Aquatic Plant Information
As contractors and pond specialists, many people ask us why having aquatic plants is so important in their ponds. The short answer is because they oxygenate the water and are a critical piece in the nitrogen cycle.
Let’s Explore
Unlike human beings and other animals, pond plants photosynthesize during daylight hours. Photosynthesis, carried out by pond plants and their 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. Aquatic plants not only add natural beauty to what might otherwise be a dull looking pond, they also serve as a valuable natural oxygenator.
Ecosystem
Water lilies, Lotus and the other 5 categories of pond plants serve another valuable function in the overall Ecosystem. 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 owner’s nightmare: the dreaded Algae Bloom, that can, if left un-managed, 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?
The general consensus in the pond community is that your pond should be planted according to the following guidelines.
For every 10 square feet of pond surface use the following amount of plants:
1 large water lily
1 bog plant(marginal)
2 bunches of oxygenating pond plants (oxygenators)
This may be a good starting point, but certainly not a strict rule. My answer is always that you should have as many plants as it takes to control your algae. Aquatic plants are known to grow and spread quickly, especially when planted directly in the bottom of the pond. Keep this in mind when planting. It is always a compromise between controlling algae sooner or later. The more you plant now, the more quickly your algae will be under control and the more plant material you will likely be ripping out in three or four years. The less you plant now, the longer it will take to control your algae and the longer you will be able to wait before you start thinning your pond.
Use your judgement, enthusiasm and budget as your guidelines. Also, don’t be afraid to ask other pond owners with established ponds for help. I’ll bet that there are plenty of people who would be willing to help a beginner by donating some of their extra aquatic plants to the new pond. I know that I personally pull out many plants each year.
How to Plant Your Aquatic Pond Plants.
Water lilies like to be planted in still water that is at least 12″ in depth. They aren’t comfortable in flowing or fast moving water. The best way to plant your water lilies is to plant them in the gravel at the required depth. If you plant tropical lilies, you may want to keep them in pots for ease of removal in the late season.
Usually when you buy your aquatic plants they will be potted. I always remove the plants from their pots and plant them directly into the pond (except for maybe tropicals which need to come back out before winter). Simply clear away some of the gravel from an area, place the plant down on the rubber and cover the roots with gravel or rocks. I’ll often tuck marginal aquatics in the spaces between the large rocks on the perimeter of the pond and stream. If you don’t have planting pockets for your water lilies in the bottom of your pond, then you may need to encircle the roots with rocks and cover them with gravel. It is important to be sure that the roots of the plants are protected to keep the fish from pulling them out and eating them. I have only really had this problem in ponds with larger Koi. Those big Koi really dig through the gravel looking for food and they can quickly destroy a new plant. As the plants develop and grow, they will send out roots under the gravel and will spread quite readily. ensuring their survival with even the most vigorous feeders in the pond.
Should I Fertilize My Pond Plants?
In general, I never fertilize aquatic plants. In my mind, this is just adding fertilizer for the algae to grow as well as discouraging the plants from getting their nutrients from the pond water. Having said that, if you want the most beautiful and vibrant water lily blooms in your neighborhood, you may need to fertilize. If you do choose to fertilize, only use aquatic fertilizer that has been specifically designed for use with aquatic plants. These fertilizers have a lower concentration of phosphorous and nitrogen.
Water Lilies & Other 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.
Category 1: Water lilies
The most beautiful of pond plants, water lilies, 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. Water lilies prefer deeper water … at least 18″ but some require water that is up to 3 ft. I’ve found that the deeper the lily is planted, the slower it will grow. I’m guessing it takes more energy to send it’s leaves to the surface which leaves less energy for root growth. Be careful to always plant them in at least 18″ of water to prevent them from freezing out over the winter.
Category 2: Oxygenators
These pond plants provide good pond oxygenation and are totally submersed beneath water. They float around your water garden or root into soil. Monkey tail, Anacharis, Hornwort and Parrots feather are examples.
