- Author: Anne Schellman
What is a Deciduous Fruit tree?
Deciduous fruit trees lose their leaves in fall, and include apple, pear, fig, pomegranate, nectarine, cherry, apricot, peach, and plum.
Planting New Trees & Understanding Where Fruit Originates
Sometimes a fruit tree mysteriously dies, and the gardener isn't sure what happened. A common cause is a tree that was planted too deeply. Root and crown rot slowly affect the tree, causing it to die years later. Watch the detailed instructions on how to plant correctly.
It's important to understand how new fruit develops and grows on the tree. Not all deciduous fruit trees produce fruit in the same place. It's important to know this so you don't accidentally cut off fruit spurs and damage your tree's ability to produce fruit. See this video for guidance. https://www.youtube.com/watch?v=-4fgVrf8XHE&t=250s
Publication - Fruit Trees: Planting and Care of Young Trees https://anrcatalog.ucanr.edu/Details.aspx?itemNo=8048
Fruit Trees: Training and Pruning Deciduous Trees https://anrcatalog.ucanr.edu/Details.aspx?itemNo=8057
Keeping New Trees Small – the Fruit Bush Method
Tired of out-of-control fruit trees? If you are planting a new tree, watch this video! It details the Fruit Bush Method, a specific way of keeping fruit trees small. See photos of 5-6' tall fruit trees planted over 30 years ago that continue to produce an ample amount of fruit. https://www.youtube.com/watch?v=ry4YAp6NzdI&t=1s
Pruning Established Trees
Other Helpful Publications
Fruit Trees: Thinning Young Fruit https://anrcatalog.ucanr.edu/Details.aspx?itemNo=8047
What about Citrus Trees?
Citrus trees such as oranges, lemons, grapefruits, lime, and kumquats are evergreen trees and need different care than deciduous trees. It's not recommended to prune citrus trees at the same time as deciduous fruit trees. Wait until spring to prune your tree for size and shape.
We are offering an online class on citrus on January 31, so watch for our registration advertisement in about a week. Locally, we will be teaching at 8 library locations about citrus during March.
- Author: Anne Schellman
Why spray for peach leaf curl disease?
Right now, the fungus that causes leaf curl is present on your trees. Once spring arrives, its spores “move” via water droplets splashed onto developing leaves. When the environment is right, these spores invade newly developing leaves, growing in between leaf cells and causing distortion of cells.
Symptoms of peach leaf curl disease include puckering leaves that curl and turn a reddish color. Often the entire first set of leaves may drop off. When new leaves begin to grow, these leaves are also infested. Twigs and shoots distort and often die. Fruit is rarely affected. However, left untreated, nectarine and peach trees begin to decline and fruit production is substantially reduced.
Often when gardeners see symptoms of leaf curl disease on their tree, they are tempted to pull off the affected leaves, thinking this will help. Unfortunately, there is little to do at this point to control the disease.
Prevention
Using Pesticides
Insects, diseases, and weeds are pests, and products used to kill them are called pesticides. Whether a product is organic or not, it can still have an impact on you and/or the environment, so be sure to follow the directions on the product label regarding personal protection, correct mixing, and application. When spraying, make sure to coat the tree until the product is dripping off. Come spring, your peach and nectarine tree trees should leaf out and grow vigorously, followed by a healthy crop of fruit.
Learn more about peach leaf curl by visiting the UC IPM website and reading their Quick Tips on it at http://ipm.ucanr.edu/QT/peachleafcurlcard.html For more detailed information about this disease, read the Pest Notes at http://ipm.ucanr.edu/PMG/PESTNOTES/pn7426.html
Coming Soon
Bare root fruit trees are arriving in nurseries and garden centers. If you are thinking about planting fruit trees but aren't sure what to plant, how to plant, and how to care for them, you'll want to attend our online Bare Root Fruit Tree Planting and Pruning Class on January 25, 2022. More details coming next week.
If you have fruit trees that produce a lot of small fruit, you may be missing an important step in growing fruit trees called "thinning." Next month we'll publish an article on how and when to thin fruit from Ed Perry, retired UCCE Stanislaus County Emeritus Horticulture Advisor.
Anne Schellman is the UCCE Stanislaus County Master Gardener Program Coordinator.
- Author: UC IPM
Peach leaf curl is a disease that affects peach and nectarine trees. Although you may not see symptoms right now in the dormant season in California, it's time to think about treatment, especially if your tree had the disease last year.
Symptoms of this fungal disease include distortion, thickening, and reddening of foliage as trees leaf out in the spring. As weather warms, damaged leaves that die and fall off trees are replaced with new, usually healthy leaves. However, after several years without treatment, peach leaf curl will cause tree decline and reduced fruit production.
Avoid peach leaf curl by growing varieties resistant to the disease. For nonresistant peach and nectarine trees, consider spraying with preventive fungicides in the dormant season just before or as buds swell.
See the UC IPM publication Pest Notes: Peach Leaf Curl for more information about the disease and management options. Always read and carefully follow all precautions and safety recommendations given on the pesticide label.
- Author: Annemiek Schilder
In this weekly blog, Dr. Annemiek Schilder, Director, UCCE Ventura County and Hansen Agricultural Research and Extension Center, shares her observations about the natural world across the seasons. As she says:
"Gently observing your surroundings with curiosity will teach you some amazing things. There are so many fascinating things happening under our noses, only wanting for an observant eye."
"What is wrong with my peach tree?"
