- Author: Elinor Teague
It's so nice to have a lush garden again (however short the time until drought resumes) but the vigorous plant growth will cause problems this summer.
Plants and trees that have suddenly outgrown their spaces this spring will obviously need to be trimmed back, but the trimming and pruning should not be a one-time major cut back. Reducing the size of the leaf canopy by more than 25 to 30 percent during the growing season removes too much of the plants' and trees' sources of energy and can cause stunted growth. A light pruning using thinning cuts to reshape the outer canopy of only those branches that are obstructing access or that risk causing property damage would be best during the summer. Leave the removal of larger branches and branch scaffold restructuring until winter when deciduous trees are dormant.
The recent overgrowth on many plants will have shaded the soil underneath the larger canopy as well as the roots that extended to the edge of the enlarged canopy. Those roots may well die back in the hot soil. Expect to see some wilting and signs of heat stress after even moderate pruning.
The second caution on pruning overgrown plants this summer involves the risk of sunburn on newly exposed interior wood. We can expect that the Central Valley will experience several heat spikes, or long periods of high daytime temperatures (above 100 degrees) along with warm nighttime temperatures, in the next few months. Sunburn is a common problem on hedges that are pruned heavily during the summer in the Central Valley with the hedge tops showing most of the damage from the sun's rays. It's best to shear hedges lightly and frequently, every six to eight weeks, in the summer. To help reduce damage from sunburn, use a mixture of half water/half white latex paint on exposed wood, especially on citrus and other fruit and nut trees, to reflect some of the sun's harsh rays. The open center or vase-shaped pruning system on most fruit and nut trees should be maintained in the summer months.
The UC ANR publication 8057 on pruning deciduous trees has line drawings of several pruning methods and a glossary of pruning terms, which provide very basic pruning information. A long time favorite pruning guide, Orthos' ‘All About Pruning,' is once again out of print but worth searching for in used book stores for its excellent detailed descriptions, drawings and photos of the proper pruning techniques specific to many tree and bush species. DK Publishing (one of the best publishers of garden books) has “Grow Pruning and Training" ISBN 9780744026832, $12.99, which seems to be a good replacement for the Ortho guide.
- Author: Lauren Fordyce
Spring is just around the corner and many types of fruit trees are starting to develop their leaves. If you are growing peaches or nectarines and are now seeing symptoms of peach leaf curl on new leaves, unfortunately it's too late to manage the disease.
According to University of California research, peach leaf curl can only be effectively managed during the fall and winter, after leaves have dropped but before buds swell in spring. After bud break (when new buds begin to open), you may notice symptoms on new leaves but at this point, there are no effective controls. Pesticides used against peach leaf curl prevent the disease as opposed to curing it. Currently there are no verified curative methods for controlling peach leaf curl during the growing season.
Peach leaf curl is a fungal disease that primarily affects peach and nectarine trees. Its spores overwinter on the twigs and flower buds, and germinate in the spring causing distorted, reddened leaves. If left untreated for several years, trees can decline and may need to be removed. In some cases, peach leaf curl can also affect fruit quality.
During the dormant season (fall and winter), spray affected trees with a fungicide containing the active ingredients copper or chlorothalonil. These active ingredients can be used alternately to limit copper buildup in the soil. Horticultural oils and other fungicides have not proven to be effective against peach leaf curl. Always read the label of the pesticide product you want to use and verify that it is labeled to treat the pest you are dealing with. To learn more about pesticide active ingredients and their potential toxicity, see the UC IPM Pesticide Active Ingredient Database.
To learn more about this disease and its management, visit the UC IPM Pest Notes: Peach Leaf Curl.
- Author: Ben Faber
Planning and Planting the Small Orchard Block
February 23-26, 2023
Course Overview
This new short course will offer a wealth of information from orchard expert, Orin Martin, long-time manager of the Alan Chadwick Garden and instructor at the UC Santa Cruz Center for Agroecology. The course will walk participants through the planning and planting of a new apple orchard block at the UCSC Farm, from site selection and soil preparation to sourcing and planting quality trees (in quality holes). At the UCSC Farm and Alan Chadwick Garden, participants will look at orchard blocks of different ages and varieties for lessons on seasonal care, pest/disease/weed management, and winter pruning. At Fifth Crow Farm, participants will visit an orchard block Martin helped plant with the Fifth Crow farmers 15 years ago and hear from the farmers about the orchard's growth, maintenance, and production for their diversified organic farm with direct markets around the Bay Area. The course includes an introductory webinar online along with a set of videos on soil preparation for the orchard block, planting, winter pruning, summer pruning, and more.
The course will have an emphasis on growing apples, but will also cover pears and stone fruit. Key considerations, concepts, and skills covered will include:
- Site selection - flat ground or sloping ground, aspect (direction of slope)
- Sunlight (>6-8 hr/day)
- Climate and weather (microclimate too)
- Soil (assessment and improvement)
- Fertility plan
- Scale and types of fruit to be grown
- Orchard layout
- Rootstock selection (size control)
- Sourcing quality trees
- Pollination factors
- Irrigation
- Weed management
- Pruning and training
- Pests/disease
- Planting and seasonal care
This is a course for anyone, novice to intermediate-level grower, wanting to learn more about the 'hows (skills and techniques) and whys (a little of the relevant science behind the hows (in bite-sized, digestible morsels)' of deciduous fruit tree growing.