Category 3: Floating pond plants
These pond plants don’t need soil and have roots that resembling hairs that dangle below their bodies. They can add tremendous effect to any water garden design. Examples of these pond plants include: Duck weed, Water chestnut, Water Hyacinth and the Water lettuce. Placement of floaters in your Bio Filter will yield added filtration and explosive growth in the plant itself. I often use large quantities of floaters in new ponds to help balance the water when the marginal plants are newly planted.
Category 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.
Category 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.
Category 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”
.Hardy Marginals
Hardy marginal plants will survive Wisconsin winters to Zone 5 and will grow the best if planted in the suggested water depths. Many of these plants are very resilient and can be planted deeper in the pond than what is specified. We plant all of our marginal plants on the upper shelf of the pond directly into the gravel, no pot, no additional soil. While all of these plants are considered hardy here in Wisconsin, the cells that are colored blue are the most hardy of these plants.
| Acorus calamus var. variegata (Variegated Sweetflag) Iris type foliage, bold white and green variegation. 30″ height, 0-6″ depth. |
| Acorus gramineus var. variegata ( Japanese Sweetflag) A small version of the above. 1’height, 0-6″ depth. |
| Acorus graminius var. variegata ‘Ogon’ (Japanese Sweetflag) Variegated leaves of green and chartruese foliage. 1′ height, 0-6″ depth |
| Aponogeton distachys (Water Hawthorn) Floating leaves, white flowers with maroon spots, spring and fall. 6-18″ depth |
| Alisma plantago (Water Plantain) Light pink or white airy flowers over attractive foliage. 2′ height, 0-4″ depth |
| Asclepias incarnata (Swamp Milkweed) Loved by monarch butterflys 2-4′ height, 0-2″depth |
| Butomus umbellatus (Flowering Rush) Pink umbels of flowers over straplike leaves. 2′ height, 0-6″ depth |
| Carex muskinensis (Bamboo Sedge) Very full sedge with a look of bamboo 1-2’height, 0-6″depth |
| Carex stricta var. ‘Bowles Golden ‘ (Golden Sedge) Beautiful golden leaves. 1′ height, 0-2″ depth |
| Eriophorum spp. (Cotton Grass) Tufts of cottony seeds heads on this attractive grass. 1′ height, 0-4″ depth |
| Glyceria variegata (Glyceria Grass) Graceful striped green and white grass. 1-2’height, 0-6″depth |
| Eleocaris sp. (Spike Rush) Fine spikey foliage, topped with small brown seed heads. 1’height, 0-4″depth. |
| Equisetum hymale (Horsetail or Scouring Rush) Jointed stems, a very different look. 2-3′ height, 0-6″ depth |
| Equisetum sciorpoides (Mini-Horsetail Rush) Jointed stems, dainty, but hardy . 6-8″ height, 0-2″ depth |
| Euphorbia palustrus (Water Spurge) White airy flowers, bright golden orange foliage in fall. 1-2′ height, 0-2″ depth |
| Hibiscus sp Giant 8-10′”flowers, available in white or pink. 4′ height, 0-6″ depth |
| Houttuynia cordata var.’Chameleon’ Pink, white, and green variegated heart shaped leaves. 1′ height, 0-4″ depth |
| Iris pseudocorus (Yellow Flag Iris) Beautiful yellow flowers, attractive foliage. 4′ height, 0-6″ depth |
| Hydrocotyle sp. (Pennywort) Trailing plant with small scalloped parasol leaves. 3-6″height, 0-2″depth |
| Hydrocotyle var ‘Crystal Confetti’ Smaller variegated form of the above 1-2″height, 0-2″depth |
| Iris vericolor (Blue Flag Iris) Beautiful blue flowers. 3′ height, 0-6″ depth |
| Iris fulva (Red Iris) A different copper red colored iris. 2′ Height, 0-6″depth |
| Iris ensata (Japanese Iris) Beautiful large, flat creped blooms, mixed colors. 3′ height, 0-6″ depth |
