Local Drought Conditions and Your Landscape

May 24, 2024
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Originally posted in 2016, but many of the concerns and remedies remain the same:

In 2015, the Flathead Valley endured months of severe drought conditions.  This was largely due to an unprecedented lack of rain in June and early July—a local record for dry consecutive days.  In addition, June 2015 was the warmest June on record for the city of Kalispell, and Kalispell continued to set record highs throughout the summer.

As of today, February 12, 2016, the US Drought Monitor indicates that Flathead County is in a state of extreme drought, and surrounding counties are in states of severe to extreme drought.  Even more concerning to us at Dudley’s Trees, Kalispell temperatures did not drop below zero for any significant length of time this last winter, if at all.  This likely means there is a significant increase in the number of insects and insect eggs that survived the winter.  We are already gearing up to encounter many urgent tree and landscape problems in 2016.

Why should Flathead Valley residents be concerned? 

Last year we realized most of our clients have unconsciously relied on the June rains to jump start and green up their trees and landscapes.  Prior to 2015, they didn’t see a need to turn on their irrigation systems or haul hoses until their lawns started to show signs of browning in early to mid July.  Then they irrigated another six to eight weeks until cooler fall temperatures arrived.

Local climate conditions in 2015 changed that mindset, but not soon enough.  Many waited for the spring rains that never arrived.  By the time they turned on their sprinkler systems or hauled hoses, their trees had already come under severe stress, and many were attacked by insects and disease because of that stress. 

Moreover, many clients with automated sprinkler systems discovered significant problems with their systems.  Prior to 2015, the spring rains greened up their landscapes so effectively that brown spots and other signs of potential problems with their irrigation systems did not appear until the hottest part of the season, and then disappeared while temperatures cooled.  Homeowners assumed this was a normal effect of temperature change.  They had no idea their systems were riddled with leaks, broken heads, inefficient heads, poor coverage, and inadequate timing until the June rains did not arrive to mask the signs.  Problems appeared early and persisted throughout the season.

Many of their irrigation problems had been undetected for months and even years.  Meanwhile, their trees and landscapes were showing signs of stress and being plagued by insects and disease.  The typical reaction was to treat the problems with chemicals, then to continue to apply chemicals to prevent a subsequent outbreak.

What does this mean for most residents of the Flathead Valley and surrounding areas?  Some or all of your trees and landscapes are likely suffering drought conditions, even if you have an automated irrigation system.  Water-stressed plants are less able to resist insects and disease.  And, because of the lack of sub-zero temperatures which help kill over-wintering insects and eggs, we anticipate 2016 will be a banner year for insect infestations.

What can you do to help remedy this situation?  We recommend a proactive approach:

  • Many shrubs and trees (especially fruit trees) can be sprayed while they are dormant with an organic oil spray.  The oil suffocates many over-wintering eggs and insects.   
  • As soon as temperatures allow, troubleshoot your irrigation system.  Check for leaking and broken heads, inadequate pressure, overly soggy areas, inadequate coverage (you should have head-to-head coverage), and leaking backflow preventers.  If your drip is on the same line as a sprinkler line, you will likely need to separate them.  Dudley will be giving a presentation on basic troubleshooting and design of irrigation systems at the Flathead Building Association’s Home and Garden Showcase at the Flathead County Fairgrounds on March 13 at 11:30 am.
  • Begin irrigating late Spring.  See our general guidelines for irrigating your trees in spring and throughout the season in our “Irrigation Guidelines for Healthier Trees” blog.
  • Your trees are the most valuable asset in your landscape.  Make sure they are being watered sufficiently.  If your clock is scheduled to water your lawn everyday, you may want to gradually adjust the schedule to more effectively water your trees.  We will soon post a blog outlining the steps to transition to a tree-friendly watering schedule that will allow time for your lawn to adapt.
  • Frequently check your trees, plants and lawn for signs of insects and disease.  Keep in mind that not all problems can or should be eradicated with repeated chemical treatments.  Ask questions and do some research before applying a chemical or signing a contract for repeated treatments.  The MSU Extension office in Kalispell is a great resource for information.

Our owner, W. Dudley Marburger, is an ISA certified arborist and a resource for information regarding plant health care, chemical treatments, and sprinkler and drip systems.  He’d be happy to give you a personal consultation regarding specific issues affecting your landscape.