Make a big splash in your water feature this season by introducing flowering or non-flowering plants. There are many qualities to consider when choosing water plants –– some plants add architectural beauty, some add lovely blossoms and many serve a very practical purpose by oxygenating the water. Certain plants help keep algae at bay, which keeps the water clear. Others aid in taking up extra nitrogen that will keep the pond or fountain’s ecosystem in good balance.
It is important to make a plan before jumping in. The size of your water feature or pond will dictate how many and what types of water plants will survive and thrive. The general rule is that plants included in the water feature should cover no more than two-thirds of the surface area. The same principles apply to water gardening as they do to vegetable gardening or ornamental gardening –– the plants should not be over-crowded. Good air circulation is essential to allow plants to flourish and remain disease free.
Remember that these plants are going to grow, so it is better to err on fewer rather than too many plants. Get out the measuring tape and figure the square footage of your pond so you can roughly know how many plants your water feature will support. The wonderful nurseries in our area have great selections and knowledgeable experts to help you enhance your pond or water feature with beautiful and beneficial water plants.
Four Categories of Plants
When deciding which plants to include, consider plants from each category to add interest and variety. Sunlight and shade will determine which plants will thrive and which will struggle in the water garden. Most aquatic plants require at least four to six hours of sunlight a day. Some plants that are considered more shade tolerant will survive in three to four hours of sunlight a day. Make a note of how much sun your pond receives and use that information when choosing plants to include in the waterscape.
Floating plants are exactly what their name implies. They are plants that float freely on the surface of the water. These plants are wonderful to include in the waterscape because they move freely and are always changing the appearance of the water garden. These plants are good oxygenators and produce varying shadows that any fish or wild life will appreciate. They can grow quickly and will need thinning, or they will cover too much of the pond’s surface. These plants include: Water Hyacinth, Water Lettuce and Giant Duck Weed.
Floating Leafed Plants
Water Lilies: A good rule of thumb to remember when deciding on the quantity of water lilies is to include one for every 10 square feet of water surface area. There are also dwarf varieties available for barrel gardens or smaller ponds. There are two types of water lilies: hardy and tropical. Tropical water lilies can be either day or night bloomers. Hardy water lilies usually bloom during daylight hours. Imagine how beautiful and dramatic a water garden planted with night blooming water lilies would be with the appropriate low-voltage lighting highlighting these gorgeous blooms at night!
Hardy Water Lilies: This group of lilies grows from rhizomes and should be planted in wide, shallow pots or baskets. The rhizome should be planted on its side and covered with an inch of soil and pebbles on top to hold it in place when it is lowered into the pond. Leave the growing tip above the soil and gravel. The pot should be submerged in 6 to 10 inches of water. Think of these like old-fashioned iris. If they are planted too deep and the rhizome or corm is covered with soil, the plant will fail to bloom. Listed below are a few of the most beautiful hardy water lilies.
• Virginia – This medium to large lily has star-shaped white flowers.
• Texas Dawn – This yellow lily has reddish brown speckled leaves.
• Comanche – These yellow blossoms turn to a coppery bronze.
• Attraction – This is a prolific bloomer with red blossoms.
Tropical Lilies: This type of water lily forms a crown and should be planted in a deeper pot than the hardy water lily. The crown should be placed in the soil near the top of the container and then covered with planting medium and gravel. The gravel will keep the plant in the container once it is lowered in the pond. If you would like to place the container in a deeper area of the pond, bricks can be stacked to raise the level of the planted pot.
• Panama Pacific – This beauty has violet colored blossoms.
• Tina – This variety is very fragrant and is a prolific bloomer.
• Director Moore – These deep purple blossoms are star-shaped and have speckled purple pads.
• Shirley Bryne – These blossoms will add a beautiful deep pink color to the pond.
Submerged plants are the workhorses of the water garden. They are the oxygenators that keep the pond healthy and able to support fish and other ornamental plants. These plants actually filter the pond water through their leaves. This process helps to provide oxygen circulating through the water and keeps algae growth under control. They are essential for the health of the other plants and any wildlife or fish that live in or around the pond.
Some of these plants, which grow completely underwater, provide a hiding place for fish to escape predators or to cool off in the shade. This group of plants is usually grown in pots in the shallow areas of the pond. If the pots tend to “float,” they can be held underwater by adding large stones to the pot surface. There are some plants in this category that are very aggressive and are considered noxious weeds so it is recommended to buy only from a local, reputable nursery. It is not recommended to buy this type of plant from a catalog. Below is a list of popular submerged plants to consider which will add beauty and balance to the water feature:
• American Pondweed – This perennial has floating and submerged leaves.
