50 Year Snow Storm Hits Arboretum Plant Collections Hard!

The record cold temperatures and snow that fell in Washington Park Arboretum between Feb 3 and Feb 11 will be one for the record books when it comes to accounting for all the plant collections damage and total losses. Over 300 horticultural plant condition reports have been submitted for curatorial review, many of which are significant in size and/or rarity. For example, the fourth and final snow storm on Feb 10th dumped more than 6″ of heavy wet snow which was the proverbial “straw that broke the camel’s back” as the weight of the snow toppled over 25 large mature tree specimens! These trees can not be saved, but may be able to be propagated if curatorial assessment warrants this action be taken. Our initial storm survey does not account for any freeze damage which won’t manifest itself until well into spring and even summer. Besides entire tree root plate failures, there are many more major deciduous tree scaffold branch failures that severely damaged our historic cherry collections along Azalea Way, Japanese maple collections in Woodland Garden, Magnolia collections and many other tree species. Not surprisingly, many of our broadleaf evergreen collections, such as our Camellias, Magnolias, and Rhododendrons sustained damage from snow loading too. The vast majority of major tree scaffold branch failures were due to inherent structural issues and defects that are common in some tree species. When a 50 year storm hits, Mother Nature has a way of clearing house by taking out the weakest structural points of connection, mostly at tree crotch inclusions that also show decay is present.

A storm of this caliper that has devastated such a wide spectrum of our plant collections deserves a name. To help ease initial staff storm shock and discouragement, I offered up a free pizza to the staff person who could come up with the best storm moniker. The winner is Drew Foster, UW Botanic Gardens Arborist, for his F.F.F. acronym February Flurry Fury of 2019! This will make it easy for record entry into our plant records database too. All joking aside, kudos to grounds staff, both Parks and UW Botanic Gardens, who did safely make it into work during the week for Feb 3rd and helped remove snow from plant collections and cleared many of our trails. I believe this storm intervention alleviated further plant damage before the final snowfall which unfortunately occurred on the weekend.

Those of you who have visited the Arboretum can see that clean-up efforts are well underway. All trails have been cleared and most imminent potential tree hazards mitigated at this juncture. However, it will be months before the majority of F.F.F. 2019 damage will be recorded and all actions addressed in the field. Large wood from tree trunks will need to remain in place until the ground firms up to allow us to gain equipment access.

On the optimistic side of things, we can now look into the future and see some new plant collection development opportunities that unfortunately this brutal snowstorm bestowed upon Washington Park Arboretum’s world class plant collections.

Here are few storm photos:

Newly planted Cornelian cherry down!
Success, Cornelian cherry standing once again!

 

Arborist in Leyland cypress removing hangers

 

Serviceberry root plate failure. Total loss.
Rhododendron root plate failure. Arborists will attempt to cable back up.
Cherry mess!
Catalpa mess!
Common breakout. Inclusion with decay.
Not such a Winter Wonderland!