Brad Withrow-Robinson, Forestry & Natural Resources Extension agent for Benton, Linn and Polk Counties.

It is shaping up to be another dry year.  Writing this in mid-month, we have seen unusually dry air and winds, creating fire conditions not usually seen until early summer.  We will likely see temperatures in the 80s and are under red-flag warnings last weekend.  In mid-April!   We could luck out, and get some serious precipitation in the next few weeks, but don’t count on it. 

We know “you can’t change the weather”.  But there are a few things under our control.  Here are some things to do in the face of a dry year.

Fire Prevention

ODF reports an unusually high number of fire starts this month.  The main cause has been back yard debris burns. 

Hold burnpiles until a safter time

A thing to do:  Do not set any debris fires this season (unless we get a significant weather change).  Instead, plan to cover piles and wait burn this fall after the rains start. 

Another thing to do:  Tell your neighbors about your choice to not burn now, and encourage them to do the same.  After all, an escaped burn next door is a very threatening fire.

Yet another thing to do:  Start taking fire season precautions now when working in the woods.  Carry your fire tools while working in the woods, doing storm clean up.  “Better late than never” not a good strategy here.

Fire Preparedness

The Labor Day fires created an awareness among residents of western Oregon about the potential of major fires.  The Extension Fire Program has created Fire Aware.  Fire Prepared., a 7-part series to help individuals and communities begin the work of being better prepared for wildfire.

A thing to do:  Watch the webinar series.  It is underway, and all previous sessions are available by recording at the Fire Program’s Online webinar guide.  https://extension.oregonstate.edu/fire-program/online-webinar-guide .

Another Thing to do: Take the preparedness actions presented in a to do list at the end of each session.  These include actions to harden your home against fire, as well as beginning to coordinate with neighbors.

Yet another thing to do:  That thing about coordinating with neighbors.  Encourage your neighbors to watch the Fire Aware. Fire Prepared. webinar series and begin a neighborhood planning process.

Seedlings

This is likely to be rough year for new plantings. Effective weed control will likely be more important than ever.  There may still time to touch up your weed control around your seedlings. Some weed control resources are here.   

Keep an eye on weed competion. It sneaks up on you!

A thing to do:  Check the weed situation in young plantings if you have them.  Treat if needed.  Be careful if using herbicides, as seedlings become more sensitive to spray when they come out of dormancy, as described in this post

Fire wood

As you do your winter storm clean up and piling remember that this is an excellent time to make firewood.  Firewood is best dried quickly, so early summer is great.  Unlike those precious boards you mill up for a “future project” which should be gently dried, firewood benefits from harsh drying conditions.

A thing to do: Cut wood early in the season and stack it loosely to catch the dry summer breeze.  This timely effort will help it dry quickly and burn cleaner in the winter.

A supply of dry wood can give satisfaction in many ways

By Amy Grotta, OSU Forestry & Natural Resources Extension – Columbia, Washington, & Yamhill Counties

We’ve discussed ongoing drought stress a number of times on this blog.  But when do we consider it dry enough to be called a drought?  There’s actually a system for that. The United States Drought Monitor updates and releases a national map each week, showing which areas of the country are experiencing drought, and how extreme the conditions are.  A variety of data sources go into their models, which I won’t begin to explain here, but their website has a lot of good information on how they determine drought conditions. In fact, all the data and visual tools on the Drought Monitor website feed the data geek in me; so if you like this sort of thing I encourage you to check it out.

If it seems like this blog has been a broken record stuck on the drought track the last few years, you’re not imagining things. But today, I want to highlight that in northwest Oregon we begin 2019 in a state of Moderate Drought, according to the Drought Monitor (see figure below; click to enlarge), even though we are in the midst of the rainy season. Continue reading

By Amy Grotta, OSU Forestry & Natural Resources Extension – Columbia, Washington & Yamhill Counties

Often around this time of year, I’ll get a question from a small woodland owner asking whether it’s worth the trouble to try to water their newly planted tree seedlings. My standard reply has always been “No”.  Of course, in most cases, it’s not even a practical consideration, because the logistical challenges of delivering water to hundreds, if not thousands of seedlings on steep or rough terrain far from any water source far outweigh any potential benefits.  I also point out that our Douglas-fir trees are adapted to withstand dry summers. After all, millions of Douglas-fir trees are planted each year in Oregon, and most of them make it without any supplemental water. And, I know one or two woodland owners who have watered trees that they were concerned about, only to have them die anyway.