Many people have probably asked this question as they have stared in concerned wonder at the distorted leaves of their peach trees. From a distance the striking color patterns may even look like peculiar flowers. Peach leaf curl is a disease of peach and nectarine trees caused by the fungus Taphrina deformans, an apt name for this fungus. Ornamental peach trees, grown for their beautiful blooms, are also susceptible to this disease.
Peach leaf curl is a common plant disease featured in many plant pathology textbooks. It may well have been the disease that convinced me to become a plant pathologist (a plant doctor) as I peered with increasing fascination at its structures under the microscope.
Allow me to digress a little to discuss that great invention: the microscope. In the late 1600's, Antonie van Leeuwenhoek, a self-taught Dutch scientist, developed a single lens microscope with up to 300 times magnification, allowing observation of bacteria for the first time. He called them “little animals”. However, it would take another 200 years before bacteria and fungi were officially recognized as causes of disease in animals and plants, laying the groundwork for modern-day medicine.
The name of this disease, peach leaf curl, is quite descriptive as the fungus causes leaves to curl and develop blister-like areas. Rainy, cool springs promote infection - as well as spore production - on infected leaves. Spores are spread by wind and rainsplash to other leaves, where they can cause new infections. The disease is not only unsightly –except to the eyes of a plant pathologist, of course - but also causes diseased leaves to drop prematurely, which weakens the tree and may lower fruit yield. In severe cases, repeated defoliations can kill a tree.
Taphrina deformans spores are produced in elongated structures called asci, a Latin word meaning “sacs”.
Have you noticed that Latin is used a lot for botanical descriptions? This is because Latin is a “dead” language and thus grammatically stable.
Taphrina's asci are lined up in layers on the leaf surface without any protective covering; therefore they are termed “naked asci”. So guess what name my Plant Pathology student volleyball team chose? Indeed, our t-shirts sported botanically correct drawings of Taphrina's asci, causing the other teams to think of us a bunch of weird science nerds. Nerds who played a pretty good game of volleyball mind you!
So what can you do to keep your trees healthy? Here are a few tips.
- If you are thinking of planting a peach or nectarine tree, investigate whether resistant varieties are available so you can avoid the problem altogether.
- For established trees, fall pruning of diseased shoots may help.
- Also for established trees, (organic) copper fungicide sprays in late fall after leaf drop and before budbreak in the spring may help.
- Addition of a horticultural oil may improve spray coverage. Be sure to follow the instructions on the label carefully.
If your tree got whacked by the disease, infected leaves will fall off and new leaves will develop but this requires the tree to expend additional energy. A foliar fertilizer application as well as fruit thinning can help the tree recover.
Related Reading:
Advice for Home Gardeners from the Help Desk of the
UC Master Gardener Program of Contra Costa County
Help Desk Response: Thanks for contacting the UC Master Gardener Help Desk about the problem you are observing on your nectarine tree.
Your nectarine tree is showing the classic symptoms of a fungal disease commonly called "peach leaf curl". It is a common problem for both peaches and nectarines, particularly in years when we have abundant rains as has now occurred this year. The fungal spores that spread the disease can be spread through splashing water and rain.
As you may already have noticed, typically the affected leaves turn yellow or brown and can remain on the tree or may fall off; they are replaced by a second set of leaves that develop more normally unless wet weather continues. Most often the disease will not show up on the developing fruit, but occasionally it does affect fruit, causing corky areas to develop on the fruit surface. Those fruits are still okay to eat—just cut away the affected area.
Unfortunately, there is nothing you can do now to stop the disease on your tree. The typical management approach for controlling peach leaf curl is to use a fungicide in the late fall or early winter months when the tree is dormant. The use of fungicides when the tree is dormant can control the development of the spores that usually survive the hot summer months on the surface of the tree bark. Those spores are reactivated by winter rains and attack the leaves when they emerge in the spring. You should plan now to consider applying such a fungicide in early December, particularly if we are having frequent rains. Just try to schedule the fungicide spraying for a time when you expect to have several successive days of dry weather so that the fungicide can work and not be washed off the tree. You can learn more about peach leaf curl and the use of fungicides to control it at this University of California website: http://ipm.ucanr.edu/PMG/PESTNOTES/pn7426.html
Since fungal spores may also be present on the fallen leaves, it is a good idea to pick up all fallen leaves. Don't put them in your compost pile unless you have a pile that regularly achieves and maintains high temperatures. If your compost piles doesn't have those high temperatures on a regular basis, you can dispose of the leaves in a green bin that goes to a waste company's compost area. Fortunately, those sites typically have compost piles that achieve the high temperatures needed to kill fungal spores.
If you have not yet fertilized your tree, this would be a good time to feed. Just be careful not to use too much fertilizer. It would be better to use less now and re-apply some additional fertilizer is about a month or six weeks. Here's a link to more information on peach tree care: http://homeorchard.ucanr.edu/Fruits_&_Nuts/Peach/ which also applies to nectarine trees.
We hope that this information is helpful. You're welcome to contact us again if you have other questions.
Help Desk of the UC Master Gardener Program of Contra Costa County (TKL)
Note: UC Master Gardeners Program of Contra Costa's Help Desk is available almost year-round to answer your gardening questions. Except for a few holidays (e.g., last 2 weeks December), we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 2380 Bisso Lane, Concord, CA 94520. We can also be reached via telephone: (925) 608-6683, email: ccmg@ucanr.edu, or on the web at http://ccmg.ucanr.edu/Ask_Us/. MGCC Blogs can be found at http://ccmg.ucanr.edu/HortCoCo/ You can also subscribe to the Blog.
