The temperatures have steadily lowered and the affects on the pond are very noticeable now. The cattail foliage has started to brown and die off. Hyacinths have changed from dark green to yellow. Last night we had our first hard frost and it took its toll on the remaining tropicals as well as perennial border plants like Bee Balm, Water Mint, Snow on The Mountain and Hostas. It’s early October in Northern Wisconsin and time to get the pond ready for fall!
The pond plants are a great place to start. Trim back the hardy plants such as Irises and Cattails and submerge them to the deepest portion of the pond; this will help ensure they will not freeze out. This works for ponds 18″ or deeper. Cold water hardy Lily Pads will continue to thrive through the fall and are the last to be trimmed prior to closing the pond for winter. I do take this time to replant them in the deepest portion of the pond and fertilize as needed. Cattails and Irises can now be divided and replanted as well. I use a simple handsaw and divide each in half, and now I have enough to balance out the pond aesthetically. Remove tropical floating plants such as Water Hyacinths since their roots stop growing (provided there are any left) and will still collect particle matter. The plants will no longer absorb the excess nutrients and will start to hinder the pond instead of helping.
With the change in temperatures, the diet of your pond fish is also changing. Koi and Goldfish will stop feeding as the water dips into the 30 – 40F degree range. It is very important for you to monitor the water temperature daily and as the water drops below 50F degrees, switch to a wheat germ based food. This is very important, as Koi cannot digest food as quickly when the temperatures are below 50F degrees. I have used TetraPond Spring & Fall Diet for the last couple of years and it has become my food of choice for the cold water seasons. It is digested easily and it does not cloud the water. Once the water temperature drops below 39 degrees, stop feeding all together.
With the change in diet, also take this time to clean out the pond. If you have to transfer fish from one pond to another, do so at this time as they are less likely to succumb to minor injury during the transfer. I recommend draining about half of the pond volume and spray down the sides to remove any buildup. Try to remove all of the leaves and debris possible using nets and or a Pond Vacuum.
Once the pond has been cleaned, replace the removed water. Don’t forget to use dechlorinators to remove chlorine, chloramines and heavy metals.
At this point, you are ready to add a pond net to prevent the leaves and debris from re-entering the pond. Make sure the net is 12 to 18 inches above the pond to prevent the leaves from sagging the net into the water. A clear pond will quickly turn dark with the color leaching from the leaves as well as the decay increasing ammonia levels. The nitrifying bacteria levels are slowed with the cool water and it will not be able to combat an influx. Additives such as Microbe-Lift Autumn/Winter Prep helps accelerate the decomposition of leaves, scum, and sediment during the fall and winter months and also gives the pond a jump start to a healthier environment in the spring.
Winter prep is around the corner. This year I am building a greenhouse type dome over the pond and adding a small heater to prevent freezing. Step by step preparation in my next post.