- Author: Anne Schellman
- Editor: Roger A Duncan
Want fall color in your landscape next year?
Read about the trees you've noticed around town that are currently “popping” with color. And, if you plant a tree now (or in early spring), you can have fall color in your landscape next year! Here are some excellent tree species to choose from that thrive in our area (USDA Zone 9b):
Chinese Pistache – Pistachia chinensis
The Chinese pistache is Ed Perry's favorite tree. Ed was the Environmental Horticulture Advisor for over 35 years at UC Cooperative Extension in Stanislaus County. He chose this tree not only for its fall color, but because it produces good shade and has “well-behaved” roots. Opt for the male cultivar ‘Keith Davey.' Female cultivars have colorful berries which although pretty, are considered messy and not suitable for over a patio.
Height: 30-50'
Light needs: Plant in full sun.
Water needs: Moderate. Does well in lawns.
Note: You can't go wrong with this tree! Also, it is not closely related to the nut bearing pistachio tree.
Maple Trees – Acer rubrum
Light needs: Plant in full sun or partial shade.
Height: 40-50'
Water needs: Regular water. Does well in lawns, but water separately from the lawn.
Note: Sprinkler water will not be enough for this tree.
Bradford Flowering Pear – Prunus calleryana ‘Bradford'
This flowering pear has cheerful white blooms in spring and produce fall color during cool winters. Their roots are well-behaved so they can be planted near sidewalk. Please note, many cultivars of flowering pear have problems such as mistletoe and fireblight. Make sure you choose a Bradford pear. After bloom, this tree does drop small fruits that are messy.
Height: 40-50'
Light needs: Plant in full sun.
Water needs: Moderate. Does well in lawns.
Note: although bred to be fruitless, the Bradford pear cross pollinates with other pears which is why it produces inedible “fruit.”
Japanese Maple Trees – Acer palmatum
Light needs: Plant in partial shade, some species (‘Emperor One') are adapted to full sun.
Height: 6-20', varies. Do some research before choosing your tree.
Water needs: Regular water.
Note: This tree can give year-round interest!
Ginkgo – Ginkgo biloba
This ancient tree existed long before dinosaurs roamed the earth. In fact, fossils of gingko leaves have been discovered from the Jurassic period! Ginkgo trees leaves turn a beautiful golden color in fall. Choose a male cultivar such as ‘Saratoga' or ‘Autumn Gold.' Female cultivars produce fruit that some people consider unpleasant.
Light needs: Plant in full sun.
Height: 30-50.'
Water needs: Moderate water; can tolerate drought but won't look healthy.
Note: Excellent street or patio tree, also does well in a lawn.
Liquidambar – Liquidambar styraciflua
Light needs: Plant in full sun.
Height: 50-60.'
Water needs: Regular water.
Note: Surface roots can crack sidewalks and come up in lawns.
Tree Notes – Choosing a Tree
When choosing a tree, look for one with leaves growing along the entire stem. Avoid trees that resemble a mature tree (with a long stem and a heavy top). The leaves are necessary to help the tree develop a strong trunk.
Tree Notes – Planting
Planting a tree correctly is essential to having a healthy tree. Follow these steps:
Step 1: Remove the tree stake.
Step 2: Dig a hole twice as wide but the same depth as the container.
Step 3: After removing the “root ball” (area of soil and roots) from the container, set it in the hole.
Step 4: Make sure the top of the root ball is lined up with the surrounding soil or a little higher.
Step 5: Fill in around the root ball with removed soil, do not cover over the root ball with soil. Make sure the root ball is still showing and is level with the ground.
Step 6: Create a basin around the base of the tree and water well.
Tree Notes – Staking
If you remove the stake from your new tree and it falls over, return the tree. Healthy trees should not fall over and do not need to be staked. In fact, a tree that can't stand upright that grows into a mature tree is likely to become a landscape hazard** in the future.
