Category Archives: pruning fruit trees

Why Prune in the Summertime?

Pruning is a good way to spend a couple of hours in your garden. I’m not talking about trimming plants into little balls but the kind of pruning that makes for a healthier and happier plant.

Sango kaku Japanese maple- summertime

If you grow Japanese maples now is the time to remove dead branches and train your tree to look like one of those specimens you see in the magazines. Thinning cuts build your ideal tree limb structure. If yours is a young tree, though, don’t be tempted to head back long branches too soon. As these mature they give your tree that desirable horizontal branching.

This principle is important to keep in mind when you train any young ornamental tree. Lateral buds grow along the sides of a shoot and give rise to sideways growth that makes a plant bushy.

Summer pruning of fruit trees controls size by removing energy-wasting water sprouts. Summer is also a good time to remove leafy upper branches that excessively shade fruit on the lower branches. Winter pruning is meant to stimulate the tree. Summer pruning uses thinning cuts-where the branch is cut off at its point of attachment instead of part way along the branch- and these cuts do not encourage new growth but control the size of your tree making fruit harvest easier.

Summer pruning also can control pests like coddling moths, mites or aphids. Just be sure to dispose of these trimmings and don’t compost them.

Espalier apple tree

If you have apricots and cherries, summer pruning only is now advised as they are susceptible to a branch killing disease if pruned during rainy weather. Prune stone fruits like peaches and nectarines after harvest by 50%. They grow quite rapidly. Apricots and plums need to have only 20% of their new growth pruned away.

Be sure to thin the fruit on your trees. That’s another good reason to keep them smaller so you can more easily reach the branches. The best time to do this is when the fruit is still small. Thinning fruit discourages early fruit drop and improves the quality of the remaining fruit. It helps to avoid limb damage from a heavy fruit load. Also it stimulates next year’s crop and helps to avoid biennial bearing. Left to their own devices, a fruit tree may bear heavily one year and then light or not at all the next year. Some types of fruit trees like peaches and Golden Delicious apples are likely to bear biennially if the current year’s fruit crop isn’t thinned.

While I have the pruners out I’ll be shearing back early flowering perennials to encourage another round of blooms. And I’ll add some more mulch to areas that are a little thin. I’ll be checking the ties on my trees to make sure they aren’t too tight and remove the stake if the trunk is strong enough to support the tree on its own.

Also I’ll be looking for any pest problems so I can do something about them before they get out of hand. I’m OK with a few holes here and there but a heavy infestation should be trimmed off or sprayed with an organic insecticide. I also inspect the tips of my fuchsias regularly for fuchsia mites and clip off any distorted growth. I hate to spray even organics on them due to the hummingbird activity.

Most importantly, enjoy your time outdoors. If a task is too big to do at one time, break it down into smaller sessions. As they say, take time to smell the roses.

 

Garden Tasks-Rain or Shine

Those of you who lived in the Santa Cruz mountains during the winter of 1982 remember it well. Following two days or torrential rains, a large section of hillside above Love Creek gave way. Thirty homes were destroyed and ten people were killed by the slide. The rainfall totaled 111 inches that year.

Rain gauge on 2/8/17 showing 99.99″ +10″ more as of 2/18/2017

During the winter of 1997 the San Lorenzo Water Department recorded 90 inches of rain. The department’s historical rainfall data goes back to 1888 and shows that during the winter of 1889 a whopping 124 inches of rain fell. This winter is one to rival the books with about 70-110 inches of rain falling so far depending where you live. We don’t aspire to break any records.

How does this much rainfall affect our gardens? If you have addressed drainage issues and are slowing, spreading and sinking all this water, congratulations. But what about the plants? Fortunately most plants are dormant or semi-dormant at this time of year. Even plants that don’t lose their leaves aren’t in growth mode yet. When a plant is actively growing either roots or new foliage it will suffer if the roots are soggy day after day. Fungal problems and root rot will take its toll on a plant. An extremely wet March or April is not a good thing.

We gardeners are the eternal optimists and hope that only gentle rains will fall through May. And during those lulls in the weather this is what I’m going to be doing over the next month.

