Mill Pond Garden will have an open day for visitors to enjoy its water gardens from 10 a.m. to 12 p.m., Sunday, July 11. For tickets, go to millpondgarden.com.

Attendees will see some gorgeous waterlilies in bloom, as well as both a large fish pond and two low-maintenance, no-fish ponds, or frog ponds. Visitors also will see lots of damselflies and dragonflies as well as beautiful butterfly koi and shubunkins, small blue carp fish. 

The nation has about 16 million home water gardens, and the Cape Region has about 1,000 private water gardens. There are many businesses that provide construction, maintenance, services, supplies, fish and ornamental aquatic plants. There are also many minimalist water gardens, often using half a whiskey barrel or other such small container.

Mill Pond Garden has three water gardens, the largest 20-by-8-feet and 30 inches deep. It is a magnet for visitors, especially children. The big pond has fish and the two smaller ones are for amphibians, insects, and plants. It is best not to have fish in a frog pond, as the fish will eat the tadpoles and frogs as well as the larvae of the dragonflies and damselflies.

There are many benefits and a few cautions regarding water gardens. The most important reason anyone undertakes a water garden is the desire to bring liveliness and beauty to the home’s outdoor space.

Birds visit to drink; frogs breed tadpoles and sing. Fish can flash beautifully between plants and even become hand-fed pets that come to and follow their owner, recognizing them by both sight and voice. Small animals come for a drink. Dragonflies are colorful and interesting to watch. Pond plants can be lovely and bear beautiful flowers, especially the waterlilies.

A pond is a hugely attractive spot for a child to discover, learn and enjoy. Often, ponds are started by children who do the construction and care on their own. Adults enjoy socializing near and watching the activity of the pond. Feeding fish daily becomes a cherished ritual.

The practical benefit of a water garden is a more diverse ecosystem in one’s own yard. At night, frogs venture abroad in a wide search for food including slugs and other unwelcome pests; even mice and voles are on the menu for a bullfrog. Damselflies’ main food source is mosquitoes; sometimes they hunt in groups for termites, ants, gnats and mayflies. They'll also eat butterflies, moths, bees, flies and even other dragonflies. 

Having a pond with fish is a commitment. It takes about an hour a week to care for a fish pond, much less than the time it takes to care for a dog or cat with walks, brushings, feeding and more. The big efforts are getting the pond started – digging, lining and equipping the pond so it operates well with water movement, filtration, and aeration – and planting it properly. Read up on the requirements first, and talk to experienced pond keepers.

For basics, Mill Pond Garden recommends a minimum 45 mil (preferably 60 mil) rubber sheet pond liner over a smoothed, dug-out surface, covered with a couple inches of sand and a couple inches of smooth large-stone pond gravel available at all big box stores in garden supplies. The stones and sand protect the rubber liner from accidental puncture and provide a surface on which algae can grow to be eaten by the fish.

A pond with fish needs places built in for them to hide from predators, and owners should put up either netting or fishing-line filaments to keep fish-eating herons out. Shade keeps the water cooler and holds more oxygen. Water plants provide habitat for insects that fish feed on and for baby fish. A fish pond should never be overcrowded. The maximum fish recommended allows one 8-inch-long koi or two 6-inch goldfish per 100 gallons of water. It’s important not to feed the fish in water below 58 degrees F, and not to overfeed. Mill Pond Garden only feeds its fish from early June to early October, only about three tablespoons of granular food per day for its 15 fish.

Fish can survive and even grow just on algae, plants and bugs in water. They do not have to be fed provided you don’t overstock your pond. Many pond owners enjoy very healthy, active fish without any feeding. If fish are not vigorously hunting and swimming around all the time in the warm seasons, they will not stay healthy. Most pond owners’ fish die from overfeeding, or from overcrowding, which can cause lack of oxygen and too much waste ammonia in water. When water quality goes down, diseases and pest infections go up. It is recommended to use a filtration system with a waterfall or fountain aeration system, and clean filters weekly.

To keep it simpler, a pond without fish requires little or no care, since frogs, amphibians, dragonflies and damselflies need no special care or water oxygenation as fish do. A no-fish pond can do fine with a once-a-year, one-hour cleanout of excess blown-in leaves, twigs and pine cones.

Mill Pond Garden is a small botanical garden on Red Mill Pond outside Lewes.

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