- Author: Gayle Nelson
By Gayle Nelson, U.C. Master Gardener of Napa County
Armed with a little knowledge and time, any homeowner can prune his or her own fruit trees. Here's a multi-point primer to get you started, beginning with some actions to take well before you prune.
Keep fruit trees under six feet in height. Train the tree in the first few years to create a strong scaffold and branch structure. This balanced, open structure and short stature will make future care easier and minimize the potential of a ladder mishap.
Thin fruit early so that remaining fruits are five to six inches apart. Discarding fruit may seem wasteful, but thinning allows the remaining fruit to develop to full size and reduces the risk of disease transmission and broken limbs.
Prune regularly. Begin right after new trees are planted and continue pruning thoughtfully throughout the tree's life. Pruning establishes a sound structure, promotes air circulation, balances shade and sun and encourages fruit production. Numerous books and online resources can advise you on how to prune each type of fruit tree correctly. Typing “UC fruit tree pruning” into your search engine will yield University of California-sanctioned publications, articles and videos for guidance.
Understand the difference between dormant pruning and summer pruning. Dormant pruning takes place in winter when the tree's leaves have fallen and you can see the branch structure clearly. Pruning during dormancy helps manage fruit production and guide the structure. It invigorates the tree, spurring growth the following spring.
Summer pruning manages the size of the tree. You can prune any time from spring through summer to train young trees, reduce tree height and improve sunlight access.
Learn some tree anatomy. Mastering such terms as scaffold branch, lateral branch, node, fruiting wood and fruit spur, water sprout and branch collar will help you understand your tree's growth cycle.
A scaffold branch is a main structural limb. Lateral branches emerge from the scaffold branches but are not as strong or upright. A node is where a leaf attaches to the shoot. Fruit spurs are short branches that produce the flowers and fruit on most trees. Water sprouts are vigorous vertical shoots that emerge from a tree's trunk or branches. They rarely produce fruit. The branch collar is the enlarged woody tissue where the branch attaches to the trunk.
Tackle some pruning vocabulary. A leader is a dormant, upright stem that usually becomes the main trunk in a tree trained to a central leader or modified central leader. “Open center” is a method of training in which three to five primary scaffold branches are developed low in the tree and the center of the tree is kept open. A thinning cut—removing a branch or cutting it back to a lateral branch—improves light penetration. Thinning, in contrast, is selective pruning done to improve branch spacing, direct growth, eliminate weak or defective branches and reduce the end weight of branches.
Assemble the right tools. Bypass hand pruners and loppers do essentially the same job but on different-size branches. A pruning saw is handy for removing larger limbs. Wearing gloves and personal protection equipment such as safety glasses is good practice.
Keep tools clean, oiled and sharp. If the tree is diseased, sanitize tools between cuts to keep the condition from spreading.
Allow plenty of time for pruning. Gather your tools and sanitizer. Now take a long look at the tree. Are there any dead or broken branches, crossing limbs or vertical water sprouts? Does the tree seem lopsided? Begin at the back of the tree or near the bottom to get a feel for the process.
Work from the inside out. Never leave a stub. When heading, cut back to an out-facing bud. When thinning, cut outside the branch collar and don't seal or paint the cut. Downward bending branches eventually lose vigor and stop producing fruit. Cut off the downward-hanging part.
Learn where your tree produces its fruit. Apples and pears bear differently than peaches and nectarines.
Do most of the pruning in the top of the tree so the lower branches are exposed to sunlight. Sun-exposed wood remains fruitful and produces the largest fruit. Shaded branches eventually stop fruiting and will never produce again without drastic topping. Balance is the key, and practice helps you get it right.
Take time to inform yourself, and you can readily manage your own fruit trees, relying on the research and recommendations of the University of California Cooperative Extension.
Workshop: SORRY The “Fruit Tree Pruning and Grafting” on Saturday, January 21, 2017 is full please see our website calendar for other workshops at http://ucanr.edu/ucmgnapa
There will be another Fruit Tree Workshop covering "10 Thing to Know about Fruit Trees" held in Yountville on Sunday, February 12, 2017, 1-3 pm. Contact Yountville Recreation, Adult Programs for details.