California fuchsia – zauchneria californica

Prune fruit, nut, shade trees and deciduous vines like clematis. Cut back woody shrubs like Mexican bush sage, artemisia and butterfly bush to stimulate lush new growth. You can cut back these plants close to the ground. Don’t use this approach on lavender or ceanothus, though. Prune them lightly after blooming without cutting into bare wood.

Prune fuchsias back by a third and remove dead, crossing branches and interior twiggy growth. Container fuchsias can be cut back to the pot rim.

mophead hydrangeas in June

Cut back hydrangeas stems that bloomed last year and apply a soil acidifier if you want the flowers blue. Although sulfur is the traditional favorite for quickly acidifying soil it is not as kind to many beneficial soil microorganisms. Coffee grounds, pine needles, peat moss and cottonseed meal are better for your soil.

I’ll wait to prune back perennials that may have their new foliage damaged in a late frost. Already damaged foliage can protect a plant from further frost damage. Mid-March is the estimated date of last hard frost in our area. Or at least it used to be.

Don’t cut back grasses yet if you get frost in the area where they grow. Wait until mid-March. If you live where you rarely get frost go ahead and prune these plants back now. I’m going ahead and pruning California fuchsia, salvia ‘Bee’s Bliss’ and hummingbird sage now. They look terrible.

camellia sasanqua

Don’t prune spring flowering shrubs and trees like lilacs, flowering cherries, plums and crabapples, rhododendrons, azaleas, camellias, weigela or spirea until after they flower. You can cut some branches during flowering to bring in cuttings for bouquets.

I can tell that spring will soon be here as the flowering plum buds are showing color. Can’t tell from the weather report, though.

Fruit Tree Care – Fertilization & Summer Pruning

Whether you grow one fruit tree or a home orchard full of them there is always something to learn from an expert and Orin Martin of UCSC Farm and the Alan Chadwick Garden is just the guy to help. With nearly 40 years of hands-on experience at UCSC he says he’s come up with a successful method of caring for fruit trees including pruning and fertilizing . “I’ve made every mistake in the book”, he laughs.

Orin_Martin_prunig_fruit_trees
Orin Martin explaining summer pruning

The UCSC Farm and Alan Chadwick Garden on the campus are both internationally known for training, research and public education. Recently I had the opportunity to join Orin during the Summer Orchard Walk at The Farm as he discussed the care of fruit trees and summer pruning to improve tree shape and productivity. Between jokes he shared many tips including the importance of fertilization and preparing an orchard for fall and winter.

Deciduous fruit trees are genetically programmed to start root growth early as they originated in the cold winter climates of Northern Iran, Uzbekistan and other central Asian areas. Their growing season begins in January or February which is 3-5 weeks prior to any visible bud swell when soil temperatures are still in the low 40’s. With this in mind Orin recommends starting fertilization early. Organic fertilizers take longer to become available to the tree and you want to maximize the early growth spurt in spring.

sunflower pollinator attractors
Sunflowers attract pollinators to garden

Orin has a recipe for fertilizing young fruit trees that is used throughout the Farm and Garden. It’s comprised of compost and an organic source of nitrogen such as blood meal, 8% Nitrogen Sustane or Dr. Earth granular. A young tree will need additional nutrients in May and possibly July if the tree is not putting out sufficient structural growth. Fast acting liquid fertilizer such as fish emulsion and liquid kelp can be substituted for the early summer feeding. The second wave of growth occurs in fall. Slow acting organic fertilizer is best at this time.

Next year’s fruit buds are formed in late spring to early summer at the same time current fruit is growing so nutrient needs are extremely important at this time. If a mature tree is growing well its yearly fertility needs may be met by growing a bell bean crop as green manure over the winter.

Ginger_Gold_apples
Ginger Gold apples with resident cats

The two resident garden cats followed our group as Orin demonstrated summer pruning of Ginger Gold apples, Flavor King pluot and Seckel pears. Most are trained to a open center with some having a modified central leader. I asked what he would do if no central leader grew after heading back a young tree whip. “Then I’d train it with an open center. You’ve got to play the hand your dealt”, he laughed.

