- Author: Donald (Don) Bollinger
A properly pruned tree produces better fruit and is easier to manage because it is kept to a manageable size. There are lots of things one can learn about pruning and lots of resources available to learn from. The topic is too big to tackle here, but I'll mention a few of the key points…
Our favorite resource is The Backyard Orchard, which has the definitive page on Pruning and Training.
Keep your tools sharp. Bypass pruners (hand size), bypass loppers (same thing only bigger), and a small saw will generally be sufficient for most pruning jobs.
Some types of trees should NOT be trimmed in the winter. These include citrus and avocados, which should be pruned very little, and not when there is a chance of frost. Apricots and cherries should be pruned in the summer, after the fruit is picked, when there is minimal chance of rain. They are both susceptible to fungal infections when pruned in the wet season.
Stone fruits (peaches, nectarines, plums, apricots, pluots) and pome fruits (apples and pears) should be pruned when dormant, mid-December to mid-February in Santa Clara Valley.
You should know what shape you are aiming for when pruning. In The Orchard, we are using an open center approach for almost all of the trees (see an excellent description in UC's publication on Training and Pruning Deciduous Fruit Trees). In this approach, the trunk of the tree is only 2 feet tall. Yes, we cut each tree to a 2-foot stick when we planted them. In the first year, we develop 3–4 scaffold branches off that trunk. The scaffold branches spread at a 45-degree angle upward and outward. Smaller branches and fruiting branches grow from the scaffolds. The resulting tree looks like a martini glass, with branches around the outside and empty space inside. No branches are allowed to grow in the center. This allows sunlight and air circulation throughout the tree, which in turn encourages the best quality fruit. We limit the trees to about 8 feet tall, pruning both winter and summer to keep the tree under control. This way, we can reach all parts of the tree from the ground, to pick, prune, spray, and cover with nets if necessary. The pictures in this post are our Elberta peach (above) and Moorpark apricot (below), pruned to an open center system.
You need to know where to cut to have the effect you are looking for (more details in the Colorado Extension on Pruning Cuts). Cutting off a branch all the way back to its parent branch is called a thinning cut, which thins out the tree for light and air circulation. Cutting a branch back to a smaller side branch is called a reduction cut. This shortens the branch and directs growth to the side branch. A heading cut shortens a branch to a bud and encourages new growth near the point of the cut. This is good for shortening a fruiting branch, leaving a short, strong branch to hold the fruit rather than a long spindly branch.
It is important to know where the tree will produce fruit (see Table 1 here). Some produce fruit on the new growth as it comes out (mulberries and persimmons), some produce fruit on last year's branches (peaches and nectarines), some on older branches (apricots and plums), some on long lasting spurs that are at least two years old (cherries and pomes). If you cut off all the fruiting branches you won't have any fruit!
With all that in mind, start pruning! First, remove any dead or diseased branches. Then remove growth in the center to restore the “open center”. Next prune each scaffold branch, ideally allowing it to become two branches a couple of feet from the trunk, and each of those to become two more a couple of feet further out. The tree never cooperates perfectly, but this is the idea we're going for. Save enough small lateral branches on each scaffold to host the fruit. Make sure you know what those fruiting branches look like for each type of tree!
One final recommendation: brush up on pruning before you start. Every year I read a couple of good web pages and watch a few videos. Look for information from the universities where the fruit grows best. Look for peach info from U. of Georgia, apple info from Washington State, cherry info from Michigan State. California, of course, excels in all types of fruit, so the U. of California information covers them all.
I assisted Allen Buchinski in a great pruning video with pictures from The Orchard (on Zoom in the pandemic year of 2021). Allen pointed me to a very effective series of 4 peach pruning videos gathered together on the Master Gardeners of Santa Clara County site.
- Author: Don Bollinger
December is a slow month in The Orchard, but there are still a couple of things going on, both related to the start of winter. First up, we have had several nights of frost as well as ice on the birdbaths. That means the citrus and avocado trees are at risk. Local weather forecasts have been calling for temperatures as low as 35 degrees. Our microclimate at MCP tends to be a few degrees cooler, with the coldest air in the valley sinking into the park. Still air and clear nights are always the coldest conditions.
Sure enough, the tender young shoots on the citrus and avocado trees have been damaged by the cold. We expected this. We could have protected these young trees; the Sacramento Master Gardeners have a great post titled Frost and Protection for Sensitive Plants that discusses ways to manage frost. We guessed (correctly) that it would not be cold enough to damage the trees. If you look at the pictures, you will see that only the tender new leaves are damaged. Unless we get even colder nights this winter, these trees will grow just fine in the Spring, with no long-term ill effects. If we see forecasts below 32 degrees, we will scramble to protect the youngest citrus and avocado trees. Last winter, our trees were OK with no protection. More mature trees (like our 3-year-olds) can survive several more degrees of cold without severe damage. But be careful. Santa Clara Valley is not always safe for citrus and avocados. There will be rare nights cold enough to kill these trees!
The cold has also finally caused the peach trees to lose their leaves. That means we can now spray for peach leaf curl. The University of California has an excellent Pest Note on Peach Leaf Curl that discusses how to manage it. Following those guidelines, we applied a copper fungicide from a hose-end sprayer until the spray was dripping from the branches. We will probably spray once more, just as the buds begin to swell but before the leaves appear.
Next up, pruning, in January and February.
Photos:
- - Top right: citrus frost damage
- - Bottom left: avocado frost damage
- Author: Don Bollinger
The Master Gardener Orchard at Martial Cottle Park is a demonstration orchard developed and maintained by the Master Gardeners of Santa Clara County. As a demonstration orchard, our mission is to help Santa Clara County residents grow their own fruit trees, using the best science-based and sustainable practices. We want to teach, show and answer questions so you can grow healthy productive trees with bountiful delicious fruit.
This blog will track what we are doing through the seasons at The Orchard. Hopefully, it will provide useful and timely info to help with your trees. We'll note planting, pruning, harvesting, fertilizing as they are happening. We'll also note less obvious things like grafting, odd fruits we are growing, and changes to the watering schedule as the seasons change.
Our first resource is The California Backyard Orchard, a website maintained by UC Davis, the institutional home of Master Gardeners in California. It has ALL the information you (and we!) need to take care of fruit trees. It starts with tree selection, before you even have a tree, through planting, watering, fertilizing, pruning, picking, and managing those pesky pests. And it has specific information for each of two dozen types of trees. When in doubt, look it up at The California Backyard Orchard.
We did a COVID-safe Zoom talk “Getting Fruit Trees off to a Good Start” in January 2021. It provides a great overview, in about an hour, of everything we did in the first two years in The Orchard.
The first trees in The Orchard were planted in January 2019, so we are now completing our third growing season. We have been minimizing fruit production to focus the trees on strong growth. The wait is over, we are anticipating our first significant harvest in 2022.
You can visit us at The Orchard. Martial Cottle Park is Santa Clara County's newest urban park. “In order to maintain its agricultural history and preserve this land for future generations”, the Cottle-Lester family donated their 287-acre farm “to the State and County for development of a park that informs and educates the public about the agricultural heritage of the Santa Clara Valley”. Master Gardeners are developing 4 acres of the park as a demonstration garden. The Orchard occupies ¾ of an acre in the Master Gardener section. Martial Cottle Park is at 5283 Snell Ave.
The easiest way to access The Orchard is to park on Chynoweth Ave near Vauxhall Circle and enter the park through the Chynoweth gate. The Master Gardener section will be on your left, the entrance is about 400 feet down the park road. Once in the Master Gardener section, The Orchard is at the farthest corner opposite the entrance.
