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Larry Sagers
Creating the right mix of aquatic plants can keep undesirable plants from taking over the pond.

Ponds have always been fascinating to me. Perhaps it was growing up in the desert, or because chasing frogs and tadpoles or trying to catch minnows was a fun pastime for little boys on hot summer days.

Regardless of the reason I am still drawn to ponds.

For me, the most interesting and enjoyable ponds recreate an ecosystem. Thundering torrents of water, dancing fountains and geyser-like water features shooting sprays high into the air never have the same fascination of those that combine water, animal life and plants.

Plants are the focus here. Aquatic plants are divided into four groups. Each have their use depending on your pond, your management style and the surrounding area of your pond.

The four types are deep water plants, bog plants that grow around the margins of the pond, oxygenators and floating plants. Creating the right mix of these plants establishes an ecosystem that allows them to grow while keeping undesirable plants from taking over.

While each pond requires tweaking to fine tune the ecology, plan on covering 60 percent to 70 percent of the pond surface with container plants with floating foliage, including water lilies or floating plants such as water hyacinth. Add submerged or oxygenating plants at the rate of one to two bunches per square yard of your pond surface area.

Since they are blooming in abundance right now, consider water lilies. In my mind, these are probably the best-known and most appreciated water plants. They are dependable performers, and there are native water lilies that thrive in high mountain lakes that survive winter.

As you select your lilies, make cold hardiness your first criterion. These beautiful flowers are divided into hardy types and tropical types. As you might expect, the tropical types must be brought indoors for the winter.

Make certain to get varieties that are going to thrive with our short growing season and cool, alkaline waters. Local suppliers and pond gardeners can help you find those that are good performers here. All hardy water lilies will survive our winters if they do not freeze solid.

Water lilies need full sun and relatively shallow water. Plant them in a group to concentrate the foliage and the blooms. For maximum growth and blossom production, place the crown of the lily 8 to12 inches below the water. They might have to be set lower in the winter for the roots to remain in unfrozen water.

While native water lilies grow in soil at the bottom of the pond, most people grow them in pots. Plants in pots are easily rearranged, and you can control the depth of your plants as they grow. It also allows you to clean your pond more easily and keep the water cleaner.

While soil selection for container growing is critical on above-ground plants, these plants need something much different. Potting soil with peat, mulch and manure is too light, and these organic materials tend to float out of the pot. As ironic as it might seem, the poor, heavy garden soil that we all try to improve — or even the silty muck from a river or pond — works better.

After planting the lily, cover the soil with a layer of gravel or stones. This helps hold the soil in place and keeps fish from digging into the soil. If your pots have large drainage holes, put a layer of gravel in the bottom to prevent the soil from washing out.

The most common question is, "Why don't my water lilies bloom or why are the blooms small?"

Young plants produce few blooms, and these blooms lack the size and color intensity of more mature plants. Plants can take three to four years to get large enough to produce big, showy blossoms.

Leaf growth is also important. If the plant is not getting enough sun it does not have the energy to flower well. Different varieties have differing sun requirements. Make certain the pot is not too deep in the water, as the plants produce the most leaves and blooms in shallow water.

Pay attention to plant nutrition. Heavy, regular fertilization produces larger, showier blooms. Most pond fanciers use slow-release tablets in the container. Follow the label directions closely because too much fertilizer encourages excessive algae growth. Water lilies cannot use fertilizer until the water is 70 degrees, so never apply it too early in the season.

Each water lily bloom lasts four or five days. The flowers open in the morning and close each afternoon. Each variety has its own schedule. Pinch off the dead blooms and leaves so they do not decay and dirty the water. Water lilies are not happy in moving water, so keep them away from waterfalls and fountains.

If you go

What: Utah Water Garden Club pond tour 2008

Where: 23 ponds

When: Saturday, 9 a.m.-5 p.m.; Sunday, 10 a.m.-5 p.m.

How much: $10 for tour book, which allows two people to visit all 23 ponds. Tickets are available at Deseret Water Gardens, Glover Nursery, Engh Gardens, Cactus and Tropicals, Fish 4 You, Ward and Child (The Garden Store), The Aquarium, American Stone and Wasatch Koi & Water Gardens

Web: www.pondutah.com

Larry A. Sagers is the horticulture specialist, Utah State University Extension at Thanksgiving Point.