Join Rainbow and become part of the “SOS (Save Our Shade)” Ribbon Program to take action against Emerald Ash Borer and save our ash trees.

Related posts:

1. Come See Rainbow Treecare At The Living Green Expo May 7-8, 2011
2. Rainbow Treecare Is At the Plymouth Yard and Garden Expo.
3. Emerald Ash Borer

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1. Zimmerman Pine Moth
2. Pine Needle Scale
3. Dry Trees

A healthy tree can grow a new set of leaves when needed, but it can be a source of stress to the tree. The growth of the first set of leaves is a heavy draw on stored energy, leaving reserves at their lowest point for the year. Building a second set of leaves costs the tree energy it would have otherwise used for growth or defense against attack from disease or pests.

Trees affected by frost injury will show the small, new leaves turning shriveled and discolored. They might fall off or remain on the tree. Most evergreen species have not started to develop needles yet, so they may have escaped injury for now.
Fruit trees may have reduced crops of fruit this year if their flowers have sustained damage.

It will take time to see the results of the changes in our weather. New leaf growth often takes several weeks to start development. Each type of tree will react differently, and each section of the Metro area will be affected differently.

If you are concerned about how frost injury may be affecting your trees, arrange for your Rainbow Consulting Arborist to visit your property. Your Arborist can assess the situation and make recommendations to support the health of your trees, such as watering and fertilization.

Fertilization can be helpful for stressed trees, but beware of applying doses of fertilizer that force rapid growth. These can further deplete the limited energy reserves of the tree. Our formulas are designed to provide what the trees need for proper response to stress with slow released nutrients.

Don’t forget that we are still in a drought. If your soil is dry, irrigate the root zone of your trees until the soil is moist down to a foot below the surface. A soaker hose works well for this task, as the water is delivered slowly and will not run off before the soil absorbs it. Soaker hoses put the water at the ground level where it is needed, and leaves the upper part of the tree dry. Avoid irrigation methods that get the needles or leaves wet, as this creates ideal conditions for infection by fungal diseases.

Kent Honl
Board-Certified Master Arborist MN-0158B
Rainbow Treecare

Related posts:

1. Tree Growth and Tree Health
2. Reduce Tree Growth Using Cambistat
3. Urban Tree Stress

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1. Meet us at the Home & Garden Show 2011!
2. Home Page
3. Trees and Drought

Wondering what’s happening with your evergreen tree this fall?  Take a look at our list and see if any might fit your situation.

10.) Your tree is a larch (tamarack) which is deciduous, it’s supposed to lose needles in the fall and grow new ones in the spring

9.)  The needles that your evergreen tree is losing are 4 and 5 years old.  Old needles are less productive than newer needles, so in the Fall most conifers shed old needles that aren’t contributing to the photosynthetic uptake of the tree.

8.)  Your tree is THIRSTY.  September was the driest Fall in 10 plus years.  Although we had an overabundance of rain this spring, it didn’t carry over in the Fall.  Conifer roots need moisture going into the winter, without it trees will drop the needles it can no longer support.  Make sure to water your trees if you don’t have in ground irrigation.

7.)  You planted your conifer tree <10 years old, covered the root ball with landscape fabric, put  limestone rock mulch on top of the fabric and surrounded your tree with landscape edging.  New planting sites are a harsh environment for trees to survive in.  Compacted clay soil reduces the growth of new roots and landscape fabric prevents water and nutrients from getting to the root system of the tree.  In addition, limestone rock holds heat that can damage roots and as water runs over the rock it raises the pH of the soil which limits the availability of nutrients to the already stressed roots of the tree.  When a tree can’t support itself with its root system it will drop needles.  Remove the rock, fabric and edging and add Prescription Organic Matter and mulch to the soil to help the roots survive and the tree to thrive.

Lirula needle cast

SNEED close up

Rhizosphera Needle Cast Spruce

6.)  Your in-ground irrigation system has been hitting the branches of your tree, coveringthe needles of with water and creating a great environment for diseases like rhizospheara, sirrococcus, dothistroma, lirula and lophodermium needles casts .  The only way to prevent the disease is to reduce the moisture contacting the needles and/or treating with preventative fungicide treatments next spring.

5.) Your tree has SNEED disorder (spruce needle drop disorder).  While the cause of the disease is not yet understood, it is known that black hills spruce and Colorado blue spruce are susceptible to the disorder if they are stressed (drought, construction etc.).  The best way to manage the problem is to improve the trees growing environment to enhance root health and use a preventative fungicide spray in the spring.

4.) You have damage due to herbicide injury from a new lawn care product, “Imprellis^®“, that was pulled from the market this summer.  Check with your lawn care provider to see if they used the product.  If they did, you can have them submit a claim to compensate you for the damage to your tree.  Most of the problems we observed this year were on Black Hills spruce and Colorado spruce although many other conifers were impacted by the product.

3.) Your tree received little to no supplemental watering during the Twin Cities harsh 7 year drought period that ended in 2010.  You may now be seeing your tree decline because two years of adequate rainfall cannot fix the damage caused by the years of drought.  Bark beetle emergence holes indicate how much damage has been done.  If you see holes (pin head size), plan on replacing the tree.  If you don’t see the holes or if you see pitch/sap coming out of the holes, water your tree and spray it with a trunk insecticide next spring to control any bark beetles that may be attracted to it.

