Water Plantain (alisma) is a perennial herb, native to Eurasia and North Africa, now present world-wide.
Water Plantain grows in shallow marshy soil along the shoreline. It has stiff lance-shaped leaves 5-8” long that stand above the water surface. Emersed leaves have prominent parallel veins. Submersed leaves are smaller and ribbon-like with less defined veins. Water Plantain has small white 3-petaled flowers which whorl around a delicate stalk that open in the morning from June through August.
Water Plantain reproduces from seed and division of corms (a fleshy bulb-like underground stem).
Water Plantain is a food source for most waterfowl & fish.
When left unattended this vigorously growing weed can become a real problem and is considered a noxious weed in California rice fields.
3 Tips to eradicate Water Plantain are:
1) Early physical removal by grabbing the main stem at center and pulling upward. Make sure to get the entire corm and root.
2) Use 2,4-D systemic herbicide for early spring control. Apply as new growth begins to appear. Repeat treatment 3-5 weeks after the first application if weeds begin to show signs of recovery.
3) Use glyphosate systemic herbicide for mid-season control. Apply when 50% or more foliage is above the water surface and weeds are in full bloom. Repeat treatment 3-5 weeks after the first application if weeds begin to show signs of recovery.