Marginals and Bog Plants

Marginals and Bog Plants

Why are aquatic plants good for filtration?

Mother Nature knows what she is doing!   She uses aquatic plants all the time!

Not just a pretty face - Aquatic plants absorb nutrients from the water. Nutrients like nitrogen and phosphorus, (a  byproducts of fish waste and decaying organic matter).  When there is standing water, there is an aquatic ecosystem.  Whether this ecosystem is pleasing to humans or not, depends on if the water looks clear and clean or not.  The nutrients in the water will be used by something.  If it's not the aquatic plants humans like, it will be ALGAE! 

Aquatic plants absorb these nutrients for and use it to flower and grow, effectively competing with algae for these resources.  This process not only helps in maintaining clear water but also improves the overall water quality, making the environment healthier for aquatic life.

The roots of aquatic plants  also serve as an ideal habitat for beneficial bacteria and other microorganisms. These microorganisms play a critical role in the breakdown of organic materials and detoxification of harmful substances in the water.  Aquatic plants use nutrients in the water and provide more surface area for beneficial bacteria too!

What are "Marginal" Plants?

 These are plants whose roots can be in the water, but the foliage is above the water.  Regular (terrestrial) plants would die if you had their root ball wet like this all the time. 

BUT there is a difference between marginal plants and bog plants!

Marginal = Plants that can have their soil line under the water more.  They are considered emergent plants because the root ball is under the water and they are emerging out form the water.  The soil line might be 6 inches under the water.

These plants are fantastic for filtering the water because they use up nutrients in the water that would otherwise be consumed by ALGAE! (cause really, algae is a plant too...) Scroll through to see photos and descriptions of great aquatic plants. 

What are "Bog" Plants?

Bog = plants that like to be in wet dirt or rocks, with their soil line right at water level or a few inches under. 

These plants are knows as Zone 1 plants (for aquatic planting.) and are perfect for wetlands and bogs that are filtering your pond. 

Arrowhead

or Arrow Arum
Botanical name: Peltandra virginica

Hardiness Zone: 5 – 11

Perennial (it will come back each year) 

Planting Depth/Habitat: Marginal, Zone 2. 0 to 6 inches.  Plant should be out of the water. The crown can be in the water. 

Size:  6 to 12 inches

Flowers: They do develop little white flowers

Tags: Marginal Plant, Planting depth Zone 2, Hardy in Colorado

What to Know:

Arrowheads bring texture and depth with their arrowhead shaped leaves.  The flowers are not the main attraction.  They are hardy to zone 5, which means they can survive when it gets as cold as -20 to -15 F.  Would help if an upside down pot was put over the crown from Jan – February. 

Take it out of the pot and put some 4 to 5 inch rocks around it to hold in place and protect from curious fish.  No need to leave in the pot.

It may spread a little, but it is not a vigorous spreader.  It likes a little shade too. 

Bloody Dock

or Water Dock
Botanical name: Rumex sanguineus

Hardiness Zone: 5 to 12

Perennial or Annual:  Perennial

Planting Depth/Habitat:  Bog Plant, planting one 1, 0 to 3 inches.  Plant leaves should be out of the water, crown in the water. 

Size:  6 to 18 inches tall

Flowers:  Not really. 

Tags:  Bog Plant, Planting depth Zone 1, Hardy in Colorado

What to Know:

A Bloody Dock plant has interesting leaves.  It likes very shallow water, but beware, if you plant it when the pond is full and the water level drops, this plant may suffer.  Find a place where the water movement is not a lot, but where the water levels wont’ fluctuate much. 

If it starts to get tall and spindly, going to seed, cut off the seed stem to help it grow more bushy. 

To plant, Take it out of the pot and put some 4 to 5 inch rocks around it to hold in place and protect from curious fish.  No need to leave in the pot.

Bulrush

or Common Rush
Botanical name: Juncus effusus

Hardiness Zone:  4

Perennial or Annual: Perennial

Planting Depth/Habitat:  Marginal, Planting depth Zone 2.   2 to 5 inches above soil line.  When they are mature they will go deeper. 

Size:  2 to 4 feet, it s a spreader!

Flowers: not really

Tags: Rush, Marginal Plant, Planting depth  one 2, Hardy in Colorado

What to Know:

This is a nice vertical plant that is great in larger ponds to add a lushness to the edge.  Dragonflies love bulrush! 

The rushes are round like onion plants and one sign that it is Bulrush is the little doodad at the top that it develops. 

