What is Creeping Field Cress (Keek)?

Creeping Field Cress: A Stubborn Garden Invader

What Is Creeping Field Cress?

Creeping field cress (Rorippa sylvestris) is a perennial herb in the mustard family (Brassicaceae), native to Europe and western Asia. It likely entered North America via ballast water or contaminated nursery stock before 1818 and now thrives along wet ditches, floodplains, soggy meadows, and even in container‐grown ornamentals.

How to Identify Creeping Field Cress

Recognize this weed by its combination of leafy, yellow‐flowered stems and spreading roots:

• Growth habit: Forms a basal rosette in the first year; thereafter stems creep or ascend 15–60 cm tall, branching mainly at the base.

• Leaves: Pinnate with 3–7 pairs of deeply lobed, toothed leaflets. Lower leaves may reach 20 cm long; upper leaves become progressively smaller and sessile.

• Stems: Typically glabrous or sparsely hairy, glossy, with ribbing along the length.

• Flowers: Bright yellow, four‐petaled (3–5 mm wide), arranged in elongating terminal racemes that flower from tip downward.

• Fruit: Slender siliques (seed pods) 1–2 cm long, straight to slightly curved upward, each containing numerous brown seeds.

• Rhizomes: White, fleshy, shallow rhizomes that root at nodes and produce new shoots—small fragments readily re‐establish.

Life Stages & Visual Aids

Use these images to match plants in your garden to creeping field cress at various stages:

Best Removal Practices

Successful control blends persistence with multiple tactics:

• Manual Removal

  • Carefully dig up entire plants using a 4-tined garden fork, removing all rhizome fragments to prevent regrowth. Begin by loosening the soil at least 4 to 6 inches from the center of the plant by inserting the fork and lifting up, then using your fingers follow the roots to their ends. Often there will be smaller plants attached to larger plants by way of underground runners. DO NOT pull plants by the tops or use a shovel to dig up plants. Doing so will only serve to cut up roots and spread them, which will quickly regrow.

  • Easiest removal is when soil is dry and friable. The roots are easier to tease out of loose soil. It is not recommended to attempt removal when the soil is heavy from recent rains as the fragile roots will break.

• Mulching & Smothering

  • Apply 10–15 cm of organic mulch (wood chips, straw) or cardboard plus mulch to block light.

  • Secure landscape fabric or tarps for at least 6 weeks over heavy infestations.

• Solarization

  • Cover cleared areas with clear or black plastic during hot months.

  • Heat buildup kills shallow rhizomes and surface seeds.

• Chemical Control

  • DO NOT use chemical control at U-Grow Gardens. Chemical usage is not permitted.

• Prevention & Monitoring

  • Inspect new organic nursery stock for white creeping roots tangled in soil.

  • Clean tools, pots, and machinery after working in infested zones to avoid spreading rhizome pieces.

By combining careful monitoring with manual and cultural control gardeners can reclaim spaces overtaken by creeping field cress. Early detection and repeated follow‐up treatments are crucial to exhaust its persistent rhizome network. If you wish to have a hands-on lesson on correct CFC removal, please contact either Karin or Stuart. We would be more than happy to show you how.