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. U. C. Master Gardeners of Napa County ( http://ucanr.edu/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.
I've often felt overwhelmed by what seems like such a complicated task. But I've learned that pruning is really not difficult. My first tip is to be aware of how pruning affects your fruit trees.
Pruning strengthens branch structure, controls size for better fruit and easier harvesting and makes the tree more visually appealing.
If you wait until warmer weather to prune, the tree will no longer be dormant. You will waste a lot of the tree's energy if you cut off blossoms that it has already created. Pruning now increases fruit size and quality. But one of the big benefits of pruning in winter and early spring is that it's easy to see the branch structure without all those leaves.
A fruit tree's vertical branches tend to be vegetative, while horizontal branches tend to be fruiting. In other words, upright branches create the leaves that supply the energy the tree needs to grow fruit. It takes both types of branches to create good fruit.
Shade inhibits flower production on fruiting branches. If overly shaded, the tree will only set fruit on the outside edges of the branches. Good pruning produces a canopy that allows for air and light flow and makes it easier to thin and harvest fruit.
You will need clean pruning shears, loppers with a 24- to 30-inch handle, and an 8- to 15-inch curved-blade pruning saw. Do not use any kind of sealer when cutting branches. Let the tree use its own natural defenses to heal the cut.
Step 1: Clean up the tree. Remove any suckers growing straight up from the roots and rootstock. Remove any dead or diseased branches and any crossing branches that are rubbing each other. If you remove diseased branches, disinfect your shears between cuts with a 10 percent bleach solution to keep from spreading the disease to other branches. Don't leave stubs. Make cuts close to the branch or trunk.
Step 2: Thin branches to allow light and air into the canopy. A good rule of thumb is to leavesix to twelve inches of air space around branches. Smaller branches need less air space than larger ones. Branches that bend downward eventually lose vigor and produce fewer and smaller fruit. Cut off the part that is hanging down. Now look for any straight, thin, vigorous branches growing straight up from the trunk or other branches. These water sprouts mainly produce leaves. They block light and air so remove them.
Strong branches that can bear the weight of fruit grow at angles of 45 to 60 degrees. If necessary, you can often bend younger, flexible branchesto force a proper angle using sticks, clothespins or ties. If a branch has hardened into a bad position, it's probably best to remove it.
Step 3: Head back and shape.This last step is easy because you're just giving the tree a haircut. Removingsome of last year's branch growth makes a stronger support for fruit. Sun-exposed wood produces the most and the largest fruit. Do most of your heading at the top of the tree to allow light to reach lower branches. Most people prefer keeping a fruit tree under eight feed to make it possible to harvest without a ladder.
Annual branch growth can be anywhere from two inches to four feet depending upon the tree's vigor, but you should be able to identify new growth by the wrinkly ring of bark encircling each stem.
Make heading cuts within ¼-inch of a bud. New growth occurs where you make the cut, so cut just above buds that face in the direction you want the branch to grow. That bud is in charge and says, “We're going this way” to the branch.
On peach and nectarine trees, remove half of last year's growth. On fig, apple, pear, plum and apricots, remove about 20 percent of last year's growth. Cherry trees are an exception; they are only pruned in summer.
Now sit back and prepare to enjoy the fruits of your labor. If you have questions about pruning or gardening, don't hesitate to call or visit the UC Master Gardeners of Napa County. See office hours and phone numbers below.
Workshop: UC Master Gardeners of Napa County will host a workshop on “Garden Planning” on Sunday, January 24, from 1 p.m. to 3 p.m. at the Yountville Community Center, 6516 Washington Street, Yountville. At a loss about what and where to plant in your own garden? Aren't sure of the factors that lead to a thriving yard? Home gardeners will examine their own garden's microclimates and receive tips and direction for choosing sites and plants suited to their particular locations and microclimates. To register, call the Parks and Recreation Department at 707-944-8712 or visit its website.
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. U. C. Master Gardeners of Napa County ( http://ucanr.org/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.
As avid gardeners,we often choose landscape plants that attract bees and insects, but what if the very plants we purchase contribute to the decline of these garden visitors?
