What Is Happening To The Aspens?


Nearly every Aspen in the Denver area is showing signs of all the trials and tribulations of the 2007 season.  The wet spring with its moderate temperatures created conditions that promoted heavy leafspot infections.  There are several leafspot diseases that cause discoloration of the leaf tissue.  Marssonina, Septoria, and the less common Ink Spot are the top three leaf diseases in Aspens and Cottonwoods.  These are the main culprits for the leaves that are falling in August and September.  Leaf damage starts out small and inconspicuous in the spring, but develop into large, ugly blotches in the late summer.  Cultural controls include cleaning up any diseased debris that has fallen on the ground.  Foliar applications of fungicides, properly timed in early spring when leaf tissue is soft can be effective, but must be conducted as a series of applications that continue as long as environmental conditions exist.  These applications in the spring can help to keep tissue happy and healthy in the fall.

Soil injections of slow release fertilizer and applications of beneficial fungi, known as Mycorrhizae, are also very helpful as remedial treatments. 


Needle Drop Is Right Around The Corner


Needle drop occurs in pines as naturally as the leaves that drop from oaks and maples every fall.  The amount of energy required to produce needle tissue is substantially greater than that of broadleaved plant tissue.  As a result, Pine trees hold their tissue longer, sometimes as long as four or five years, depending on the species.  Ponderosa pines can drop so many needles in the fall that it appears the tree is dying.  Please don’t be alarmed, this needle drop is normal.  Needle drop in pines is a result of a physiological process, and is a sign of good tree health.  Other species that drop abundant amounts of needle tissue every few years are White pines, including Vanderwolf’s pine, and Lodgepole pine.  It is a good idea to take a digital picture each year so you can track the normal progression of needle drop, making it easier to pick up on trends that may not be normal.





Fireblight: Winter is the best time to prune


The characteristic shepherds crook in the terminal branches is a tell-tale sign of a current infection of the bacteria known as Fireblight.  This pathogen often finds its way into twig tissue during the spring when the environment is moist and temperatures are more moderate.  Hailstorms that cause very small injuries in the twigs create a pathway for infection.  Current treatment practices include foliar applications in the spring of a Copper solution when the leaf tissue is soft and porous.  Pruning is also recommended to reduce the likelihood of the infection spreading into healthy tissue.  Pruning during the growing season can be problematic if care is not taken to sanitize tools to prevent the unintentional spread of this disease.  Finally, a direct trunk injection of an antibiotic solution once per year can help to reduce the severity of the infection. 

It is important to keep in mind that all the treatment recommendations should be performed on a continuing basis.  New infections can occur each year, and it is crucial to not become complacent after a tree has recovered from an infection.




Is There Something Crawling In Your Pine Tree?


Pine trees become host every September and October to an aphid that is easy to recognize.  The Giant Grey Aphid is suitably named for its large size, over a quarter inch in length, and distinct grey color.  Their adult stage is relatively short, and therefore its numbers can become abundant very quickly.  Damage is characterized by a chlorotic and spotty appearance in the needle tissue.  Further dessication may develop in the tissue as winters become dry.  These insects are simple to control with timely foliar applications.  Chemical treatments include synthetic insecticides and natural horticultural oils that lessen the impact on the environment. 




With fall around the corner it is a critical time of the season to become proactive with our lawn care.  What are the most important lawn care factors to consider every fall to ensure that you have a healthy lawn when spring arrives?  The fact is if you combine a fall aerate and fertilization you are helping the roots of your turf retain water and the necessary nutrients during the very dry winter months that we experience in Colorado.  Falls plan is critical to the success of having a green healthy lawn in spring. 



Aeration is a major component to a healthy lawn.   Aeration helps to break up compaction, reduces run off and allows the lawn to uptake water, oxygen and nutrients. Aeration will promote root growth.  Roots continue to grow throughout the winter storing food that will allow the to plant survive until spring arrives.   For those lawns that have a thatch level greater than ˝ inch are at risk for lawn problems.  Thatch robs lawns of key nutrients and water.  Thatch also provides an environment for damaging insects.  By core aerating you will help reduce thatch buildup.



Fall fertilization for lawns is one of the five most important applications of the season.  The benefits from fall fertilization includes a healthier turf and root system before winter and it will stimulate a lawn to green up earlier in the spring without excessive top growth. 



The cooler weather of fall is the prime growing season for our lawns but with that comes the cooler season weeds.  You may experience seeing the dandelion among other weeds. The best time to treat these weeds is in fall.  The battle to have a weed free beautiful lawn can be accomplished by staying consistent with a good fertilization and weed control program combined with good cultural practices.



Fall is an excellent time to reseed thin lawns or areas of the lawn that have been damaged from insects, drought stress, dog damage or disease.  It is important for you to remember that the seed must stay moist for germination to occur.  This typically is about 21-28 days.  Mountain High will be happy to provide you with an estimate for seeding!



Adequate water is essential for maintaining optimum growth, density and color of your lawn.  Even though temperatures will be cooling off and soon we may be able to reduce the amount of water we are applying our dry and windy conditions here in Colorado require us to continue to water throughout the fall and into winter. Apply enough water to moisten the soil to a six-inch depth. This will help develop a deep root system that can better survive drought conditions.  Winter watering is critical to our lawns just like trees.  The challenge being that sprinkler systems are shut down and we will have to hook up the hose and sprinkler.  This effort proves to be worth it verses having a lawn that in spring is damaged by winter desiccation and or mite damage.  Water is your best preventative against the brutal dry winters.  Despite what most of us think our snowfalls do not provide adequate water for lawns, trees and shrubs.


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