Be careful though, it can try to take over if not watched.  It doesn’t like the deeper water so that does help. 

Cardinal Flower

or Lobelia
Botanical name: Lobelia cardinalis

Hardiness Zone:  3 – 9

Perennial or Annual: Perennial

Planting Depth/Habitat: Bog plant, Planting Zone 1 or 2. 3 to 6 inches

Size:  it can get as tall as 4 to 5 feet! When it is doing well it can spread 1 to 2 feet. 

Flowers: RED!

Tags:   Planting Zone 1 or 2, Bog Plant, Hardy in Colorado

What to Know:

If you want to attract hummingbirds this is your plant!  It’s tall flower spikes will last for weeks!  This plant also likes partial shade/partial sun

Good area to plant is tucked in areas in the stream. 

I recommend planting a bunch together, I think they look better that way. 

Cattail - Dwarf

Botanical name: Typha minima

Hardiness Zone: 3

Perennial or Annual: 2 to 3 feet

Planting Depth/Habitat: Bog Plant.  Planting Zone 1. Loves wet muddy soil.  2 to 6 inches.

Flowers:  corndog looking things. (stiff flower stalks)

Tags:  Bog Plant, Planting Zone 1, Hardy in Colorado, Invasive

I really don’t understand why they aren’t called “Corn Dog plants”.  Wait, they were probably named before corn dogs were invented…that’s why! 

What to Know:

Stems leaves are flat, similar to garlic. Thrives in standing water.  They are a very nice border in a larger pond and aquatic life loves them. 

These can spread.  Caution – do not plant in regular standard cattails if you have a pond smaller than 100 feet.  They can seriously take over.  Be careful even with miniature or dwarf cattails as they spread easily. 

Unless you are super hands on with your pond, or do not paying extra money to remove cattails (they are super hard to get out!) – do not use cattails at all! 

Chordata Chameleon

Botanical name: Houttuynia cordata ‘Variegata’

Hardiness Zone:  5 –  10

Perennial or Annual: Perennial

Planting Depth/Habitat: Bog plant, Planting Zone 1, 3 to 6 inches

Size: 6″-12″ in.

Flowers: tiny white, but that is not the main interest with this plant. The first photo shows Chordata Chameleon between impatiens. 

Tags:   Bog Plant, Planting Zone 1, in Colorado

What to Know:

This little plant has such beautiful leaves (leaves mottled with green, yellow and red.) and will spread (but not too much) through rocks on the edge of a steam and look so nice near a bridge as it will go somewhat under it.  This plant really softens edges.

(photo is the green and red-ish leaves, not the pink impatiens!) 

Good area to plant is tucked in areas in the stream. 

Don’t crowd this plant too much as it won’t put up a big fight!

Cork Screw Rush

Botanical name: Juncus effusus ssp. spiralis

Hardiness Zone:  3 – 8

Perennial or Annual:  Perennial

Planting Depth/Habitat: Bog plant, planting zone 1.  6 inches down is as deep as you could go. 

Size:  1 to 1 1/2 feet tall

Flowers: Not really.

Tags: Bog Plant, Planting Zone 1, Hardy in Colorado

What to Know:

These spiral type leaves have a crazy look for variety in your pond plants.  If you really like things looking nice and tidy, these might not be for you.  

One variety, the Blue Medusa looks similar with a deeper blue/green color in the stems. 

Photo credit: https://www.robsplants.com/plants/JuncuEffus

Creeping Jenny

Botanical name: Lysimachia Nummularia

Hardiness Zone:  3 –  10

Perennial or Annual: Perennial

Planting Depth/Habitat: Bog plant, Planting zone 1.  0 to 4 inches 

Size: 2″-14″ in. can spread 2 to 4 feet!

Flowers: little yellow flowers

Tags:   Bog Plant, Planting Zone 2,  Hardy in Colorado

What to Know:

This a fantastic plant to soften up edge or hide a little liner that might be showing.  

You’ve probably seen this as a terrestrial plant.  You might have also seen the same plant name, and the plants looks somewhat different. Here is the secret: although they look slightly different and the aquatic plant costs more..THEY ARE THE SAME PLANT!  YES!  They are darker green when planted in soil and lighter when planted in water.  

Just buy the cheep ones at Walmart (not kidding!) like I do and put them everywhere.  Not invasive, they spread just the right amount!