If seeds, plants or flowers have recently been treated with neonicotinoid pesticide, these plants may do more harm than good. First developed in the 1980s, neonicotinoids (neonics) are the first new class of broad-spectrum pesticides in over 50 years.Then eonicotinoid group includes imidacloprid, one of the most popular garden insecticides sold in stores.
Neonics are widely used in horticulture and agriculture for a variety of pests. Like most powerful insecticides, they affect the insect nervous system; however, neonics themselves are comparatively safe for birds and mammals.
A systemic pesticide, neonics are absorbed by the plant and transferred through its vascular system. Consequently, the plant and, to some degree, its nectar and pollen become toxic to insects. The toxin remains active in the plant for weeks and detectable in the soil for years.
Untreated plants can absorb these chemicals from treated plants nearby. As pollinators feed on these plants, they may be exposed to the pesticide. This exposure can have a variety of effects, depending on dose and sensitivity.
Effects on an insect can include disorientation, a weakening of the immune system and death. Even slight exposure to neonicotinoids can affect some bees' ability to navigate or detect odors, impairing their ability to forage for food. While this may seem like it's better than dying, a bee that can't forage effectively may be as good as dead.
In 2013, European Union member states voted to prohibit the use of three neonicotinoids—imidacloprid, clothianidin and thiamethoxam on flowering plants and some crops. A mass die-off of bumblebees in Oregon that same year was attributed to a misapplication of neonicotinoids on linden trees. This outcome led Oregon authorities to adopt permanent restrictions on dinotefuran and imidacloprid, both neonics.
While neonics have little effect on honeybees, they can have profound effects on native solitary bees and bumblebees. These species don't get the headlines that honeybees do, but they are important pollinators.
Many home and garden retailers have already agreed to eliminate neonic-treated plants from their nurseries. When purchasing a plant that is or soon will be in bloom, look for a tag that states that it is neonic-free.
When applying pesticides, read labels carefully. Look for warnings that the pesticide may have adverse effects on pollinators. Follow application instructions, both for your own safety and to avoid killing non-target insects such as pollinators. Consider the consequences of using systemic insecticides containing imidacloprid, clothianidin, thiamethoxam, acetamiprid and dinotefuran, especially on blooming plants attractive to bees.
Avoid combined fertilizer-insecticide products as many of these contain broad-spectrum insecticides. Use safer products such as horticultural oils or soaps. More importantly,practice Integrated Pest Management techniques to control garden pests.Visit http://www.ipm.ucdavis.edu/ for more information on these methods.
Broad-spectrum insecticides are not selective. They can kill beneficial insects like ladybugs as well as other predators and parasites that control pests. That said, neonics don't kill all insects that land on a plant, only insects that eat the plant or its parts. Unfortunately, this can include bees and other beneficial insects if the plant is, or soon will be, in flower and attractive to bees. On plants that are wind pollinated, such as oaks and grasses, this is less of a concern.
Bees and other pollinators pollinate 70 percent of the world's flowering plants, and more than 30 percent of the plants that produce food. As informed gardeners, we have choices. We can purchase safe garden plants and flowers and limit our use of neonics. Creating pollinator-friendly gardens as a food source for beneficial insects is one step to protecting all bees and pollinators.
Workshop: U. C. Master Gardeners of Napa County will host a workshop on “Fruit Tree Pruning and Care” on Saturday, January 16, from 9:30 a.m. to 2 p.m. The workshop includes a lecture session from 9:30 a.m. to 11:30 a.m. at the University of California Cooperative Extension office, 1710 Soscol Avenue, Napa. A hands-on session at a local orchard follows, rain or shine, from 12:30 p.m. to 2 p.m. Please dress for outside weather. On-line registration (credit card only); Mail-in/Walk-in registration (cash or check only).
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. U. C. Master Gardeners of Napa County ( http://ucanr.org/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.
Then I knew it was time to prune, and I felt faced with a daunting task. The first thought that came to mind was the medical principle: Do no harm.
I knew that I needed sharp tools so I got out my pruning shears and loppers. With the help of a little steel wool, a sharpening stone and a few drops of mineral oil, my pruning arsenal was ready for deployment.
