Ask the Gardener: Bladdernut, fungus gnats, rose black spot and more

Posted on: June 27, 2018 | Written By: Doug Oster | Comments

Gardening editor Doug Oster gets asked a lot of questions. A lot. And he doesn’t mind offering gardening advice. But rather than just limiting those answers to the person who asked, we thought it might be a good idea to share that wealth of knowledge with everybody.

There are three ways to send in your questions:

• Email askdoug@535mediallc.com

• Submit your question on our “Your Garden” section of our site

• Send us a message on Facebook.

(The questions may be lightly edited for grammar/clarity/etc.)

• • •

Ruth: Is this poison ivy? I’m thinking not. While it has leaves of three, they seem to be growing from a central point opposite each other, not alternating like poison ivy. New leaves don’t appear to be red. And the leaves are very finely saw-toothed, which I read poison ivy leaves never are. Closest thing I can come up with similar is bladdernut.

Doug: (After reader Jo Ellen confirms it’s bladdernut): Good call Jo Ellen. It’s not poison ivy.

• • •

Moxy: I need suggestions on how to get rid of what I think are fungus gnats in my potted basil & jade plants. I tried letting the dirt dry out but the basil almost died. I vacuumed a lot up. Would it help to replace all the dirt?

Doug: Drying out is the first defense. Repotting will do the trick, too. If the plant is outside, try to keep it on the dry side. Good luck!

• • •

Ann: Any solution to rose black spot?

Doug: An organic fungicide will help. The best time to apply it is before seeing signs of damage. That ship has sailed. I like this stuff though, called Serenade (available here.)

• • •

Dennis: Hi Doug. Are there many perennials that will do well in our winter zone in large raised bed gardens like the one pictured (4’x4’x24″H)?

Doug: Most perennials will be happy in a bed like that. The first thing to consider is if it’s shade or sun. Choose the right plant for the right place. Then think about how big the plant will get. I would stay with plants that are robust for your climate, not something that’s marginally hardy.
With any container, even one that big, you could use the thriller-filler-spiller formula for planting. Using something big and spectacular in the middle, then some plants that are shorter around it and choose varieties that trail over the edge.
You could also think about mixing annuals and perennials together in a bed like that. Have some fun.

• • •

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