How Do You Take Care of a Pond Plant? Top 10 FAQs

No pond or waterfall is complete without plants. They add color and life to the water feature, softening rock edges and providing shelter for fish.

They also help keep your water clear. The more plants you add to your pond, and the wider the variety, the more nitrates they’ll pull out of the water. These nitrates will fuel string algae growth if left unchecked – so we recommend adding lots of plants to help keep your ecosystem balanced.

New to water gardening? Don’t worry! Here are some answers to common questions we hear:

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What Kinds of Plants Can I Put in My Pond?

Pond plants are plants that don’t mind having consistently wet feet. This trait makes them different from terrestrial plants, which might drown or rot if they don’t have a chance to dry out.

When choosing plants for your pond or waterfall, make sure to buy ones grown specifically for aquatic use. (This includes every plant we sell at Splash). While some terrestrial plants might do fine in the pond, sticking to aquatics will ensure the plants you pick are already accustomed to wet conditions.

Pond plants fall into a few main categories: marginals, floating, waterlilies and lotus.

Marginal Plants

Marginals are the types of plants that sit in the damp or slightly submerged margins of your pond – in the stream, on plant shelves, tucked into the rocks, etc. This is the largest category of plants and includes everything from stream and bog plants to larger varieties that don’t mind a foot or two of water.

Some popular marginals include:

> Browse more marginal plants

Water Hyacinth

Floating Plants

Water Hyacinth

Floating plants are exactly what they sound like. These plants – mainly water hyacinths and water lettuce – float freely in the pond, without soil, with their roots hanging down.

> See more floating plants

Waterlilies

Waterlilies are probably the most popular category of pond plant. Plant them in about 2 feet of water, then watch their lilypads and flowers float on the water’s surface.

> Browse waterlilies

Lotus

Lotus look a little like waterlilies, but with big flowers and leaves that grow above the water. These showstoppers like to live with their roots submerged in about 10 inches of water, or in a moist container.

> See our most popular lotus varieties

> Check out our in-depth guide to the different types of pond plants

What Kinds of Plants Can I Put in My Disappearing Waterfall?

Any marginal aquatic plant that can tolerate moist soil will do well in a disappearing or pondless waterfall.

Some popular choices include Creeping Jenny, Golden Creeping Jenny, Bog Bean, Miniature Horsetail and Pitcher Plants.

> Browse more marginal plants

What Pond Plants Reduce Algae?

Any plant you add to your pond will help reduce string algae. Reducing algae has less to do with the specific kinds of plants you use and more to do with the amount of variety you have.

Plants and string algae both feed on nitrates, a natural byproduct of your pond’s nitrogen cycle. While string algae will eat any kind of nitrate, plants only pull out specific kinds depending on the plant’s needs. A red leaf will consume a different nutrient than a green leaf, a flowering plant will use different kinds than a leafy one, etc.

The more plants you have, and the wider the variety, the fewer nutrients will be left to feed algae.

Plants are most helpful for removing string algae – the stringy, gunky stuff that clings to your rocks. This algae is different from the single-cell algae that turns water green. If you have green water, check out our guide for fixing it here. 

Note that string algae is a natural, normal, expected and beneficial part of a balanced pond ecosystem. Even with a great variety of plants, you’ll likely always have a little bit of string algae in your pond – and that’s OK!

If you still have more string algae than you would like after adding a variety of plants, try one of these fish-safe treatments:

  • SAB Stream and Pond Cleaner: A fish-safe powder that kills existing string algae on contact
  • Barley Straw Extract: Helps prevent new string algae from growing but won’t kill existing algae
  • Clear for Ponds Autodoser Pouch: If you have an Automatic Dosing System, alternate between the Maintain and Clear pouches to help reduce algae. (When using Clear, make sure not to exceed the dosage recommended for your pond size.)

How Do I Put Plants in My Pond?

You have a few options when it comes to putting plants in your pond or waterfall.

Plant Them in Your Rocks and Gravel

Pond plants will grow directly in gravel and a little bit of soil. You just need to have a pond with a rubber liner and gravel bottom. You do not need to keep your pond plants in a pot or basket – in fact, we prefer not to!

To plant directly in your pond, just move a little bit of gravel to the side, gently press the roots and a little bit of soil against the liner, then cover the base back up with rocks.

This is our preferred method of planting at Splash for most types of plants because it keeps the ponds looking natural. We’ve also found that fish are less likely to root around in plants that are directly planted than they are ones that are still in pots.

Keep Them Potted

If you don’t have gravel in your pond, or if you just prefer pots, the pots that you buy your plants in will work fine in the pond. Just make sure the pot has holes in the bottom if it’s not completely submerged so that the soil stays moist.

(Tip: Some people like to cut the top couple inches of the pot to help it blend in better.)

Use a Fabric Planter

You also have the option of moving the plant into a fabric planter made specifically for aquatic plants.

These planters are usually sturdier than nursery pots because they can flex with the growth of the plant. They also have a lower profile, helping them blend in better with their surroundings. Some even have draw strings that help you keep dirt contained.

Plant a Floating Island

Floating Island among Water HyacinthsA floating island is simply a plant pot with a kind of innertube around it to help it stay afloat.

