You may have seen Mistletoe hung in doorways over these past few weeks. It is a traditional holiday decoration, but when it's growing on trees in the landscape, this parasitic plant may not seem quite as charming.
Broadleaf mistletoe (Phoradendron macrophyllum) is an evergreen parasitic plant that grows on a number of landscape tree species in California. Hosts of broadleaf mistletoe include alder, Aristocrat flowering pear, ash, birch, box elder, cottonwood, locust, silver maple, walnut, and zelkova. Other species of broadleaf mistletoe in California include P. villosum, which infests only oaks, and Viscum album, which attacks alder, apple, black locust, and cottonwood.
Dwarf mistletoes (Arceuthobium spp.) infest pines, firs, and other conifers in forests, and can be a problem in forest landscapes such as in the Sierra Nevada foothills.
Leafy mistletoes have green stems with thick leaves that are nearly oval in shape. Plants often develop a rounded form up to 2 feet or more in diameter. The small, sticky, whitish berries are produced from October to December.
After the mistletoe seed germinates, it grows through the bark and into the tree's water-conducting tissues, where rootlike structures called haustoria develop. The haustoria gradually extend up and down within the branch as the mistletoe grows. Initially, the parasitic plant grows slowly; it may take years before the plant blooms and produces seed. Broadleaf mistletoes have succulent stems that become woody at the base. Old, mature mistletoe plants may be several feet in diameter, and on some host species, large swollen areas develop on the infected branches where the mistletoe penetrates. If the visible portion of the mistletoe is removed, new plants often resprout from the haustoria.
Dwarf mistletoes are smaller plants than broadleaf mistletoes, with mature stems less than 6 to 8 inches long. Dwarf mistletoe shoots are nonwoody, segmented, and have small scalelike leaves. While broadleaf mistletoe seeds are dispersed by birds, dwarf mistletoe seeds are spread mostly by their forcible discharge from fruit, which can propel seeds horizontally into trees up to 30 to 40 feet away.
Broadleaf mistletoe absorbs both water and mineral nutrients from its host trees. Mistletoes also can produce energy through photosynthesis in their green leaves. Healthy trees can tolerate a few mistletoe branch infections, but individual branches may be weakened or sometimes killed. Heavily infested trees may be reduced in vigor, stunted, or even killed, especially if they are stressed by other problems such as drought or disease.
In newly developed areas or in older established areas where trees are being replaced, the ideal method of controlling or preventing mistletoe is to plant trees believed to be resistant or moderately resistant to mistletoe. Avoid trees like Modesto ash, known to be especially susceptible to mistletoe infestation. Some tree species appear resistant to broadleaf mistletoe. Bradford flowering pear, Chinese pistache, crape myrtle, eucalyptus, ginkgo, golden rain tree, liquidambar, sycamore, and conifers such as redwood and cedar are rarely infested. These or other resistant species should be considered when planting in infested areas, or when replacing infested trees.
For treatment of existing trees it is important to remove mistletoe before it produces seed and spreads to other limbs or trees. Mechanical control through pruning is the most effective method for removal. Growth regulators provide a degree of temporary control but repeated applications are required. Severely infested trees should be removed and replaced with less susceptible species to protect surrounding trees.
The most effective way to control mistletoe and prevent its spread is to prune out infected branches, if possible, as soon as the parasite appears. Using thinning-type pruning cuts, remove infected branches at their point of origin or back to large lateral branches. Infected branches need to be cut at least one foot below the point of mistletoe attachment in order to completely remove embedded haustoria. It is best to call an arborist if mistletoe is infesting your trees and you are unable to reach it to prune it.
Mistletoes infecting a major branch or the trunk where it cannot be pruned may be controlled by cutting off the mistletoe flush with the limb or trunk. Then wrap the area with a few layers of wide, black polyethylene to exclude light. Use twine or tape to secure the plastic to the limb, but do not wrap it too tightly or the branch may be damaged. Broadleaf mistletoe requires light and will die within a couple of years without it. It may be necessary to repeat this treatment, especially if the wrapping becomes detached or if the mistletoe does not die.
Simply cutting the mistletoe out of an infested tree each winter, even without wrapping, is better than doing nothing at all. Even though the parasite will grow back, spread is reduced because broadleaf mistletoe must be several years old before it can bloom and produce seed.
For a list of Certified Arborists in our area or for more information related to mistletoe, you can contact the UC Master Gardeners at 209-953-6112. More information can be found on our website: http://sjmastergardeners.ucanr.edu/CONTACT_US/
If you have a fruit tree, you know that gardeners are not the only ones who enjoy the bounty of the harvest. There are many pests — such as scales, aphids and mites –that feast on the tender plant parts and these same pests overwinter on the fruit trees. Dormant oils help control these annoying pests and are safe for use on fruit trees.