Allowing your new tree to sway with the wind helps it develop a strong trunk and root system. The only time it is recommended to stake trees is in areas with heavy wind. In this case, two stakes should be used, and then removed after one year. Learn more about tree staking in the Planting Landscape Trees publication below.
Tree Notes – Water
All newly planted trees need regular water for the first 2-5 years after planting. Regular water means keeping the soil moist but not too wet or allowing it to dry out. Once their roots are established, trees need deep water once or twice per month during the dry season (May-October), depending on temperature, tree species, soil type, and other factors.
Resources
Stanislaus County Tree Guide
Looking for more tree recommendations? Visit our publications page and scroll to the bottom of the page to click on our “Trees in Your Home Garden” publication at https://cestanislaus.ucanr.edu/Gardening_Publications/
Planting Landscape Trees
https://anrcatalog.ucanr.edu/pdf/8046.pdf
*University research has shown that adding amendments such as compost and fertilizer to planting holes does not help trees; in fact, it can cause problem. Read more at https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=46215
**worried you may have a hazardous tree in your landscape? Download this free guide for tips on how to inspect it. https://anrcatalog.ucanr.edu/pdf/8365.pdf
/h3>/h3>/h3>/h3>/h3>/h3>/h3>/h3>/h3>/h3>/h3>/h4>- Author: Denise Godbout-Avant
As the long, hot days of summer slide into cooler, shorter days of autumn, seasonal changes are occurring in my garden. Not as many plants are blooming, the leaves on deciduous trees and plants are becoming drier and starting to change color. Some plants are producing autumn berries that will sustain many birds as insects, another source of food, begin to disappear.
Quite a few butterflies have been showing up in my garden to take advantage of flowers that are still blooming. Butterflies I have been seeing include painted ladies (Vanessa cardui), common buckeyes (Junonia coenia), fiery skippers (Hylephila phyleus)and cabbage whites (Pieris rapae).
With the advent of winter, butterflies disappear since they cannot tolerate temperatures below 55°F or rainy weather. So, what happens to butterflies in the winter???
Some Butterflies Migrate
Some butterfly adults migrate south, overwintering in warmer climates.
Monarch butterflies are known for their astonishingly long spring and fall migrations. Both the eastern monarchs and western monarchs began their southern migrations in late August or early September from southern Canada/northern USA to their overwintering sites. The eastern variety generally heads to the oyamel fir forests in the mountains of central Mexico, whereas the western Pacific species have a shorter journey to California's coastline. You may see some western monarchs this fall resting or feeding on flowers in your garden as they fly through the Central Valley on their way their overwintering sites in coastal areas such as Santa Cruz, Pacific Grove, Pismo Beach, and San Diego.
Other Winter Strategies
Most butterflies spend winter in the same area they spent summer.
Some lay their eggs in autumn on, or close to, their specific host plants with the eggs hatching the following spring. The common hairstreak (Satyrium californica) eggs are laid attached to twigs of oaks with the caterpillars feeding on newly emerged spring leaves.
Some butterflies weather the cold as pupa within a chrysalis in a sheltered spot. During this time, the pupa will enter diapause (where development stops). An antifreeze chemical in their blood allows them to survive cold temperatures. Once the days lengthen, it will resume its transformation, emerging as an adult just as in time for blooming flowers that provide nectar. The tiger swallowtail's chrysalis (Papilio rutulus) will take refuge in deep shrubbery. The anise swallowtails (Papilio zelicaon) and cabbage whites also generally overwinter as a pupa in their chrysalis. Fiery skippers usually overwinter as pupae buried in leaves, but some adults will migrate to southern California.
Mourning cloaks (Nymphalis antiopa)go into dormancy as an adult. Their blood also contains an anti-freeze. They tuck themselves into cracks and crevices of rocks and trees.
Leaving the Leaves
- Learn which butterflies live in your area and grow native plants for those specific species.
- Offer nectar plants in the fall and spring months for butterflies that are migrating, emerging from overwintering, or getting ready to go into winter dormancy/hibernation.
