Water Gardening Maintenance

All gardening requires a degree of on-going maintenance. Installing a water garden does not mean endless hours of work per week.

  • Ensure you situate your pond correctly in the very beginning. This will minimize your overall work load.
  • Choose an area on your property that receives at least 6 hours of direct sunlight per day if you intend on having flowering aquatic plants.
  • Be sure the site is level and not at the lowest part of the garden where runoff (especially lawn fertilizer) will upset the delicate natural balance.
  • There are only 2 ways to combat algae and permanent green, smelly water:
  • Use swimming pool chemicals to keep water clear
  • Use plants, fish, and/or a biological or mechanical filter.
     
Water Gardening Maintenance

Spring

  • Remove the floating pond de-icer or any other device you have used to keep the ice from freezing over during the winter.
  • Reinstall pumps, filters, and lights.
  • Check the water pH with a test kit. The correct pH is between 6.8 and 7.4. If necessary, treat the water with a pH adjuster.
  • Clean out leaves and organic debris that might have accumulated at the bottom over winter.
  • Move existing hardy plants from the bottom of the pond to their proper depth when the water temperature is 4°C (40°F).
  • At 15°C (60°F), start feeding fish low protein food when the water is 10°C (50°F). Start fertilizing plants with convenient tablets. To maximize growth and bloom, fertilize once a month until September.
  • Add floaters such as annual Water Hyacinth and Water Lettuce as well as new water plants when the water temperature is 18°C (65°F).
  • This is also a good time to switch to a high protein fish food.
     

Water Level

  • Check the water level of your pond frequently especially during periods of hot weather. If it goes down too far it will cause temperature fluctuations that can adversely affect plants and fish.
  • Top up regularly.
  • When first filling a new water garden, it’s recommended that the water sit for a week before plants are added.
  • Wait an additional week after that to add fish.
     

Fish & Scavengers

  • Adding scavengers such as aquatic snails and tadpoles help the biological balance in your water garden.
  • Add Fish to your water garden. These are beneficial because they eat mosquitoes and other insect larvae as well as some algae. However, don’t overstock your pond. Too many fish can deplete oxygen, promote algae growth, and reduce water quality.
  • Stock 2.5 cm (1”) of fish per one square foot of pond surface area. Figures are based on the size of the fish at maturity. Common goldfish require very little care. Koi, on the other hand, must be fed regularly, need better filtration, and may outgrow a small water garden. You can reduce the amount of waste from koi by using a low ash fish food.
     

Filters

  • Check all filters in your pond once a week. Less output from fountains, waterfalls, or pumps may indicate that a hose is clogged or the filter is dirty and may require cleaning or replacing.

Summer

  • Thin out plants if the water surface becomes too densely covered.
  • Simply skim the water for an overabundance of such plants as blanket algae and duckweed or trim out a few Lily leaves.
  • Remove all faded blooms and yellowed foliage so they can’t decompose in the water. If left, algae will proliferate and potentially turn the water cloudy and green.
  • Watch for brown spot on Water Lily and Lotus foliage. If detected, remove infected leaves immediately and keep the plant growing vigorously by thinning/dividing when necessary.
  • Insects that can attack water plants include aphids, Water Lily beetle, China mark moth, and midges.
  • Aphids are the easiest to control by blasting them off foliage with a garden hose. Fish will consume them gladly and ladybugs and lacewings are natural predators. If aphids persist, spray with Safer’s Insecticidal Soap. But use it in moderation if you have fish.
  • China mark moth affects Water Lilies. They cut off a small piece of leaf and form a cocoon on the underside. They can be rubbed off by hand or treated with BT (Bacillus Thuringiensis), a natural and safe form of control.
  • Leaf-mining midges are small, mosquito-like insects that lay their eggs on the leaves of aquatic plants. Larvae are transparent and almost invisible. They tunnel into the leaves and eat the foliage between the veins, leaving visible trails. Remove any leaves that show these trails.
  • Water Lily beetles also lay eggs on foliage. When the grubs hatch they mine the leaves. Remove these leaves and hose down the remaining foliage. In fall, be sure to remove the dead stalks of marginal plants as this is where they like to overwinter.
     

Fall

  • Stop fertilizing aquatic plants and continue to remove yellowing or dying foliage.
  • If you have fish, switch to food that’s formulated for cooler water temperatures.
  • As leaves on trees and shrubs turn colour and start to drop, cover the whole water garden with protective black, mesh netting. It will keep leaves from falling into the pond. If leaves are allowed to accumulate in the bottom and decompose there algae will be a huge problem the following spring. Scoop or vacuum accumulated debris from the bottom before winter.
  • Remove pumps and electrical equipment.
  • Never drain the water. A preformed, rigid pool without water can crack or warp due to the freeze/thaw cycle. In more extreme cases it can heave itself right out of the ground without the weight of the water to keep it securely anchored. A water garden formed with liner needs the water to retain its shape, to maintain beneficial bacteria, and to help overwinter hardy plants and fish.
  • Install a pond heater or bubbler to keep an area of water from freezing so oxygen can continue to be available to fish and toxic gases like methane can escape.