After spending what seemed like hours reviewing each of my 10 fruit trees, I concluded that I had no idea what I was doing. Pruning was not going to be the easy task I had envisioned, and I was concerned about violating the “Do no harm” rule. Research was required.
Thanks to several books and the Internet, I developed a better understanding of pruning, starting with why it's necessary. Top three reasons: You prune to strengthen the branching structure;to control tree size for ease of harvesting; and to both promote and control fruit production. Lastly, at least to me, you prune for aesthetic appeal. I care less about how the tree looks and more about how much fruit it produces and how the fruit tastes.
After my research, I was able to formulate a general pruning approach. By general, I mean that fruit-tree pruning is not a one-size-fits-all endeavor. Different trees have different needs.
Start by removing any dead, damaged or diseased branches. Dead wood will be dark or brittle, often with the bark falling away. Diseased wood is often a different color than the other branches. You can, and should, prune dead, damaged and diseased wood at any time of year. Whenremoving diseased wood, be sure to clean your toolsafterward so you not spread disease to other trees. Use a solution of 10 percent bleach and 90 percent water.
Next, remove any suckers, the branches growing from the base of the tree. Then cut off any water sprouts, thin branches that usually grow straight up. They will never bear fruit, and they just sap energy from the plant. Removing them early in the pruning process will help you see the structure of your tree and make it easier to see where further cuts are needed.
Prune out downward-facing branches as they will be shaded and won't be productive. Remove any branches that cross or rub against larger branches. Over time, the sustained rubbing would damage both branches.Each branch that remains should create an angle of at least 45 degrees.
Now focus on thinning interior branches so that sunlight can reach all the fruit. Light penetration is essential for flower-bud development and for optimal fruit set, flavor and quality. Be ruthless. You can safely remove up toone-third of the branches. Cut off all spindly growth.
Although a mature tree may be growing in full sun, a dense canopy may not allow enough light to reach the interior. Thinning the canopy also enhances air flow through the tree, minimizing the risk of fungal diseases.
Last but not least, prune your fruit trees to the desired height. I don't want to get out a ladder every time I want an apple or peach, so about eight feet is the maximum height for me.
After you finish pruning, practice good sanitation and cleanup the area. Remove fallen leaves, mummified fruit remains, twigs and branches. I put everything except diseased wood in my compost pile. The diseased wood goes into the yard-waste bin.
I have covered what you should do. Now I'll mention acommon practice to avoid. Do not apply sealing compounds or dressing to pruning wounds. Research shows that these materials seal in moisture, which promotes rot. Leave the cuts open so they can dry and heal naturally.
Now it's time to sit back, relax and dream about sampling the year's first peach, apple or plum. You've earned it.
Pruning Workshop: Napa County Master Gardeners will host a workshop on “Fruit Tree Pruning” on Saturday, February 22, from 9:30 a.m. to 11:30 a.m. (indoor lecture) and from 12:30 p.m. to 2:30 p.m. (outdoor hands-on workshop). Lecture location is the University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Outdoor location to be determined.Now is the best time to prune your fruit trees. Learn techniques to keep them healthy and productive. Please dress for outdoor weather. Online registration (credit card only) Mail in registration (cash or check only)
Napa County Master Gardeners welcome the public to visit their demonstration garden at Connolly Ranch on Thursdays, from 10:00 a.m. until noon, except the last Thursday of the month. Connolly Ranch is at 3141 Browns Valley Road at Thompson Avenue in Napa. Enter on Thompson Avenue.
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. Napa County Master Gardeners ( http://ucanr.org/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County
I imagine that these farmers high up in the Andes are growing potatoes much as their ancestors did when the tubers were first domesticated between 5000 and 8000 B.C. It's pretty staggering to think how long humans have been growing potatoes.
An estimated 4,000 varieties exist worldwide, but here in Northern California we have a smaller selection. Still, seed catalogs offer a variety of types, such as fingerlings and russets, and a range of skin and flesh colors, including pink, white, red, purple and yellow. Varieties vary in size and number of days to maturity. Some are best for baking, others better suited to frying or boiling.
