Next time you go for a walk in Upper Park, look closely at the different plants you see. Notice the enormous diversity of shapes, colors, and forms. There are trees, shrubs, perennials and annuals, all different shapes and sizes of leaves, and tremendous variation in flower color and structure from one species of plant to another. This diversity is the result of evolution over the ages. Plants have adapted to the specific conditions of their native habitat. These conditions include climate, availability of water, soil type, and interactions with other organisms. Adaptations can be structural or physiological.
The beavertail cactus (Opuntia basilaris) is a kind of prickly pear cactus. It lacks long spines but its flat, fleshy pads are covered with small bristles that have barbed tips. The bristles help shade the pads and also protect the cactus from being eaten. The pads themselves are modified stems. They have a waxy cuticle to reduce water loss and store water within. During periods of drought the pads shrivel and then plump back up when rain returns.
All plants have very small holes called stomata on the underside of their leaves. The hole can open for exchange of carbon dioxide and oxygen gases or close to maintain the proper balance of water. Most plants open their stomata during the day to take in carbon dioxide for photosynthesis. They close the stomata at night to retain water. Plants in the cactus family, plus some succulents and certain orchids, open their stomata at night and close them during the day. They have a modified photosynthetic cycle, called Crassulacean Acid Metabolism (CAM), which helps to reduce water loss during gas exchange. Carbon dioxide enters the open stomata at night when less water will be lost to the outside air. The carbon dioxide is then fixed and combined with another chemical to form an organic acid. The acid is then stored until the daytime when sunlight is available to finish the process of transforming it to sugar. CAM is an example of a physiological adaptation.
The forests of the Coastal Redwood (Sequoia sempervirens) are lush, green, and typically receive a generous amount of rainfall during the winter but little rain during the summer. How do the redwoods survive the dry season? While the North Coast doesn't get much rain in the summer, it does have regular fog. Scientists have long suspected that redwood leaves, especially those near the top of the tree, are able to absorb water from fog without adversely affecting photosynthesis. When stomata are covered by even a thin film of water, the water can block the flow of carbon dioxide into the leaf, limiting photosynthesis.
Think about plant adaptations when choosing plants for your garden. Generally speaking, the better a match between a plant's adaptations and the conditions in your garden, the better the plant will perform. If you choose a plant native to an area that is much different from your garden, you will probably need to make some changes in your garden so it can provide for more of the plant's needs.
Want to learn more about this topic? Attend our workshop on Adaptations of California Native Plants (Wednesday, May 22), part of the Master Gardeners' 2024 Spring Workshop Series. For information about all the workshops, and to register, visit our website. All workshops are free, but registration is required.
PLANT SALE! Mark your calendar for our plant sale on Saturday, May 18, 2024 from 9 am–noon. The sale will be held at the Master Gardeners Demonstration Garden at Patrick Ranch. The plants, which are selected to thrive in our climate, have been propagated by UC Master Gardeners of Butte County. For more information and a partial list of the plants that will available, visit our website.
UC Master Gardeners of Butte County are part of the University of California Cooperative Extension (UCCE) system. To learn more about us and our upcoming events, and for help with gardening in our area visit our website. If you have a gardening question or problem, email the Hotline at mgbutte@ucanr.edu or leave a phone message on our Hotline at 530-552-5812. To speak to a Master Gardener about a gardening issue, or to drop by the MG office during Hotline hours, see the most current information on our Ask Us section of our website.
A colorful perennial has been brightening spring gardens for many weeks. Azaleas are the easy-to-care-for stars of semi-shaded locations. The most common varieties are evergreen azaleas, which are more accurately described as having “persistent-leaves.” They grow a set of spring leaves which are dropped in the fall, and a set of summer leaves which persist through the winter.
Azaleas are long-lived and can be used as permanent plantings, so consider the following factors before planting them in your yard.
Exposure: Azaleas prefer cool, partially-shaded sites, such as under under pine, oak or maple trees.