2.) You put a patio around the trunk of the tree, or did some other home remodeling/construction  project that removed or damaged a majority of the root system of your tree.  By removing or damaging tree roots, you remove it’s energy reserves that support everything above ground, you will lose needles and likely the whole tree.

1.) It was last year’s Christmas tree and you should have recycled it 10 months ago

Still can’t figure it out?  Give us a call and one of our certified arborists can stop by to help.

Related posts:

1. Trees and Drought
2. Dry Trees
3. Spruce Needle Drop

Sawfly larvae look like caterpillars and can defoliate the trees they are on, but are not typically wood borers.  We sent the pictures in to Jeff Hahn at the University of Minnesota and he said they looked like dogwood sawflies.  Since it was completely new to us we asked a few other experts at the University of Massachusetts, Purdue University, Oregon State University and Ohio State University and they all supported the diagnosis.  We must point out that several of our University colleagues had even observed this phenomenon personally.

Dogwood sawfly, after feeding on the foliage of dogwood, seeks shelter to overwinter.  In nature it finds decaying logs to crawl into where they create a hibernating chamber in which they pupate.  Unfortunately, in urban areas where rotting logs are scarce, they are finding other places to chew into and hibernate; including siding, decks and any other location where soft wood is available for them to chew into and create their hibernacula.

The best plan for managing the problem is to replace the decaying wood.  But, if that’s not an option right now, Rainbow Pest Experts have treatments that will reduce the populations of these bugs.  Just give us a call.

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1. Forest Tent Caterpillars Have Hatched In The Twin Cities Area
2. Dealing With Dead And Dying Ash Trees
3. Winter Damage & Injury

Set your soaker hoses out about 2-3 feet away from the trunk of the tree and let it soak into the soil for a good 2-3 hour stretch.  If you have in ground irrigation, let it run for an extra 30 minutes in areas where you have trees so the water can soak below the roots of the grass and get down to where the trees can get to it.  If you want to go old school, put your hose end sprinkler out (try to keep the water  from hitting the trunk of the tree) and use an old coffee can and a ruler to make sure you are getting 2″ of water out on the area around your tree.  If none of these options are viable, give Rainbow a call and we’ll help develop an irrigation routine for you that will fit your individual trees needs.

Related posts:

1. Now is a great time to examine trees for winter snow and ice damage.
2. Watering Drought Stressed Trees
3. Trees and Drought

Rainbow Treecare Certified Arborist, Tony Kunda, receives the “Eagle Eye” award for the first confirmed sighting of an adult Japanese Beetle this year.  Tony, our consultant for the Southwest Metro area, identified an adult beetle feeding on ornamental grape vines in Excelsior, MN.  This early sighting indicates the start of the battle to protect susceptible plants.

Japanese beetles damage the blossoms and the foliage when the feed. They feed on all plants in the Rosaceae family including all roses, apples, plums, pears, hawthorn; grapes (ornamental and cultivated); lindens (Littleleaf and Basswood); willows; birch; small maples; and even Larch.  When a beetle finds a good food source it leaves a scent behind that attracts other adult beetles to come and feed.  Therefore a little damage can turn into severe damage over a short period of time.

Besides covering plants with fine netting, the only way to protect trees and shrubs from damage is to use insecticides.  For beetle control on untreated trees, we recommend a soil applied systemic called Transtect^® that moves quickly through the root system and into the leaves. Trees that were treated with Xytect^® (imidacloprid) this Spring or last Fall have enough of the compound in the foliage that the beetles will leave the tree or will die when they consume the foliage.  Once adults begin feeding in large quantities we will recommend use of foliar applied sprays that have a 14 day residual to kill the beetles that are attacking the trees.

We prefer the use of soil applications to reduce the potential for drift and non-target impacts.  However, it’s important to schedule the soil treatments very soon to insure it will be in the foliage when the beetles start feeding heavily on the susceptible trees.

Xytect^® and Transtect^® are plant-based products that have been modified from the nicotine molecule.  The sprays we use are also plant-based.  They are pyrethroids, which are derived from the pyrethrum molecule that was isolated from chrysanthemum flowers.

If you have any questions on how best to protect you plants from Japanese Beetle, please contact your Rainbow Treecare Consulting Arborist.

Related posts:

1. Japanese Beetle
2. Decreasing The Potential Spread Of Disease And Insect Infestation
3. Black Vine Weevil

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1. Aphids
2. Insects and Diseases that Affect Trees
3. Boring Insects

This insect is not always a problem, but when populations become large, can defoliate trees with their feeding.  If the larvae are caught when small, they can be effectively treated with an insecticidal soap.  As they get larger and their webbing becomes heavier they are more difficult to manage.

Rainbow Treecare can schedule a spray or soil application treatment to control forest tent caterpillars and prevent damage to your trees.

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1. Service Area
2. Russell Kennedy
3. Conifer Sawflies