Cup Plant: A Plant You Can Look Up To
Judy and I like tall perennials, and we have lots of them in the garden. I mean really tall, like you have to look up to see the flowers. We’ve considered starting an organization for ourselves and others who admire towering plants. It could be called the American Prodigiously Tall Plant Society (APTaPS).
Anyhow, of all our really tall perennials, the absolute tallest is the Cup Plant (Silphium perfoliatum). In our garden, it grows a to a good 10′. If you look at the leaves at the bottom of this picture, you can see how the leaves are perfoliate – the main stem passes right through them. As a result, the leaves form cups that catch rainwater – hence the common name.
Late July and August is when Cup Plant is topped by bunches of yellow daisy-like flowers,
We have a patch of Cup Plant at the back of our Front Island Bed. At this time of year it blooms with Sweet Joe Pye Weed (Eutrochium purpureum) and ‘Purple Rooster’ Bee Blam (Monarda didyma).
Cup Plant has a reputation as a thug but I do not find it difficult to control. Sure, you will find volunteers popping up here and there but I just yank them out of the ground or cut them at the base. It’s really a gentle giant.
Cup Plant is very beneficial for wildlife. The flowers attract bumblebees, native bees, honey bees, and predators of insect pests. Some native bee species nest in the hollow stems. After the flowers fade, Goldfinches come to feast on the seeds.
Not surprisingly, given its height, Cup Plant needs some support in our garden. I use rebar for stakes and lots of green twine.
Some gardeners are put off by Cup Plant’s size and enthusiastic self-sowing. Not us. We love its dramatic height and the giant contribution it makes to wildlife habitat in the garden.
gardeninacity 
Lovely! I love its large leaves and square stems!
Very interesting. I hadn’t heard about this plant before, and was wondering why it was called Cup Plant!
That is some plant! Love the proposed name of your society.
You could be a charter member, in exchange for a generous contribution.
😉
I have always admired this tall handsome plant yet it doesn’t have a spot in my garden. Maybe I should remedy this.
No time like the present. Well, probably better to wait until fall.
I’ve been reluctant to let this prodigious grower get a foothold, but you have me thinking …
Amazing plant — it will even grow in shade. Nice to use it place of a shrub where you want height but not width. I’ve never had to stake but Jason’s soils may be very rich indeed. Yes, seeding is a bit of an issue out here on the prairie — it has migrated to my hay lot along with a whole lot of other stuff! I think this would be manageable in a home garden.
I’ve found it to be so.
Fortunately our neighbors have some and I can enjoy them and hope they wander over.
The odds are pretty good they will come for a visit, then make themselves at home. On another subject, I think my comments on your blog are ending up in your spam folder. Just thought I’d mention it.
Nope, I get them. I just trash them off the email and read them on the WordPress site. I just get a lot of email..Appreciate the concern and notice…thanks!
Unfortunately in CT, this plant is on the invasive list. Apparently it likes the growing conditions here just a little too much :).
Wow, I had no idea. According to NPIS, it’s native to CT, in fact all of New England except RI.
Kinda like my seven foot Joe-Pye weed. Especially the self-sowing part.
Yes, just so. We have some of that also.
Love it! Ours is now blooming as well but it doesn’t get to 10′ – perhaps 7 or 8. We do have some popping up in some pretty strange places this year – this is the first time that’s happened (we’ve had them for over 7 years) so I’m wondering why that is.
I’ve noticed that also with some plants – they hang around for years and then all of a sudden they start self-sowing.
Thank you for the info on the cup plants. I want to plant some in a corner of my yard, but feared it would be uncontrollable. Yours looks great with Joe pye and bee balm.
It’s a good idea to surround it with other taller, aggressive plants, like Joe Pye and NE Aster.
My only issue with very tall plants is finding something a little shorter to plant in front of them. And then something shorter, and on and on. It looks like you’ve been successful with that.
I enjoy the challenge.
There are some cup plants in the “natural area of our neighborhood park, along with common milkweed. So we can enjoy vicariously!
Good to hear the park has a natural area.
I like the acronym! I’m in! If I had more sun, this plant would be in my garden. It’s one of the fishman’s favorites. 🙂
You can be a charter member, for a small fee. I wish I had space to grow other Sulphiums, like Compass Plant and Prairie Dock.
Your front garden reminds me of mine! I’m thinking I’ll keep the Silphium, but may need to severely edit it, to keep it vaguely in the space that it’s in. What a wonderful plant to enjoy, however! The flower visitors are amazing, from butterflies to bees.
Agreed. Have you tried growing any other Silphiums?
AWESOME!!! I will have to see if I can find some. They would be great here!
I hadn’t heard about cup-plant either, and thought the only really tall yellow daisy flowered bloomers (not sunflowers) were helianthemums. 🙂 Very interesting!
Oh, there are several very tall guys in the genus Silphium that are worth trying.
I would gladly join your tall plant society! I love tall plants, especially native ones that benefit wildlife. Cup plant has been on my list for awhile of plants to grow at some point. It’s such a cool plant!
You can be one of the founders of our society!
Interesting plant, Jason. Is it hardy or invasive? Lovely photos!
It can certainly be aggressive, I would not recommend it for a formal garden. But in a more naturalistic garden, it can be controlled.
Hello Jason, I like the acronym of “APTaPS”, have a nice ring to it. The only plants we have that are this tall currently are trees and shrubs, when we get round to creating the large herbaceous border, we’ll be needing the help of APTaPS for ideas on what to grow at the back.
Glad you like the name, I thought it sounded authoritative.
Lovely, I like tall plants too. More monardas to make me jealous.
Very interesting. I had a neighbor who specifically always wanted to plant tall plants.
Then s/he and I are soul mates.
Love it, cups and all
very good article! congrats!
Thanks.
Cup plant looks like a good candidate for our garden. I don’t mind for the most part if plants self sow. If they come in thickly, they help shade each other from the intense sun here.
I’m guessing Cup Plant could handle the sun, although not if the soil is very dry.
Goodness, that is tall, a fantastic plant indeed. You two should go ahead and form that society, I’ll be your first member.xxx
I could appoint you chair of a committee. What committees do you think we should have?
I live north of Atlanta and became familiar with this plant about fifteen years ago. I now have it in my own garden and have not seen it being invasive in this area at all. Although it does need staking, I think it a worthy addition to the Southern landscape.
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