“Ladderless” harvesting and care is the goal to pruning in summer and winter. Summer pruning from early August to mid September stops growth and is done to limit height and length of branches to encourage more fruiting shoots. Winter pruning creates the tree’s structure. “When you don’t want a tree any taller, stop winter pruning”, Orin told us.

UCSC Farm_Garden_crops
UCSC Farm crops

Throughout the orchard walk Orin Martin shared interesting tidbits of information. Seems that pest problems such as European blister mite and pear slugs are being observed here at for the very first time.

The USCS Farm & Garden has free monthly guided tours as well as a calendar of educational talks and events. It is open daily for everyone to learn and enjoy. Kids tours are offered during the school year in the Life Lab Garden Classroom.

Do I Really Need to Dormant Spray and Prune my Fruit Trees?

Gummosis canker on dwarf nectarine- Photo courtesy of Sherry Austin
Gummosis canker on dwarf nectarine- Photo courtesy of Sherry Austin

A Facebook friend recently posted a picture of gummosis on her dwarf nectarine. While pruning her fruit trees she found the sticky stuff and shared her plight. While some folks post pictures of babies and political opinions on their Facebook page, my friends post pictures of plants and their fruit trees. Yes, if you haven’t already done so, this is the time to winter prune fruit trees and apply dormant spray to fend off diseases and insect pests. With rainfall expected throughout the spring this is not the year to omit this important task.

Why prune your fruit trees in winter? The reasons to prune fruit trees are to increase fruit production, develop strong 45-degree branch angles to support fruit load, remove limbs that grow down or straight up, maintain tree size and maintain fruit spurs. The dormant season is the best time to train a fruit tree during its first three years. Pruning trees during the dormant period tends to have an invigorating effect on the tree. Good for a young tree, not so good if you are trying to control size.

Gummosis on plum in summertime
Gummosis on plum in summertime.

Pruning of dead or diseased branches can be done anytime, however, the sooner the better. And don’t prune suckers in the winter. This insures they will grow back in the summer. Over zealous winter pruning can result in waterspouts so go easy at this time of year. Summer pruning, done in June or July, decreases size and vigor which helps to slow the growth of a tree.

Often I’m asked whether to paint a wound with sealing compound after pruning. This is no longer recommended as it encourages wood rot. A tree is best protected by proper pruning technique and timing. With this in mind, don’t prune during late spring or fall as a tree is most vulnerable during those times. When you cut away part of a plant, a would is left, susceptible to pests and diseases. To avoid trouble always prune so as to make small wounds, rather than large ones. Trimming a bud or twig produces a smaller wound than waiting until it is a large limb. Rubbing off a sucker bud leaves a smaller wound than if you want until it has a year’s growth or more.

My friends sticky amber gum oozing from her dwarf nectarine branch is the tree’s reaction to stress. Cankers or sunken lesions covered with gum may be caused by mechanical injuries, such as lawnmowers or pruning, insects, winter damage, sun scald, herbicide injury or various fungal or bacterial infections. Practice good sanitation by removing and destroying cankered limbs.

You can prevent or control many diseases and overwintering insects by applying a dormant spray this month. This can be the most effective spray of the season. Fungal diseases such as peach leaf curl, fire blight, scab and anthracnose as well as insects including aphids, San Jose scale, bud moth, leaf roller, coddling moth and whitefly larvae, mealybugs and mites can all be controlled.

There are several types of dormant sprays and all three types are considered organic. Lime-Sulfur or copper can be mixed with horticultural oil which smothers overwintering insects and eggs. This spray is good for all fruit trees except apricots which should be sprayed in the fall with copper and this month with horticultural oil.

Apply dormant spray when the temperature is above 40 degrees. Make sure you cover every nook and cranny of each branch and trunk until the tree is dripping and spray the surrounding soil. Spray only plants that have suffered from pests or disease. Sprays, even organic, can kill beneficial insects as well. Even though they’re organic, dormant sprays can be irritating to skin and eyes, Wear long sleeves and gloves and eye protection.

I hope I don’t find any pictures on Facebook of your plant pests or diseases but post away if you something wicked your way comes and I’ll try to help.