Dormant sprays or delayed dormant sprays are a generic term for an application of pesticides—including fungicides, highly refined horticultural oils and oils in combination with a pesticide– that are applied to leafless deciduous trees during fall, winter, and early spring. All fruit and nut trees and many landscape trees and roses are susceptible to aphids, mites, scale and specific insect and disease problems affecting fruit quality and tree health
Some dormant sprays are applied to control over-wintering insects, while others are used to prevent disease infection. While dormant sprays are commonly used on fruit trees, they can also benefit roses and other ornamental shrubs that might develop insect or fungal disease problems as the warmer weather arrives in the spring. Dormant sprays should only be used in conjunction with good garden sanitation. Be sure to rake up and dispose of all fallen leaves and debris that may harbor fungus spores and overwintering insects.
Dormant oil is a refined petroleum product formulated for fruit tree use. It has been in use for well over a century in commercial orchards, and is still regularly used today. It is classified as an insecticide, and acts by coating over-wintering insects hiding in tree trunk and limb bark with a suffocating layer of oil. Oils used at this time of year include insecticidal oils, narrow range, supreme and superior oils. Dormant disease control applications use materials such as copper, lime sulfur, Bordeaux, and synthetic fungicides.
Dormant sprays provide efficient and economical treatment for a number of over-wintering pests and diseases such as: scale, peach twig borer, aphid eggs, leaf curl, powdery mildew and shot hole.
Here is a partial list for fruit trees:
• Apple and pear – dormant oil helps control scale, overwintering aphids, mite eggs and pear phyla.
• Apricot – dormant oil helps control scale, mite and aphid eggs and peach tree borer. Never use sulfur on apricots.
• Cherry – is susceptible to oozing from gummosis (Bacterial canker) and may respond to dormant sprays containing fixed copper.
• Peach and nectarine – require repeated applications of fixed copper spray to control peach leaf curl. In December or January, prune off half to two thirds of last season's growth to stimulate new fruiting wood. Spray the ground after removing leaves and branches. Use dormant oil if scale is present.
• Plum and prune -dormant oil helps control scale and overwintering aphid and mite eggs. Apply copper for shot hole fungus. Heavy pruning may be needed to help control tree size. Spray ground after clean up.
• Nut trees- remove any nuts still hanging on the tree. Spray with dormant oil to control scale. Oil sprays also help control peach tree borers and mite eggs.
Applying dormant or delayed dormant treatments
A dormant spray may not be required every year in the backyard orchard. For some insect pests and diseases, one dormant application may be adequate with good spray coverage. For other problems, up to 3 applications may be necessary for good control. Decide if you need to apply by noting the amount of insect and disease pressure during the previous growing season. If you decide to spray always read the label and follow the directions, more is not better. Make sure you dress in protective clothing, including long pants, a long-sleeved shirt, chemical-proof gloves, and safety goggles.
Treat at the beginning of dormancy in late November and again just before the buds begin to open in February or early March. One way to remember when to consider dormant spraying is to do so around Thanksgiving, Christmas and Valentine's Day. Once flower buds begin to open you may damage fruit and kill pollinating bees if spraying is done at this time. Therefore, it is important to spray at the proposed times before “bud break”. Spraying after pruning allows maximum coverage since there are no leaves to block the spray. A good time to spray is right after a period of rain or foggy weather but not during fog, rain or right before a freeze. Avoid spraying trees that are showing signs of drought stress.
Sprays can be applied with a pump sprayer or hose-end sprayer that is sized appropriately for the number of plants you need to spray. The sprayer should be clean, in good working order and not been used for any herbicides. Spray the entire dormant plant taking care to saturate every branch, stem or cane as insects and the tiny dust-like spores of fungal diseases hide in the smallest nooks and crevices. Don't use a dormant spray on any plant that has any leaves or is actively growing. Leaves, especially tender new growth, may be damaged by the spray from the impurities in the oils or the reflection of the sun off the oil.
Dormant oils generally won't harm beneficial insects since they are applied at a time when beneficial insects aren't present on fruit trees and have a low toxicity level to humans and mammals. Furthermore, dormant oils won't leave harsh residue behind. It loses its ability to control pests once dried.
If you have a gardening related question you can contact the UC Master Gardeners at 209-953-6112. More information can be found on our website: ucanr.edu/sjmg
A very basic concept has sparked an exciting revolution with this generation, but it is far from new. Upcycling is the act of taking something no longer in use and giving it a second life and new function. Some of the best examples of
Thrift is still a trend today and a big reason some people upcycle. Others enjoy the artistic aesthetic. One of the biggest reasons for the rebirth of upcycling is the positive impact on the environment. Items destined for the dump are rescued and remade into something useful.