Forget Me Not

Botanical name: Myosotis Scorpioides

Hardiness Zone:  3 – 9

Perennial or Annual:  Perennial

Planting Depth/Habitat: Bog Plant, 2 to 4 inches, but great stuck between rocks even in the stream. 

Size:  1 to 6 inches

Flowers: Yes!  tiny blue flowers everywhere!

Tags:  Bog Plant, Planting zone 1, Hardy in Colorado

What to Know:

Make sure you check the zone and color as these come in different varieties.  They come in pink and white but I love the blue! 

These guys have been spreading up my stream in  most perfect way!  

Horsetail Rush - Dwarf

Botanical name: Equisetum scirpoides

Hardiness Zone:  4 –  9

Perennial or Annual: Perennial

Planting Depth/Habitat: Bog plant, Planting Zone 1.  1 to 3 inches

Size: 8″-12″ in. 

Flowers: Not really

Tags:   Bog Plant, Planting Zone 1, Hardy in Colorado

What to Know:

Make sure you don’t get the full size version of this.  They spread and can be invasive.  The Dwarf Horsetail Rush gives an interesting look with its jointed, hollow stems. They say they are evergreen but often turn brown in the winter. 

Great on the edge in very shallow area for a larger pond.  Will be a great filter. 

Deer don’t care for this plant much, or so I’ve heard. 

Lizards Tail

or water dragon, or breastweed
Botanical name: Saururus cernuus

Hardiness Zone:  3 – 9

Perennial or Annual:  Perennial 

Planting Depth/Habitat: Bog and sometimes Marginal when mature. Planting Zone 1.  2″-6″ in.

Size: 1′-3′ ft

Flowers: White

Tags:  Bog Plant, Planting Zone 1, Hardy in Colorado

What to Know:

Easy to put in, just put some gravel on the roots to hold in place, the plant will do the rest.  I love the spiky tail of white flowers! They have a citrus-y smell to them, which is nice. 

Loosestrife - Yellow

Botanical name: Lysimachia Punctata

Hardiness Zone:  4 – 8

Perennial or Annual: Perennial

Planting Depth/Habitat: Bog plant, Planting Zone 1, 1 to 3 inches

Size: 2 to 3 feet tall 

Flowers: Lots of yellow flowers! 

Tags:  Bog plant, Planting Zone 1, Hardy in Colorado

What to Know:

Butterflies love these flowers!  Shallow wetland plants, hides even large rocks.  Beware, it could spread – a lot, so make sure you keep in check or have a large pond when you use this plant. 

Louisana Purple Iris

or water dragon, or breastweed
Botanical name: Saururus cernuus

Hardiness Zone:  4 – 9

Perennial or Annual:  Perennial 

Planting Depth/Habitat: Bog Plant, Planting Zone 1, 2″-4″ in.

Size:  2 to 3 feet when mature. 

Flowers: velvety dark purple

Tags:  Bog Plant, Planting Zone 1 Hardy in Colorado

What to Know:

There are a variety of purple irises.  Louisiana Iris Black Gamecock is one of my favorite!  They are the really dark purple.  

Iris of any kind can be invasive, so be mindful about where you place them and know you may have to cut out tubers if they get going too much. 

They are a wonderful part of natural plant filtration and even when they are not in bloom they are beautiful. 

These plants bloom a bit later than the yellow iris because they like heat. 

Plant terrestrial irises just outside the pond near where the water irises are going for an almost seamless look. 

Marsh Marigold

Botanical name: Caltha palustris

Hardiness Zone:  3 – 8

Perennial or Annual: Perennial

Planting Depth/Habitat: Bog Plant, Planting Zone 1, 1 to 3 inches

Size: 12 to 18 inches. (height and spread) 

Flowers: Yellow flowers in the spring, 1st to bloom! 

Tags:  Bog Plant, Planting Zone 1, Hardy in Colorado

What to Know:

These will be the first plants to bloom in the pond!  I recommend planting and odd number all over the pond!

The waxy green leaves are lovely even when not in bloom.  There are several varieties to choose from and the Giant one can block the pond view if you are not careful where you plant it!

Mint - Aquatic

or just mint.....
Botanical name: Mentha aquatica

Hardiness Zone:  4 – 9

Perennial or Annual:  Perennial 

Planting Depth/Habitat: Bog plant, Planting Zone 1,  2″-4″ in.

Size:  8 inches to 18 inches. 