Any plant that can tolerate moist soil will do well in a floating island. We like to use taller plants – like dwarf canna or star grass – in the middle of our islands, and fill in the edges with aquatic groundcovers – like creeping Jenny or lemon bacopa – that will spill over the edges of the island.

Floating islands work great in any pond and can be an easy way to add a variety of plant life to ponds that lack the shelves needed for planting directly in the pond.

> Check out our full guide to planting a floating island

What Kind of Soil Can You Use in a Pond?

Aquatic plants can grow in your pond gravel without much soil. If you choose to keep your plants in some kind of planter, though, you will need to use an aquatic potting media.

Aquatic potting media is denser than regular potting soil, meaning more of it will stay with your plants and out of your water. You can also rest assured that aquatic potting media will be completely safe for your fish.

Even with the right potting media, you might see a little bit of soil make its way into your pond. This is normal and will clear up on its own with help from your skimmer.

If you like to keep your pond spotless and don’t want to wait for the dirt to settle, place a Fine Filter Pad in your skimmer to catch the extra tiny particles of dirt. Simply place the pad anywhere in the skimmer where the water will pass through, then remove the pad as soon as the water is clear.

Add a flocculant like Rapid Clear for even faster results.

How Deep Can I Put My
Pond or Waterfall Plants?

The amount of water your pond plants will tolerate varies greatly depending on the plant. Some plants only like the very shallow water of a stream or waterfall, while waterlilies can go as deep as 24 inches.
 
Check the back of your plant tag for details on the exact conditions your new plant likes. The tag should have lots of other helpful information too, like the plant’s expected height and how much sunlight it needs.
 
Each of our tags at Splash also has a QR code you can scan with your phone for additional tips.
 
Lost your plant tag? Check out our plant database to find all the information you need.

How Much Sun Do Pond Plants Need?

Again, the answer depends on the specific plant.

Some – like waterlilies – will survive in full shade but need lots of sunlight to produce big beautiful blooms. Others prefer shadier spots, while most prefer some mix of sun and shade. Check your plant tag or look up the plant in our database to see what’s best for your plant.

> Check out some of our favorite shade-tolerant pond plants

Should You Fertilize Pond Plants?

Most plants in your pond will pull all the nutrients they need directly out of the water. Waterlilies and lotus, though, need a little extra help to produce big, beautiful blooms.

Fertilize your lilies and lotus about once per month from May until September. (If you bought your lily from Splash, you can wait until one month after your purchase to fertilize your plant for the first time). We use two tabs of fertilizer in each of our one-gallon waterlily pots, and three tabs in each of our lotus pots. Simply press the tabs into the soil near the base of the plant.

Fertilizer can also help plants (including marginals) that aren’t looking their healthiest. Just add a tab or two as needed until the plant looks happy.

Will Pond Plants Survive Winter?

Some pond plants will survive the winter in most parts of the U.S. Others will not. We call plants that will survive the winter hardy (perennial), and plants that will not survive tropical (annual).

At Splash, we make it easy to tell whether your plant will survive the winter in our region by color-coding the tags. Anything with a blue tag is winter-hardy here, while anything with an orange tag is tropical.

If you buy your plants somewhere other than Splash, you’ll need to look for a hardiness zone on the plant tag. Southcentral Pennsylvania is in Zone 6 – meaning any plant that is hardy to Zone 6 or lower will survive the winter here. A plant that is only hardy to Zone 8, on the other hand, will need to come indoors unless you live farther south.

Check out the map on the USDA’s website to see your region’s hardiness zone.

We recommend adding a mix of hardy and tropical plants to your pond. While you might not like the idea of buying plants that won’t grow back every year, tropicals add a variety of bright colors and unusual shapes that you won’t typically find in hardy plants. They also take different nutrients out of the water, helping to prevent string algae.

Popular tropical plants include cannas, tropical waterlilies, taro, water hyacinths and water lettuce.

> Browse more tropical plants

By the way – just because your hardy plant doesn’t spring back to life during the first warm days of the season doesn’t mean it’s dead. Some plants take time to wake up from winter dormancy. Check the back of your plant tag to see when your specific plant will bloom.

Related: When Will My Waterlilies Bloom?

Should Pond Plants Be Cut Back in Winter?

How much work you put into winterizing your pond plants is up to you.

Most hardy (perennial) pond plants go dormant when the weather starts to cool. Tropical (annual) plants, on the other hand, will often continue flowering until the first or second frost of the season.

Remove any tropical plants that you want to preserve before the nighttime temperature drops below freezing. Anything you keep in the pond past that point will die and need to be removed.

Hardy plants don’t need much prep going into winter. You can cut back tall plants if you want to keep the pond tidy or need to install netting, or you can leave them be and let the birds and wildlife use them for winter food and shelter.

(Have pitcher plants in your pond? Check out our specific tips for winterizing them here.)

By the way – you don’t need to “sink” your waterlilies in winter. Hardy lilies will generally survive the winter just fine in the same water depths where they spend the summer (about 18 to 24 inches deep).

> See more tips for getting your pond winter-ready