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.