Flora

Flora

Typical water garden plants are divided into 3 main categories: submerged, marginal, and floating.

1. Submerged plants are those that live almost completely under the water, sometimes with leaves or flowers that grow to the surface such as with the water lily. These plants are placed in a pond or container usually 1-2 ft. below the water surface. Some of these plants are called oxygenators because they create oxygen for the fish that live in a pond. Examples of submerged plants are:

• Water lily (Hardy and Tropical)
• Hornwort (Ceratophyllum demersum)

2. Marginal plants are those that live with their roots under the water but the rest of the plant above the surface. These are usually placed so that the top of the pot is at or barely below the water level. Examples of these are:

• Iris or Flag
• Water-crowfoot (Ranunculus fluitans)
• Bulrush (Scirpus lacustris)
• Cattail (Typha latifolia)
• Taro, Elephant Ear, roots for poi (Colocasia esculenta)
• Arrowhead (Sagittaria latifolia)
• Lotus (Nelumbo)
• Pickerelweed (Pontederia cordata)

3. Floating plants are those that are not anchored to the soil at all, but are free-floating on the surface. In water gardening, these are often used as a provider of shade to reduce algae growth in a pond. These are often extremely fast growing/multiplying. Examples of these are:

• Mosquito ferns (Azolla)
• Water-spangle (Salvinia)
• Water-clover (Marsilea vestita)
• Water lettuce (Nile lettuce) (Pistia stratiotes)
• Water-hyacinth (Eichhornia crassipes)

Some areas of the United States do not allow certain of these plants to be sold or kept as they have become invasive species in warmer areas of the country, such as Florida.

Algae are found in all ponds. There are hundreds of species of algae that can grow in garden ponds but they are only usually noticied when they become abundant. Algae often grow in very high densities in ponds because of the high nutrient levels that are typical of garden ponds. Generally alga attaches itself to the sides of the pond and remains innocuous. Some species of algae, namely the dreaded 'blanket weed' can grow up to a foot a day under ideal conditions and can rapidly clog a garden pond. On the other hand, free floating algae are microcopic and are what cause pond water to appear green.