RAH - I suspect that something such as waterfowl, turtles, muskrats, or grass carp ate your plants. Eel grass is very hardy and if planted as a healthy condition it is hard to kill; it even tolerates common herbicides. Plant the seedlings correctly and most importantly keep the herbivores away and it grows easily and well.

V. americana has a tendency to tolerate somewhat turbid, both soft and hard water. When well established it will compete with phytoplankton for dissolved nutrients and cause more water clarity which allows it to grow deeper into the pond sometimes as deep as 18ft when water visibility is 6ft+. I have seen V.americana leaf ribbons as long as 6-7ft tall in clear water ponds and some marinas of Lake Erie. IMO this is too tall of an ideal submerged plant for most ponds. Beds of ribbon leaf shaped eel or tape grass is very good fish habitat as it allows fish to hunt through the upright plant ribbons. The ribbons of eel grass are noticeably more dense compared to water lily stems which I think is better fish habitat compared to eelgrass.

For ponds I prefer the red variant that was sent to you. I call this one 'red tipped eelgrass' because the leaf ends are reddish or burgundy.. 'Red variant" does not grow as tall and leaves are not as wide as the standard V. americana. If one is in the southern states the spiral eelgrass is a short variety and grows less than 12" tall. I really like this type. I planted some of the spiral eelgrass in a northern Ohio pond and the last time I visited the pond the plants had not spread very much and were isolated to the area where they were planted. I planted quite a bit of my cultured spiral eelgrass in my pond and Chara crowded it out. I think V.sprialis is a more warmwater species that struggles to survive in ponds that get ice cover. Chara IMO is a more aggressive plant compared to eelgrass; at least the short varieties.

To reduce your chances of losses of the next planting, plant some of it in a kiddie wading pool, half barrel or similar short sided container with 1"-3" of garden soil or soil mixed with sand. An outside aquarium would also work to get plants growing & multiplying in case the pond planted plants do not survive. You would need to add a little sprinkling of fertilizer if you used all sand in the container. Garden soil or pond mud should have plenty of nutrients for growing eel grass. Initially you should probably use an aquarium aerator / bubbler to keep the pool / container water from becoming stagnant on the surface. As the plants multiply and spread during the summer water quality in the tub should improve and aerator would not be needed. Transplant the eel grass into the pond in fall. I grew several sprigs of seedling spiral eelgrass in shallow pans and tubs that were set into the beach bluegill spawning area. By fall the containers were full of green luscious plants.

I think one of my client's all perch pond has lots of the standard V. americana eel grass. A few years ago he tried to kill it, the curly leaf and the water lilies with herbicide and eelgrass gradually regrew. Note in IA, IL, IN OH, PA region eel grass is a warm season plant and does not produce leafy ribbons for transplant until sometime in June. By mid-late August it produces the corkscrew stems of the flower and seed heads that reach the surface