But this year, after fielding the question of watering young trees again, I started to think a little more about my standard answer. After all, all signs are pointing another drought year. Scientists predict that summers in the Pacific Northwest are only going to get hotter and drier in the future.  In light of these factors it doesn’t seem like an unreasonable question. Continue reading

Brad Withrow-Robinson, Forestry & Natural Resources Extension Agent for Benton, Linn and Polk Counties

In my previous post, I summarized what I think we know about this ecological whodunit. In this post, I look at what it might mean for landowners in the area.

Now What?

Pouch fungus commonly appear one year after trees are attached by beetles like flatheaded fir borer or fir engraver. Phot by Dave Shaw, OSU Forestry & Natural Resources Extension

We seem poised for another stressful summer. May 2018 has turned out to be one of the driest on record, and we are unlikely to catch up in June. Long term forecasts are for another warm dry summer. We will just have to wait and see how it unfolds. But whatever happens this summer, I think we can expect to continue to see more sick, dying and dead trees. There are several reasons for this.

First, many trees are already stressed or injured by the past hot drought events and are in a vulnerable condition. While not yet lost, this stress makes them less resistant and more susceptible to the insects and diseases that are lurking about. A mild summer, or several mild summers would help. But even then they will not recover immediately. Their earlier stress and injuries also hamper their ability to recover and rebuild their resistance, even under good conditions.

An analogy might be of me falling off a ladder. The injuries I suffered when I hit the ground continued to affect my health and recovery long after I stopped falling (it is harder to exercise with a broken leg). It will take a while to recover, even if I stay out of trouble. It will take longer (or could kill me) if I keep falling off the ladder. For the trees, each of these summers is like another fall from my ladder.

Second, some trees are already lost. It may not be obvious, and they may still have needles, but they have been mortally wounded or have already been attacked by insects and will not recover, however our summer turns out. It is just a matter of time before those losses become apparent. Continue reading

Drought-damaged trees have become a common site in the Willamette

Brad Withrow-Robinson, Forestry & Natural Resources Extension Agent for Benton, Linn and Polk Counties

 

Many of our readers have been tracking this issue over the last several years through the articles on this site. But I imagine many of you are wondering what to expect next, or are being asked by friends and neighbors who are concerned about your trees or theirs. Or just wondering what is going on. What to say?

So, here is a synopsis of what I generally see going on, and the consequences. A bit risky to do, given the role of individual sites and specific conditions. But this is such a widespread phenomenon, it warrants some interpretation, even at the risk of over-generalizing. But I provide the antidote at the end: links to more detailed information.

 

It is hard to miss all the dead and dying trees in the area. I have been getting dozens of calls about them. So what is going on, and what is to blame? It seems time to revisit this sylvan whodunit: What is killing all these Willamette Valley trees?

Who is involved? Douglas-fir is by far the most frequent casualty, along with other conifers such as grand fir and some ponderosa pine. But trees of many sorts are being affected –

Drought symptoms may include dead branches, dead tops and low vigor. Or all of the above. Photo by Dave Shaw, OSU Forestry & Natural Resources Extension.

hardwoods as well as conifers, both native and non-native. Many of the usual suspects – different beetles and fungi- can be found at the scene too.

What is happening? Symptoms often include dying branches and dead tops, low growth and vigor, sparse crowns, what we have called the “Willamette Valley crud”. It is now often progressing to the death of the tree. This may be happening to individual trees or groups of trees. The younger trees are usually the first involved at a site, eventually joined by older trees.

Where is it happening? This is certainly a Valley-wide phenomenon. But within the Valley, we are seeing the most significant damage in certain situations more than others. Sites with seasonally wet, poorly drained soils, or sites with rocky or shallow soils, exposed south facing aspects tend to be most hard-hit. These are places that we think of as marginal sites for most conifer trees. Our conifers are well adapted to the area, but not every site. Continue reading

By Amy Grotta and Brad Withrow-Robinson, OSU Forestry & Natural Resources Extension

Group mortality of Douglas-fir in May 2015.  Douglas-fir beetle was found in all these trees.  Photo Kara Shaw
Group mortality of Douglas-fir in May 2015. Douglas-fir beetle was found in all these trees. Photo Kara Shaw

We have certainly experienced some significant drought conditions lately.  Stressed and dying trees are showing up all around the Willamette Valley, with concern that this could lead to beetle outbreaks and still more trees killed.  Is it time to throw in the towel, cut your losses (so to speak) and just salvage everything that is looking poorly?  Maybe, maybe not.  The decision needs to be considered carefully, weighing individual sites and stand conditions along with your objectives for your property.  Anybody considering a salvage harvest needs to look before they leap. Continue reading

Brad Withrow-Robinson, Forestry & Natural Resources Extension Agent, Benton, Linn and Polk Counties.

