Pontederia cordata (Pickerel weed)

Pontederia cordata (Pickerel weed) comes from the Americas, so is not native, but I do recommend it for wildlife ponds as it flowers late in August and September, long after most native plants have ceased producing flowers and nectar. This provides a valuable food source for invertebrates as they prepare for overwintering. The strong dark green oar shaped foliage sets off the blue bottle-brush flowers perfectly and the whole plant provides great contrast against the mainly grassy foliage of many aquatic plants.