Go get a thermometer asap. It is one tool I use all the time. Mine is attached to a piece of string and sits in the skimmer year round out of sight.
Any marginal natives can go in the bog and shallow shelves.
Arrowheads, Pickerel Weed, Marsh Marigold, Cat and Horsetail(w/caution), Lizard's Tail, Hair grass, Iris, Sweet Flag, any of the Rushes and Reeds, Cardinal flowers in Blue and Red, and many sedges to choose from. Most of these can be "found" in roadside ditches and retention ponds, or purchased from nurseries and garden centers. I would wash the soil from the roots and quick dip them in a mild bleach solution if collecting from the wild.
Good choices for the bog because of hardy growth.
These plants should be used with caution because of rapid, spreading growth that could cause problems in the main pond. Nothing serious, but they will run. Contained in a bog, they will grow and spread nicely. Water Mint, again the Horsetail and Cattails because they have sharp running roots, Umbrella Plant, and although Tropical, the Papyrus' make great bog plants since they have great growth rates. They can be easily over wintered indoors. Of these, I would do the umbrella plant. I have it in my shallow bog shelve and it rocks. It gets tall (3-4') but not overwhelming. The water flow goes through a big, thick mass of roots that also helps the snails and frogs overwinter in. I started out with a small 1 gal. pot that had maybe 5-6 shoots. It is now a good 2'x2' and looks awesome. It will get much bigger but I cut about 30% of it out each spring to keep it in bounds. It grows over the shelf and starts to sag along the outside of it since it has no support below it. I have to use a small, folding, camping saw to cut it free from the main plant since the roots are so thick and fiberious. This year I have thinned it twice during the growing season. In a bog, I would just let it go.
Three great plants that will spread along the edges and into the water.
Creeping Jenny, Forget-me-not, and Hair Grass. I have them all and they are great space fillers and soften the edges nicely. I have pics. if you would like. The Forget-me-nots bloom w/tiny blue flowers and look awesome. It also will remain green below the waterline in the winter. In spring, it starts growing early and provides a spawn site for the goldies.
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