After a hard day there is nothing more relaxing than the sound of running water, the sight of fish moving and plants floating. Last year on the show we built several ponds but maintaining these ponds causes many problems. Randy feels that a pond must first be built correctly. All ponds need a filtration system because bacteria colonizes in the inner portions of a filter and they consume all the organics. Once organics are removed from the water then the algae, being a single celled plant, has no food. With no food the algae ceases to grow and water will clear. Algae constantly multiplies and divides as long as it is getting food, when the food source is removed the algae dies. Food sources for algae might be excrement from fish, plant material that has died and fallen to the bottom and the residual food from feeding fish. People tend to feed their fish too much food, they only require 2 or 3 feedings each week. The idea is to have the fish become scavengers along the bottom of the pond, where they will find bits and pieces of plants that they will use for food. Plants help keep a pond clean as well. They take in Carbon Dioxide and give off Oxygen. The Oxygen is then used by the fish. The food the fish eat becomes available to the plants. This creates what is known as the "Nitrogen Cycle." If you remove parts of the cycle you'll end up with green water.
A filtration system is an essential part of a clean pond. Randy shows us a trickle down filter. There is a filter mediate pad that captures sediment falling on the pad. Below are lava rocks, used because they have a lot of surface area, the more surface area the more bacteria. The bacteria colonize over the surface area of the lava rock and remove the sediment and nutrients from the water. Again, without nutrients the algae has no food, therefore it dries up and the water clears. Randy refers to this system as an aquatic septic tank. Oxygenators are a must for every pond. Anacharis and Mares Tail take in Carbon Dioxide and give off Oxygen, which makes for healthier bacteria growth. Bacteria requires Oxygen to survive. Randy suggests one bunch of plants like this for every 3 square feet of surface area. These plants are hardy, survive over winter, and multiply over time. There is lead on the roots to keep them down where they will colonize, they could be put in a basket of rocks. They help keep the water clear and provide a place for the fish to lay their eggs and for fish to live. Water Hyacinths and Water Lettuce are good plants for the surface area of your pond, they shade the surface of the pond. These plants block the sun. Without sun and without a food source the algae has no way to survive, therefore the water stays clean. These plants multiply rapidly so for an area of 100 square feet use them initially in 2 or 3 square feet. Ideally 60%-70% of the surface should be covered by some type of floating vegetation. The roots in the water absorb Nitrogen, help pull nutrients out of the water and they block the sun. All important in keeping water clear. We've discussed Oxygenators, the submerged plants and the floaters (Water Hyacinth, Lettuce, etc.). As well Azolla and Water Lilies are important. Azolla Carolinianas, is native, is a surface floater and blocks the sun in ponds. Azolla is called "Fairy Moss." It is a single cell plant, it has a tendency to spread, so use it sparingly. It spreads, but can be removed if it overwhelms the area, by using a skimmer net. It is healthy for fish. It is green in the shade but when put in the sun it turns vivid red. It works in both environments. Water Lilies are a staple in most ponds. They block the sun by covering the surface. Hardy Lilies survive the winter in zone 7. Tropicals only survive in water temperatures above 75 degrees, therefore they are typically put in later in the season. Tropical Lilies have a dramatic variation in leaf form. There are leaves that are wavy on top, leaves that have speckles, leaves that produce smaller plants - called Viviparous. These produce a small plant nodule coming off the main plant. Importantly there are color variations. Tropical Lilies range from what is called "Green Smoke," which is a green flower to purple to lavender to white and some of the finest pinks ever seen. There are night blooming types that aren't available with Hardy Lilies. Night blooming Lilies are blooming when you're home to enjoy them and they have an outstanding fragrance. In the winter they can be put in a jar with sand and a small amount of water and brought inside. Once in the pond, submerge medium and larger hardy and tropical Lilies 18-24 inches. Hivolla is a small yellow Lily and it grows 15-16 inches below the surface. They're planted in pots, which controls the growth since they will grow to the size of the pot. The larger the pot the larger the plant. Feeding is important. Water Lilies are heavy feeders and are typically fertilized once every two weeks with pond tablets. Drive these tablets into the root zone of the plant. Most everyone is fascinated by fish in ponds. Randy primarily stocks fish that are hardy, they survive winters in zone 7. Butterfly Koi are imported from China and are a mainstay in Koi ponds and water gardens. Koi ponds are void of plants because Koi are vegetarians, they eat plant life. Koi need big filtration systems with large bacteria filtration systems. Goldfish are ideal for water gardens.
