full color for a couple weeks now. None of my other maple varieties are showing any color but that?s okay as I?ll be able to enjoy the upcoming show for many months. That is, if strong winds don?t dry out the leaves prematurely. I?ve watered well hoping this won?t happen. 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.

Crape Myrtle

The vivid colors in a leaf are always there. They are just masked by the green chlorophyll which is busy making food by photosynthesis while the sun shines. Come autumn, shorter days and cooler temperatures cause the trees to switch into energy-storage mode and their leaves stop producing chlorophyll. For the few weeks before the leaf falls to the ground it is colored only by natural pigments. It’s these colors – red and purple anthocyanins, yellow and orange carotenoids – that make fall foliage so glorious, sometimes anyway.

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

Forest Pansy redbud

California native, Cercis occidentalis (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 Easterm redbud, Chinese flame tree (Koelreuteria bipinnate), ginkgo, Idaho locust, Chinese pistache, crape myrtle, witch hazel, all maples, liquidambar, katsura, dogwood, locust, cherry, crabapple, oakleaf hydrangea, barberry and smoke tree.

Now through late fall is a good time to shop for trees that change colors because you can see in person just what shade of crimson, orange, scarlet or gold they will be.

Fall Bulbs

Tulips welcoming spring

Last year I dropped the ball. Thinking that the daffodils in pots from last year would bloom enough in the spring to satisfy my spring fever I didn?t get any new ones. Well, I was wrong and I?m not making that mistake again. Although it?s a little early to plant bulbs in our area, I have several bags of daffodils and tulips ready and waiting for the ground to cool.The selection of bulbs is always best early in the fall.

My garden is shady all winter and most of spring so my growing conditions aren?t the best. That?s why it?s worth it to me to get some new bulbs each year. Sure, there are a smattering of daffodils that have naturalized on my hillside but it?s a meager display and when spring fever hits, well, you know how hopeful and eager we all are.

Deer resistant daffodils

A word to the wise, squirrels, mice and moles are observant and crafty. Once they discover newly planted bulbs, they’ll assume it’s food. Just disturbing the earth is a tip off for them. Daffodils and narcissus bulbs are toxic but if they dig them up then leave them exposed with just a nibble taken, so much for any spring flower display. Protect your bulbs with wire baskets or spray them with foul tasting repellent, letting the spray dry before planting. You can also bury the bulbs with ground up egg shells. Another way to foil squirrels is to plant the bulbs deeply, This only works if you have good drainage, however. Next year, if the squirrels start nibbling the foliage as it emerges try spraying it with hot pepper spray.

Valthemia bloom for a very long time.

One of the more unusual bulbs I grow in pots is Forest Lily (valthemia bracteata). I got several bulbs over 25 years ago and each fall as the bulb re-emerges I look forward to it?s months-long blooming season. The handsome foliage lis thick and wavy, looking somewhat like a succulent but it?s the huge, showy dark pink flower spikes that bloom from February to May that I love. I grow them light shade and allow them to go summer dormant. Valthemia are native to the northern Cape area in South Africa where it grows on rocky slopes along the famous Namaqualand Flower Route.

Another bulb I’ve wanted to grow for a long time is Ixia viridiflora and now I have the chance. A friend divided hers and gave me a handful of bulbs a couple months ago. They need to be completely dry in summer so planting in pots will be perfect for this most striking and unusual bulb. Few plants can beat it for sheer brilliance of flower. Each flower is a brilliant turquoise green with a purple-black eye in the middle. The dark eye is caused by the deep blue sap of the cells of the upper epidermis. The green color is due to the effects of light being refracted from the cell wall and granules embedded in the pale blue cell sap. Amazing flower. I??m looking forward to photographing my own next year.

What about bulbs in the shade? Bulbs that will bloom in light shade are crocus, scilla, tulips, grape hyacinth, leucojum, snowdrops, chionodoxa and lily of the valley. Many from the daffodil clan, including jonquils and narcissus will grow, bloom and naturalize year after year under tree canopies or other lightly shaded areas.

Parrot tulip

Whatever you bulbs you choose to try this fall, you will be happy you planted some bulbs come spring. And to help them bloom again the following year fertilize them at the time of planting with bulb food or bone meal worked into the soil a couple inches at the bottom of the hole. Mature bulbs respond to an early spring feeding with the same fertilizer.

Why Plant Cover Crops?

Cover crop mix

Every drop of rain that hits bare soil is destructive. Over 3000 years ago the Chinese increased their soil’s fertility and protected it from erosion 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.

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 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.

Orin Martin shows the extensive root system of bell 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 innoculants 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.

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