Two Red Oaks Topple in Arboretum

June 24th, 2010 by UWBG Horticulturist

Root wad of fallen red oak in west lagoon

Two leaning mature red oaks (Quercus rubra) fell last week in the arboretum. The one that went down at the north end of Azalea Way, near our famous propped Willow oak, was witnessed by several onlookers as our arborist Chris Watson was hurredly trying to stablize it from going over. He never had a chance. The popping and cracking noises from severing roots on the backside kept getting louder and more frequent. It was sad and awesome at the same time. Not many people get to see a large tree go down on its own volition.  The other oak is located at the water’s edge in the west lagoon area. This oak was significant from a curation standpoint too.  It was wild-collected in the Adirondacks in 1958 by the Morton arboretum. Arboretum staff hope to keep its massive root wad (see photo) intact for interpretive and educational opportunities.  Both oaks were leaning and growing in shallow soils, had insufficient support roots, extraordinary spring growth and wet, heavy foliage when they failed. The fact that there were two trees of the same species topple  at approximately the same time was indeed a rare coincidence in the arboretum.


Pacific Connections – “Chilean Gateway” Notice

March 26th, 2010 by UWBG Horticulturist

Upcoming Pacific Connections Phase 2 Construction

33 trees will be removed under the Pacific Connections Phase 2 Project. These trees do not contribute to the horticultural collection.  They are being removed as a management tool and to make way for the new Chilean garden.

Location: Pacific Connections Garden – Chilean Immersion Forest NE quadrant of intersection of Lake  Washington Blvd. and Arboretum Drive.

Timeframe: April 19 -23, 2010

Safety: Service roads and trails near tree removal operations will be clearly signed “Closed” for  this removal and a detour will be set up to route pedestrians around the removal.

Contact: Andy Sheffer, Seattle Parks and Recreation, for  additional information. or 206.684.7041


WPA Coming Attraction: Mason Bee Boxes

February 19th, 2010 by UWBG Horticulturist

Mason Bee Box

Arboretum staff will be assisting mason bee hobbyist Dave Richards (JohnnyAppleBeez, LLC) install several mason bee boxes in trees throughout the Arboretum grounds. The gentle, native mason bee is a better pollinator than the honeybee, but doesn’t travel nearly as far from its nest. Boxes will be up until June. An interpretive sign about mason bees will soon be posted up at the Arboretum apiary.

8 boxes similar to the one in the photo will be installed throughout the Arboretum grounds


J.A. Witt Winter Garden: SE Bed Renovations

February 18th, 2010 by UWBG Horticulturist

The UWBG horticultural crew will be making renovations to the southeast bed, which will include removing, relocating, or protecting other UW plant collections in the project area, followed by regrading of the bed and soil remediation. The 2009-2010 fall and winter planting of new winter-interest trees, shrubs, and ground covers will also take place.

This project will reclaim over 5,000 sq. ft. of bed space that is now detrimentally shaded by elm trees. It will also renew UW Landscape Architecture Professor Iain Robertson’s original 1987 Winter Garden design intent.

This renovation was made possible by a gift from the Arboretum Foundation, which was given to them from Lake Washington Garden Club, Unit 3.

Renovation information sheet.