Shop Products
Houzz Logo Print
njbiology

Ideal Depth of Bog-Garden? 16-18', 24', or 30'?

njbiology
18 years ago

Some sources say that a bog garden should, ideally, by 2.5 feet deep - i think that sounds like over-kill.

Of course, too shallow would cause problems with insufficient water-retention and overwintering[?]

I live in zone 6b [NJ], where we can go down to -15f. What do you think I should make my peat/sand bog garden, without going anyfurther in depth then is useful/ideal?

i think my frostline is 18"

Comments (14)

  • njbiology
    Original Author
    18 years ago

    quick note: although 16"/18" is fine for most root systems, as a minimum, what is the best depth [zone 6] - for instance, would plants do better if its 24" then if it's 16"?

    [plants like marsh-marigold, orchids, and CPs]

  • sal_mando
    18 years ago

    Man, you are totally obsessed with this bog depth issue:) If you just really need someone to tell you the absolute one number for how deep to make your bog, I'll be happy to do it.

    Here is the formula for bog depth:
    (18 divided by your zone)*6 = depth in inches

    Don't vary from that or EVERY PLANT WILL DIE AN EXCRUTIATINGLY HORRIBLE DEATH!!!!! I mean it, there will be a lot of wailing and gnashing of the teeth and similar bad stuff like that. Better follow that formula. It looks like science, doesn't it? Must be real.
    (You may want to bury a unipolar magnet under there, too, just to be on the safe side.)

    Hope that helps,
    Bob

  • njbiology
    Original Author
    18 years ago

    although i am unaffected by what you wrote, i can point out that there are specifications of inches of water above certain aquatic plants' crowns - some will rot in 4" but thrive in 2".

    as for depth in a bog garden, if one were to make theirs 10", cardinal flower root-systems would not reach their potential - so, id like to know EVEN IF, though not, 'just to know' if there is an advantage to 2 feet depth over 1.5 feet.

    if we just learn/discover things that are, entirely, practical or appl., then we would still be in the 7th C. B.C.

  • sal_mando
    18 years ago

    I apologize that my attempted humor came off as snotty. What little point I had was that there is probably as much art as science to some of this, and that at some point you have to just decide to dig that hole and hope for the best. I don't know if enough people have done this sort of thing, enough times, in the right zones for there to be any good data on the absolute best way to do it.
    I am in the process of building my first bog (peat based for carnivorous plants), and I never imagined how much work goes into the construction of one of these things. I don't think that it could ever hurt to make it as deep as time, your back, shovel and budget will allow. I am making mine 18" because I had heard that number a few times and it worked out with the size hole that I wanted and the cost of the liner. Is it the best depth? I guess I'll know if it is good enough in the next couple of years. I can imagine a lot of other variables - sunlight, late night marauding animals, pollution - having more impact than depth.
    I did not mean to offend you, and I will try to refrain from attempting humor late at night.
    Good luck with your bog.
    Bob

  • kwoods
    18 years ago

    Well..... I laughed.... was that wrong? ;-)

    I can't tell you what to do either but I can tell you what I did. I've had an artificial bog for five years now after moving from an area where I used to grow bog plants plunked right in the wet ground. I grow terrestrial orchids and CPs mostly.

    I built a small retaining wall with stone so I didn't have to do too much digging. The resulting "hole" ended up being around two feet deep (sorry, I don't usually measure these types of things, coulda been more or less). I lined that with some old thick carpet so tree roots wouldn't be able to get through easily and so the liner wouldn't be otherwise compromised. I lined that with a PVC liner. I then filled the bottom 6"-8" inches (appx., again sorry didn't measure) with foam packing peanuts, this is so there is always water in the bottom but the peat does not rot. I cut just a couple slits around 2" (there I go not measuring again) from the top of the liner. I OVER-filled the rest with 50/50 (again appx., I really hate measuring) peat sand mixture by around 6". Some areas of the top where I wanted calopogon or rose pogonia I topped with additional sand. When I plant certain things (eg. Cypripedium) I might amend the mix to make it drain a little faster/slower. A fairly large area outside the liner also stays wet (amended with the same peat/sand mixture) and I use that to grow additional bog plants and orchids. Most of the surface I "mulch" with long fibered sphagnum each spring. In winter I lay a large burlap "blanket" on top of the whole deal and mulch with leaves. In five years I've lost one beautiful Darlingtonia (I still miss her) and a few thread leaf sundews. I'm in a slightly colder microclimate of zone 7 on the North shore of Long Island and I grow lots of southern CPs that have done real well. I have around 30 CP flowers getting ready to blossom.

    Hope this helps some, again sorry for all the approximations.

  • kwoods
    18 years ago

    By the way if you're in Jersey you've gotta make it down to Webb's Mill in South Jersey. It is UNREAL this time of year and worth whatever trip you might have to make. Good luck with your bog!

  • plantfreak
    18 years ago

    KWoods,

    I like your idea about foam peanuts at the bottom of the bog. I do a similar thing by putting a pumice like material at the bottom of my little container bog and put the bulk of the organic material towards the top where most of the roots are anyway. Your bog sounds very interestings, it would be fun to see it in its full glory.

