Sacramento fall leaf season looks spectacular; enjoy it while you can
Gingko trees add vibrant splashes of yellow-gold leaves to the Sacramento area's show of fall color. Other street trees add red, orange and crimson.
Kathy Morrison
Following sunny and warm days, recent overnight lows in the 40s (and longer nights) have brought out rich rainbow hues of yellow, orange and red. Those pigments are revealed when more darkness and chilly temperatures “turn off” the green chlorophyll in leaves, and the other colors can shine through. With fewer hours of daylight, foliage stops producing chlorophyll and the green pigment disappears.
According to the U.S. Forest Service, the major influencer on autumn color is that growing darkness.
“As days grow shorter, and nights grow longer and cooler, biochemical processes in the leaf begin to paint the landscape with Nature’s autumn palette,” says the forest service, an expert on colorful fall foliage.
Carotenoids (as in carrots) give leaves yellow, orange and brown hues. Anthocyanin, which is stimulated by bright fall light and excess sugars in leaves, is responsible for the reds as well as any bluish or purple tones.
“During the growing season, chlorophyll is continually being produced and broken down and leaves appear green,” the forest service explains. “As night length increases in the autumn, chlorophyll production slows down and then stops and eventually all the chlorophyll is destroyed. The carotenoids and anthocyanin that are present in the leaf are then unmasked and show their colors.”
Some trees are particularly known for their fall display. Maples, for example, reveal their variety by their autumn foliage. Red maples live up to their name with scarlet leaves. Sugar maples become bright orange-red. Black maples turn glowing yellow.
Oaks tend to turn red or russet but some species – such as black oaks – go gold. (And live oaks stay evergreen.) Oaks also tend to hold onto their colorful leaves long after other species have dropped their foliage.
With mature urban forest, Sacramento’s older neighborhoods boast the best color. Look for the gingkos, Chinese pistaches, scarlet maples and liquidambar trees in Land Park, Midtown and East Sacramento. Carmichael, Fair Oaks and Greenhaven also have many brilliant maples, crape myrtles, flowering pears and other autumn stars.
Recent weather boosted Sacramento’s color show.
“A succession of warm, sunny days and cool, crisp but not freezing nights seems to bring about the most spectacular color displays,” says the forest service. “During these days, lots of sugars are produced in the leaf but the cool nights and the gradual closing of veins going into the leaf prevent these sugars from moving out. These conditions – lots of sugar and light – spur production of the brilliant anthocyanin pigments, which tint reds, purples, and crimson. Because carotenoids are always present in leaves, the yellow and gold colors remain fairly constant from year to year.”
Enjoy that color show while you can. By the end of next week, those pretty leaves may be only a memory (or mulch).
According to the National Weather Service, a storm front is expected to hit Sacramento on Tuesday. The combination of wind and rain (possibly an inch) will likely knock down most of that foliage. Our attention will turn from admiring all those leaves to raking them up instead.
So snap your leaf photos now. As the forest service says, “The countless combinations of ... highly variable factors assure that no two autumns can be exactly alike.”
Comments
0 comments have been posted.Sacramento Digs Gardening to your inbox.
Sites We Like
Dig In: Garden Checklist
For week of Nov. 26:
Concentrate on helping your garden stay comfortable during these frosty nights – and clean up all those leaves!
* Irrigate frost-tender plants such as citrus in the late afternoon. That extra soil moisture increases temperatures around the plant a few degrees, just enough to prevent frost damage. The exception are succulents; too much water before frost can cause them to freeze.
* Cover sensitive plants before the sun goes down. Use cloth sheets or frost cloths, not plastic sheeting, to hold in warmth. Make sure to remove covers in the morning.
* Use fall leaves as mulch around shrubs and vegetables. Mulch acts as a blanket and keeps roots warmer.
* Stop dead-heading; let rose hips form on bushes to prompt dormancy.
* Prune non-flowering trees and shrubs.
* Clean and sharpen garden tools before storing for the winter.
* Brighten the holidays with winter bloomers such as poinsettias, amaryllis, calendulas, Iceland poppies, pansies and primroses.
* Keep poinsettias in a sunny, warm location – and definitely indoors overnight. Water thoroughly. After the holidays, feed your plants monthly so they’ll bloom again next December.
* Rake and remove dead leaves and stems from dormant perennials.
* Plant spring bulbs. Don’t forget the tulips chilling in the refrigerator. Daffodils can be planted without pre-chilling.
* This is also a good time to seed wildflowers and plant such spring bloomers as sweet peas, sweet alyssum and bachelor buttons.
* Plant trees and shrubs. They’ll benefit from fall and winter rains while establishing their roots.
* Set out cool-weather annuals such as pansies and snapdragons.
* Lettuce, cabbage and broccoli also can be planted now.
* Plant garlic and onions.
* Bare-root season begins now. Plant bare-root berries, kiwifruit, grapes, artichokes, horseradish and rhubarb.