Flowers: tiny, light purple

Tags:  Bog plant, Planting Zone 1, Hardy in Colorado

What to Know:

I love to plant this where I can easily reach it to break off some leaves to put in my tea! 

This is so easy to grow.  Just put the root ball 1/2 way into the water or all the way in and prop with rocks so it doesn’t move! That’s it! Pollinators are attracted to the flower of the mint so you will see bees and butterflies on it. 

Mint can be invasive, so keep and eye on it and pull any that is heading where you don’t want it to go. Keeping an eye on it may not even be good enough…so if you are really hands on and want to try it – go for it.  If not, stay away from mint!

Obedient Plant

or False Dragonhead
Botanical name: Physostegia

Hardiness Zone:  5 – 11

Perennial or Annual: Perennial

Planting Depth/Habitat: BOg Plant, Planting Zone 1 Soil line right at waterline or a couple inches below. 

Size:  can get 2 to 4 feet tall!

Flowers: lavender-pink (can get it in white too) 

Tags:  Bog Plant, Hardy in Colorado

What to Know:

The obedient plant is semi-aquatic in that it really needs shallow water or soil that is moist. Its lavender-pink spikes of flowers are a big attractant for butterflies, bees, humming birds and other pollinators. Grow near the edge of the pond. 

It does prefer full sun. Fertilize once a month in the summer. (use fertilizer tabs!) 

Pennywort

Botanical name: Hydrocotyle verticillata

Hardiness Zone:  5 -11

Perennial or Annual:  Perennial 

Planting Depth/Habitat: Bog Plant, Planting Zone 1,  2 inches

Size:  up to 10 inches, but usually low lying.  Creeping spread

Flowers: no

Tags:  Bog Plant, Planting Zone 1, Hardy in Colorado

What to Know:

Plant these as shallow as you can.  The mature plant will grow out into the water and will develop floating mats of leaves. 

If you put in in a side area in the stream it will eventually cascade down the stream! 

There is a also a variety that looks different than this, the variegated Pennywort. 

Pickerelweed

Botanical name: pontederia cordata

Hardiness Zone: 3-10

Perennial or Annual:  Perennial 

Planting Depth/Habitat: Bog Plant, Planting Zone 1, Soil line right at waterline – I’ve got mine even deeper. 

Size:  10″ to 4 feet!

Flowers: spiky blue/violet

Tags:  Bog Plant, Planting Zone 2, Hardy in Colorado

What to Know:

This aquatic gem, has luxuriant, glossy foliage resembling arrowheads and showcases striking spikes of blue-violet flowers, each measuring 4-6 inches.

These blooms are a magnet for hummingbirds and butterflies. It blooms well into October! 

Pitcher Plant

Or Sarracenia Bug Bat
Botanical name: Sarracenia

Hardiness Zone:  5-10

Perennial or Annual: Perennial

Planting Depth/Habitat: Bog Plant, Planting Zone 1,  Soil line at water line.

Size: 8 inches 

Flowers: The foliage of these plants are red and green – it might flower a little, but the pitchers are what is interesting. 

Tags:  Bog Plant, Planting Zone 1, Hardy in Colorado  (barely!)

What to Know:

This is a carnivorous plant!  Yes!  It lures bugs into the pitcher and then dissolves them for a snack!

It is really a Zone 5 plant ( we are Zone 4 here on the Front Range in Colorado) but, if you have a protected and sunny space it might work.  I had one in our pond for about 3 years when a really bad cold spell finally got it. 

Purple Loosestrife

Botanical name: Lythrum salicaria L.

Hardiness Zone: 3-10

Perennial or Annual:  Perennial 

Planting Depth/Habitat: Bog Plant, Planting Zone 1, Soil line right at waterline – I’ve got mine even deeper. 

Size:  8 feet!

Flowers: spiky pink/violet

Tags:  Bog Plant, Planting Zone 2, Hardy in Colorado

What to Know:

Bees love this but, it seeds readily and can produce over two million wind-dispersed seeds per year!
The flowers has pink-purple petals and produces tall flower
spikes and stands up to 8 feet tall.
 Purple loosestrife can displace
native vegetative communities.  

So because of that, I’m going to recommend staying away from it.  I listed it, because it does come up and pond people should know what hey are planting! 

Sensitive Plant

Or Mimosa
Botanical name: Neptunia Aquatica

Hardiness Zone:  9-12

Perennial or Annual: Annual

Planting Depth/Habitat: Bog Plant, Planting Zone 1,  Moist soil, to over 4″ above crown. 

