Pond plants do more than just look pretty. They help keep your water clean, give animals a place to hide, and make your pond feel more natural. But one question we often hear at BR&D Landscape is: How big will these plants get?

The answer depends on a few things, like what kind of plant it is, how much sun and space it has, and how well it’s cared for. In this blog, we’ll walk you through the different types of pond plants and how big you can expect them to grow.

BR&D Landscape showcases how big pond plants get with pink water lilies and large lily pads blooming on a calm, reflective pond surface.

Four Main Types of Pond Plants

There are four main types of pond plants. Each one grows in a different way and reaches a different size. Let’s take a look at them one by one.

  1. Floating Plants

Floating plants sit on the top of the water. They don’t grow in soil, and their roots float freely in the pond. These plants are great for shading your pond and helping stop algae from taking over.

Common floating plants:

  • Water Lettuce and Water Hyacinth – These plants grow on the surface and can each reach about 10 inches wide. Over time, they can spread and cover large parts of the pond.
  • Duckweed and Azolla – These are tiny plants, each just a few millimeters across. But they grow quickly and can cover the pond’s surface fast!

What to know: Floating plants don’t usually get tall, but they can take up a lot of space if not managed.

  1. Submerged Plants

Submerged plants grow entirely under the water. These plants are like the lungs of your pond—they give off oxygen and help keep your water healthy.

Common submerged plants:

  • Elodea
  • Hornwort
  • Vallisneria

These plants can grow several feet long and fill up space underwater. They’re great for fish to swim through and hide in.

What to know: Even though you may not always see them, these plants can grow fast and need trimming if they get too thick.

  1. Marginal Plants

Marginal plants grow around the edges of your pond, where the water is shallow. Their roots stay in the water or wet soil, but their stems and leaves grow above the surface.

Common marginal plants:

  • Cattails and Reeds – These tall plants can grow 5 to 10 feet high!
  • Water Lilies – These have big leaves that float on the water. Some types can spread 6 to 12 feet across the pond.

What to know: Marginal plants can become very tall or wide, so be sure to give them space to grow.

  1. Bog Plants

Bog plants grow best in very wet soil, not deep water. These plants are great around waterfalls or in special planting pockets near the pond.

Common bog plants:

  • Pickerel Weed
  • Marsh Marigold
  • Japanese Iris
  • Canna Lilies

Most bog plants grow between 2 and 4 feet tall. They add lots of color and texture around your pond.

What to know: These plants usually grow upright, so they’re easy to see and enjoy from a distance.

What Affects How Big Pond Plants Grow?

Pond plants don’t all grow the same way. Even the same plant can grow differently depending on where it’s planted and how it’s cared for. Here are some things that affect plant growth:

  1. Sunlight

Most pond plants need sunlight to grow. The more sun they get, the bigger and faster they grow. Some plants do okay with a bit of shade, but full sun is best for most.

  1. Nutrients

Just like other plants, pond plants need food. They get nutrients from the water and soil. If your pond has lots of fish or decaying leaves, there may be more nutrients in the water—which means plants can grow bigger and faster.

But be careful! Too many nutrients can lead to out-of-control plant growth or algae problems.

  1. Space

If a plant doesn’t have enough room to grow, it will stay small. But when it has plenty of space and the right conditions, it can really spread out. That’s why it’s important to know the full-grown size before you plant it.

How to Keep Pond Plants Under Control

It’s great when pond plants grow well—but sometimes they grow too well! That’s why pond maintenance is so important. Here are a few tips:

  • Trim and divide plants once or twice a year. This helps them stay healthy and keeps your pond from getting too crowded.
  • Remove old leaves and flowers to keep the water clean.
  • Keep an eye on floating plants, since they can take over quickly if left alone.
  • Watch water lilies and marginals to make sure they’re not shading out everything else

Frequently Asked Questions: Pond Plant Sizes

  • Q: How fast do pond plants grow?
    A: It depends on the plant and the conditions. Some, like duckweed, grow very fast and can cover your pond in weeks. Others, like water lilies, may take a season or two to fully spread out.
  • Q: Can pond plants get too big?
    A: Yes! Without trimming or dividing, some plants can take over your pond, block sunlight, or make maintenance harder. Regular care helps keep things in balance.
  • Q: Will pond plants survive the winter in Denver?
    A: Many hardy plants will survive winter here, especially if your pond is deep enough. Others, like tropical plants, may need to be brought inside or treated as annuals. We can help you choose the right plants for Colorado’s climate.
  • Q: Can I plant too many pond plants?
    A: Yes. Too many plants can crowd the pond and cause water quality issues. It’s best to start with a mix and adjust as you see how they grow. We recommend about 60–70% plant coverage in summer for balance.
  • Q: Do I need special soil for pond plants?
    A: Pond plants usually grow in heavy garden soil or aquatic planting mix. Regular potting soil is too light and can float away. We can help you plant them the right way so they stay put and thrive.

Ready to Get the Most Out of Your Pond Plants?

Whether you’re building a new pond or need help managing your current one, BR&D Landscape is here for you. We know what grows best in Denver and how to keep your pond looking its best all year long.

Contact us today to schedule a consultation or seasonal maintenance visit. Let’s make your pond a beautiful, thriving part of your backyard!