Birds in the Garden · Perennials

Cup Plants: Great for Pollinators & Summer Showers

I was so happy the rain came Monday night instead of during the day on Tuesday – my one day each week to spend in the garden. I decided to tackle a garden area yet to make it to the top of the Reclaim my Gardens, Reclaim my Life list and began weeding at one end. I pulled weeds from the bed as far in as I could reach from the edge, wanting to let the soil dry a bit before moving farther into the garden. The weeds surrendered from the moist soil easily until I got to an area with self-sown cup plants.

Throughout the neglected years in my landscape, rhizomatous perennials claimed more than their fair share of space and self-sowing plants, like Silphium perfoliatum, attempted a garden takeover.

Silphium perfoliatum is most commonly called cup plant but is also referred to as Indian cup, rosin weed and carpenter weed. It is a native of the tallgrass prairies and can now be found growing along railroad tracks, in meadows, beside prairie streams, and in low-lying areas at the edges of woodlands.

At first glance, it may be mistaken for a sunflower but is easy to distinguish by its tall sturdy square stems that seem to grow right through pairs of large, scratchy leaves.

Their leaves join together at the bottom forming a cup that holds water from summer rain, a sprinkler or even morning dew.

Cup plants are important to a variety of wildlife and beneficial insects. Birds drink water from their cups and seek shelter in their dense colonies; butterflies, bees and other pollinators sup nectar from their flowers; birds, especially finches, devour their flower seeds in fall; and native bees and other pollinators use parts of the plant to build their nests in the soil beneath them. Considering their wildlife value, I almost gave them a pardon from the compost bin, but there are two other large patches on either side of a shed and these 7-foot tall towering perennials self-seeded themselves right at the front of the border. The phone call a second before midnight did not come and no stay of execution was granted.

I could have tried to transplant them to another spot with the conditions they prefer – average to moist, well-drained soil in full sun to part shade – but they develop large, hard-to-move root systems as they mature, and these were mature plants. In the future when I spot seedlings, I will move them near the ditch where they can self-sow themselves silly and give the neighbors bright golden yellow flowers to look at from July to September.

I began cutting down stems at their bases collecting quite a handful before lifting them out of the garden. As the title of this blog post predicted, I received a summer shower. Whoosh! All those little cups full of water from the previous night’s rain spilled down right on top of me. I guess the plants got the last laugh.

Although I need to keep a closer eye on their propensity to reproduce, I would never remove Silphium perfoliatum entirely from my landscape for several reasons:

  • It has a lot to offer wildlife, butterflies, bees and other pollinators.
  • It requires very little maintenance.
  • It provides a bright spot of late summer-early fall color.
  • It is an ideal backdrop for other perennials in my large gardens.
  • It is fun to show kids and other garden guests their cups filled with water.

Cup plants are easily planted by seed in fall. Just sprinkle seeds collected from plants in September and October on the soil and let nature do its thing.

Have you ever grown this colossal beauty? Did you notice all the birds, bees and pollinators stopping by? Did you delight in finches snacking on its seeds? Garden with me!





6 thoughts on “Cup Plants: Great for Pollinators & Summer Showers

  1. I have blooming cup plants for the first time this year. We love them. I bought them at a Master Gardener’s plant sale two years ago. They’re in the shade, I think, if I’m able, I might move them to the front yard into the sun for next year. Friends have them and they’re twice as tall in the sun.

    1. I would suspect their root systems won’t be that large yet, so you should be able to move them. Keep an eye out for seedlings! LOL

  2. Questions about our cup plants were among the most received during the 2017 Buffalo Garden Walk. They are gorgeous right now!

  3. Well, my young cup plant is still “relatively” small, but I did decide to deadhead, based on all of your recommendatins at the Fling.

    And I’m planning to see if size mgt works, too, not my usual style of gardening!

    1. Hi Lisa. I will still probably not deadhead my two large clumps of cup plants, letting the finches have their feast, BUT I did promise myself to either transplant seedlings or pull them WHEN THEY ARE SMALL so I don’t have to work so hard to remove them EVER AGAIN. LOL!

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