05/27/2026
May 2026 sampler of Plant Answer Line questions:
• What is this pink-flowering tree near the corner of Dayton Ave N and N 83rd Street? Could it be Judas tree?
After checking OSU’s landscape plant database and our encyclopedia of trees, we believe this is a Judas tree (Cercis siliquastrum) as you mentioned.
• What is wrong with my twenty-year-old doublefile viburnum? Parts have just died, and the main stems are bumpy.
These have a limited lifespan. One of the images that you shared also has heavy markings of what looks like viburnum crown borer damage. These borers attack stressed plants. Here is a description of the damage from the Morton Arboretum: “The larva of the viburnum crown borer is the damaging stage. The larvae tunnel under the bark of the main trunks and roots and may be found anywhere from a few inches below the soil line up to 18 inches above the soil line. The first symptom noticed is dieback of entire branches. Other symptoms include swellings, cracks and emergence holes at the base of the plants.”
• Can you help me determine if this is poison hemlock? It does not have purple splotches on it anywhere.
Because of the relatively small size and the lack of purple/red splotches on the leaves, we don't believe this is poison hemlock (Conium maculatum). Instead, it looks like either Queen Anne's lace (Daucus carota) or bur chervil (Anthriscus caucalis). Without seeing the flowers, these two can be hard to distinguish. Both have hairy multi-compound leaves and are Eurasian species. Queen Anne's lace is taller (up to 4 feet) with large umbels of white flowers. Bur chervil is approximately 3 feet tall with small greenish flowers in clusters. In answering this question, we used Weeds of the Pacific Northwest by Mark Turner and Sami Gray, published in 2024.
• These peonies from the florist didn’t open normally. Are the brownish green stamens caused by mold?
If you're in King County, please send your photo to the Master Gardeners at [email protected] for evaluation. Peony growers are frustrated by "bud blast," an umbrella term for failure to flower once buds set:
https://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/insects-pests-and-problems/environmental/bud-blast
• What are these trees on UW’s Seattle campus? I’m pretty sure they are a crabapple of some kind.
According to the UW tree inventory, these trees are Malus tschonoskii (Tschonoskii crabapple).
• Is Parrotia persica a shallow-rooted tree?
The Selectree database (https://selectree.calpoly.edu/tree-detail/987) lists this tree as having low potential for root damage. A Mount Vernon wholesale grower says they are shallow-rooted, in his experience, which calls for extra care in siting them: https://urbanforestnursery.com/inventory/tree-profiles/persian-ironwood/
• Please recommend some recent books in your collection for professional landscapers and designers.
Sure: here is a list of ten favorites:
https://hortlib.kohacatalog.com/cgi-bin/koha/opac-shelves.pl?op=view&shelfnumber=493&sortfield=author
• I’m curious about Fragaria ‘Lila Diamond.’ Do the berries attract pests?.
The fruits of Fragaria 'Lila Diamond' are edible, but we haven’t heard of them attracting pests. They are considered good for wildlife, as they attract bees and butterflies with their flowers.
• What is this hairy black dime-sized spider with a face-like white pattern on the back of its abdomen?
You’ve just met the bold jumping spider, Phidippus audax—a harmless garden friend to humans.
