6 Best Fast Growing Pond Plants For Quick Coverage That Prevent Algae

You walk out to your pond on a sunny morning and see it: that murky, green haze is back. Algae blooms seem to happen overnight, turning a beautiful water feature into a soupy mess. This isn’t just an eyesore; it’s a sign that your pond’s ecosystem is out of balance. The good news is that you don’t need to reach for expensive chemicals, you just need to recruit the right team of plants to do the work for you.

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Using Plants to Naturally Beat Pond Algae

Algae, at its core, is just a simple plant. It needs two things to thrive: sunlight and nutrients. A green pond is simply a pond with an excess of both. The most effective, long-term strategy is to introduce other plants that outcompete the algae for those same resources.

Fast-growing pond plants fight a two-front war. On the surface, floating plants spread their leaves to create shade, starving the algae of the sunlight it needs for photosynthesis. Below the surface, both floating and submerged plants act like powerful filters, pulling excess nutrients like nitrates and phosphates directly out of the water column. This nutrient theft leaves nothing for the algae to feed on.

This approach is about creating a balanced, self-sustaining system. While chemical algaecides offer a quick kill, they don’t solve the underlying problem. They often lead to a cycle of dead algae decaying, releasing more nutrients, and fueling the next, even worse, bloom. Using plants is about fixing the cause, not just treating the symptom.

Water Hyacinth: A Fast-Floating Algae Fighter

Water hyacinth is one of the most powerful natural filters you can put in a pond. Its long, feathery roots dangle in the water, absorbing huge amounts of nutrients that would otherwise feed an algae bloom. Above the water, its broad, waxy leaves spread quickly to form a dense mat of shade.

This plant is an absolute workhorse. In warm, sunny conditions, a handful of hyacinths can double their coverage area in just a couple of weeks. They also produce beautiful lavender flowers, adding an ornamental touch while they clean your water.

However, its greatest strength is also its biggest liability. Water hyacinth is extremely invasive in warmer climates and is illegal to own or transport in many states. If you can legally use it, you must be diligent about containing it and removing excess plants regularly to prevent them from clogging waterways or escaping your property. Think of it as a powerful tool that requires responsible handling.

Water Lettuce: Quick Shade and Nutrient Control

If you want the shading and filtering benefits of water hyacinth with slightly less aggressive growth, water lettuce is an excellent choice. Its velvety, rosette-shaped leaves look like small floating heads of lettuce and spread rapidly to cover the surface. Like hyacinth, it has a robust root system that sops up free-floating nutrients.

Water lettuce spreads by sending out runners that sprout new plants, creating a dense, interconnected mat. This provides excellent shade and also offers shelter for small fish and frogs. It’s a fantastic option for getting that critical 50-60% surface coverage needed to suppress algae growth.

The main tradeoff with water lettuce is its sensitivity to cold. In most climates with freezing winters, it will act as an annual, dying off with the first hard frost. This can be a benefit, as it prevents overgrowth year after year, but it also means you’ll likely need to restock it each spring.

Hornwort: The Submerged Oxygenating Powerhouse

Not all algae fighters work on the surface. Hornwort is a submerged, rootless plant that does its work entirely underwater. It looks like a feathery, green bottlebrush and grows in dense masses that directly compete with algae for dissolved nutrients.

Because it has no roots, you can simply drop bunches of it into your pond and let it go to work. It floats freely in the water column, absorbing nutrients wherever it goes. As a bonus, hornwort is a prolific oxygenator, releasing oxygen into the water which is vital for healthy fish and beneficial bacteria.

Hornwort is incredibly hardy and will grow in almost any light condition, from full sun to partial shade. Its only real downside is that it grows so fast it can become tangled and may need to be thinned out with a rake once or twice a season. Removing the excess plant matter is a great way to physically pull the captured nutrients out of your pond’s ecosystem for good.

Anacharis (Elodea): A Hardy, Fast-Growing Choice

Anacharis, also known as Elodea or waterweed, is another submerged oxygenator that is a staple in pond management. It can be planted in pots on the pond bottom or, like hornwort, simply be weighed down and dropped into the water. Its long, leafy stems grow rapidly towards the surface, absorbing nutrients along the way.

This plant is exceptionally good at clarifying water. It not only competes with algae but also helps trap fine sediment, leading to a cleaner, clearer pond. Anacharis is also very cold-hardy and will often survive the winter at the bottom of the pond, giving you a head start on algae control in the spring.

The primary consideration with Anacharis is its vigor. In a nutrient-rich pond, it can grow so densely that it chokes out other plants and can even impede water flow if you have a pump. Regular trimming is essential to keep it in check. It’s a fantastic plant, but you have to be willing to manage it.

Parrot’s Feather: Rapid Surface Coverage Plant

Parrot’s Feather is a versatile plant that blurs the line between submerged and floating. It typically roots in shallow pots or along the pond’s edge and sends out long, creeping stems that form a dense, feathery mat across the water’s surface. This provides excellent shade while the submerged portions of the plant absorb nutrients.

The bright green, fir-like foliage is very attractive and provides fantastic habitat for dragonflies, frogs, and baby fish. It’s particularly useful for softening the hard edges of a pond, giving it a more natural look as it spills over rocks and liners.

Be warned: like water hyacinth, Parrot’s Feather is considered an invasive species in many areas. Its ability to grow from tiny fragments makes it a serious threat to natural waterways if it escapes. Always check your local regulations before planting it, and never, ever dispose of trimmings in or near natural streams or lakes.

Duckweed: Maximum Coverage with a Warning

Duckweed is, without a doubt, the fastest-growing pond plant on this list. These tiny, free-floating plants can cover the entire surface of a quiet pond in a matter of weeks, blocking nearly 100% of sunlight from reaching the water below. If your primary goal is maximum shade in minimum time, nothing beats it.

It’s also a nutrient-removal machine and is so high in protein that it can be harvested and fed to chickens or ducks. For a purely functional farm pond, it can be a valuable part of the system.

However, you must understand what you’re getting into. Once you have duckweed, you will likely always have duckweed. It is incredibly difficult to remove completely, as even a few remaining plants will quickly repopulate. It will stick to nets, filters, and anything else that touches the water. Use it only if you are fully prepared for a permanent, total-coverage plant and don’t mind its uniform, green-carpet appearance.

Planting and Maintaining Your Algae-Blocking Plants

The strategy here is to create a diverse and layered defense. You want a combination of plants working together. Aim for a mix of surface floaters for shade (like Water Lettuce) and submerged oxygenators for nutrient absorption (like Hornwort).

Your initial goal should be to achieve 50-60% surface coverage with floating plants during the peak growing season. This is the sweet spot for blocking enough sunlight to inhibit algae without cutting off too much light for your submerged plants. Simply add a few starter plants in the late spring and let them multiply.

Maintenance is not a chore; it’s a crucial part of the nutrient cycle. As these fast-growing plants thrive, they are locking up the excess nutrients that were causing your algae problem. Periodically scooping out and composting a portion of your floating plants physically removes those nutrients from the pond forever. This prevents them from being released back into the water when the plants eventually die and decay.

Ultimately, managing a pond is about fostering a balanced ecosystem, not fighting a chemical war. By choosing the right combination of fast-growing plants, you’re not just covering up a problem; you’re creating a healthy, resilient environment where algae simply can’t get a foothold. It’s a solution that works with nature, saving you time, money, and frustration in the long run.