- Skip raking the leaves in your garden in autumn and leave standing plants alone until midspring, so overwintering butterfly larvae, pupae and adults have a place to hide. If leaving the leaves on your lawn is too messy for you, consider not disturbing the leaves in your planters.
- If you find what looks like a dead chrysalis (many resemble dead leaves) in your yard, garage, shed, do not disturb it. A butterfly may well emerge in the spring.
- Avoid using pesticides as much as possible.
Resources
- Art Shapiro's Butterfly Site: https://butterfly.ucdavis.edu/butterflies
- Butterflies in Your Garden, Publication from UCCE Stanislaus County :https://ucanr.edu/sites/CEStanislausCo/files/345791.pdf
- Xerces Society - Pollinator Plants: Central Valley of California: https://xerces.org/publications/plant-lists/ppbi-california-central-valley
- California Native Plant Society: https://www.cnps.org/
- UC Davis Arboretum – Larval Hosts for Butterflies: https://arboretum.ucdavis.edu/blog/larval-host-plants-butterflies
Denise Godbout-Avant has been a UC Cooperative Extension Master Gardener in Stanislaus County since 2020.
/h3>/h3>/h3>/h3>- Author: Lauren Fordyce
Tomatoes are ripening all over California right now keeping many gardeners and tomato lovers busy picking, canning, and eating. But what may not make gardeners happy are seeing curled leaves and not knowing why. There are many reasons why your tomato leaves may be curling or rolling. Being able to narrow down possible causes takes a bit of detective work, but using this article and UC IPM's Plant Problem Diagnostic Tool can make it achievable!
Tomato leaf curl can be the result of:
Environmental stressors
Leaf curl on tomato is often caused by environmental stress, not necessarily pathogens or insects. Too much or too little water or nutrients, can make leaves curl. A wet spring, followed by warm weather can cause physiological leaf roll. Leaves may roll downward and become firm and leathery. Usually, the lowest leaves are affected most and the plant appears healthy otherwise. When conditions become more favorable, like more water if the plant hasn't been getting enough or consistent watering, environmental stressors will often resolve themselves and the plant will recover.
Plant pathogens
Several viral infections can cause tomato leaves to curl. Curly top virus causes leaves to cup downward, become thick and brittle, and stunts plant growth. Tobacco mosaic virus results in mottled leaves that appear stringy and distorted. Tomato spotted wilt virus causes downward-cupped leaves and necrotic spots. It is important to note that viruses can be transmitted to tomatoes, and other garden plants, by sap-sucking insects. Therefore, their control is important in preventing these viruses. There is no treatment for virus-infected plants, so it is best to remove and dispose of them.
Insects
Aphids, whiteflies, thrips and other sap-sucking insects can cause leaves to curl by sucking plant juices out of the leaves. Check the undersides of leaves to look for these insects. Once you have identified the culprit, see the UC IPM fact sheets (Pest Notes) on various methods for managing them.
You may see some ‘good bugs' around the garden too. Many natural enemies will feed on these pest insects, so keep an eye out for lady beetles, lacewings, and minute pirate bugs. Also look for signs of parasitization (like aphid mummies) from parasitoid wasps!
Herbicide injury
If you recently applied an herbicide near your tomato plants, their leaves could be curling from herbicide drift or contamination. When tomato plants come in contact with herbicides, like 2,4-D, their leaves may curl or cup and become distorted.
How can you prevent tomato leaf curl?
- Choose pathogen resistant tomato varieties.
- Harden off plants or wait for the weather to warm up before planting outside.
- Ensure tomatoes receive consistent and adequate water.
- Use the correct amount of fertilizer.
Visit the UC IPM website for more information about tomato pests, issues, and cultural controls. If you have additional questions, please contact your local UC Master Gardeners for more information.
