I was at a workshop on the Emerald Ash Borer last week at Reinstein Woods Environmental Education Center. This is at a local state park and their prime attraction for visitors at this park is the ponds over flowing with pink waterlilies. Is this detrimental to the pond life?
It really is a beautiful sight, but I was asked a question by one of the participants at this workshop knowing I was a Cornell volunteer and landscape designer. They wanted to know if the waterlilies are detrimental to the pond habitat. I don’t install waterlilies in landscape ponds and this is the reason why – they can possibly do what you see above.
I am not that knowledgeable on waterlilies, but do know there are some that are native. They also spread, but are enjoyed by wildlife like the deer, so their numbers can be maintained. It puzzled me why they had this pink invasive variety in the ponds, so after the event, I called one of their naturalists.
She explained the white and yellow natives Nymphaea odorata, were originally planted, but in the 1950’s Mrs. Reinstein and her daughter introduced the non-native pink. Over time, the native waterlilies disappeared and all that remained was the non-native.
What the park workers quickly realized was the pink variety was not that tasty to deer. The deer will eat them, but not with the same enthusiasm as the white native variety. The pink is cultivated from the white, but it is also more dominant in reproducing.
So as I assumed, the waterlilies are a detriment to the ponds. They produce so much vegetative debris each spring which in turn makes the ponds more shallow from the repeated build-up. The density of pads will shade the pond which changes the ecology of the habitat. Direct sunlight is important to fish for proper vitamin and mineral absorption, so a completely shaded pond would cause fish not to thrive.
The park official told me although they have removal efforts, there is no way to keep the ponds under control.
The park workers have been removing waterlilies from the ponds, but this is a monumental chore with how the roots form root mass – where you need a hatchet to remove established roots.
Many keep them in pots, but over time, the lilies likely will abandon the pots to established themselves in the bottom of the pond.
This is how ponds get like what you see in this post. As you can also see, winter does not keep them in check. As pretty as they are, there is a lot of maintenance to keeping them for a pond. It is also recommended not to use them so as not to have them end up in park ponds and lakes.