Wetland, Aquatic Plants & Pond Structure For Your Pond

There are a number of nurseries that sell wetland and aquatic plants for your pond.  Wetland species, such as water iris, cattails, Sagitarria and others, can be planted around the fringe of your pond to give a more natural and appealing look.  Trees (willows, cottonwood) can provide shade and cover during hot summer months.  Too many trees, however, can result in too much shade, too much overgrowth and a dumping of organic matter into the pond each fall as the trees loose their leaves.  A balance of sunny and shady spots, with deep (6-8') and shallow (18"-2') water levels, give fish opportunities for spawning, dormancy in winter months and escape options from predators.

We encourage use of native vegetation around ponds, and discourage use of invasive species, such as yellow iris, etc.  There are many wetland nurseries that can assist in providing aquatic plants.  Some live in the water (such as water lilies), some live on the banks of the pond (such as cattails and iris), and others live around the pond (such as willows). All of these plants absorb "fertilizer" from fish and other aquatic organisms in the pond, and provide oxygen, shade, and "pond structure" necessary for providing an aesthetic ecosystem.  Logs and rocks contribute to a more native environment, while again providing diversity within the ecosystem.  Potted water lilies can be placed in the shallow areas.  The potting helps to ensure that they don't take over the pond.  Native water lilies are more likely to survive colder winter temperatures.  Floating islands can be used in lined ponds, again to provide pond structure, shade, and use of plants to absorb "fertilizer" in the pond.

Lets visit a bit about pond structure.  It is natural for a pond to have tree trucks, limbs and rocks in the water.  These provide cover for fish from that osprey, hovering above, in addition to providing shade.  Smaller limbs provide an ideal place for aquatic plants and smaller fish to hover.  They provide a good escape opportunity for smaller fish seeking a haven from the larger, pedator fish.  Common predators at Santiam Valley Ranch include the Great blue heron, green heron, osprey, kingfisher, river otter, mink, raccoon and others.  Providing options for escape may help in protecting your fishy friends.

DO NOT BUY PARROT FEATHER FOR YOUR POND (an invasive species from South America)! It will cover your entire pond.  This species, and others, are prohibited in Oregon for placement in ponds, and for good reason. We unfortunately got parrot feather into one of our ponds, and it took almost 10 years, coupled with relentless energy, to get rid of that plant.

 If your pond is truly warm-water (e.g., shallow and warm in the summer), if you have little introduction of new water, and if there is any source of nutrient loading, you will have more than enough aquatic plants.  In fact, you will get sick of aquatic plants!  Elodea, mylfoil, and algae are all indications of a normal, healthy warm-water pond.  These plants can become so dense that fishing is impossible. On the other side, the dense nature of these weeds provides much cover for small fry and fingerling, and are a forest for phytoplankton and zooplankton upon which the fingerlings feed. 


At Santiam Valley Ranch, we also deal with aquatic pond weeds.  Here,
Kevin Dahl is pulling out weeds so we can move the sein net through the pond.

There are a number of ways to control aquatic vegetation--and surely more ways are being devised every day! Here are few ideas and you can use any combination as you want:

  1. chemical control: There are a number of aquatic herbicides (Sonar, Diquat, etc.) on the market that kill aquatic plants without damaging fish and other aquatic organisms. These are generally expensive. Contact your local farm store. Aquacide Company publishes a great brochure indicating aquatic weeds and recommendations for chemical control. This 30-page brochure can be obtained by calling (800) 328-9350, or check out their web page: www.KillLakeWeeds.com

  2. mechanical control: Rakes and other devices are available for "harvesting" aquatic weeds. This is a lot of work--but the decomposing plants make great compost!

  3. increase aeration/mixture of water: The addition of a fountain or aerator can help to keep water moving, thus minimizing build-up of aquatic weeds in a specific location of the pond. This can be expensive, and requires wiring, etc., but if it is consistent with your pond's aesthetics and purpose, it can be a nice addition.
    If you decide to use an aerator on your pond, place the diffuser at the deepest location within the pond. Gases, such as methane, are heavier than water and flow to the deepest location in the pond. If left there, they form an area of poisonous gases. Sometimes during hot summer weather, there can be an inversion in the pond. Oxygen is depleted and this can result in suffocation of the fishes. Placement of the diffuser in the deepest location with vent gases and maintain oxygen.

  4. increase cover/decrease sunlight: Plants do not do well without sunlight. So, if sunlight penetration is decreased, there will be fewer thriving aquatic plants. To achieve this, ponds can be fertilized to the point of creating a phytoplankton bloom. One must be careful when fertilizing ponds, however, because if not done properly and consistently, you may instead feed the aquatic plants and have an even greater problem!
     In this same vein, if the pond is covered (even in small areas) with floating plants (water hyacinth, water spinach), structures (docks, floating islands) or even black plastic, the aquatic weeds in those locations will be reduced/eliminated. Another option is "Aquashade", a chemical product used to decrease sunlight penetrating throughout the water.

  5. decrease nutrient load: If your pond is experiencing an excessive amount of algae, you may have excessive organic nutrients entering the pond (e.g., pond located close to septic system, run-off from recently fertilized fields, etc.). A pond filled with algae can indicate high phosphorous content, which can also be an indicator of lots of fish! An option to decrease algae is using barley straw, which we carry at Santiam Valley Ranch.

  6. barley straw for algae control: Barley straw is placed into the pond with half in the water and half on shore. The interface between the water and air on the barley straw gives off a chemical that interferes with the reproduction of some sorts of algae. When we use barley straw on our ponds, there is a substantial decrease in algae, which lasts for several years. You can learn more about barley straw on the internet.
    Santiam Valley Ranch sells barley straw for $20 per bale (around 50-60#).

  7. grass carp: No fish, frog, crayfish, or other aquatic species will eliminate algae or aquatic weeds. Grass carp has a reputation for eating vegetation, however, from our own experience, their progress is s-l-o-w. It will take several years for their impact to make a difference, whereas pond owners would prefer a more immediate impact. If you chose to stock too many grass carp, in a few years you will have zero ecosystem in your pond. The grass carp will eat everything, and you will loose the plants that process fertilizer, emit oxygen, provide escape areas for young fish, and denude the shade and protection for other fish. Grass carp play a useful role in irrigation ditches or in man-made altered habitats that are subjected to continual intrusion. Be careful about stocking grass carp in a eco-friendly pond environment, and if doing so, stock less than more.

 



Grass carp as they arrive at the ranch.  These carp were shipped by air from
Keo Fish Farms and are about 12" in length.  They are DNA certified as
triploid (sterile).

Right
, Ken is holding a Grass carp after five years, approximately 3' in length.