Mulch: A two- to three- inch layer of organic mulch (leaves, pine bark, wood chips) will conserve moisture and help discourage weeds. Extend the mulch a couple of inches from the main stem to keep the bark dry.
Watering: Azaleas are shallow-rooted. If possible, use soaker hoses or drip irrigation to slowly water the base of the plants. Overhead irrigation may promote disease.
Fertilizing: If planted properly, supplemental feeding is unnecessary.
Pruning: The best time to prune is in spring, just after the plant has finished blooming.
My existing plant didn't bloom, now what? --You may already have azaleas and are disappointed that they no longer bloom. You may need to give them more sun, perhaps by opening up the branches of the overhead trees, as well as pruning the azaleas to increase next year's buds.
Reasons for stingy flowering or lack of blooms include:
- The azaleas were allowed to dry out or to have wet feet. A two- to- three-inch- deep layer of mulch can help with water retention. Check the irrigation to make sure they are not being over-watered.
- Fertilizing with too much nitrogen may interfere with blooming. Did the plants receive fertilizer while you were feeding the grass?
- If you pruned after the flower buds developed, next year's flowers were inadvertently removed. Prune shortly after this year's flowers fade.
- Less than three hours of sun per day reduces the number of buds. Prune overhead trees, or consider moving the plant and its root ball to a better location.
PLANT SALE! Mark your calendar for our plant sale onSaturday, May 18, 2024 from 9 am–noon. The sale will be held at the Master Gardeners Demonstration Garden at Patrick Ranch. The plants, which are selected to thrive in our climate, have been propagated by UC Master Gardeners of Butte County. For more information and a partial list of the plants that will available, visit our website.
UC Master Gardeners of Butte County are part of the University of California Cooperative Extension (UCCE) system. To learn more about us and our upcoming events, and for help with gardening in our area visit our website. If you have a gardening question or problem, email the Hotline at mgbutte@ucanr.edu or leave a phone message on our Hotline at 530-552-5812. To speak to a Master Gardener about a gardening issue, or to drop by the MG office during Hotline hours, see the most current information on our Ask Us section of our website.
If you are noticing droopy, dried-out flower clusters on your pears, Asian pears, quince, apples or crabapples, fire blight may be the cause.
The first sign of fire blight is often the blackening of flowers, shoots or leaves followed by a watery, light tan ooze from affected shoots. Open flowers are the most common infection site and remain susceptible until petal fall.
Initially, fire blight infections might be localized, affecting only a flower cluster, but then the infection grows downward, extending into twigs and branches. These twig cankers kill more and more tissue as they advance. Dead, blackened leaves and fruit cling to dead branches throughout the season, giving the tree a scorched appearance -- hence the name “fire blight.” The pathogen can kill highly susceptible trees, while others may suffer significant branch dieback. Once infected, the plant will harbor the pathogen indefinitely unless the cankers are pruned out well below the infection.
Monitoring trees regularly, a couple of times a week, will allow you to identify and deal with new fire blight strikes before they become a branch infection. It is important to remove and destroy any new fire blight infections before they spread and affect more tissue. Dip pruning shears in a 10-percent bleach solution after each cut.
If fire blight strikes have been ignored, the infection will spread and infect the branch. Once the wood is infected, the branch must be pruned out well below the infection. In this case, you will need to remove the diseased wood in summer or winter when the bacteria are no longer spreading through the tree. Again, dip pruning shears in a 10-percent bleach solution after each cut.
If fire blight occurs on a trunk or major limb the wood may be saved by scraping away the bark down to the cambium layer in affected areas (removing both outer and inner bark). When scraping look for long, narrow infections that can extend farther down the branch or trunk. If any are seen, remove all discolored tissue plus six to eight inches more beyond the infection. This procedure is best done in winter when trees are dormant and bacteria aren't active. Don't apply any dressing to the wound. If the limb has been girdled, scraping won't work and the entire limb must be removed.