Many garden upcycling ideas start with items around the house and a need for something. So, before you throw away or recycle broken or used items, give them a second look and ask yourself if they can be used in the garden. A quick search on the internet under “repurposing or upcycling in the garden” will give you all the inspiration you will need to get started. We aren't all artists, but with some elbow grease and a little creativity, even the novice can fashion some fun and quirky statements for the landscape.
Here are some of my favorites to help get you started!
- One of the first projects to come to mind are upcycled garden containers like an old bird cage with a spill of charming succulents in the bottom. Paint old tires in vibrant hues, stack them and fill with dirt. Use colanders to make hanging baskets or decorate an old dresser and plant in its drawers. An old chandelier can be spruced up with some paint and makes a great hanging flower planter. Whimsical items take on even more charm when plants are installed in them. Children's rain boots, rusty tool boxes, old tins, teapots, glassware, and more provide interesting planting options.
- Install an old mailbox onto a fencepost near your garden, and use it to keep gloves, tools, seed packets, and other necessities nearby and safe from the elements.
- Milk jugs are amazing garden tools! They can be used as cloches, seed starters, scoops, waterers, dusters, upside-down vegetable planters, and more!
- Yogurt containers, egg cartons, and toilet paper rolls cut in half make perfect containers for holding soil and starting small plants from seeds. Make sure to poke a few holes in the bottom of anything that is solid to allow water to drain.
- Use plastic mesh baskets from cherry tomatoes or strawberries to protect newly-sprouted seedlings such as corn, cucumber, melons, and squash from birds. By the time the seedlings are tall enough to reach through the tops of the baskets, they are no longer as tender and detectible as the birds prefer.
- Save sets of jars for sorting and storing seeds you've collected. Use the same type of jar for each type of seed for quick sorting. Choose the jar size to match the quantity of seeds you have. Place them together on a shelf for quick, at-a-glance recognition and easy retrieval.
- While some plants require lots of room to be happy, succulents actually do better in small containers or planted close together. Colorful food cans make great homes for succulents!
- Don't throw out that chair with the broken seat! Turn it into a pretty planter for petunias and other flowers.
- Planting veggies and need some plant labels? You can paint old kitchen spoon vibrant colors and add your sprouting seedling name. Old mini blind vanes or pained rocks work well too! If you have some wine corks lying around, you can stick them on a bamboo skewer and write the name on the cork for a unique label.
- Turn an old, broken bike into a cool planter. Paint it bright colors, install a planter or basket at the handle bars and park it amongst a wildflower garden.
- Decorative garden balls are an inexpensive alternative to the classic gazing ball. Take an old bowling ball or mason jar, add some paint and glue on some flat marbles (glass gems), pennies, or old costume jewelry to create a unique garden decoration.
With upcycling, the possibilities are limited only to the materials you already have on hand and your creativity. Dig around your basement or garage or scour yard sales to find objects that appeal to you. Then get out the paint, super glue, twine, glue gun and any other decorating tools you need and go to town. Upcycling in the garden can be a fun, family project that let's everyone put a special touch on your outdoor spaces while making a positive impact on the environment.
Storm damaged trees are something many homeowners will have to deal with at some point. This last storm brought
Although some tree failures are not predictable and cannot be prevented, many failures can be prevented. By inspecting trees for common structural defects, many potential failures can be corrected before they cause damage or injury. It is best to make inspections before stormy weather and immediately afterward.
You should inspect healthy and unhealthy trees on a regular basis. Large trees have a greater hazard potential than small trees and should be inspected more frequently and in greater detail.
Always make your inspections from the ground, do not climb the tree or use a ladder to improve your viewing perspective. If you suspect a hazardous condition, immediately contact your utility company and consult an arborist who has the equipment and training to conduct the inspection safely. If you determine that a tree is a potential hazard, keep people, pets, and vehicles out of the area until the hazardous condition has been corrected.
Thoroughly inspect the tree for the following defects:
Determine whether the vertical axis of the tree has recently changed and check the ground around the base of the tree for uplift or exposed roots. If the tree was vertical but has moved from the vertical position, it is called a leaner. These are trees that are in the process of falling and could fall completely at any time and require immediate attention.
Some trees develop more than one trunk, which are often weakly attached and prone to splitting apart— especially those with narrow angles of attachment. This condition is a concern in large trees. Inspect the point where the trunks meet.
Weakly attached branches
Inspect large branches (greater than 3 inches) at the point where they attach to the trunk. Trees with many branches arising from the same point on the trunk are weak and potentially hazardous. If one branch breaks, the others are more likely to fail.
Cavities, large decay pockets, and other evidence of decay
Inspect the trunk and large branches for cavities or large decay pockets. If you find cavities or decay at a point where loads are great (where branches meet or at the base of the trunk), they are a concern. If a cavity or decay pocket is especially large and is at a key structural location, the tree is more likely to fail.