- Author: Kat Kerlin
Reposted from the UC Davis College of Agricultural and Environmental Sciences news
Redwood Trees Have 2 Types of Leaves, and They Do Totally Different Things
Quick Summary
- Redwoods have two types of leaves, one to make food and the other to absorb water
- Study is first to estimate whole-crown water absorption in a large, mature tree
- Leaf types shift places on the tree depending on if environment is wet or dry
- Findings can help scientists monitor trees' adaptability amid a changing climate
Redwoods are among the most well-studied trees on the planet, and yet their mysteries continue to surprise and delight scientists and nature lovers.
Scientists from the University of California, Davis, discovered that redwood trees have two types of leaves, and those leaves have completely different jobs, according to a study in the American Journal of Botany. Together, these functionally distinct leaves allow the world's tallest trees to thrive in both wet and dry parts of their range in California, without sacrificing water or food.
Division of labor
The peripheral leaf spends its working hours making the tree's food — converting sunlight into sugar through photosynthesis. Its colleague, the axial leaf, does almost nothing to help with photosynthesis. Instead its specialty is to absorb water. In fact, the study found that a large redwood can absorb up to 14 gallons of water in just the first hour its leaves are wet.
How does that compare to other trees? Scientists don't know. This is the first study estimating whole-crown water absorption in a large, mature tree. Because large redwoods have over 100 million leaves, this absorption record may prove hard to beat.
In wet forests, photosynthesis can be inhibited by films of water covering leaf stomata when they get wet. For redwoods, the different leaf types allow the trees to get wet and still be able to photosynthesize. The peripheral leaves have a waxy coating that slows water absorption but may help them continue photosynthesis throughout the wet season.
“I'd be surprised if there weren't a lot of conifers doing this,” said lead author Alana Chin, a Ph.D. student in ecology with the UC Davis Department of Plant Sciences at the time of the study. “Having leaves that aren't for photosynthesis is in itself surprising. If you're a tree, you don't want to have a leaf that's not photosynthesizing unless there's a very good reason for it.”
Trading spaces
The study also found that leaves can shift their “office space” along the tree depending on whether the environment is wet or dry.
In the wet, rainy north coast, the water-absorbing leaf type is found on the tree's lower branches, leaving the upper, sunnier levels to the photosynthesizing leaf type. That dynamic flips for redwoods in their southern range: The water-collectors live among the tree's higher levels to take more advantage of fog and rain, which occur less often in the drier environment.
To arrive at their findings, the authors collected shoot clusters from six redwood trees at five forest locations stretching from wet Del Norte County to the dry Santa Cruz Mountains and exposed them to experimental fog. They estimated the water absorption potential for seven additional trees — including the tallest living tree — and took samples at varying heights.
They then compared the anatomy and measured photosynthesis of the peripheral and axial leaves to understand their function. They also developed a physics-based causal model that allowed them to determine the leaf traits that regulate absorption rates.
Amid all the findings, Chin is most excited to have found an easy and effective way to indicate redwood trees' ability to access fog. Researchers can monitor how and if redwoods are adapting to climate conditions and a future, drier world by simply looking at the visible waxes covering the two types of leaves — something that could be captured on a cell phone camera and shared by other scientists or even members of the public.
Superlative species
Redwoods are renowned for their resilience in the face of many natural threats and inspire numerous superlatives: They are among the planet's biggest, tallest, oldest trees. They have tannin-rich heartwood, fire-resistant bark and pest-resistant leaves. This new finding is another example of their ability to respond to environmental conditions, like drought and water stress.
“The cool thing here is their ability to thrive under all these circumstances and adjust themselves to these different environments,” said Chin, who grew up near the redwoods in Mendocino County. “That things like this can be happening right under our nose in one of the best-studied species out there — none of us assumed this would be the story.”
Study co-authors include Paula Guzman-Delgado, Jessica Orozco, Zane Moore and senior author Maciej Zwieniecki of the UC Davis Department of Plant Sciences, as well as Stephen Sillett, Lucy Kerhoulas and Marty Reed of Cal Poly Humboldt, and Russell Kramer of Dipper and Spruce LLC in Washington.
