Can I have a koi pond in the Upper Peninsula?

– Posted in: FAQ, Mailbag

A reader asks:

I am considering relocating to a colder clime (UP of Michigan) and I have never gardened further north than Wichita, KS so am wondering if I can have a koi pond if I run the heater (I do this now to keep a spot open in in the ice) and what plants do well.. I love iris, daylilies, peonies, shrub roses, daffodils, japanese maple, bee balm, phlox, clematis, hosta, etc. all of which I have now. not finding much information with my first quick search. Anyone have any comments or help for me with a web site reference? Thanks in advance for your time.

I know there are gardeners from Michigan’s Upper Peninsula reading this blog, and others from similar climates. Please respond to Amy in the comments.

About the Author

Kathy Purdy is a colchicum evangelist, converting unsuspecting gardeners into colchicophiles. She would be delighted to speak to your group about colchicums or other gardening topics. Kathy’s been writing since 4th grade, gardening since high school, and blogging since 2002.

In the end, this may be the most important thing about frost: Frost slows us down. In spring, it tempers our eagerness. In fall, it brings closure and rest. In our gotta-go world–where every nanosecond seems to count–slowness can be a great gift. So rather than see Jack Frost as an adversary, you could choose to greet him as a friend.

~Philip Harnden in A Gardener’s Guide to Frost: Outwit the Weather and Extend the Spring and Fall Seasons

Comments on this entry are closed.

Pete October 23, 2013, 9:26 pm

Hi, I’ve got a small 9 ft X 12 ft (30 inches deep @ deepest point)) pond in one of the Detroit suburbs (Sterling Heights) that has been the year-round home of almost 60 goldfish for five years(until this summer). The goldfish did great as long as I kept a hole in the ice to let gases escape and added an aeration pump to keep the water oxygenated. This spring I made the mistake of introducing new goldfish and they introduced some micro-organisms that quickly killed off all but 15 of my originals. I replaced the depleted goldfish ranks with about 20 small koi (2-3 inches long) that I purchased over the course of the summer from Meijers (for about $6 each). They were doing great until the temps started dropping about two weeks ago. Since then, I’ve been pulling dead Koi out of the pond every few days (most are small, 3 inches- but a couple have been the larger ones – about 6-7 inches long- they grow fast when they are well fed!) I monitor the water temp very closely and it has dropped significantly the last couple of weeks (from around 67 F to 48F by this morning) plus the daily temps have been up and down like a yo-yo- 80F last Friday, to 34F overnight last night Tuesday). I am not too optimistic for the remaining Koi this winter. Seems like they are much more sensitive to the rapid temp changes than the goldfish who have been through 5 winters with no fatalities (until the aforementioned epidemic and a few Heron picnics on Memorial Day or Labor Day). I used to bring my goldfish in for the winter before I deepened and enlarged the pond but they didn’t do as well in the two 30 gallon aquariums and I used to lose 10% every year. I will let you know in the spring how well the Koi have done but I am not real hopeful. I’ll probably be back to “only” goldfish by next summer!

CJ November 15, 2009, 10:21 pm

I live in the lower peninsula of Michigan, and I happily grow all those plants you mentioned. However, the UP is colder, zone 4ish, depending on where you live up there. I think most of those plants will do fine, if you mulch well in the winter, plant in excellent soil, and water regularly. I am not sure about how koi would over winter there. Good Luck!

Jenn February 16, 2009, 10:31 am

My father in law has a koi pond, he brings fish in in the winter, puts them in a big plastic box (rubbermaid?) in the garage over the winter. We live in Michigan, but not the upper. We’re more like the thumb area. His fish are very pretty, and have multiplied, so they must be very happy! He has had his koi pond for years.

Dianna December 31, 2008, 6:56 pm

sorry forgot to say the pond is nearly 1000 gallons.The smaller 150 gallon is solid with ice but there are no fish in that only plants.

Dianna December 31, 2008, 6:54 pm

The UK weather is very cold this year -5 this evening,,we keep the pond covered with bubble wrap,layers of it and an ice heater.The fish look pretty miserable huddled around the heater.Apparently the ghos koi are tougher,but the other koi I may bring in if this gets worse.

Karin November 11, 2007, 5:10 am

I checked out Melissa’s blog about overwintering goldfish in a shallow pond. I believe she used the word nervewracking at some point, and that is where I am now when I look out the window at the frozen fishpond.

