Summertime pond care is important when summer arrives, We are already breaking heat records in New Orleans and it's not even officially summer yet. 90 degree temperatures and 110 heat indices are making everything miserable, including our gardens and our ponds.
Keep fertilizing your water lilies. They are heavy feeders and will keep blooming until October when the days start to shorten or until the temperatures sink below 55 degrees F.
If you have lotus, they want more fertilizer than water lilies. I feed them at least twice weekly, even every ten days with one aquatic plant tab per gallon of pot. You rarely have to fertilize other pond plants because fish waste takes care of that for you, but if you are not satisfied with the plants growth, stick an aquatic plant tab in those too. You may wish to stagger your feeding because aquatic plant tabs fertilize all the plants in the pond including the dreaded green algae that will grab nutrients before they can get to what you really want to feed. Bury the plant tabs in the pots and make sure they are covered with soil or sand.
I keep at least 70% of the top of the pond covered with floating plants like water hyacinths, water clover and water lilies especially in the summer to give the fish some shade and some places to hide from predators. Egrets, herons, raccoons, and even your own Labrador retriever are looking for extra food and your pond is a brand new all you can eat buffet that you laid out especially for them. I even suggest making a cave for your fish. You can buy them already made or make your own out of a couple of flower pots on their sides or a flat rock on top of a couple of block shaped ones. The fish don't care how fancy their new digs are, as long as they are safe.
Remove dead foliage as soon as you can. As water lilies grow, the outer ring of leaves starts to yellow and die. Cut those off as close to the pot as possible. A water lily bloom opens and closes for about three days, then dies. Remove it as close to the pond as possible. If other plant foliage yellows and dies, cut it off and remove it. If foliage is allowed to decompose in the pond, waste material builds up, removes available oxygen and can foul the pond and kill your fish. Removing dead plant material makes room for new growth and sure does make the your pond look nicer. It's about the same as tending the rest of your gardens.
Those of you who feed your fish, do not feed them more than what they can eat in 5 minutes, and only 1 - 3 times daily. If the fish do not eat the food, it too, will decompose in your pond and foul water. Also remember that the more the fish eat, the more fish waste you will have to feed algae and make your pond turn green quickly.
Keep your pump running
Maximize your aeration. Warm water does not contain as much oxygen as cooler water, so your fish can struggle to breathe. And just when the warm water holds less oxygen, the fish need more. Add an airs tone or another pump to your pond. Be sure you keep your pump running 24 hours daily in the heat of summer. If your pond is shallow, less than 18" deep, more aeration is a must. If your pond is 3' deep or more, you are safer. The fish can go to the bottom where the water is cooler and more oxygen is in the water, but still keep those pumps running.
What not to do:
Clean your filter only occasionally, if it is a biofilter. If it is a mechanical filter, e.g., foam rubber that strains out suspended material, clean it often. Your biofilter grows a colony of bacteria that can eat the sludge and decomposed organic matter in your pond. Cleaning your biofilter destroys that bacteria colony forcing it to start growing all over again. If you do clean it, kick start it with one of the bacteria products on the market. I like Microbe-Lift PL. It not only kick starts your biofilter, regular use, following the directions on the bottle can keep the dreaded string algae or blanketweed at bay.
Enjoy your pond
During the summer, it is time to relax next to your pond after work. Entertain your friends on weekends, show off your garden, your pond and your beautiful waterfall. Bring out your iced tea or glass of wine, sit and enjoy yourself.