| Iris Louisiana Large, bold flowers, many varieties available.3′ height, 0-6″ depth |
| Iris siberica (Siberian Iris) Mixed colors, smaller flowers over narrow foliage. 2′ height, 0-6″ depth |
| Juncus effusus spiralis (Corkscrew Rush) An unusual plant with twisting stems. 1′ height, 0-6″ depth |
| Juncus effusus (Common Rush) Dark green, reed like foliage. 18″ height, 0-6″ depth |
| Juncus glauca (Blue Rush) Steel blue spikes 2’height, 0-6″depth |
| Juncus effusus ‘Gold Strike Rush’ Dark green with golden vertical stripes. 18″ height, 0-6″depth |
| Ligusticum umbelliserae (Lovage, Water Celery) Bright green foliage, flowers, floating or 0-6″ depth |
| Lobelia cardinalis (Cardinal Flower) Brilliant scarlet spikes. 2-3′ height, 0-2 depth |
| lysimachia nummularia Ruffled little leaves of bright yellow, tiny yellow flowers.4″height, 0-2″depth |
| Mentha aquatica (Aquatic Mint) Fragrant pink flowers over aromatic foliage. 1’height, 0-6″depth |
| Mimulus gluttens (Yellow Monkey Flower) Trailing plant, yellow flowers with red speckles.1’height,0-2″depth |
| Mimulus ringens (Monkey Flower) Lavender flowers, long blooming. 1-2’height, 0-6″depth |
| Myositis aquatica (Forget Me Not) Lots of bright blue flowers over clear green foliage. 1’height, 0-4″depth. |
| Myriophyllum aquaticum (Parrot’s Feathers) Trailing blue green foliage. 0-12″ depth |
| Oenenthe javanica (Rainbow Pastel Celery) Don’t miss this one! Bold white, lavender, pink, and green leaves, airy white blossoms, and —a great filter plant. 1’height, 0-6″depth |
| Orontium aquaticum (Golden Club) White spike flowers with bright golden tips.1′ height, 0-6″ depth |
| Peltandra virginica (Water Arum) White calla bloom over glossy green arrow-shaped leaves. 1′ height, 0-6″depth |
| Pontederia cordata (Pickeral Rush) Blue spike flowers, sun or shade. 2-3′ height, 0-12″ depth |
| Pragmites australis (Candy Stripe Reed) Pink, green, and white striped grassy foliage 2’height, 0-6″depth |
| Pragmites australis aurea (Golden Reed) Bright yellow green foliage 2’height, 0-6″depth |
| Ranunculus repens (Buttered Popcorn) Bright mound of gold and green variegated foliage 1’height, 0-2″depth |
| Sagittaria latifolia (Arrowhead) White flowers, attractive arrow shaped leaves. 2′ height, 0-1′ depth |
| Saururus cernuus (Lizard Tail) Fragrant white flowers in graceful drooping spikes. 2′ height, 0-6″ depth |
| Scirpus tabernaemontani var. zebrinus (Zebra Rush) Bold cream and white barring. 3″ height, 0-1′ depth |
| Scirpus lacustri var. ‘alba’ (White Bulrush) Beautiful white stripes. Choice variety. 3’height, 0-1′ depth |
| Spartina pectinata var. aureomarginata (Variegated Cord Grass) Yellow edges on graceful leaves. 3′ height, 0-6″ depth |
| Thalia dealbata (Hardy Canna) Purple red flowers held high above foliage. 4′ height, 0-1′ depth |
| Thypa varieties (Cattail) Well known for its cattails. 2-4′ height, 0-1′ depth |
| Thypa sp. var. ‘Europa’ (Mini-Cattail) Tiny cattails over blue green foliage, a great plant. 1′ height, 0-1’depth |
| Thypa var. ‘variegata’ (Variegated Cattail) White striped foliage, a choice variety. 3′ height, 0-1′ depth |
| Veronica beccabunae (Veronica) Trailing shiny leaves, small blue flowers all summer. 0-6″ depth |
Hardy Water Lilies
These water lilies will be able to survive Wisconsin winters as long as they are planted at least one foot below the surface of the water. Many people suggest only planting these lilies in one foot of water, but we have had very consistent good luck planting them two or three feet deep. Usually we plant them in planting pockets in the bottom of the pond before filling it with water.
