Osu_mg_medium Metro Master Gardeners Oregon

Metro Master Gardener Volunteers from Multnomah, Washington, and Clackamas Counties in Oregon.

(This group currently has 7 experts available to answer questions)

Questions asked to this group

black walnut tree

I have a volunteer black walnut tree (about 1" diameter, 8' tall) growing in the parking strip. Should this be removed now to prevent sidewalk damage and toxicity to other plants?

Multnomah County OR Posted 3 days ago

Ailing Coral Bark Maple

  • The tree was planted professionally. The following year we accidentally broke off a couple of major branches, leaving the tree looking lopsided. I am not sure when we noticed the dark streaks on the trunk. The 3rd year we talked with an arborist about trimming the tree to make it more balanced. He diagnosed it with
  • verticillium wilt, an air borne disease and nothing we could do about it but it would not hurt the tree. He trimmed it lightly in March and said it would fill in with new growth. Three days ago (May 17) a small branch (about the size of my little finger) fell off and we thought nothing of it. A day later a large branch (size of my fore arm) fell off during the night. I am enclosing pictures of the tree and the open wound left by the broken branch. Is there any hope for the tree? What is the treatment for the tree? the soil? Should we take it out and replant it?

Multnomah County OR urban forestry verticillium wilt Posted 5 days ago

Giant Apple Tree

Hello, We have a GIANT, old apple tree in our backyard and love it. However it is totally overgrown and out of control. In an attempt to learn how to care for it better, we recently took a pruning class. We did our best to cut it away from the house and garage in early spring and now need to bring in a professional to help with the top. My question is this: for a summer prune, when should this be done? Before of after it produces apples? I have received conflicting advice and would love a third opinion. Thank you!!!

Multnomah County OR apples pruning fruit trees Posted 11 days ago


Any thoughts on how to save my lawn from dying in the attached picture? We are watering the lawn a lot. I’m assuming it is something else? I’ve always had this problem while living in Oregon.

Washington County OR lawns and turf Posted 11 days ago


I've been receiving emails from a West Virginia nursery trying to sell me ramps- (Allium tricoccum and A. burdickii). Sounds very easy to grow and good to eat, but I'm concerned they also might be invasive here. Do you know? Thanks. Carol B.

Washington County OR ramps allium Posted 16 days ago

Yellow fungus

This fungus just appeared in my planter box what is it???

Multnomah County Oregon slime mold Posted 17 days ago

Where can I buy home-garden quantities of Sudex cover crop seeds?

I am planting winter and summer cover crops to improve clayey garden soils for vegetable growing, using a no-till system. I understand that Sudex hybrid grasses are perhaps the best way to inject roots into the soil during summer, and that Sudex is widely used by farms. But when you search for Sudex on the internet you get a lot of advice to use it but hardly anyone retailing it. I found one source in the East that will sell it but the shipping costs more than the seed, and they don't specify the cultivar. There must be some in Oregon. (Last year I bought straight Sorghum at Concentrates.)

Multnomah County Oregon cover crops Posted 18 days ago

How obtain early-flowering cereal rye for clay soils, and how early is it?

It is now May 7 (2019), my cereal rye cover crop is 6-7 feet tall, but it hasn't flowered. Highs are forecast in the 80s and 90s this week. I want to cut it down to transplant summer vegetables. As an organic gardener, I don't use herbicides to terminate crops, and I must want until end of flowering to cut the rye or it will grow back. I am using the rye primarily to improve clay soil in a no-till system. That's the plan, anyway. In some beds, I am rotating with Sudex for long-term improvement. I understand that there are varieties of cereal rye that bloom earlier. How earlier? What are these cultivars? And where can a home gardener find them in 5-10-20lb lots?

Multnomah County Oregon cover crops Posted 18 days ago

black spot on roses

I’ve used sprays and systemic rose food that are supposed to combat black spot. Nothing works. Any suggestions?

Washington County Oregon plant disease roses Posted 20 days ago

Sharon rose deadhead

What time of year can I deadhead a Sharon rose outside shrub? Can I do it now in May? I know nothing about them. Thank you!

Clackamas County Oregon trees and shrubs pruning Posted 21 days ago