Tag Archives: fruit trees

How to Control Pests & Diseases

I love it when a nice reader takes the time to call me to suggest a topic they’d like to see me write about or remind them what needs to be done at a certain time of year. Take Helen, who lives in Spring Lakes in Scotts Valley, for instance. Helen told me she grows tomatoes in the summer and has 4 fruit trees including a satsuma plum, an espaliered apple and a tangerine. Helen battles peach leaf curl on her plum and coddling moth larvae inside her apples and would like to know exactly what to use and when to control these problems. So this column is for you, Helen.

Spray dormant fruit trees now for fungal and insect control. Coddling moth control is in March or April.

I know we’ve had a lot of rain which makes gardening and spraying difficult. 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, 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 only 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.

Spinosad has been shown to suppress fungal diseases. Do this when the buds swell but before they open. Do not spray 36 hours before rain in predicted. Be sure to spray the ground around each tree.

Coddling moth control requires a different approach. The larvae of this particular moth is one of the few caterpillars that are likely to be found inside pear or apples. University of California Integrated Pest Management website has complete information about controlling this pest.

The website is http://ipm.ucanr.edu/PMG/PESTNOTES/pn7412.html

The bottom line for coddling moth control is the timing of insecticide spray applications, especially with newer, less toxic pesticides like spinosad. The coddling moth overwinters as full grown larvae within thick silken cocoons under loose scales of bark and in soil or debris around the base of the tree. The larvae emerge as adult moths mid-March to early April. To be effective your spray application must be timed for when when they are active.

Starting three to four weeks after bloom, check fruit at least twice a week looking for the first “stings” or any mounds of reddish-brown frass. If you scrape the frass away you will see the tiny entry hole where the newly hatched larvae has just entered the fruit. Spray the tree as soon as you see the first sting after removing any fruit with stings as the insecticide won’t kill any larvae that have already entered the fruit. Coddling moths can have three or four generations per year.

According to the website, for most backyard situations, the best course of action might be to combine a variety of non chemical methods and accept the presence of some wormy fruit. Be sure to cut out the damaged portions because they might contain toxins generated by mold.

Oh and by the way, Helen told me she is 88 years young so if Helen can do it, you can too.

Kurapia – The Perfect Groundcover

A groundcover is defined as any plant that grows over an area of ground. They are usually low-growing, spreading plants that help stop weeds from growing and prevent moisture loss. We gardener know that they do so much more in the landscape. Living ground covers add beauty to the garden filling in between plants while holding the soil in place and preventing erosion. They contribute to soil health by encouraging microorganisms. A garden wouldn’t thrive as well without ground covers.

Kurapia_groundcover
Kurapia groundcover growing in part shade

With this in mind I encourage many kinds of ground covers in my landscape. It’s a difficult place to find the best ones because of the lack of winter sun and only 5 hours of good summer sun. Still I’ve found a choice one that I’d like to share. It’s tough and reliable in many situations including hot summer gardens. If it will grow in my yard it will surely grow in yours.

Kurapia is ta deep rooted, low water use, low maintenance ground cover. It’s parent is in the Lippia genus and has naturalized worldwide. However, Kurapia has been bred to have sterile seeds and its growth habit is much more compact and tamed. Though it is sterile with respect to seed production, it does flower and is bee and butterfly friendly, blooming from May to October. This is a good groundcover if pollination of nearby fruit trees is needed or your want to encourage bees in your garden for general pollination. If bees are an issue for someone in your family Kurapia can be mowed once or twice a month to cut the blooms off. Mowing benefits this groundcover making it grow denser which naturally surpasses weeds once it fills in.

Kurapia_closeup
Closeup of Kurapia flowers

Kurapia has been extensively studied at UC Davis and UC Riverside comparing it with No Mow as well as other drought tolerant cool and warm season grasses. Kurapia exceeded them all going 52 days without water and still maintained its green color. An extensive root system that goes as deep as four feet and a dense 2” to 3” tall mat-like top is the secret. The California sod grower recommends more frequent irrigation but it still requires just 60% of the water of a traditional lawn.

Kurapia does not require much fertilization either. One time in the spring for growth and flowering and once in the fall to keep the green color through the winter is sufficient. Mine looks great year round and I have to confess I’ve never fertilized it. Kurapia is evergreen and does not have a dormant period though growth stops or slows does in the winter. It spreads and self repairs by stolons. This groundcover grows in sun to partial shade requiring only three hours of sunlight. However it tends to stay more compact in full sun.

