Water features, large or small, are beautiful in their own right, but when you add plants they are transformed, taking on a totally different feel. Often we think of pond plants as just waterlilies and “weed”, the ubiquitous plants bobbing around below the surface, but there’s a lot more to pond plants.
Plants are not simply an aesthetic addition to your water garden. They help to keep the water clear and clean by feeding on nutrients. They also provide habitat for frogs, and if you have fish they help keep the water oxygenated, as well as providing places for the fish to hide from the hot sun and predators.
Understanding the major characteristics of pond plants will help you achieve the perfect water garden. Plants that grow in ponds tend to fall into a few different categories. These are based mainly on where they like their roots to be positioned. Here are the main groups:
Deep water is generally defined as being from 30cm to 1.2m or more. Deep-water plants need to have their roots down in cool water, protected from sunlight. They will have floating leaves, and flowers on long stems. Native water fringe (Nymphoides crenata) is a good example.
These plants live in the deeper parts of the pond, and will generally remain underwater. These include the types of plants you may see in aquariums, such as grass-like species, and other underwater plants such as the partially emergent water milfoils (Myriophyllum sp.). They will add extra oxygen to the water, which is essential if you have fish.
Technically, these fall into the deep water category, but the flowering waterlilies (Nymphaea spp. & cvs) and lotus or sacred lotus (Nelumbo spp. & cvs) tend to be addressed individually because they’re planted mainly for their flowering. Leaves and flowers will be on the surface, held on long stems.
In nature, these plants tend to grow in various water depths up the banks of ponds or streams, as opposed to on the bottom.
These are loosely defined as those that like 15–30cm of water over their roots. The beautiful purple-mauve or white flowering pickle rush (Pontederia cordata and var.) fits this category.
These are the plants that grow at the point where land and water meet, so the water depth may be from 0–15cm. Louisiana iris (Iris spp. and cvs) are the prime example, as they thrive in boggy soil and shallow water on the pond edge.
It’s worth noting that the line between deep and shallow marginals is a bit blurry—many species will grow across both depth ranges.
As the name implies, floating plants float on the pond’s surface, and do not root into the base or sides. Seasoned water gardeners now approach floating plants with caution, as many have a track record of becoming nuisance plants, quickly covering the entire pond surface and blocking out light to plants below.
Some floating plants, such as water lettuce (Pistia stratiotes) and water hyacinth (Eichhornia crassipes), were once commonly grown, but have become invasive and are now declared weeds.
There are, of course, useful and desirable floating plants—just take the time to select the right ones. Duck weed, for example, can double in size every few days in warmer weather, but makes an excellent food source for fish, tadpoles and waterbirds, and helps maintain water quality.
Aquatic plants add a totally new dimension to your water garden. To get the most from water plants, try to add a range of species from the different categories that will be suitable for your pond type. This way you’ll be creating a more balanced and natural ecosystem, and the performance of all components—plants, water, fish and wildlife—will be improved.
Growing conditions will vary with the plants you select, so take the time to research before you buy.
If there is a waterfall or fountain in your pond, be aware that some water plants, such as waterlilies, don’t like rapidly moving water. Take this into account when choosing and positioning your plants.
If your waterlilies aren’t flowering, the most common reason will be that the water is too shallow (less than 30cm) or too warm, or both. When planted in small water bowls or pots and shallow ponds, waterlilies may flower the first year, using their stored buds, but not the next. They’ll need deeper, cooler water to flower.
Don’t forget to talk to a plant specialist in the nursery for additional advice and tips.
Very few pests attack water plants. Aphids may appear on flower buds and new shoots, but they generally don’t pose a problem.
Just how do you get the levels you need for planting in a pond? If you are building a larger pond using a pond liner, simply profile the soil of the basic pond shape with tiered steps to allow for planting.
If you are adding a pond using a pre-fab shell, you’ll find that many have steps built in for the different planting levels.
If you already have a pond, you may need to take the old-school approach and prop up pots on bricks or rocks.
Waterlilies: the most romantic and breathtaking of the aquatic plants, waterlilies are a water garden must-have.
Japanese maple: looking to add an Asian edge to your water garden? A Japanese maple is just the thing!
Ginger: add serious tropical appeal to ponds with gorgeous gingers.
Check out our huge range of plants now and get your garden growing!