When selecting new fruit trees, choose those that are less susceptible to fire blight, if possible. The most susceptible varieties are Fuji, Gala, Golden Delicious, Granny Smith, Gravenstein, Jonathan, Mutsu, Pink Lady and Yellow Newton. Unfortunately, most pear varieties are susceptible to fire blight.
PLANT SALE! Mark your calendar for our plant sale onSaturday, May 18, 2024 from 9 am–noon. The sale will be held at the Master Gardeners Demonstration Garden at Patrick Ranch. The plants, which are selected to thrive in our climate, have been propagated by UC Master Gardeners of Butte County. For more information and a partial list of the plants that will available, visit our website.
UC Master Gardeners of Butte County are part of the University of California Cooperative Extension (UCCE) system. To learn more about us and our upcoming events, and for help with gardening in our area visit our website. If you have a gardening question or problem, email the Hotline at mgbutte@ucanr.edu or leave a phone message on our Hotline at 530-552-5812. To speak to a Master Gardener about a gardening issue, or to drop by the MG office during Hotline hours, see the most current information on our Ask Us section of our website.
The devastating Camp Fire of 2018, along with the numerous fires North State residents have experienced since then, have led many of us to focus on creating a defensible fire-resistant landscape around our homes. As noted in this column last Friday, the key to establishing defensible space is to utilize plants that are fire resistant and judiciously space them both horizontally and vertically.
Shrubs that are fire resistant include ceanothus, butterfly bush, spirea, rose of Sharon, Oregon grape, lilac, mock orange, potentilla, forsythia, cotoneaster, island bush poppy, currants, camellia, azalea, monkey flower and viburnum. Aloe and other succulents are generally considered fire-resistant but avoid succulents such as ice plant that produce mats of flammable dry material.
Choose deciduous trees such as maples, oaks, sweet gum (liquidambar), locust, redbud, dogwood, ash, toyon, and smoke tree. Citrus and deciduous fruit trees such as cherry, peach and plum are fire resistant. Although most conifers are highly flammable, redwoods are the exception to the rule and are a desirable tree in a firewise landscape.
Highly flammable plants often have an excess of fine dry or dead material and contain volatile waxes, terpenes, or oils. Their sap is gummy or resinous and aromatic. They may have loose, papery bark as well. Examples of flammable plants are sagebrush, conifers (cedar, pine, juniper, fir, Italian cypress), broom, rosemary, eucalyptus, palms, feather and fountain grasses and dry annual grasses. These plants should be avoided when planning a firewise landscape; if they already exist in a landscape, consideration should be given to removing them.
For more information on creating fire resistant landscapes, see the Firewise Landscaping section of our website. For more information on creating fire resistant landscapes, attend our Firewise Gardening workshop on May 2, 2024, part of the Master Gardeners' current Spring Workshop Series. For information about all the workshops, and to register, visit our website. All workshops are free, but registration is required. There is plenty to choose from workshop-wise this month and next: In addition to Firewise Gardening, topics covered include composting, native bees, pest management, weed identification, and California native plants.
UC Master Gardeners of Butte County are part of the University of California Cooperative Extension (UCCE) system. To learn more about us and our upcoming events, and for help with gardening in our area visit our website. If you have a gardening question or problem, email the Hotline at mgbutte@ucanr.edu or leave a phone message on our Hotline at 530-552-5812. To speak to a Master Gardener about a gardening issue, or to drop by the MG office during Hotline hours, see the most current information on our Ask Us section of our website.
It's springtime, and many of us are adding new plants to our gardens. That means it is also a good time to review the principles of creating defensible space around our homes.
