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The Arbor Advisor
> Stop Destructive Plant Disease in its Tracks
> Get Awesome Apples with ‘Liberty’
> Dangerous Yard Activities that can Maim
> Top 10 Disease Resistant Trees

Want disease-free apples? Grow a ‘Liberty’!

By Terrill Collier

Liberty apple Grow your own mouth-watering apples with a disease-resistant ‘Liberty’.

As I plan to add to my orchard this spring, I am no different than my clients in wanting low maintenance and disease free fruit. In Western Oregon and Washington we can grow amazing fruit. Just remember, our rainy climate is unlike the dryer fruit growing regions of Hood River and Washington State. Some of the familiar commercial apple varieties of Golden and Red Delicious, Fuji and Granny Smith do poorly here because of disease problems. By choosing wisely we can select disease resistant varieties that are low maintenance and taste delicious with full flavor that only a locally grown tree ripened fruit can provide.

Our major apple and pear disease problems include:


Apple & Pear Scab

A fungus which thrives in moist climates, causing damage to leaves, shoots and fruits. The spores live on fallen leaves and diseased leaves should be cleaned up and composted.


A fungus that prefers warm, humid (but not wet) conditions and causes significant damage to leaves and shoots in summer. It will also cause russeting (brown splotches) on fruit.

Liberty apple blossom Bright blossoms and tasty fruit are yours for the having when you plant a disease-resistant Liberty Apple Tree.

A ‘Liberty’ apple is a new, improved, disease resistant variety. I have grown this variety and can attest to its resistance to scab and mildew and to the full crispy flavor of this tasty fruit. If you have a small yard or want to easily pick fruit from the ground, grow this tree on a dwarf (M-26) rootstock. Liberty bears large, attractive, bright red, McIntosh-like fruit with sweet, slightly tart flavor, crisp and juicy flesh. Liberty is great for eating fresh, juice and baking. Liberty ripens in mid to late September and stores well for up to three months. Unlike many varieties that need a pollinator, Liberty is self pollinating. This easy care, heavy fruiting apple is highly recommended for home gardeners.

Other recommended disease resistant apple varieties include: Chehalis, Enterprise, Goldrush, and William’s Pride.

To help combat disease problems in fruit trees, we offer The Collier Arbor Care Fruit program. It’s an organic treatment program designed to prevent the major disease and insect problems of fruit trees. If you’re concerned about disease in your fruit trees or would like to find out more about the program, give us a call today.

One of the eight warning signs of a hazard tree is a tree that has begun to lean. Pay close attention to trees that have recently moved from a vertical position.
Scab disease on a flowering pear. Plant diseases infect during wet Spring weather, but preventative treatments need to be applied before and after the rains.

Stop Destructive Plant Disease in its Tracks

Our ultra rainy Spring of 2010 will be remembered as the year of the blight disease for the devastating effects on fruiting, flowering and ornamental trees and shrubs. From Brown Blossom Blight and shot hole diseases in the Cherries and Plums, Anthracnose in the Maples, Sycamores and Dogwoods, and mildew everywhere else, foliar diseases had a destructive impact on the health of our plants in 2010. Additionally, because of the water-logged soil conditions, many plants died due to root rots such as Phytophthora, which kills many evergreen plants such as cedars, juniper, photinia, and rhododendrons.

As we enter the new growing season of 2011, the wet, rainy and, hence, disease promoting weather is repeating itself. What can be done to prevent the destructive effects of disease in the landscape? Proper diagnosis is the first step, so call a Collier certified arborist to troubleshoot and recommend disease prevention measures. As with many things in life, prevention is the key. Timely treatments, proper pruning and nutrition will all help to minimize problems and maintain plant health.

Disease Prevention Steps

  • Call a Collier certified arborist to properly diagnose your landscape disease problems.
  • Schedule a preventative disease treatment or Plant Health Care Program with Collier Arbor Care and protect your landscape investment. Early preventative treatments are the key — once you see the disease it is often too late.
  • Prune out diseased plant parts. Thin out branches and foliage to improve air circulation and encourage quicker drying and lessen disease.
  • Where a plant has died from a particular disease such as Verticillium don’t replant with the same species or the new plant will get the same disease. Replant with disease resistant varieties. (See Top 10 Disease Resistant Trees)
  • Improve your soil with and provide plant nutrition with Collier’s all Organic Soil Health Program with compost tea, organic fertilizers and beneficial mycorrhizae. Healthy soil and plants are keys in overcoming plant disease problems.

For information on specific diseases, refer to the Fact Sheets section of this site.

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8 Dangerous Yard Activities That Can Maim

During sunny weather, this 15kw solar system provides all the power that Collier Arbor Care’s office needs — plus extra that it sends back to the electric grid.
Hornet nests are well hidden in trees, shrubs or in the ground. Check plants and outdoor areas carefully to prevent attacks and stings.
During sunny weather, this 15kw solar system provides all the power that Collier Arbor Care’s office needs — plus extra that it sends back to the electric grid.
Always secure the bottom of the ladder on level ground and never go above the top step. Call Collier Arbor Care if your equipment isn’t up to the job.

Gardening and yard work are some of the most popular leisure activities for Americans, but who knew about their dark side. Each year thousands of us are rushed to the emergency room or sadly the morgue, with yard work related injuries: cuts, falls, missing fingers — even freshly mowed feet.

