Silphium perfoliatum - Cup Plant

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    Purchase Silphium perfoliatum - Cup Plant

    Silphium perfoliatum - Cup Plant

    SKU: C18660



    The large pointed leaves of the Cup Plant join its square shaped stems forming cups that catch and store rainwater so birds and butterflies often come for a drink and hummingbirds regularly visit. In the fall, goldfinches descend upon the plants to devour the seeds. Silphium perfoliatum occurs naturally in moist environments but does very well when planted in the garden.

      Late Summer
      Full Sun
      4' - 10'
      Sand to Clay
      Dry to Moist
    Approx. 12 seeds per pack - 35 seeds per gram

    Attracts Butterflies, Hummingbirds & Songbirds!
    Deer Resistant!
    Makes Great Cut Flowers!
    Juglone Tolerant!

    All Wildflower Farm seeds are hardy through growing zone 3, organic and non-GMO.


    Indoors: Cold, moist stratification. Start at least 5 weeks before outdoor night temperatures are reliably in the 10 C (50 F) range. Mix the seed with a slightly moistened, sterile, soil-less growing mix. Put this in a labelled, sealed plastic bag and store in a refrigerator for one day. The next day place this in the freezer for one day. Repeat this for one week, alternating between the fridge and the freezer. After stratifying, plant seed 0.64 cm (1/4 inch) deep in pots. Keep moist but not soggy and very warm (21 C - 70 F). When seedlings are 5 cm (2 inches) tall or more, transplant into the garden spaced 30 cm (1 foot) apart.

    Outdoors: Plant seed 0.64 cm (1/4 inch) deep in a prepared seed bed in late fall so that the seed overwinters and germinates naturally in spring.

    Outdoors Alternative: In late fall through to mid-winter fill plastic pots with a slightly moistened, sterile, soil-less growing mix. Plant seed 0.64 cm (1/4 inch) deep in pots and label the pots. Place them outdoors in an area where they will experience the snow and cold of winter. The seed will germinate in the pots in spring as the weather warms up. Be sure to water the pots regularly in spring and once the plants are 5 cm (2 inches) tall, transplant them into your garden.