- UC Marin Master Gardener Events & Classes
Garden Help from UC Marin Master Gardeners
- Farmers Markets
- Help Desk
- Growing in your garden now - blueberries
- Inviting butterflies into the garden
- Paying attention to mushrooms
- Compost for every corner of your spring garden
- What's the best way to plant a fruit tree?
- How to protect plants from frost
- What's that plant?
- Bright spots of color help lift the drabness of the winter garden
- Books for Marin gardeners
- Benefits of School Gardens
- Trees: not just nice to look at
- Dealing with mosquitos
- Epilobium – California fuchsia
- Why bees matter, and how you can help
- Picking the Right Plant for the Right Place in Your Garden
- What's That Plant?
- Keeping Cut Flowers Fresh
- Late Summer Color
- Growing Summer Squash
- Short on space? Containers to the rescue...
- Herbs: tough, attractive, practical
- These plants are true companions
- Companion planting in the vegetable garden
- Get Grounded – Healthy Soil Does Matter
- Mushrooms on the March
- Our Gentle Winters are Good for Vegetables
- Rodents like it Warm
- Know What Makes an Invasive Species Invasive
- California Natives - Plant Like a Native
- Consider a Simple Water-Catchment System and Rain Garden/Bioswale Before Winter Rains Arrive
- Have You Scheduled a FREE Bay-Friendly Garden Walk?
- A Green Autumn
- Rx for Pests: Ants
- Fine Tune Your Garden
- Colorful Drought-Tolerant Plants Thrive in Marin
- Water Restrictions and Recognizing Signs of Water Stress
- UC Researcher Is Helping Plants Survive the Drought
- Summer Is Perfect For Peppers
- Do the Leaves on Your Trees Look Scorched?
- Fine Tune Your Garden
- How to Recognize Drought and Water Stress
- Spring is the Time for Potatoes, Asparagus and Citrus
- Don't Let Stink Bugs... Bug Your Vegetables
- Harvesting Berries
- Water Heroes
- Natural Cold Storage
- Fruit Trees; Why We Treat Them in Dormancy
- Fondness for Old Friends
- What Happens to Garden Bad Guys in Winter?
- Plants that aren't blown away by the wind
- A hill o' beans
- Fruit tree thinning
- Fragrant plants: Add some chocolate or Kool-Aid to your garden
- Top 10 resolutions for Marin gardeners
- Trees with interesting bark shine in winter
- Who says your garden has to be green?
- Plant bulbs now for spring beauty
- Gardener's checklist for fall
- Cover crops boost soil in vegetable beds
- Rx: Living with deer
- Growing berries in Marin
- How to build healthy soil
- Gardener's checklist for summer
- Water-saving tips for the home garden
- Gardener's checklist for spring
- Stop the popping - Controlling hairy bittercress
- How to control aphids
- Brightening up the winter garden
- Selecting a fruit tree
- What to plant and harvest in the winter vegetable garden
- Rain, rain, don't go away
- Gardener's checklist for winter
- Getting rid of rats
- Fall: a time for planning and planting
- Asparagus: spears for years
- Lawn: use it or lose it
- Rx for powdery mildew
- Community Outreach Projects of UC Marin Master Gardeners
- Great Gardening Information
- Selecting Plants
- Marin Master Gardener Independent Journal Articles
- How to Become a Master Gardener
Fruit Trees; Why We Treat Them in Dormancy
Spraying before the trees bloom is important because copper is toxic to bees and other pollinators, and horticultural oil will smother them. For some diseases, however, you will have to spray while the tree is in bloom. Fire blight and brown rot are both examples. In this case, it is best to limit your spray to hours of the day when foraging insects are most likely to have returned home.
There are a number of reasons to spray some fruit trees with copper and oil. While the copper acts as a general fungicide, helping to prevent everything from peach leaf curl, to brown rot, to rust, to fire blight, oil serves as a spreader-sticker that also kills overwintering insects like wooly apple aphids.
Not every fruit tree should be sprayed with copper and horticultural oil, and trees that may benefit from spraying in one climate, don’t need to be sprayed in others. Persimmons, pomegranates, mulberries, and citrus are examples of trees that, at least in our San Francisco Bay Area climate, don’t need to be sprayed with copper and horticultural oil. That being said, peaches, nectarines, plums, grapes, pears, and apples can all benefit from a dormant spray to help fight off fungal infections carried by the rain and overwintering insects.
Keep in mind that, although copper is used by organic growers, it is a heavy metal and will ultimately end up in your soil. Toxic build-ups are possible over time.
Spraying the trees
Spray on a dry day when the copper won’t be washed off by rain or diluted by fog for at least a few hours (a few days is preferable). Mix up the liquid copper and horticultural oil in the sprayer, making sure to follow the directions carefully for both. In my case, Kelly’s horticultural oil and 27.15% copper solution called for 3 tablespoons of oil and four tablespoons of copper per gallon of water. A Gilmour hose-end sprayer, available at many nurseries and hardware stores, attaches to the end of a garden hose and mixes the water with the copper and oil solution. 8 tablespoons per gallon on the peach and nectarine trees and four tablespoons per gallon on the pear trees.
While dormant spraying is easy enough to do yourself, it’s worth exercising caution. Contact your local extension office or try to find knowledgeable nursery-folk to make certain that you are using the proper proportions and only spraying trees that really need it. A visit to the local hardware store garden section conveys the dizzying number of chemicals available to anyone who feels like paying the price and why it imperils our natural environment.
This article was compiled from an original post on the gardening blog Overall Gardener by Sarah Phoenix.
Find the original article here: http://www.overallgardener.com/tis-the-season-for-dormant-fruit-tree-sprays/.