About the Instructor
Orin Martin is the author of Fruit Trees for Every Garden: An Organic Approach to Growing Apples, Peaches, Plums, Citrus and More (2020 American Horticultural Society Book Award Winner). Since 1977, he has taught classes, lectures, and workshops to thousands of home gardeners, apprentices, students, and budding farmers.
About Fifth Crow Farm
Fifth Crow Farm, a diversified organic farm founded in 2008, is located in Pescadero about 35 miles north of Santa Cruz. The three farmer/owners—Teresa Kurtak, Michael Irving, and John Vars—and a committed team of farm staff manage 30 acres of row crops, a 24-variety apple orchard, a young pear orchard, and a pastured egg operation, marketing through a CSA and farmers markets throughout the Bay Area, as well as to restaurants. For information about their farm and orchard operation, visit their website.
Registration Information
Pre-registration for the course is required. The course carries extension credit from UCSC Extension and has a $200 fee. REGISTER FOR THIS COURSE
Scholarship Information
Scholarships are available. APPLY NOW FOR A SCHOLARSHIP
Course Schedule
- Thursday, February 23rd, 5:30-7:00pm — Online introductory webinar
- Saturday, February 25th, 9:00am -12:00 pm — UCSC Farm; 1:00-4:00pm — Alan Chadwick Garden
- Sunday, February 26th, 9:00 am-12pm —Fifth Crow Farm
See Also
- 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.
/h3>/h3>/h3>/h3>/h3>/h3>- Author: Help Desk Team
Winter is an ideal time to plant a fruit tree. Although it requires some patience, success is best using bare root trees. There are many advantages: the trees are lighter and easier to handle; you can get a good look at the roots; they cost less than leafed-out potted trees; the tree is dormant and less apt to be stressed by handling; and the roots don't have to adapt again to new soil. The main disadvantage is that you should get the tree in the ground within a few days after purchase, and it may take 2–3 years before some trees produce fruit.
Fruit trees are an investment and deserve some thoughtfulness to ensure you plant the right tree (appropriate for your climate zone) in the right location (good drainage, minimum 6 hours sun per day). Digging the planting hole before buying the tree will let you check for drainage and an adequate amount (2–3 feet deep minimum) of soil. Here is a website showing how to test soil including drainage: https://marinmg.ucanr.edu/BASICS/SOIL_813/evaluate/
Selecting a healthy bare root tree is critical to get your investment off to a good start. Buy your tree from a reputable nursery that has a wide selection. You don't want a tree with roots that have been in a container too long. These roots may be kinked and will look like they are circling the root ball. These roots tend not to spread and that deprives your tree of needed nutrients.
When preparing the hole for your tree, follow the steps as described in the article linked below to give the roots room to spread and to prevent the graft site from sinking below soil level. Backfill with native soil. As you can see from the diagram below, most of the root ball should be above the original soil level to avoid crown rot. The tree will also settle.
And unless you want a huge tree with more fruit than most families could possibly eat, prune the trunk back to about knee height after planting. This takes some courage, but your tree will reward you with plenty of fruit that is easy to reach. Wait until the weather will be dry for at least several weeks to prune apricots, apriums, and cherries.
Other considerations are pollination requirements, ultimate tree size, chill hours, and disease susceptibility. Pollination is necessary for good fruit production. Some fruit trees have flowers with both male (anthers) and female (pistils) organs and can self-pollinate, such as persimmons and Bartlett pears. Other trees have flowers with both male and female organs but cannot self-pollinate and will require a second tree planted within 100 feet for fruit production, such as many apple varieties and Asian pears. Still others have separate male and female flowers.
Deciduous fruit and nut trees require a certain number of “chill hours” below 45°F to produce. It is important to select only varieties that have chill hour requirements equal to or lesser than the chill hours listed for your area. This reference discusses chill hours and has links to fruit tree requirements for Contra Costa County: https://ccmg.ucanr.edu/files/77176.pdf
It's important to know which diseases and pests a particular fruit tree is susceptible to. For example, apricots and their crosses such as aprium and pluot are prone to infection by the Eutypa fungus and unlike most deciduous trees, should be pruned in late summer before the weather gets damp. Check the reference below. These references have links and information regarding fertilization, pollination, pests and diseases, and characteristics of various fruit trees.
Despite our recent rains, we are still in a drought. Most fruit trees need substantial amounts of water to become established and as they mature and produce fruit. This link has information about drought tolerant fruit trees, shrubs and vines: https://crfg.org/wp-content/uploads/Drought-Tolerant-Fruiting-Trees-Shrubs-and-Vines-Presentation.pdf
Articles with step-by-step planting guides:
• https://sonomamg.ucanr.edu/Food_Gardening/Additional_KG_Articles/Planting_Bare-root_Fruit_Trees/
• https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=46072
• https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=38836
Excellent video with step-by-step planting guide (UC does not recommend any particular business but this nursery has good videos and does not advertise its products):
• https://www.youtube.com/watch?v=fP-2TGlNo50
More information:
• The Big Picture: https://homeorchard.ucanr.edu/
• Fruit trees for Contra Costa County – great reference to help you decide what to buy, and a pollinating guide: https://ucanr.edu/sites/ccmg/files/228958.pdf
• Fruit tree pests and diseases: http://ipm.ucanr.edu/PMG/GARDEN/fruit.html
Help Desk of the UC Master Gardener Program of Contra Costa County (EAS)