Pontederia cordata, commonly called pickerel weed, is a vigorous, deciduous, emergent marginal aquatic perennial that typically grows 2-4’ tall. It is native to quiet waters at stream and pond margins from Nova Scotia south to Florida and Texas. In the wild, it is frequently seen growing in dense colonies. Glossy, narrow, arrowhead-shaped green leaves (to 10” long) have rounded cordate bases and rise well above the water surface. Tiny, tubular soft blue flowers are densely packed into erect, 3-6” long spikes atop flower stalks typically rising 1-2’ above the water surface. Plants flower freely from June to October. Flowers give way to starchy seeds with distinctive toothed ridges. Flower spikes droop after bloom, releasing the distinctive seeds into the water. Seeds are edible off the plant or can be dried and added to granola cereals. Very young leaves can be used as salad greens. Dragonflies and damselflies commonly lay their eggs on plant stems near the water surface. Fish (albeit more than just pickerel) may seek shelter in clumps of these plants, hence the common name of pickerel weed. Winter hardy to USDA Zones 3-10. Needs full sun for best flowering. Set plants in mud at the margins of a pond or in containers (rich organic loams) in a water garden under 3-5” of water. It can be grown in water or bog gardens, pond edges and in large containers or tubs.
Growing Instructions for the Pickeralweed
The seeds have a period of dormancy. They can be planted outdoors in the fall or winter for spring germination or they can be cold stratified to simulate winter conditions and to break their dormancy at any time of the year. 1. Mix the seeds in wet sand. 2. Store the seed mixture in the refrigerator for 6-8 weeks. 3. The seeds have the best rate of germination under water. Put the seeds on the surface of soil that is under water. The seeds can also be sown on soil that is not under water. Sow seeds on the surface of saturated soil, such as mud. The seeds need constantly moist soil. 4. When the seedlings are a few inches tall, they can be transplanted.