Size: 3 to 5  inches but in warm waters can spread 1 to 5 feet!

Flowers: Might get little pink or yellow bloom.  The leaves of these plants are are very delicate and close when you touch them! 

Tags:  Bog Plant, Planting Zone 1

What to Know:

The Sensitive Plant is not usually sold as an aquatic plant here in Colorado.  It’s usually sold as a terrestrial plant. When kept in a normal pot they grow up and get very spindly.  They are fun though because then will close down when touched and look like dead sticks!  It takes a while for them to open back up.  They need a lot of water as that is how they open up and close, through the movement of water in their branches. 

In the water they grow out and lay on top of the water.  Very cool!  These are a small plant and are good in a pond if the pond is small and you can put it in a place where you can walk up and get a good look at it. I have never seen them spread far as the water temperatures aren’t high enough for long periods of time. 

Sweet Flag

Or Golden Sweet Flag
Botanical name: Acorus Gramineus ‘Ogon’

Hardiness Zone: 4-11

Perennial or Annual:  Perennial 

Planting Depth/Habitat: Bog Plant, Planting Zone 1, Soil line right at waterline – 

Size: 6″-1′

Flowers:  No

Tags:  Bog Plant, Planting Zone 1, Hardy in Colorado

What to Know:

Sweet Flag has a citrus scent when it is bruised or pinched.  (I don’t know why we would go around pinching it…)

Its grass like leave are sword shaped and bright.  Adds great texture to the foliage at the pond.  Adds to the filtration and clarity of the water!

Thalia

Or Red Stemmed Alligator Flag
Botanical name: Thalia geniculata ruminoides

Hardiness Zone: 8-10 

Perennial or Annual:  Annual

Planting Depth/Habitat: Bog Plant, Planting Zone 1, (2 to 6 inches down) 

Size:  4 to 6 feet!

Flowers: violet

Tags:  Bog Plant, Planting Zone 1, 

What to Know:

Broad leaves are gorgeous!  An annual here in Colorado, it may not have time to get super tall.

Blooms are violet and bloom out taller than the plant.

Water Celery

Or Variegated water celery
Botanical name: Oenanthe javonica

Hardiness Zone:  5-11

Perennial or Annual: Perennial

Planting Depth/Habitat: Bog Plant, Planting Zone 1,  Soil line at water line.

Size: 1-2 feet 

Flowers: tiny white flowers

Tags:  Bog Plant, Planting Zone 1, Hardy in Colorado

What to Know:

Alright, yes, this is a great filter plants….However, this plant is extremely invasive.  That being said, in some situations it is perfect.

Stay away from Water Celery if it is an area you may want other plants (ever)!  We put in one small plant and when it started spreading, I thought we should take it out.  But we didn’t.  I will be forever pulling this plant out!  It traveled its way up the stream trying to crowd out other plants. 

It can really wind its roots through rocks and tight places which is what makes it so hard to get out. 

So when is it perfect?  When the pond has steep sides, no shelves, and no way to plant plants.  Put this plant in as best you can so the roots touch the water.  Then just stand back.  First year you’ll have amazing growth and will be pleased.  2nd year you will be amazed that it is growing out of places you can’t even reach! Read my Water Celery Epiphany HERE to find out more. 

Water Iris

Or Red Stemmed Alligator Flag
Botanical name: Thalia geniculata ruminoides

Hardiness Zone: 3-9

Perennial or Annual:  Perennial

Planting Depth/Habitat: Bog Plant, Planting Zone 1, (0 to 6 inches down) 

Size:  2 to 4 feet

Flowers: Yellow is the most common in Colorado but iris come in most colors.

Tags:  Bog Plant, Planting Zone 1, 

What to Know:

Iris are a staple pond plant. They add so much to the natural filtration process.  They bloom in the late spring (depending on the variety you have).  After blooming their green broad leaves are still beautiful. 

For a relaly lush look you can plant terretrial 

Yerba Mansa

Botanical name: Anemopsis californica

Hardiness Zone:  5-9

Perennial or Annual: Perennial

Planting Depth/Habitat: Bog Plant, Planting Zone 1,  2 inches below water (soil line) 

Size: 6 to 12 inches

Flowers: white flowers

Tags:  Bog Plant, Planting Zone 1, Hardy in Colorado

What to Know:

The long center coned flowers are very white.  These are not invasive and have been coming back in our pond every year.