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How to Plant Ironweed Seeds


Always sow seed directly before the first frost. The seeds need cold soil temperatures to properly germinate and sprout.


Never plant ironweed near a garden. The flower propagates naturally and its roots establish themselves one foot deep into the soil. They are extremely hard to get rid of once the flower has been allowed to grow to maturity.

Ironweed is native throughout the South and Midwest. It can be found naturally in old unused pastures. It produces vivid, purple clusters of blooms in late summer and fall. Ironweed is generally thought of as an undesirable plant due to its ability to rapidly propagate and spread throughout an entire garden. The seeds are light and detach from the tip of the blooms. Anytime ironweed is in bloom on a windy day, the plant will be propagated throughout the garden. Save this plant for a wildflower garden or wildlife habitat. Monarch butterflies cannot resist the flower’s sweet nectar.

Obtain ironweed seeds either off of an existing flower or from your local garden center. The best time to do this is in late fall, directly before the first frost. Buy a large amount of seeds (50 or more) to ensure adequate cross-pollination.

Find an area that is large, wide, sparse and far away from any garden that needs special tending. These flowers spread very easily and will crowd out your desirable plants if given the chance. Look for an area with full to partial sun in rocky or sandy soil.

Till the soil in the desired location. No compost or fertilizer will be needed for the soil.

Sow the seeds directly below the soil, about an inch deep. Plant the seeds 6 inches to a foot apart. Ironweed grows 3 to 5 feet in height with 6 inch wide flower clusters. Planting more than 6 inches apart will ensure a thick bundle of blooms without the flowers crowding each other out.

Firm the soil over the seeds and keep the soil moist but never soaked. The seeds will germinate in winter and should sprout up in spring. Once sprouted, the flowers will gradually establish themselves and will no longer need watering or tending.

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