Pond plants | Water lily pads & aquatic plants are beneficial to your water garden

Photosynthesis - The purpose of water lily pads & pond plants.

Unlike human beings and other animals, pond plants photosynthesize during daylight hours. Photosynthesis, carried out by pond plants and it's land based relatives involves combining the chemical compounds carbon dioxide (CO2) and water (H2O) to produce carbohydrate (energy) and oxygen (O2). Any pond environment can never have too much oxygen as this is the basic requirement not only for your fish to be able to breathe but also for the beneficial bacteria, living in your Bio Filter to successfully convert ammonia to nitrate during the nitrogen cycle. As you can see aquatic plants not only add natural beauty to what might otherwise be quite a dull looking pond feature but also serve as a valuable natural oxygenator.

Effects of lilly pads on algae in ponds: Water lilies, aka Lotus flowers and the other 5 categories of pond plant serve another valuable function in the overall eco system. They compete with green water for phosphates and nitrates, the end result of the Nitrogen Cycle. This helps to control the spread of every pond keepers nightmare the dreaded Algae Bloom that can if left unmanaged result in the suffocation of your pond fish. Water cress is an excellent water plant choice for nitrate removal.

How many pond plants should I use in my fish pond or water garden?

As a rule of thumb I would advise that for each square meter of surface area (10 square feet) consider using the following number of pond plants:

  • 1 large water lily
  • 1 bog plant
  • 2 bunches of oxygenating pond plants (oxygenators)

This is only a guide and it is possible to vary it slightly to fit in with your own water garden designs.

When planting My Aquatic pond plants what should I be aware of?

Water lily pads are an aquatic plant species that like still water that is at least 23" or 60cm in depth. They aren't comfortable in flowing or fast moving water. A convenient way of planting your nymphae (water lilies) is to plant them, firstly in a plastic plant pot and then plant (or anchor) the pot in your pond at the required level.

Only ever use aquatic compost (fertilizer) that has been specifically designed for use with aquatic plants. These composts have a naturally lower concentration of phosphorous and nitrogen. Initially when you bought the water plants they would have been supplied in baskets containing aquatic compost.

Ensure that you cover up the roots and soil because your koi and goldfish will happily eat away at the roots, thereby reducing the effectiveness of the plant in consuming excess nitrate.  Pebbles and gravel are an excellent way of preventing your plants from becoming "fish food".

When planting marginal plants you may find it useful to use coco mats or coir as a means to hold the plant in position. You can also mix a bit of aquatic compost together with the coir. Place pebbles on the mat to keep it submerged.

Water Lilies & Aquatic Pond Plants

The 6 classes of pond plants are: Water lilies that root deeply at the bottom of your fish pond... Oxygenators that are often rootless & totally submerged ... Floating pond plants that add beauty to any pond design e.g. Duck Weed ... Partly emerging pond plants that root into mud & their flowers project out of the pond ... Marginals, the most common aquatic pond plant that likes marginal (shallow) areas and Bog plants that like boggy (muddy) areas.

Beautiful water lillyCategory 1: Water lilies

 - The most beautiful of pond plants, water lily pads (aka Lotus flower) are available in many colors. The 2 most common are Carnea (pink) & Alba (white). Water lilies are vigorous growers so ensure that only a max of 2/3 of the pond surface is covered. Nymphae prefer deeper water ... at least 23" but some require water that is up to 3 ft.

Parrots feather - a natural pond oxygenator plantCategory 2: Oxygenators

These pond plants provide good pond aeration and are totally submersed beneath water. They float around your water garden or root into soil. Monkey tail,  Water crowfoot; Water violet, Hortwort and Parrots feather (see picture) are examples.

Water lettuce floating pond plantCategory 3: Floating pond plants

This species of pond plant doesn't need soil and has roots that resemble hairs, that dangle below it's body. They can add tremendous effect to any water garden design. Examples of these pond plants include:  Duck weed, Water chestnut, Water Hyacynth and the Water lettuce (see picture)

Pickerel plantCategory 4: Emerging marginal pond plants

These plants survive around the edges of the pond where the depth is about 6".  You may need to anchor them down with rocks or large pebbles to prevent them from blowing over. Examples include: Bog Arum, Striped water grass, Pennywort, Double Marsh Marigold, Japanese Iris, Japanese arrowhead, Zebra rush and Pickerel plant (see picture).

Marsh Marigold pond plantCategory 5: Marginals

These are the most common type of pond plant and are found in the shallow areas of your water garden. They are sometimes referred to as bog plants because they are more than capable of existing in muddy (boggy) areas. Examples include Bog Primula, Reed Mace, Pickerel, Water Buttons and the Marsh Marigold (see picture). 

Cardinalis "Ruby slippers" aquatic pond plantCategory 6: Bog plants

These can be shrubs, trees or herbaceous plants that usually live in muddy, damp and shady areas where the maximum water coverage is about 2" (5cms). The herbaceous varieties normally die during the cold winter months. During the summer months they add variety and color to the pond design. Examples include: Lobelias, Goatsbeard, Yellow star flowers, scarlet flowers, water Iris, Clematis Iris and the Cardinalis "Ruby slippers" (see picture).