Red
| +Attraction | Always in demand, bright rose red blossoms |
| Baby Red | A treasure in a tub garden, deep crimson blossoms |
| +James Brydon | One of the darkest reds |
| Gypsy | Free blooming red |
| +Rembrandt | Bright red |
| +Splendida | Deep pink double turning rose red |
White
| +Albida | Very reliable and fragrant |
| *+Moondance | Star shaped, free blooming, over mottled foliage |
| Odorata | Very fragrant native with bright green foliage |
| Queen of the Whites | Great bloomer with slight fragrance |
| Virginalis | Glistening beauty with over 45 petals |
Pink
| +Arc en Ceil | Beautiful foliage of pink, green and white |
| +Fabiola | A profuse bloomer |
| Glorie du Temple | Pale pink, changing to white, extremely double |
| Hollandia (Darwin) | Huge double medium pink, early bloomer, fragrant |
| M Wilfron Gonnere | Large, with many double flowers, a great choice |
| Mayla | Bright fuchsia and fragrant |
| Mrs. Richmond | Large medium dark pink |
Yellow
| +Chromatella | Bright yellow, good choice for a pond with limited sunshine |
| +Joey Tomachek | Vivid yellow, great bud count |
| Sulfurea | Many soft yellow blossoms, one of the first to bloom in spring |
| Texas Dawn | Giant bright yellow, blossoms held high over mottled foliage |
Changeable
| +Aurora | A little charmer with beautiful mottled leaves |
| Commanche | Yellow changing to bronze/copper, mottled foliage |
| +Indiana | Bright splash of color, good for small ponds and tub gardens |
| +Sioux | A very reliable bloomer, great in tubs |
Peach
| +Barbara Dobkins | Large glistening peach blossoms |
| Carolina Sunset | Bright and cheery with heavily mottled leaves |
| +Colorado | Long bloom season, salmon shades |
| Florida Sunset | Mottled foliage, beautiful flower form |
Floaters
These plants simply float on the top of the water. Often times these are placed in top of the biofalls. They do a great job of filtering water and removing nutrients. Place a stick or piece of fishing line across the biofalls to keep these plants from choking off the waterfall. Weights or fishing line can be used in the pond also to keep these floaters out of your skimmer. All of these plants are tropical and will not survive our winter.
Water Hyacinth – Eichhornia crassipes
Water Lettuce – Pistia stratiotes
Submerged Oxygenators
These plants are usually sold in pre-weighted bundles. Just toss them in and they will do the rest. They will root directly into the pond bottom and will provide excellent cover for the fish. They also take nutrients out of the water which helps to minimize algae growth. These plants will need thinning from time to time, as they grow rather vigorously.
Anacharis
Hornwort
Use Common Sense, There is No Magic Potion!
Plants are a vital part of every natural eco-system pond. Without them we would need to resort to chemical water treatments. With their help, we can maintain clear beautiful ponds the way mother nature intended them to be, all natural. In my opinion, most new pond owners don’t comprehend the vital importance of plants in the pond and they don’t plant enough. If your pond is turning green with algae, don’t go buying some fancy “promise you the world” water treatment. These products are better at removing money from your wallet than removing algae from your pond. Even the ones that do work are only a very short term fix that will disrupt the balance of your pond. Instead, spend your money on pond plants. These are the real workhorses of the water garden. They work hard for you every day and they get more effective each day.