• Bushy Pondweed – This is an annual plant with graceful, ribbon like leaves that range in color from dark green to purple.
• Hornwort – This rootless plant with dark olive green leaves is sometimes called coontail.
• Parrotfeather – This is a submerged perennial that grows well in shallow water with gray green leaves to add color and contrast to the pond.
Bog and Marginal Plants
Bog plants are happiest growing in areas with varying degrees of moisture. Some grow best in constantly moist soils, while others are happiest growing in consistently standing water. There are many species of bog plants that will add height, texture and color to the water garden. Many have variegated leaves that will add drama to the water feature. This is a large group of plants that include:
• Lotus – Every water garden should have a lotus. It should be planted in large tubs and submerged so that there are 4 inches below the water surface.
• Sagittaria – Commonly referred to as Duck potato, Broadleaf arrowhead or Indian potato, it has sturdy round leaves with a stem of white flower-like blooms that add light and color to the water garden.
• Flag Iris – This perennial is a must for the water garden and adds texture with its strappy leaves and color with its prolific blooms. It is very happy growing on the edge of the pond.
• Cattails – These plants add architectural beauty and interest to the water garden and thrive in the boggy areas of a pond.
• Horsetail Grass – This plant has been around for thousands of years. It has stiff upright branches that are ringed with dark circles giving it a look similar to bamboo. It is obviously easy to grow since it has survived and thrived for such a long time and certainly adds drama to the edge or bog area of a pond.
• Papyrus – Also an ancient plant used to make paper in ancient Egypt, Its sturdy upright stems support a plume of green, thread-like stems that are prized by flower arrangers.
Many of these bog plants are called marginal plants and can be planted in the wet areas surrounding the pond. Choose ones that will add reflective beauty and interest near the edge of the pond. Consider choosing marginal plants that have interesting bark or trunks. Think about the placement of these plants along the edge of the pond and try to position them so that they are reflected on the water by the morning or afternoon sun. Think about the structure that they will add to the area during the growing season and during the dormant winter season.
It is important to consider plants that are not just grown on the edge of the pond but in the surrounding landscape. Most water features and ponds are organic in shape, so the surrounding landscape should blend well with this style. Think about what trees would enhance the water feature by adding reflective beauty. Also, consider the shade that they will cast as they mature, which may then change the nature of the pond. Many times it is preferable to have nothing around the pond and let it be the star of the landscape. Study the area and books, then talk to the experts at the garden centers, and your pond will definitely be a star.
Chores for the May Gardener
Whew! May is a busy month for the gardener. Get ready. Get set. GO!
• Plant annuals and perennials that you didn’t have time to plant right after Good Friday. It is usually safe to plant caladiums in May.
• Peruse the garden. Are some areas shadier than they were in previous years? If so, adjust your plant choices or prune to let in more light.
• Fertilize your grass around Mother’s Day.
• Go on a Rose Tour on Mother’s Day. Look for rose shows in our area.
• Get outside as much as you can. Look around. See something blooming that you admire? Find out where it is and add it to your landscape or container garden.
• Fertilize annuals and perennials with a liquid fertilizer or slow release osmocote.
• Prune any shrubbery that has outgrown its space.
• It is a good time to prune boxwoods by hand.
• Cut out any dead limbs in small trees and shrubs.
• Look for fungus on hydrangeas. Treat accordingly.
• Keep a diary of what is blooming and what is not doing so well. Check years past to see if there is a trend.
• If you have espaliered trees, now is the time to prune and to strength any ties to the structure.
• Keep an eye on irrigation. Make sure it is doing what you want it to do and not just watering your driveway!
• Prune citrus trees after harvest. If the foliage looks weak, treat with a citrus fertilizer. Make preserved lemons with your citrus bounty!
• Plant herbs in a convenient space near the grill or the kitchen door.
• Enjoy your outdoor living space now that most of the pollen is gone.
What’s in Bloom?
Take a leisurely drive around Columbia’s old neighborhoods to see what is blooming. Stroll through your favorite garden center to see what they have to offer. Here are a few things you may see in bloom; Vitex, Kousa Dogwood, Rhododendron, Confederate Jasmine, Oakleaf Hydrangea, Daylilies, Roses, Salvia, Impatiens, Larkspur, Poppy, Shasta Daisy, Stokesia, Verbena, Yarrow, Snapdragons, and later blooming Azaleas and Iris.