Carnivorous Plants/Outside Planter
QUESTION: I want to place a permanent planter in my garden using a 55 gallon garden pond, kidney shaped. I want to dig the whole in s box, place weed block on the hole then put the pond in. I plan to stone on top of the plastic. I have peat and organic perlite. What do I need to do to this setup to be successful? Also, how many plants could I plant? I have 1 pitcher, 2 sundews and a Venus. I live in NW Ohio.
ANSWER: Hi Colin,
This type of above ground pond makes a very nice bog garden. You have all the basics covered. The biggest thing to think about is water for it. When you're not getting rain you will need a source of low-mineral water. During hot weather you will need to water daily. If you're tap water is hard, you might consider a small reverse osmosis unit you can hook up to a garden hose to slow drip onto the garden. Hydrologic makes some nice units: http://www.hydrologicsystems.com/collections/reverse-osmosis
The number of plants you put in it will just depend on your plant varieties, and how big they are. Venus flytraps don't crowd much, and hardy sundews such as D. filiformis and D. intermedia will spread over time. Sarracenia will start to crowd, so about every 2-3 years you will have to take out the big plants and divide them, or use the opportunity to try different varieties. Most of the trumpet pitcher varieties grow very quickly while S. purpurea and S. psittacina and hybrids are much slower. You could also add a hardy butterwort to this mix like P. grandiflora or P. vulgaris.
Lastly, really stay on top of weeding. In bog gardens and large planters sedge grasses and other weeds can take over very fast, so that will be an on going issue.
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QUESTION: Thanks for the input on the plants, I would love to find some hardy butterwort, any suggestions? I have city water with standard filtering, chlorine and fluoride, will that reverse osmosis work with this? I was planning on setting up a couple more collection barrels for rain water, but do I need to drill drain holes in the tub or can I keep and capture the water I use. I also planned to supplement with distilled water as needed. Any thoughts?
Oddly, chlorine and fluoride don't bother them all that much especially if they are getting rained on periodically. It's the hardness (minerals) that are the problem. Since you're in Ohio, I can almost guarantee your water is hard. A reverse osmosis unit works well with city water provided the iron content isn't real high. You would know if it was since you would have red all over sinks and showers.
Definitely put drain holes in your bog garden. Undrained containers are a big no-no for any kind of plant since you get bacterial build-up and anoxic conditions that will cause root rot. To minimize water loss some go a little lighter on the perlite in your mix so that you have more peat. That helps to retain water. You need some perlite for drainage, so don't use pure peat.
If you have long stretches without rain in the summer in Ohio, distilled water can get expensive real fast. An RO unit will pay for itself quickly in that situation. You can also use the discharge off of the RO unit for regular plants such as a vegetable garden. (We do this in our nursery.)
We sometimes have P. grandiflora for sale in March. Otherwise this is the only source I currently know of: http://www.bestcarnivorousplants.net/index.php?node=cat&id=15-pinguicula-tempera