Conifer trees around the Valley continue to show signs of severe drought and heat stress this year. This should not be news to many readers:  young dead trees are now a common sight throughout the Valley.  Also, I wrote about this problem in past Tree Topics blogs (See stories from  May and September 2015 for background) but have new updates for this season.DSCN2333cr

I think you can expect to continue seeing similar damage to Douglas-fir this year and that symptoms will continue to unfold as the season progresses. Some of the trees damaged late last year did not show that damage immediately. The damage did not become evident until the trees came out of dormancy and began to grow this spring.  Also, the various insect and disease organisms that take advantage of       weak and damaged trees are likely to continue with their business this year, causing new signs of drought damage to show up during the season.  Happily, those players like Douglas-fir cankers and twig weevils do not typically blow up and kill healthy trees.  This suggests things will look much like what we saw and described last year and is likely to continue to unfold this season and maybe longer, whatever weather we get.  “It is important to understand that the effects of drought damage do not go away suddenly when the rain starts again” cautions Christine Buhl, ODF Forest Entomologist “drought can impact the tree’s whole plumbing structure, and affect the growth and vigor of the tree for years.”

Continue reading

By David Shaw, Forest Health Specialist, OSU Forestry and Natural Resources Extension

Douglas-fir killed by drought
Douglas-fir killed by drought

The summer of 2015 is shaping up as a big year for drought and drought related forest health issues throughout Oregon, but especially in the Willamette Valley, SW Oregon, and in Eastern Oregon.

In late summer, it can be very difficult to discern whether insects, disease, or drought and heat are causing tree dieback and deaths, but we are becoming pretty confident that drought and heat together are influencing much of what we see.  In this report I outline and describe some of the more common problems we are seeing with conifers and hardwoods as of early September.

Continue reading

By Brad Withrow-Robinson, Forestry & Natural Resources Extension Agent, Benton, Linn and Polk Counties

drought stressYoung Douglas-fir trees with dying branches or tops turning brown, then red have become a common sight all around the Willamette Valley this spring. What is going on?

This “flare out” of branches and tops are classic drought symptoms in Douglas-fir, which we are linking to last year’s weather when we had a particularly long, dry and very hot period late in the summer. Late season drought injuries to the stem and leader do not always show up when they occur, but often express themselves the following spring as trees start to grow. We have these drought damage events from time to time here in the valley, most recently in 2013 and again before that around 2000. Older trees typically have milder symptoms, but the many older, flat-topped Douglas-fir trees you see are a reflection of past droughts and non-fatal damage. Continue reading

drought stressThe phone has been ringing off the hook lately with calls from people describing sick and dying Douglas-fir and other conifer trees. The trees are of a wide range of ages and in many environments and settings, although most calls have been coming from within the valley margin and have to do with young trees.

So far, the answer is generally: “It is drought stress”.  Huh, in May? Well it has been a dry winter and spring, … but that is not the issue.

My best explanation is that we had a pretty hard end of summer last year. Remember that? NO rain until mid-October then, Boom, it was winter. By then, many trees had started running out of water, killing tops or branches, and leaving leaders and branches susceptible to attack by various opportunistic pests.

We started seeing a few classic signs of drought stress (tops dying and branches “flaring out”) at the very end of the season last year, but late enough that many did not have time to show up before the weather turned. Injuries had occurred, so it was just a matter of time before they expressed themselves, which is happening now. The recent hot weather seems to have made it more sudden and dramatic.

This happens from time to time. Here are two good articles a few years back by the ODF Forest Health team explaining Dead tops and Branches (with Good pictures), and about Drought and Mortality.

It is important to keep in mind that the Willamette Valley can be a challenging climate for trees. Many of our soils in the valley are poorly drained, which is hard on most of our conifers, and other soils are fairly shallow and cannot hold much water. Also our summers are hotter and drier than in the mountains. Heat and drought stress can kill trees outright, or more often just put the trees under stress, which can then lead to pest problems (as explained in the two publications above). From what I am seeing and hearing, the major cause of the problem now seems to be drought stress. Insect or diseases which able to take advantage of a stressed tree’s condition may sometimes be involved, but they are generally not the cause of the problems.

Finally, weather can be more stressful when trees are overcrowded, so thinning stands to keep trees vigorous with adequate growing space may be helpful in the long term. Right now, we just have to wait it out, and hope we get some serious rain this year, or we will see this problem intensify.

We all better get out there and wash the car…..

Brad Withrow-Robinson