Posts Tagged: fall
Plant a Tree Now for Fall Color Next Year!
The colors of autumn are especially beautiful this year. Tree leaves are turning brilliant shades...
Monarchs on the Move...So Many Mysteries
Monarchs on the move...so many mysteries. Where do Western monarchs go after leaving their...
A tiny monarch egg. Image taken on Nov. 14, 2023 in a Vacaville garden. (Photo by Kathy Keatley Garvey)
A monarch caterpillar sharing a milkweed leaf with aphids. This image was taken Nov. 15, 2023 in a Vacaville garden. (Photo by Kathy Keatley Garvey)
Two monarch caterpillars sharing a milkweed leaf. This image was taken Nov. 15, 2023 in a Vacaville garden. (Photo by Kathy Keatley Garvey)
A very hungry monarch caterpillar on the move. This image was taken Nov. 18, 2023 in a Vacaville garden. (Photo by Kathy Keatley Garvey)
Hi, there! A monarch caterpillar faces the camera. This image was taken Nov. 14, 2023 in a Vacaville garden. (Photo by Kathy Keatley Garvey)
Fall Colors Explained
Welcome to Fall!
It's my favorite season and likely for many of you, as well. Beyond the holidays and extra time with family and friends, nature radiates its beautiful hues. In addition to lovely foliage, deciduous trees often expose exquisitely shaped and sturdy trunks. And, of course, there is the lovely fall foliage showcased by many species.
Did you ever wonder why trees "turn" color in the fall? The short answer: It's primarily a function of long, cool fall nights and short, sunny days. The longer answer? Chlorophyll is responsible for the basic green color of leaves we see in spring and summer and is a necessary component of photosynthesis, which uses sunlight to manufacture sugar (food) that is stored during the dormant period of the year. Carotenoids produce yellow, orange and even brown pigments in crops such as carrots, squash, bananas and many ornamental plants such as daffodils and poppies. Anthocyanins are red and orange in color and are most linked to lavish displays of brilliant fall foliage. They also give rise to coloring of strawberries, plums and cherries.
Here's the kicker: While chlorophyll and carotenoids are present in leaf cell chloroplasts throughout the entire growing season, during fall chlorophyll begins to break down. Voila! The lovely yellow and orange hues we all look forward to seeing are finally exposed. In addition, red hues (called anthocyanins) are produced in fall. So, in reality foliage doesn't "turn" orange or red at all.
Interestingly, the actual timing of color change varies across species and appears to be genetically inherited. The same species will exhibit a similar color scheme in cool temperatures in higher elevations at nearly the same time as it does in warmer lower elevation climates.
The intensity of color can vary quite a bit however. Where do temperatures enter the picture? Both the amount of color and the overall intensity of fall color is very linked to weather conditions that occur prior to and during the actual time the chlorophyll in leaves winds down. The most brilliant displays occur after several warm, sunny days and cool, crisp (above freezing) nights. This is because although lots of sugars are made in leaves during sunny daytime hours, the corresponding cool nights prevent the sugars from moving out. The amount of soil moisture also helps ensure that from year to year fall colors vary even in the same trees. So, either a late spring or a prolonged drought can both delay the display of fall color by a few days or even a few weeks.
What's the recipe for the most brilliant fall display? Most likely a warm, moist spring followed by a warm summer and sunny fall with cool autumn nights. Although fall color is not nearly as spectacular in lower elevations of Southern California compared to other colder areas of the nation, the liquidambar or American sweet gum (Liquidambar styraciflua) offers some pretty impressive fall color and an impressive 300 to 400-year life span. (Did you know that liquidambar got its name because it at one time was a sought-after chewing gum for Native Americans?)
Two “climate-ready” tree species with lovely fall foliage that grow in both the west portion of the county and the desert are the ‘Keith Davey' Pistache, a large street and park tree sporting crimson to scarlet colored foliage and its relative, the ‘Red Push' Pistache, a hybrid between P. atlántica x P. integerrima) which has lovely red foliage as it emerges in Spring as well as Fall. Others include the Raywood Ash (Fraxinus oxycarpa 'Raywood') sporting a reddish-purple hue in the fall, and the ‘Sunburst' Locust (Gleditsia triacanthos var. inermis 'Sunburst') which offers a vivid display of fall color. Unfortunately, it is susceptible to the Invasive Shot-Hole Borer. If you have one of these lovely trees already, take good care of it to help it stand up to this aggressive pest!
Happy Fall! Enjoy the cooler weather, family and friends, and lovely trees!
Raywood Ash source national gardening association
Where do butterflies go in the winter?
As the long, hot days of summer slide into cooler, shorter days of autumn, seasonal changes are...
Fall is Planting Time
The Mediterranean climate of Contra Costa County has us spoiled for choices in growing handsome perennials and shrubs, including many native plants that attract local beneficial insects and nourish our ecosystems. Whether you are planning a new garden or adding to an existing one, references abound to help you select and plant perennials successfully.
September through Thanksgiving is the best time to plant most perennials and shrubs, especially California natives. The soil is still warm enough to encourage good root development and most importantly, cool weather and winter rains get plants off to a good start. Make sure you water them well when first planted, then continue watering until winter rains start.
Plants adapted to a Mediterranean climate need moisture until their root systems mature (with some succulents being exceptions). These plants may still need water during the summer to look their best but will tolerate a long dry summer much better with well-developed roots.
“Drought-tolerant” is a somewhat misleading term. Several dry months during our typical Mediterranean summers do not result in a drought. “Climate-adapted” or “water-smart” are more helpful terms to describe plants. These are adapted to the normally dry summers and wet winters common in many Mediterranean areas. Water conservation during any California summer makes economic and ecological sense.
Some reliable favorites include Toyon (Heteromeles arbutifolia), Sunset Manzanita (neat and tidy), De la Mina Verbena (Verbena lilacina 'De La Mina'), Salvia ‘Bee's Bliss' (needs room), Flowering Currant (Ribes sanguineum), Epilobium, Yarrow, and California Buckwheat. Check the Native Plant database listed below to see which plants will do well in your zip code or in a particular spot in your garden.
The first four references below are robust websites to help you select perennials that will work in Contra Costa County. We are biased toward water-wise California natives, although perennials from other Mediterranean climates can do well here. If you have a lot of garden space, you may want the help of a professional landscaper (see last reference).
• East Bay MUD water-smart plants (natives and non-natives): https://www.ebmud.com/water/conservation-and-rebates/watersmart-gardener/watersmart-plants
• UC Davis “All Star” Plant Database (natives and non-natives): https://arboretum.ucdavis.edu/plant-database
• Contra Costa County water-saving plant database (natives and non-natives): https://www.contracosta.watersavingplants.com/search.php
• Native plant database from California Native Plant Society: https://www.calscape.org/
• How to find a landscape professional https://rescape.memberclicks.net/directory
Help Desk of the UC Master Gardeners of Contra Costa County (EAS)
California lilac (Ceanothus spp.)
Toyon (Heteromeles arbutifolia)