The key to establishing defensible space is to utilize plants that are fire resistant and judiciously space them both horizontally and vertically. Increasing the space between plants limits the ability of fire to spread. As a rule of thumb, Cal Fire recommends that on flat ground the space from the edge of one shrub to the edge of the next be twice the height of the shrub. For example, if shrubs are two feet tall, they should be spaced four feet apart. If the shrubs are growing on a moderate slope the space between them should be four times the height of the shrub. The space between trees should be 10 feet from canopy to canopy and increase to 20 feet on a moderate slope.
If a fire reaches the crown of a tree, its heat intensity increases and this can increase the combustibility of surrounding vegetation. Low tree branches create fuel ladders that allow fires to climb into a tree. To prevent fires from ‘crowning,' these ladder fuels must be eliminated. Cal Fire recommends that the lower branches of a mature tree should be pruned to create a clearance of three times the height of the shrubs beneath it. For example if a shrub is four feet tall, the tree should be pruned so that there is 12 feet of clearance between the top of the shrub and the lowest branches of the tree. For younger trees, the lower one-third of branches should be removed.
Applying mulch is a good strategy for conserving soil water, reducing weeds and preventing erosion. Normally, materials such as wood chips, shredded bark, leaves or straw are used as mulches because these organic materials have the added benefit of enriching the soil and improving its water-holding capacity. However, organic materials burn, so within the five feet closest to a home, it is recommended that non-combustible mulches of rock, gravel, pavers or broken concrete be used instead of traditional organic materials.
When planning a firewise landscape, the contribution of hardscape features should not be overlooked. Decomposed granite, cement, asphalt or gravel pathways and driveways make effective firebreaks. Structures such as patios and masonry walls and water features like pools, ponds, and streams will also impede the advance of a fire.
Before moving beyond the 30-foot home defense zone, mention should be made of items that do not belong too close to a home. Most propane tanks should be located a minimum of 10 feet from any structure, and woodpiles should be at least 30 feet away. A cord of seasoned firewood contains the energy equivalent of approximately 174 gallons of gasoline! Would you store that much gasoline on your porch? Also, flammable liquids such as gasoline, paint thinner, and turpentine should be properly stored away from ignition sources and combustibles.
If organic mulches are used in the reduced-fuel zone, a 2008 study showed that a mulch of composted wood chips spread two to three inches deep showed the slowest fire-spread rate of the eight mulches tested. A potential disadvantage of wood chip mulches is that they tend to smolder and can be difficult to extinguish. In general, fine, stringy mulches such as shredded bark burn more rapidly than larger chunks.
Establishing defensible space can be summarized by the following three R's: 1) Remove dead and dying plant material; 2) Reduce the density of vegetation and ladder fuels; 3) Replace hazardous vegetation with less flammable, well-irrigated fire resistant plants.
Further information on fire safety for homeowners can be found on the Cal Fire website at Home - Ready for Wildfire. And for property owners who are considering landscaping from scratch, the Sonoma-Marin Saving Water Partnership has developed eight fire-rebuild landscape design plans that are well worth considering (Water Smart Landscape Design Templates - Sonoma- Marin Saving Water Partnership).
For more information on creating fire resistant landscapes, attend our Firewise Gardening workshop on May 2, part of the Master Gardeners' 2024 Spring Workshop Series. For information about all the workshops, and to register, visit our website. All workshops are free, but registration is required.
Why not buy some plants for your fire-resistant landscape at the Master Gardeners' Plant Sale on Saturday, May 18, 2024? The sale will be held at our Demonstration Garden at Patrick Ranch, 10381 Midway, between Chico and Durham, from 9 am till noon. For more information, and a partial list of plants, see our Plant Sale webpage.
UC Master Gardeners of Butte County are part of the University of California Cooperative Extension (UCCE) system. To learn more about us and our upcoming events, and for help with gardening in our area visit our website. If you have a gardening question or problem, email the Hotline at mgbutte@ucanr.edu or leave a phone message on our Hotline at 530-552-5812. To speak to a Master Gardener about a gardening issue, or to drop by the MG office during Hotline hours, see the most current information on our Ask Us section of our website.
