Several years ago I dug a pond on a patch of lawn up the hill from our house. I now think that a pond garden is one of the easiest and the most entertaining kind to maintain. It also is a great tool to demonstrate ecological relationships since as it matures, a complex web of interacting players emerges.
I was never happy with the fountain I had constructed originally when I built the pond. It was more or less a temporary solution. So last week I decided to redo it.
The spillway outlet for the pond originally ran out the south end of the pond and this work is on the North end. Now it remains to remove the rocks from the old spillway, install a 4 inch underground drain, and backfill the trench and lower pumping pond.
Dragonfly nymphs in their last instar crawl up the stems of pond plants where the adult emerges . I see many exoskeletons still clinging to the stems:
INSTAR: An instar ( i/ˈɪnstɑr/, from the Latin “form”, “likeness”) is a developmental stage of arthropods, such as insects, between each moult (ecdysis), until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or assume a new form. ( Wikipedia)
In August the bloom of Azolla has started to increase. I added Azolla to the pond several years ago and have in the past had to skim it off as it covers the complete surface in late summer. It does provide good compost material with high Carbon and Nitrogen content. It normally cannot live in Northern climates but somehow has survived well here in the pond.
There is a theory called the “Azolla event ” where it is believed that Azolla in the tropical Arctic 39 million years ago fixed so much Carbon that it reversed global warming. Reference .
Last fall I got this small plant with floating leaves and small yellow flowers. It spreads asexually with stolons near the water surface. It also was winter hardy Zone 8-10 as it overwintered in the pond. This one was supplied to a plant store by a local company here in Victoria, Applied Aquatics.