water lily - illustration by Helen KrayenhoffWater gardens have been a part of civilization for thousands of years; from the hanging gardens of Babylon to ancient Japanese koi ponds, water gardens have provided an outlet for artistic expression and a sanctuary for thought and reflection. Today the term “Water Gardening” can mean many different things, from a small water feature that provides relaxing sound to a full sized pond with both fish and plants. By answering some commonly asked questions we hope to make water gardens less intimidating. 

How do aquatic plants differ from terrestrial plants?

The main difference between aquatic and terrestrial plants is the way they respire (breathe) in their respective environments. Plants that grow in wet soils or under water have structural differences that allow them to absorb and move oxygen and carbon dioxide in ways that terrestrial plants don’t.

What is aquatic soil and why do I need it?         

The most important reason to use aquatic soil versus garden soil is to minimize the amount of organic matter going into your pond. Made mostly of clay, sand, and rock, aquatic soil has very little organic matter. Too much organic matter in your pond will result in an increase of nutrients, and if the nutrient level is higher than your filter and or plants can consume, you will find yourself stuck with algae blooms and an environment toxic to fish and other beneficial life.

Why can’t I keep my new aquatic plant in the pot I bought it in?

We highly recommend aquatic planting baskets. Many aquatic plants are sold in pots that do NOT have drain holes. Allowing the plant’s roots to have physical contact with the water will increase their ability to act as a filter for your pond. And, aquatic planting baskets are important for plant and pond maintenance. Since many of these plants are fast growers, dividing and pruning is necessary for maintaining their health. This is easier when you are able to lift the plant out of your pond, and it simplifies pond cleaning. 

How deep can this be planted?

We offer five classes of aquatic plants here at the nursery; bog, marginal, emergent, submerged, and floating. Floaters can be placed into the water and left to float freely wherever the current or wind may take them. Bog plants like wet feet. For this reason, they are best planted in either the splash zone of your pond’s waterfall, or at the lowest and soggiest point in your yard. Some bog plants can tolerate sitting in water, but most like to have their crown above the water’s surface. Marginal plants can be planted in 1”-8” of water, calculated from the crown of the plant to the surface of the water. Emergent plant’s leaves and flowers actually break the surface of the water and are healthily planted at a depth of 12”-24” below the water surface. Submerged plants prefer to be planted in 18”-36” deep water.

How do I keep my pond’s water clear?

Planting a variety of plants that tolerate different water depths is one of best ways to maintain a healthy, balanced pond. This is because your pond water is similar to your garden’s soil, in that there are different bacteria, fungi, gasses and nutrients at different depths. If fish are added to the equation additional filtration will be needed. There are a wide variety of filters on the market today. Which kind of fish, and how many will dictate the type of filter you will need. 

How do I get my water lilies to bloom?

Warm days and sun will help. Then, feed, and prune, feed and prune. Water lilies are hungry plants during the growing season. A heavy feeding once a month is crucial for these plants to perform the way they should. The other trick is to remove BOTH leaves and flowers as they near the end of their life cycle. Take note of when your water lilies’ leaves start to turn yellow, and your lilies’ flowers stop blooming. Removing tired leaves and flowers will trigger your water lily to produce more blooms.

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