The study was funded by the National Science Foundation and a Katherine Esau Fellowship from UC Davis.
Media Resources
- Alana Chin, UC Davis Plant Sciences, alanaroseo@gmail.com. Chin is currently based in Switzerland. (Please note time difference for interview requests.)
- Kat Kerlin, UC Davis News and Media Relations, 530-750-9195, kekerlin@ucdavis.edu
- Author: Denise Godbout-Avant
People often rake their leaves and put them out to be picked up as trash. I have always preferred to leave the leaves for my garden.
If you take a walk in a forest, you'll see leaf layers several inches deep around trees and bushes. Fallen leaves have a complex relationship with trees and nature, providing many benefits which can be reproduced to some extent in our gardens.
Natural Mulch
Fallen leaves have the same weed suppression and moisture retention properties of shredded wood mulch—and they're free! Where mulch is desired as a decorative element, what could be more seasonally appropriate than a pile of brightly colored fall leaves? This natural mulch also provides insulating winter cover from cold temperatures for roots, seeds, and bulbs.
A Web of Life in Leaf Litter
Leaf litter isn't just free fertilizer and mulch. It provides food and shelter for a wide variety of living things including spiders, snails, worms, beetles, millipedes, mites, toads, frogs and more—these in turn support mammals, birds, reptiles, and amphibians that rely on these creatures for food.
Detritivores (organisms that eat dead or decaying plants or animals) break up and excrete leaf litter. Fungi and bacteria then take over and complete the recycling process converting these smaller pieces into nutrients which then sustain neighboring plants. They in turn help support biodiversity by becoming food themselves.
Numerous bird species such as robins and towhees forage in the leaf layer searching for insects and other invertebrates to eat.
Raking up leaves and putting them in the trash could have the unintended consequence of removing some of next year's garden butterflies and moths, many of which are pollinators. Most butterflies and moths overwinter in the landscape as an egg, caterpillar, chrysalis, or adult. In all but the warmest climates, they often use leaf litter for winter cover. Fritillaries and wooly bear caterpillars will tuck themselves into a pile of leaves for protection from cold weather and predators. Some Hairstreaks lay their eggs on fallen oak leaves, which become the first food of the caterpillars when they emerge. Swallowtail butterflies disguise their cocoons and chrysalises as dried leaves, blending in with the “real” leaves.
Bumble bees also rely on leaf litter for protection. At the end of summer, mated queen bumble bees burrow an inch or two into the earth to hibernate for winter. An extra thick layer of leaves is welcome protection from the elements.
All of which makes leaf litter an integral part of a complex web of life.
What You Can Do
Composting leaves is a terrific way to recycle and create a nutrient-rich garden soil amendment at the same time. Some gardeners opt for shredding their fall leaves for use in compost piles. Like people who mulch their lawn leaves with a mower, consider leaving some leaves undisturbed in garden beds and lawn edges. If space allows, you could create a leaf pile, allowing it to break down naturally, or add the leaves gradually to your compost pile over time. Such efforts will keep leaf litter critters safe and allow you to benefit from the rich garden gift that falls from the trees above.
While it is ideal to “leave the leaves” permanently—for the benefits mentioned above—if you do decide you need to clean your garden and remove the leaves in spring, try to wait until later in the season, so as to give the critters that have been protected by fallen leaves over the winter time to emerge and depart.
Some gardeners may be concerned that autumn leaves, matted down by rain or snow, could have a negative impact on their perennials. However, a thick layer of leaves provides additional insulation against chilly weather and protects newly planted perennials from frost which could damage tender roots and shoots. Anyone who has spotted fragile spring seedlings popping up in the woods knows that all but the most fragile of plants will erupt through the leaf litter in spring without trouble.
So, leave the leaves. While you can't perfectly emulate a forest, your garden will be healthier and more diversified, you'll help support a vast array of wildlife, and you'll reduce the strain on landfills.
Denise Godbout-Avant has been a UCCE Stanislaus County Master Gardener since July 2020.
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