Sisymbrium crassifolium

Thick-Leaved Wallflower: A Propagation Primer

The Thick-leaved Wallflower, scientifically known as Sisymbrium crassifolium, is a captivating plant with its delicate yellow flowers and unique fleshy leaves. While not commonly found in gardens, its hardiness and beauty make it a worthy addition for any plant enthusiast. If you’re intrigued by this resilient species, knowing how to propagate it is key to expanding your collection or sharing its charm.

Two Paths to Propagation

Sisymbrium crassifolium can be propagated in two main ways: by seed and by cuttings.

1. Seed Propagation: From Tiny Specks to Verdant Life

This method, while requiring a bit more patience, offers the reward of witnessing the entire life cycle of the plant.

  • Seed Collection: Monitor your mature plant in late spring or early summer for the development of seed pods. Once the pods turn brown and papery, carefully collect them and store them in a cool, dry place until ready to sow.
  • Sowing Time: Spring is the ideal time to sow the seeds. The warmth and sunlight provide optimal conditions for germination.
  • Sowing Medium: Use a well-draining seed starting mix. Sprinkle the seeds on the surface and lightly press them in, ensuring they are not buried too deep.
  • Watering and Care: Maintain a consistently moist environment for the seeds but avoid overwatering, which can lead to rotting.
  • Transplanting: Once the seedlings develop a few sets of true leaves and are large enough to handle, they can be transplanted into individual pots or directly into the garden.

2. Propagation from Cuttings: Cloning Your Favorite Wallflower

This method is faster and offers a higher success rate, especially for preserving desirable traits of a specific plant.

  • Timing is Key: The optimal time for taking cuttings is in late spring or early summer when the plant is actively growing.
  • Selecting Cuttings: Choose healthy, non-flowering stems that are approximately 4-6 inches long.
  • Preparing the Cuttings: Using a sharp, sterilized knife or pruners, make a clean cut just below a leaf node. Remove the lower leaves, leaving a few at the top.
  • Rooting Hormone (Optional): While not strictly necessary, dipping the cut end in rooting hormone can encourage faster and more successful root development.
  • Planting the Cuttings: Insert the prepared cuttings into a well-draining potting mix, burying at least one leaf node.
  • Moisture and Light: Place the cuttings in a warm, bright location but out of direct sunlight. Maintain a humid environment by covering the pot with a plastic bag or placing it in a propagator.
  • Root Development: Roots will typically develop within a few weeks. Gently tug on the cuttings to check for resistance, indicating root growth.
  • Transplanting: Once the roots are established, carefully transplant the cuttings into individual pots or your garden.

Caring for Your New Thick-leaved Wallflowers

Whether grown from seed or cuttings, these hardy plants thrive in well-drained soil and prefer full sun to partial shade. While somewhat drought-tolerant, regular watering, especially during dry periods, encourages healthy growth and abundant blooms.

Propagating your own Sisymbrium crassifolium can be a rewarding experience, allowing you to connect with this fascinating species on a deeper level and enjoy its unique beauty for years to come.