Mushrooms and conks growing on the bark of trees or on exposed roots indicate root rot or wood decay. As the decay progresses, the wood is weakened and failure is more likely.
It is very important to have your tree inspected by an arborist if you find cavities or decay. Tree size and weight distribution should be considered when deciding if the tree is a hazard. Do not attempt to clean out or seal a cavity or decay pocket—you may be doing more harm than good.
Inspect the trunk and large branches for cracks. If a crack is found, determine if it extends into the wood or is confined to the bark. Insert a pencil or other object into the crack and measure its depth. Look into the crack to see if you can tell the thickness of the bark and whether the crack extends into the wood.
Cracks confined to the bark are not usually a problem, but there is reason for concern when the crack extends into the wood. Deep cracks indicate that a separation of the wood within a trunk or branch has occurred and the tree has become structurally weakened. If you find a crack, it is best to have it inspected by an arborist.
Hanging or broken branches (hangers)
Hangers are branches that are broken but have not fallen from the tree. They may still be partially attached or completely separated and lodged in the canopy. Inspect for branches that are hanging down from a break point and for branches that have broken off completely and are resting on other branches. Hangers should be removed as soon as possible.
Dead branches (deadwood)
Branches that have died will eventually fall off and can cause damage when they fall. Inspect trees that lose their leaves in winter when they are in full-leaf (late spring through early fall). Evergreen trees can be inspected for deadwood at any time. If you find deadwood, plan to have it removed. This does not have to be done immediately, but should not be ignored
Obtaining professional advice and services
The best assurance of getting quality advice or tree work is by hiring an arborist certified by
the International Society of Arboriculture (ISA) or a consulting arborist who is a member of the American Society of Consulting Arborists (ASCA). Certification does not guarantee quality performance, it is only a means of helping you select an arborist who has a demonstrated level of knowledge and technical proficiency. You should verify that your arborist is insured and check his or her references. When you call for service, the arborist will come out and assess the storm damage to your trees and explain the best way to repair the tree if it is salvageable.
When Tree Damage Repair Is Not an Option
Trees are beautiful, valuable assets to a property and in most cases an arborist will exhaust all other options before deciding that a tree must be cut down. Unfortunately, some storm damaged trees are simply beyond repair, and complete removal is the only safe course of action.
- Author: Nadia Zane
One of the best ways to improve your soil and plant health is to apply compost, which is decomposed organic matter full
Yes, you read that correctly: worms.
I don't mean tossing food on the ground for worms and less desirable wildlife find. I am talking about vermicomposting, the process in which worms eat your kitchen scraps so the bacteria in their guts can break down nutrients into a form that plants can use. It is a tidy, contained system that recylces food waste, feeds the soil, and connects us with the circle of life (sans heart-wrenching deaths of cartoon lions).
Next you need to get bedding. Bedding provides worms with a place to get away from kitchen scraps to reproduce; it also provides a food source if kitchen scraps are scarce (or unfavorable). The simplest source of bedding is shredded newspaper, but you can also use regular paper, corrugated cardboard, dried leaves (watch for chemicals), or coconut coir. Bedding material needs to be damp enough to feel like a wrung-out sponge. Add a handful of soil, which contains grit for their digestion.
Worms eat almost anything that was once living, but if this is your first time, it's best to stick with vegetable and fruit
There are thousands of worm species worldwide, but only a few are good candidates for worm bins. Redworms (Eisenia fetida) are the the most common, as they live in groups, feed on organic matter at the soil surface (this is why your bin should be less than 12” deep), and lack feelings of wanderlust, making them ideal for closed quarters. Start with a pound of worms, which can be purchased at fishing supply stores or online. Be sure to cover the bin to block out light.
Worms turn their bedding and kitchen scraps into a fine, dark material similar to ground coffee. The simplest harvesting method involves shoving the finished material to one side of the bin, placing fresh bedding and food in the empty side, and waiting for the worms to migrate. This could take several weeks and will never be a complete evacuation. Dumping the bin out onto a large, plastic sheet and scooping the vermicompost off the top (allow worms to work their way down by shining a lamp on the pile) is more thorough and allows you to evaluate whether you want to make any changes in your worm routine.
Although vermicompost is great for any garden plant, it is especially beneficial for veggies. Apartment-dwellers can practice vermicomposting as well and use the finished product on potted plants or give it to friends with gardens. It's difficult to use too much; try to go with a minimum 1/4″ layer. You can scratch it lightly into the soil if desired, especially if you do not use mulch, which prevents it from forming a crusty layer in hot, dry weather.
For more tips and tricks, see Mary Appelhof's excellent book on vermicomposting, entitled Worms Eat My Garbage (Flowerfield Enterprises, 1997).