It’s important to incorporate a variety of marginal plants to achieve a natural look for your ecosystem pond. Marginal plants are found growing around the edges, or margins of your water garden. There are hundreds of selections to choose from and they all offer different shapes, sizes, textures, and colors.
Attractive and Beneficial
Aside from providing beauty and naturalization, marginal plants bring plenty of other benefits to water gardens. From a filtration perspective, the plants remove excess nutrients to starve algae from its food source. They also entice and protect wildlife, and you can find them in many different hardy or tropical variations.
To create the most natural look possible, you want to place marginal plants directly into the gravel. This allows them to prosper in the soil and filter the water successfully. Plants like thalia, bulrush, and reeds need to be planted in an aquatic pot encircled with rocks and gravel. This way their roots can’t damage the pond liner.
Marginal plants are most effective planted along the edges of a stream. Water continually flows down the stream and passes the roots of the plants to provide optimal water filtration. Their roots also absorb additional nutrients to prevent algae from rearing its ugly head. You want to create the look of a natural stream with beautiful plants flourishing in the water along its edges.
You want to consider water depth, sun exposure, and location to select the proper plants for your pond. The main concern with water depth is how much water a plant can handle above its crown. With this in mind, most marginals fare best planted on the first shelf of the pond. Make sure to select a variety of different heights, foliage types, and flower colors to create an appealing mix.
Once you find a combination of plants you like, it’s time to plant them in your water garden. First, start washing off most of the dirt around the root system. Be careful not to disturb the plant’s root system by removing too much. After getting rid of the excess soil, plant it in the pond and fill gravel in around the root system.
You can use this same method for planting in a stream if you use marginal plants that tolerate moving water.
Special Care for Aggressive Plants
Be careful if you choose an overly aggressive plant. It’s best to leave them in a pot to contain their roots from spreading into your pond’s liner. It’s important to note most aquatic plants desire width over depth in their own growing areas so allow enough room for them to spread out. The majority of marginals are shallow-rooted making depth less of an issue than surface area.
For planting, fill a hole-less aquatic pot with 2-3” of hefty topsoil, inserting the fertilizer in the bottom of the pot. Since these marginals aren’t planted in the gravel, you need to fertilize them because they can’t properly draw nutrients from the pond water in a pot.
Continue filling in around the plant’s roots with topsoil. Fill the pot within one inch of the top and tightly pack the soil. Then conceal it with a ½ to one-inch layer of gravel. The gravel needs to be close to even with the previous soil level.
Looking after marginal plants in an ecosystem pond is quite easy. Get rid of any decayed, discolored, or excess plant material as necessary. Remember, marginals don’t require fertilizers (unless they’re in a pot) because they thrive from the nutrients in the pond.
During the winter, trim the plants around two or three inches above the water’s surface. For spring care, remove all dead plant debris and thin out the marginals directly planted in the gravel; otherwise, they overwhelm your pond because their growth isn’t restricted by a pot.
Waterlilies may be the centerpiece of your water garden, but marginals hold more importance in their functionality as a natural filter for your pond. They also benefit the appearance of your pond by softening edges and helping it blend into the surrounding landscape. When you begin the planning process of a backyard water garden project, don’t forget to include marginals because they help naturalize your pond like no other aquatic plant.