Kurapia will handle light to moderate foot traffic. It cannot take consistent high traffic though it is very walkable. My dog Sherman finds it great for his morning constitutional and I’ve never seen yellow spots as a traditional lawn will get.

Kurapia is hardy to 20 degrees though in tests it has survived temperatures as low as 12 degrees. It’s deep root system is unparalleled for erosion on slopes. Did I mention it takes 60% less water and how much you mow is up to you? Like I said, if it will grow in my garden under less than ideal conditions it will grow in yours.

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.

Bare Root Fruit Trees- What, When and Why?

Autumnalis flowering cherry blooming in January
Autumnalis flowering cherry blooming in January

I have an Autumnalis flowering cherry tree that blooms year round. The last blooming cycle started in late November and it’s still blooming now despite heavy rains. This tree came into my life 20 years ago as a bare root tree. We’re old friends. Now is the time to add ornamentals and edibles like fruit, nuts, berries and vegetables while they’re available in bare root form. They are easy to plant, economical and establish quickly.

Every year there are more fruit tree varieties available in bare root including delicious time honored heirloom varieties as well as modern favorites. It’ll be hard for me to decide which ones I’ll recommend for edible gardens I design this year.

Several years ago Orin Martin, the manager, master orchardist, horticulturalist and

Apple variety
Apple variety

teacher extraordinaire at UCSC Alan Chadwick garden visited a group of fellow landscape designers bringing with him a bag of his favorite apples. As he cut slices of each for us to sample his highest praise went to Cox’s Orange Pippen, Golden Delicious, American Golden Russet, McIntosh and Mutsu apples. Plant these varieties and you could be eating apples from August through October. Did you know that at one time in American history russet apples were the most desired and wages were actually paid in cider made from russet apples?

Bare Root Fruit Trees in bins with sawdust
Bare Root Fruit Trees in bins with sawdust

If it’s peaches you crave, Renee of Mountain Feed & Farm Supply shared with me some peach leaf curl resistant varieties they carry. Listed by UC Integrated Integrated Pest Management Program they include Frost and the Q-1-8 white peach. The Frost is a medium-sized, freestone yellow peach with a delicious flavor. It has showy pink flowers in the spring. They ripen in July and require 700 hours of winter chill. The Q-1-8 peach ripens in July also. This white-fleshed, semi-freestone peach is sweet and juicy like Babcock and has showy blossoms in late spring. Peaches are self-fruitful and don’t require another peach to pollinize them.

What fruit tree varieties can you grow here in the mountains? Well, almost everything. Most of us get 700-900 chilling hours per winter. What does that mean? Well, many fruit trees, lilacs and peonies need a certain number of hours during dormancy where the temperature is 45 degrees or less. You can give the plant more chilling in the winter and that’s just fine but not less. Those in coastal Santa Cruz can grow Fuji apples as they require only 300 hours of chilling but not Red Delicious. We can grow both.

What if you don’t get full sun where you’d like to grow fruit trees? Apples, pluots and plums are good choices for an area that gets some sun- at least 5 hours- every day during the growing season. The ideal is full sun but these trees will still set and ripen some fruit in partially shaded conditions. With peaches, nectarines or apricots it’s a different story. These fruits need hot sun to develop sweet, tasty fruit. Too little sun and they will not deliver anything close to what you have in mind.

Shop for your plants in January or February while they are still dormant. Once leaves emerge or flower buds start to swell tree roots have already started growing. You want your tree to start developing new permanent roots in their final home. Stone fruits such as apricots, peaches,

Bartlett pear
Bartlett pear

plums and cherries are going to start waking up first so they are best put in the ground soon. Fruit trees like pears and apples wake up later so you can wait a bit longer to plant those varieties.

With this in mind be wary of spring sale bare root stock. Also trees in packages may have had their roots pruned to fit inside or the packaging material may have dried out or become soggy. Better to see the roots for yourself before you bring your new addition home.

When May rolls around I’ll be anxiously awaiting the first cherries, apricots and peaches. Then the early nectarines arrive, sweet and juicy followed by the plums that ripen next. Later in the summer apples, figs and pears make their debut as well as late ripening plums and peaches. With a little planning you can have fresh fruit 7 months of the year.

By growing your own fruit you’re not at the mercy of mechanical harvesters and shipping practices. You can grow fruit and harvest it when the time is right. Homegrown fruit is a world apart from agribusiness and much less expensive than the Farmer’s Market.