That Texas Chainsaw massacre could happen in your backyard this weekend. Many weekend warriors in the garden may not think to protect themselves from the dangers of yard work. When in doubt hire a professional arborist who has the safety training, the skills and the excellent safety record to tackle your backyard project. Collier employees have gone 1423 days without a time loss accident — an admirable achievement for our safety-minded 16 certified arborists performing tree, shrub and lawn services in your landscape.

1 —You Fall off a Ladder

About 136,000 people get a fast ambulance ride each year to the emergency room because of ladder related accidents. Secure the bottom of the ladder on level ground to prevent slippage.

2 — Chainsaw Massacre

There are more than 40,000 chainsaw injuries per year. The average chainsaw injury requires 110 stitches and cost an average of $12,000. Thirty-six percent of the injuries occur to the legs, knees and feet, so wear boots and chainsaw chaps for protection. Other required safety gear includes hard hat, eye and ear protection, gloves and chainsaw with anti-kickback devices.

3 —Electrocution from Planting Trees

Before you decide to decorate your yard by planting that new tree or putting in a fence make sure you “Call before you dig”. Protect yourself from hidden underground utilities like electrical, gas, and water before digging in your yard. In Oregon call the number: 1-800-332-2344 before you dig to locate and discover hidden utilities.

4 — Mowing the Toes Instead of the Grass

Mind the bare toes and the flying debris when lawn mowing. Some 80,000 Americans go to the hospital because of accidents involving lawn mowers. The majority of victims are children and the elderly.

Wear safety glasses and closed toed shoes. Keep kids and pets away from mowing operations and never hold your kids in your lap while using a riding lawn mower.

5 — Losing a Finger While Trimming the Bushes

Mind your fingers when trimming hedges. U.S. Consumer Product Safety Commission reports that hospital emergency rooms treat more than 400,000 outdoor garden-tool-related accidents each year. Wear gloves and keep hands and fingers away from power shears, saws and pruners. Wear eye protection too.

6 — Insect Alert

Spiders and bees and ticks — OH MY! Many people visit the emergency room due to wasp stings, and spider bites. Ticks can transmit diseases like Rocky Mountain spotted fever and Lyme disease. Watch out for yellow jacket nests in the summer, especially if you are allergic to stings.

7 — Deadly Garden Plants

Your favorite garden plant could send you, your children, or your pets to the emergency room if ingested. Beware of popular ornamentals like rhododendron, kalmia, lily of the valley, daffodils and foxglove, to name a few. Also beware of poison oak (leaves of three let it be) that can cause a severe rash and itching when encountered.

8 — Garden Chemical Dangers

Garden chemicals are a common cause of accidental poisoning in children. Store concentrated chemicals in locked areas to prevent accidental poisoning.

Some garden chemicals, especially some of the old ones, can be toxic when miss-applied or over used. Dispose of all chemicals properly at designated recycling stations. Collier Arbor Care has organic tree, shrub, lawn and fruit tree programs that are gentle for people, pets and the environment, but tough on pests and diseases.

There’s no need to risk injury or illness to enjoy a beautiful landscape. Collier Arbor Care is here to offer assistance and advice in keeping your landscape looking great. Always feel free to call or send an email to discuss any of your landscape concerns.

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Top 10 Disease Resistant Trees

Paperbark Maple (Acer griseum) 20-30’ — Exfoliating orange bark for winter interest. Leaves are divided into three leaflets, green with silvery underside, bright red fall color, Full sun or shade, slow growing specimen tree.

Liberty Apple (Malus domestica ‘Liberty’) 15-20
— Disease resistant. Apples are a bright red color. A juicy sweet dessert apple. Great for fresh eating and a good keeper.

Plume Cryptomeria (Cryptomeria japonica ‘Elegans’) 20-40’ — Evergreen tree with feathery, soft bluish green foliage turns copper colored in winter. Grow in full sun.

Katsura Tree (Cercidiphyllum japonicum) 40-60’ — Multi-stemmed tree for sun or partial shade. Heart shaped foliage. New growth is red fading to green ten yellow fall color. Few pest problems.

Korean Dogwood (Cornus kousa) 15-25’ — Anthracnose resistant, white showy flowers in May followed by raspberry-like fruit. Yellow or scarlet fall color.

Sweet Bay Magnolia (Magnolia viginiana) 15-25’ — Spring flowering. Creamy large flowers, very fragrant. Grows in sun, wet soils. Lustrous green deciduous foliage.

Sourwood (Oxydendrum arboreum) 20-30’ — Spectacular orange-red fall color, bell shaped white flowers in spring. Grow in full sun, well-drained moist soils.

Persian Parrotia (Parrotia persica) 15-30’ — Exfoliating gray bark, showy tiny crimson flowers in early spring. Choice tree, orange fall color. Grow in full sun.

Japanese Stewartia (Stewartia psuedocamellia) 20-40’ — White, camellia-like flowers in summer, wonderful orange exfoliating bark. Orange-red fall color. Grow in sun or partial shade, well-drained soil.

Japanese Snowbell (Styrax japonicus) 20-30’ — Showy white, pendulous flowers in late spring. Horizontal branching, non-aggressive roots, pest free. Yellow fall color. Grow in sun or partial shade.