Question about Marginals - redoing my pond and need advice

(karen) Little Rock, AR(Zone 7b)

I am redoing my pond and I really want to have a very shallow ledge around the edge for planting marginals. I don't want them to be in pots just planted directed into some sand or gravel around the edges. I was thinking of about 5-6 inches deep but I saw somewhere that 10-12 inches of water was best for marginals. I really want the edges to look like a natural pond where the water just laps up to the rocks and plants are growing along the bank.

Is this going to be too shallow to plant marginals in? I'll have a shelf further in that will be about 10-12 inches deep but I'm not going to want to see the line for 12 inches all around the pond.

Athens, PA

kjuddy -

You can very easily do this. We did this and have our shelf/bog area at about 10-12". We foamed in rocks standing straight up to hold pea gravel and the plants are planted directly into the pea gravel. You could have the different levels you want for the different marginals that require different depths if you want. We just cut all the marginals back in the fall - Novemberish for my zone, so that we dont' have a lot of dead decaying plants in the pond during the winter.

The thing that is nice about this is the extra filtration this lends to the pond. We have 4 sides with different areas that are set up this way and the larger area has a small pump running directly into the larger shelf/bog area - this also helps to filter the water.

I say go for it....there are a lot of different plants that thrive in this type of a set up - water celery, water iris, pickerel weed, water hibiscus, acorus.... the list is endless.

(karen) Little Rock, AR(Zone 7b)

Carolyn thanks for the info I guess my real question is does the shelf for marginals NEED to be 10-12 inches or can it be more shallow like 5-6 inches if I am planting directly into it?

Athens, PA

If you can have the shelves at 10-12" deep, I would. That would be more filtration....

Frederick, MD(Zone 6b)

Carolyn, I don't know if you used a liner in your pond, but if so... Did you run the liner under your shelf/bog area also? Or is the pea gravel directly on top of your soil base, so that the marginal plants can send their roots down into it if they want -- I don't know if they need "dirt" or not, maybe they get plenty of nutrients from the pond water. ?

Athens, PA

Jill -

My liner is under the shelves as well. I have not had any issues yet with no soil for the plants to put down root. I do think the water celery is indestructible. I noticed there are some areas on the outside of the pond where the water celery has jumped outside of the pond and rooted. I usually just mow right over it.

Frederick, MD(Zone 6b)

Cool. I got some water celery in my order from TWL, and it went into shock I think... but I don't think it's quite dead, because I see a couple of little green shoots. I hope it re-establishes, because I think you're right about it being one of those plants where, once you have it, you've got it permanently.

(karen) Little Rock, AR(Zone 7b)

Thanks for the help - I actually finished up the pond today - well not finished but finished digging and lined it and filled it with water. I'm goning to let it sit for a couple of days to make sure everything is okay then work on the waterfall and hope to finish in a couple of weekends. I decided on about 6-8 inches at the top level 10-12 at the second level and then 24 or so in the deepest part of the pond. Hopefully, I'll have some pics soon!

(Mary) Anchorage, AK(Zone 4b)

I have had water celery up here planted in tubs that hang from side rock just below the surface. I don't have any shelf (drat). It went nutso and spread across the surface of the pond fairly quickly. Got into the cracks of the rock wall even. Kind of miserable to get out. The good side is that come winter, it dies. Bad side is that I really had to work to get it out so that it wasn't rotting in the pond all winter. but the fish love it. Can't get fat fish eating celery. lol. Did the same with pickeral grass and dwarf cat tails. TWL has a great selection. I have tried planting in panty hose and stuffing in cavities in the rock with mixed success. After Carolyn's comments that stuff would grow in pea gravel I am eliminating the dirt from the pond.

Frederick, MD(Zone 6b)

Thanks for the input -- if my water celery survives, I'll know what to expect!

Frederick, MD(Zone 6b)

Carolyn, I just googled your location -- dang, you're almost in NY! I guess you won't be driving down for the VA spring plant swap, maybe not for the eastern PA one either... but check the threads on the mid-atlantic forum, just in case! I was going to see if I could bum some water celery from you at one of the swamps... mine looks like it's croaked; maybe I needed to do a better job acclimating it?

I'm sure I'll be tempted again by some lovelies in the TWL sale next year, so I can order another start of water celery and try again. The horsetail seems to be doing OK but hasn't grown any roots down into the pot yet... mini cattails are also hanging in there. Hopefully they'll be rarin' to go by the time I actually get my bubbler bog built!

Lakewood, WA(Zone 8a)

I, too, have a marginal area filled with only pea gravel, and the water is only about 6 inches deep in some areas. At the very front edge, the water barely makes it above the gravel. There is no dirt in my pond at all because I got tired of cleaning it all the time when the koi tip over pots. My water celery grows fine in just a few inches of water with the gravel alone. I also plant some water lilies directly into the gravel since I never get enough heat and sun for them to really get out of control. I also have some short native reeds that grow well there. I've had LA iris planted in the gravel (they grow nicely but hardly bloom here so I ripped those out after about 8 years of trying), and I have a variegated water iris that likes it there, too.
I say go for it. You won't regret getting the soil out of the pond.

Omaha, NE(Zone 5a)

So... who is "TWL"?

Athens, PA


I wish I was going to the swaps this year - It would have nice to go to Terri's down in the Poconos, but there is already so much that is going on! If you want, I can send you some water celery. Just dmail me your addy.

TWL is 'Texas Waterlily'. They do a co op each year. I have only heard good things about them, however I have never ordered anything from them.

Dallas, OR(Zone 8a)

I have marsh marigold planted in the shallow places and rock crevices, They are the first plant in the pond every spring. I love them.

Thumbnail by BeaHive
(Mary) Anchorage, AK(Zone 4b)

I have ordered from TWL for four years and they are prompt, dependable, and always send extras. Freight is very reasonable, even to me up here. I am having the outfit that built my pond come over and do an estimate to redo the edge of my pond. The one end is simply sluffing into the pond. Poor design. May pay them to remove the gravel bottom and say myself the backbreaking labor. Plus they will do it faster. For sure all pots are coming out and dumped, then refilled with either pea gravel or kitty litter. Same with any pots that hang from sides (no shelves). I also am seriously sick of dirt dumped into my pond. Mostly by me not my fish.

Frederick, MD(Zone 6b)

Let's hear it for having somebody else do the "heavy" work! Good plan.

Carolyn, thanks, you've got Dmail!

(Mary) Anchorage, AK(Zone 4b)

And by the way, Beahive, your pond is lovely. I really like your plants around it. Maybe it's just because it is so dead out there right now, but my pond looks so stark. i have to look at old pictures to remind me it really is rather pretty in the summer

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