Pruning, Thinning and other Early Summer Tasks

Last week the first real taste of summer weather arrived and it was a wake up call for me. Over the past couple of months I’ve planted several new plants that will be drought tolerant once established but for now their root system requires more frequent watering than my established plantings. I’ll have to wait for the cooler weather starting in late September to plant any major additions to my landscaping. But for now I love to be out in my garden and there are lots of other things I can do to enjoy my time outdoors.

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.

Japanese_maple.1600
Japanese maples

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.

Cherries.1600
Bing cherries

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.

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.

OLYMPUS DIGITAL CAMERA
Red Delicious apple

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.

And I’ll be looking for any pest problems so I can do something about them before it gets 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 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.

A Little Slice of Heaven in the Santa Cruz Mountains

toolsOutside of the historical agriculture exhibit at the Santa Cruz County Fair I have never seen so many antique farm implements and tools. Vintage tractors and parts were tucked underneath massive black walnuts. The winding driveway was dotted with more equipment, tractor wheels and parts. A storage shed displayed a collection of vintage chain saws and other small tools. California poppies bloomed in small clusters. I was here to visit an old friend in the hills above south Felton near the Toll House resort to see if I could help with advice about his ailing plum trees.

Al HIley has lived in this idyllic location since Vista_from_house.2048he was a boy and that’s a long time as his 92nd birthday is this month. His father bought the 18 acres in 1906. The original house still stands shaded by a grape vine arbor that protects the door and windows in the heat of the day. He lives close by in another house where he enjoys a vista which includes Mt. Umunhum, the Summit and Boulder Creek. Al says he used to be able to see downtown Felton but the redwoods have grown since the late 1800’s when this area was logged.

I had to laugh that Al was asking me for advice. He’s been farming this land starting since WWII ended. His father pAl_Hiley_in orchard2.1600lanted the original walnut trees in the hopes of making a profit from his land but “he was no farmer”, according to Al. I glanced at the catalogs on the 12’ long redwood burl coffee table. You can tell a lot about a person from what they read. Strewn about were several tractor catalogs, Popular Mechanic magazines, Heartland cataantique_chainsaws.1600logs, miscellaneous tool catalogs and a book entitled ‘Chainsaws: A History” which touts to be the first book on the worldwide history of the chainsaw.

With his lab, Sonny, at his side, Al and I went out to the orchard to take a look at the fruit trees. Originally in the 1960’s he had about 95 fruit trees. He grafted different kinds of apples onto his father’s trees and planted peaches, and pears as well as plums and prunes. We passed the blueberry bushes which were starting to show some fall color. Nearby grew a fig with a gnarled trunk the likes I have never seen. Loaded with hundreds on hundreds of ripening figs he invited me back to pick some when they ripened.

Al couldn’t verify the exact variety of red apple that caught my eye. It also was  loaded with beautiful fruit. He red_apples.1600got me a bag to pick as many as I wanted to take home and they are crispy and juicy. He grows a yellow delicious apple also but after eating the red variety I didn’t think anything could rival them.

The plum trees weren’t doing as well. They all had some yellow leaves and golden colored sap oozing along the branches. This condition is called gummosis and occurs often in stone fruit trees like cherry, apricot, peach and plum. It can be caused by several very different things.

The tree may have gumming from a pathogen that invades and kills bark and cambial tissue through a wound such as a pruning cut, sun scald or hail. If you scrape the outer bark under the sap the dead phloem will appear cinnamon brown in color Prevention is the key to managing this problem. Keep trees healthy with optimal watering, mulching and nutrition.

gummosis_on_plum.1600Borers can also cause gumming. In a plum tree, weakened trees or places where wounds have occurred will be susceptible. Ooze is often clear. Management of these pests is difficult and may include bark sprays during the growing season.

If you are not sure that a pathogen is causing the gummosis, scrape the outer bark away. If the inner bark is still cream colored and healthy, the oozing is caused by non-living factors and there is nothing you should do. If the wood is tan to brown, it is dead, and was most likely killed by a pathogen.

For my friend, Al’s plum trees I determined that the gummosis was caused by excessive irrigation. Due to the drought, Al had tried to limit watering during the summer. When he saw the trees being stressed he deep watered several times in the past month or so. The apple trees loved it but not the plums. He is happily going to deep water much less often until the trees go dormant.

I left Al and Sonny with the promise that I’d be back when the figs ripened. I’m sure I’ll be needing a fresh supply of apples, too.