Japanese Trapdoor Snails will typically go along the sides and eat filamentous type algae that grow along the side of the pond. Alligator Gar will grow to 3-4 feet in a water pond. They eat the small fish, thereby controlling the population in the pond. Turtles will eat plants and fish in your pond. By using fencing around the perimeter of the turtle area, leaving walking space along the outside of the pond allowing the turtles to come out and sunbathe and by feeding them everyday they then don't look to the fish as a food source. They will consume plant material but use Hyacinths, which are fast growers, to address this problem. The Red Eared Slider is somewhat aggressive, you wouldn't want to put your finger in front of it. Over time they will identify with you, realize you are the food source and will come to the edge of the pond and wait for you. They can be fun as pets. They are cold blooded, their core body temperature will go down to about the same temperature as the water. In winter they go to the bottom of the pond and either burrow into, underneath or beside the plant. Randy has cinderblocks coated in rubber, at the deep end of his pond, in about 3 feet of water, and in the winter they live inside those.
A Barley Bale is ideal for keeping a clear pond, one free from algae. It is placed in the pond, after about 2 weeks it begins to break down and for whatever reason, it's a little mysterious, it keeps algae under control.
Different people like different types of fish. The slower, more graceful fish are the common Fantails. The Aranda has a large, bulbous, orange cap, on top. It is a very unique fish, not as hardy in the wintertime as some of the Fantailed. Sarassa Comets are a type of pond comet, but have been bred for the difference in colors between red and white. They come in different forms.
Albino Catfish will eat debris from the bottom. Since most ponds are black they stand out, particularly on the bottom. They will eat some of the smaller fry in the pond, but that is ok because you want to keep the population under control. They will grow to a fair size and are unique to view.
Calico Shibunkin are a beautiful substitute for Koi. They grow to 14-16 inches over a three year period and have nice finage.
Goldfish are Koi look alikes, yet don't require the fuss and bother of Koi. And they aren't vicious eating plants.
Orange and Blacks are a color variation of Calico Shibunkin. They both are winter hardy.
Koi have been raised for thousands of years in the Orient. Some have been known to live over one hundred years and may be passed down from generation to generation. Some Koi will grow to in excess of 36 inches in length and up to 20 pounds in weight.
Big fish need big filtration systems. It is mistaken notion that fish will grow to fit their environment. People make the mistake of putting large fish in a small environment. Koi in any sized container will grow to its adult size with proper care and feeding.
It is a good idea to put water garden fish in water gardens and Koi in Koi ponds.
Dr. Rick and Randy look at plants suitable for a "bog environment" as opposed to a water garden. One of the most important places in the garden or pond is where the water meets the soil. Dr. Rick refers to plants that work in this environment as Marginals. A Marginal or bog-type plant is any plant that would thrive in moist soil to 2-3 inches of water. Pickerel Rush is one example. It is a hardy plant for zone 7, it has beautiful blooms, comes in white and purple and will bloom throughout the summer. It can be used in a pond or in a container or a wet spot in the yard, as long as it stays moist.
To keep the soil moist in an area it may be necessary to build a bog. The soil depth is approximately 10-15 inches with gravel on the bottom and a Peat Moss Humus combination on the top, then run a soaker hose through the middle, to provide an opportunity to flood it periodically.
Another plant ideal for this environment is Variegated Sweet Flag, calamus Veriegatus. It is winter hardy and keeps its foliage in winter. It tends to lighten darker areas. It's called Sweet Flag because when the foliage is crushed it releases a sweet scent.
Star Grass, Dichromena Colorata is hardy in zone 7 and 8. It's self contained, is not an aggressive grass, is beautiful later in the summer because it develops white top edges.
Another great plant to transition from the water to the garden is Lysimachia Nummularia, Aurea, Creeping Golden Jenny. It likes full sun to partial shade and quickly forms matts of golden foliage.
Colicatious are not winter hardy in a pond but planted in the ground in zone 7 they will survive. In the water they will grow to 18-24 inches, in the ground they will grow to 4-7 feet tall. They require plenty of water and a lot of fertilizer and thrive in sun to partial shade. Their black and deep purple color is popular in the garden and looks great mixed with cooler colors. It provides good foliage texture and color in a water garden.
Iris are a diverse group of plants and ideal for the water garden. There are different types, for example German or Bearded Iris, they are not great plants for a water garden. Native Iris from Louisiana have been hybridized for the last 20-25 years, during this time some spectacular varieties have been developed. Anne Chouning is a fantastic new hybrid. They range from yellow, such as Pseudacorus Iris, to dark purple to pink to lavender. In zone 7 it went down to 5 degrees last winter and with a wind chill, well below zero, it damaged some of the foliage and appears to have caused damage to the rhizome. Iris Borers have been a problem and in this case the tubers are not as vigorous as normal and the plant is more susceptible to disease. Other than that one shouldn't experience a lot of disease or insect problems with Iris. Dead head them and you can get a second bloom. Fertilize water gardens every 2-3 weeks with an aquatic type fertilizer. It will keep water plants healthy into late summer. Irises are one of the few plants that stay green in the winter. If massed they give a soft edge to the pond. At the same time they provide a vertical element to the pond. They really catch the eye. They're a great choice.
Ponds are fascinating, yet versatile elements in the garden. Dr. Rick thanks Randy for his time and for sharing his expertise.