Ludwigia

  • Excessive growth decreases open water habitat and blocks out light
  • Decomposition of plants can lower water quality
  • Interferes with recreational activities (beach access, boating, fishing)
  • Can decrease flood retention capacity and increase downstream flood impacts
  • Ludwigia mats can get in the way of current mosquito control methods
  • Careless removal of ludwigia can cause spread downstream

Tips for Removing Ludwigia – Get it before summer starts!

  • Manually remove weeds before they flower (April or May). Keep removing resprouts before flowering
    (July –August are peak seeding months)
  • Ensure that all parts of the plant are removed as rapid growth can occur from small pieces of the plant
  • Ludwigia may make rich compost but be sure it is composted far away from the river so it cannot
    spread
  • DO NOT let pulled weeds (even small pieces) float downstream! Even small parts of the plant can float downstream and invade another beach. Even if the plants are dead you must remove them because dead plants will decay and deoxygenate the water.
  • DO NOT rake weeds into the river
  • Floating booms can contain aquatic weeds and enable easier and safer removal
  • Rapid response to new invasions is key to control of weed – Get new plants before they get big!

Remember:

Always do good without causing more harm: prevent downstream spread! When you see new Ludwigia plants remove them promptly before they mature and seed!

Scarlet Wisteria

Scarlet wisteria, Sesbania punicea, is an ornamental woody shrub or small tree that grows to 14ft with clusters of bright red-orange drooping flowers and acacia like compound leaves. Wisteria produces large distinct seedpods that can get up to 3-4 inches long. When shaken in the wind these pods make a rattling sound giving this it the common name “rattlebox”. This plant is listed HIGH priority for removal by the Cal Invasive Plant Council due to its ability to aggressively take over riverbanks.

Scarlet Wisteria Threats for People and Wildlife:

  • Heavy water user
  • Shallow root systems increase erosion
  • Creates dense thickets
  • Displaces native vegetation
  • Toxic and potential lethal to humans and wildlife if ingested

Scarlet Wisteria Lifecycle & Habitat:

Flowers and seedpods are produced in late spring and persist through fall between June and September. A single plant can produce between 100-1000 pods annually. Seed germination rate is high and the seed bank can last for many years. Scarlet Wisteria favors warm moist environments and is most problematic when growing along the banks of rivers, streams, creeks, wetlands and marshes. It forms dense thickets and quickly colonizes entire riverbank systems.

Scarlet Wisteria:  How you can help Russian Riverkeeper eradicate it!

  1. Call us if you see it – even if unsure – please contact us with location and whether it has seeds.
  2. Provide access to Dry Creek for eradication workdays, looking for boat launch or plant waste haul-out locations or where we can access plants on foot. We can provide insurance coverage.
  3. Volunteer for Wisteria Eradication workdays-TBA June to September – experience boaters for water work and people to help haul out plant material as it is removed.
  4. Donate to Riverkeeper’s Scarlet Wisteria Eradication Project – mark your donation SWEP to support our costs and ensure we win the battle against this thirsty invader!

If you see Red Wisteria please call us at 707-433-1958 or e-mail info@russianriverkeeper.org with the location, number of plants and if it’s seeded yet.