After returning from Peru, I began to grow potatoes in my own garden. I have since learned a lot, having planted them in many different conditions. Potatoes need well-drained soil rich in organic matter; they do not do well in heavy clay. They have shallow roots and need constant moisture but will rot if the soil is too wet. Full sun is required. Being sensitive to frost and heat, they do best as a spring or fall crop in Napa County.
Local nurseries have seed potatoes available for sale now. Potatoes are susceptible to a host of diseases (remember the Irish potato famine?), so you should always plant certified seed potatoes rather than starting with supermarket potatoes.
Potatoes are members of the nightshade family (Solanaceae), which also includes peppers, eggplants and tomatoes. To prevent soil-borne diseases, rotate these crops so that you never grow nightshade plants in the same plot two years in a row. A three-year rotation is even safer.
A day or so before planting, cut your seed potatoes into chunks, each containing one to three eyes. The eyes are the buds from which your potato plant will sprout. If your store-bought potatoes have ever sprouted, they sprouted from an eye.
Bury seed potatoes four inches deep. A few weeks after the leaves emerge, you need to “hill” the plants by mounding more soil around the stems. Hilling will increase your yield because new potatoes grow between the original seed and the soil surface.
Each growing season, Napa County Master Gardeners select a fruit or vegetable to “field test” in our home gardens. We compile and analyze our results for the benefit of the public. We now have a blog called “Spill the beans "where you can find the results of our field trials and other timely gardening information. You can subscribe to the RSS feed for our blog on our website (http://ucanr.edu/sites/ucmgnapa).
Last year the field-test committee trialed three different potato varieties: ‘Mountain Rose' (an early-maturing variety with rose-colored skin and flesh);‘Russian Banana' (an heirloom fingerling variety); and ‘Sieglinde' (a yellow, waxy mid-season type). With more than a dozen Master Gardeners participating, representing a variety of growing conditions and irrigation techniques, it was interesting to see the results.
The greatest yield came from raised-bed gardens with drip irrigation. Several participants planted their potatoes in Grow Bags (porous fabric pots), while others planted in the ground. Some watered by hand while others had drip systems. Some gardeners had success burying their seed potatoes in a tower of straw instead of planting in soil. As the plants grew, the gardeners added more straw.
For all of us, the take-home message was that gardens with regular watering and well-drained and well-cultivated soil produce the greatest yield. I confess that I planted mine in a bed without irrigation. They did not do well in the summer heat, and I never harvested anything. But I am happy to note that the potatoes are coming up again in that bed, and I will try to take better care of them this time.
My family's favorite part of potato growing is the harvest. Early-maturing varieties may be ready after only 60 days. My children and I get very excited when the plants start to flower. That's a sign that you can plunge your hand into the soil and find some new potatoes.
At this point, you should stop watering and let the foliage turn yellow and die back. If you leave the new potatoes in the ground for at least two more weeks, the skins will harden and the potatoes can be harvested and stored in a cool, dark place. Alternatively, you can leave them in the ground until you are ready to eat them.
For more information, consult “Growing Potatoes in Napa County” by former county farm advisor Dean Donaldson. You can find this document online on our website(click on Gardening Resources, then on Healthy Garden Tips). Or pick up a copy during our office hours (address below).
Workshop: Napa County Master Gardeners will host a workshop on “Fruit Tree Pruning” on Saturday, February 22, from 9:30 a.m.. to 11:30 a.m. (indoor lecture) and from 12:30 p.m. to 2:30 p.m. (outdoor hands-on workshop). Lecture location is the University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Outdoor location to be determined. Now is the best time to prune your fruit trees. Learn techniques to keep them healthy and productive. Please dress for outdoor weather. Online registration (credit card only) Mail in registration (cash or check only)
Napa County Master Gardeners welcome the public to visit their demonstration garden at Connolly Ranch on Thursdays, from 10:00 a.m. until noon, except the last Thursday of the month. Connolly Ranch is at 3141 Browns Valley Road at Thompson Avenue in Napa. Enter on Thompson Avenue.
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. Napa County Master Gardeners ( http://ucanr.org/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.