    Another consideration about depth is the water holding capacity of the bog. In this regard, I think bigger is better since we want it to hold water. When I lived in Florida I had bogs in various sized kiddy pools. In the dry season (April-May) the smaller pools would constantly be drying out and I had to water using mineral ladden well water. Once the summer rains kicked in, no problem, but the dry periods were difficult. So I say give that bog some depth! PF

  • dzs1945
    18 years ago

    for KWoods,Whats at Webb's Mill in South Jersey?
    daniel

  • njbiology
    Original Author
    18 years ago

    Hey, Bob. It's ok.

    I dont know if i prefer CPs to things like rushes and arrums - id like to use some soil.

    also, i dont think that peat really rots much - and even with the styrofoam, that means there is a vault of aerobic water and that might be more bacteria infested then rotting peat.

  • kwoods
    18 years ago

    Hi PF,

    Just got a digital camera and took a bunch of shots of some of my currenty blooming orchids. I'll get some shots of the bog and post 'em when the CPs start blooming.

    daniel, Webb's Mill is a beautiful bog that has loads of interesting stuff in it.

    NJbiology, you're worried about aerobic water in the bottom of your bog but you're going to put soil in your mix? The idea behind an acid peat bog is that the mix is pretty much nutrient poor/anaerobic, adding soil is going to introduce more nutrients/microbes/bacteria etc. than just about anything else I can think of. Thought you were looking for info on acid peat "true" bog. Guess it depends on what genera you are planning to grow, some interesting things can be learned through trial and error, let us know how things turn out.

  • njbiology
    Original Author
    18 years ago

    Well, i wanted to only use peat and sand, but i think the pH will be too low and make growing arrowhead, arrum, and pickerel plant unlikely/impossible.

    considering that some people grow these in a bog, they must be using soil - maybe if i stop the liner 4" from ground level - so that no water can be left standing and the upper 4" will not be soggy - maybe, then it wont smell or cause rot - anyone have any ideas on this - cause i dont think the plants that i grow in the pond as marginals would survive the acidity of straight peat and require more nutrients - in fact, i should mention, im going to have a separate bog for CPs and in that will only be peat and sand - but i need to completely surround my 32 x 20 pond with a bog - 2 feet all around - and i dont think CPs and orchids would be a good idea for this, since in nature i would find more things like arrowhead and arrum, instead of orchids. So, i need to figure out a substrate that will not be a problem in terms of smell and in terms of growing the typical pond edge plants.

    a few feet from the pond, i will design an informal CP bog which will appear to be an extension of the bog that surrounds the pond.

  • sal_mando
    18 years ago

    Now I finally understand. You are going to have both a true bog (peat and sand, low pH, little to no standing water) and a wetland (neutral pH and standing water). I have thought all along that you were talking only about a true bog.
    If you are going to build an environment for arrowhead etc, you won't need any peat in that. They like mud. You still don't want a lot nutrients in there because of the stink factor. For those sorts of plants, then it will make a difference how deep it is because of the different water depths that the plants need.
    You are going to put a 2' wide bog around the whole 20'x32' pond? Wow, that is a huge pond and a lot of digging. I wish I had that kind of room. But I wouldn't want to do all that digging. I hope that you can post pictures someday. And I definitely want to see KWoods pictures, too.
    Bob

  • kwoods
    18 years ago

    NJbio,

    now I get it! Cool idea. I grow lots of things that have different ph requirements and what I do is create little pockets or areas for them and vary the drainage, mix, ph etc. I alter ph with lime, sulphur, vinager water and keep a close eye on it with a ph meter.

    I also saw your other posts asking about orchids and soil mix etc. I take a slightly different approach, I first figure out what I want to grow then I research (often obsessively) the conditions it needs to do well. If you can match conditions for a single species chances are there are a lot of associated plants that will grow under those conditions as well. Google thuja bog, or northern white cedar associates and see what grows there for instance.

    All right you guys I didn't have any pics of the whole bog but I posted some of it's residents and other things I grow on the woodlands forum. Hope I did it correctly.

    Here is a link that might be useful: Orchid pics

  • plantfreak
    18 years ago

    The word "bog" really is too vague. Even "true" peat bogs come in all different varieties, althought the conditions in each are very similar. I totally agree that trying to grow pickerel weed, etc in a peat based acidic bog is not the best idea. They may make it, but they will never thrive. For example, I tried growing cardinal flower in a straight peat based, nutrient poor bog once and it wasn't that happy.

    I don't mean to hijack the thread, but nice pics KWoods! Your calceolus has most likely got macranthos in it, so it is probably the natural hybrid x ventricosum. It is beautiful. That really short guy with the inflated lip looks like C. tibeticum to me, what did you buy it as? All are very nice plants. PF

Sponsored
Maruca Design / Build
Average rating: 4.8 out of 5 stars20 Reviews
Exceptional Residential Design and Remodeling Services in Fairfax