I live Uppsala, Sweden, which on our charts is borderline zones 3-4, temperatures to minus 20 C. We installed a small pond (600 liters, which could be about 150 gallons??? I’m bad at conversion) that I think is about the same size as Melissa’s Mom’s 125 gallon pond. We have three goldfish. I have been preparing to move them indoors, but you and some others suggested that even a shallow pond the key is to keep the water circulating. Our pond is 40 cm (16″?) deep at the deepest.

Doesn’t that sound TOO shallow?

Also, I haven’t been good about removing decaying plant material. Should I crack the ice and do that if I let the fish stay in the pond?


Pete October 24, 2013, 10:10 am

HI, I just saw your old post about the small goldfish pond and I’m sure that it is way too late to do anything but… was wondering how things turned out? It sounds like your pond was about the same size as my first one which I removed and expanded to my current 9ft X 12 ft that I dug and built myself. When I still had the old smaller insert, I always caught the goldfish and wintered them in a couple of 30 gallon aquariums in the basement so their water temp was around 72 F from fall until spring. I got mixed messages from several pet and garden stores regarding the depth requirements (my insert was 18 inches at the deepest point) and only about a third of the people thought this was deep enough for wintering over. I didn’t want to take a chance so I always moved them indoors for the four years I had this setup. When I built the new pond, it was with the intent to not have to relocate the fish again, ever! This worked fine with goldfish for 5 years (see my other post about the Koi). If you did choose to leave your three goldfish outside in the winter, You will definitely need to add an airpump(bubbler) to make sure they have oxygen, and also will have to keep an air hole open in the ice to let gases escape so that the fish don’t get poisoned from the biproducts of plant breakdowns and fish contaminants. I have a floating heater that I only plug in as needed to keep an opening in the ice. On one occasion when the heater stopped working, I used warm water to melt a new opening into the ice until I could free up the non-functioning heater and replace it with a new one. I have been told that you shouldn’t try to break up the ice with a hammer as the vibrations may scare the hibernating fish into a heart attack but I cant confirm that this will actually happen.

Water-Garden-Fish-Pond August 15, 2007, 10:44 am

The only thing you need to make sure is that you know the depth of the water that freezes in wintertime and make sure you build it much deeper than that. I would be interested to know if there were any other reasons. If anyone knows please let me know.

Chris July 29, 2007, 6:09 pm

I almost forgot… you can’t reliably grow most Japanese maples in the UP… but you can grow the two new varieties of elderberry that look just like laceleaf japanese maples.

Sambucus Black Lace (introduced in 06, really rare and hard to find) is jet black with beautiful laceleaf foliage. There is another one with lime yellow foliage, but I don’t remember the name. I remember because I just bought my first two today after looking for them since I first saw them in catalogues (promptly sold out) last fall.

Brooke July 28, 2007, 5:23 pm

I’m from a family dating back over six generations in the UP. I left. I keep moving south so that I can grow more. I am sure some folks wouldn’t mind moving fish in and out by the season, but eight to nine months of the year spent mostly indoors drives most people to either drink or take up some awful hobby like bluegrass (I’m having a little fun at my Dad’s expense, here)…Why on earth are people moving up there? That I cannot fathom…

flake July 28, 2007, 6:25 am

Hi we have lived in the central UP of Michigan where we have grown a garden over 30 years and have had a small pond for 3 years.
We had goldfish the first two we brought them in over winter. Have many friends with koi and some do bring them and winter them in their basement but one women has a very big deep pond and successfully leaves hers in she has koi and gold fish and fancy golds she puts small thing I was thinking it was heat and some kind of air bubbler over the winter. (Which by the way is very very very very long. LOL The seasons have changed since the 70’s. If you move here you must love the snow. Unless you move to the banana belt. Which is down at Garden. Hope this helped

flake ( In the Upper Peninsula of Michigan) who put her pond in the wrong spot..

Chris July 24, 2007, 1:44 pm

Liquid water won’t even get much below 32 degrees. Its chemistry. If a fish can survive in 32 degree water in Florida, they can survive in 32 degree water in Antarctica.

So all you need to do is make sure the pond doesn’t freeze all the way through. You can do this with a heater, but a more common way is to just keep the water constantly moving and circulating. Then of course depth will matter as well, the deeper the better.

For plants… I’m afraid you’ll have problems growing Japanese maples unless you can provide them with a microclimate (pack one in tight near your house, or by a larger tree for instance). The others should do fine, maybe not the phlox, and the deer & rabbits will probably eat your hostas.

One of the issues is where you live of course. Keweenaw Peninsula, or just barely over the bridge? Inland, or near a lake? (Lakes will provide warmth in the winter from wind passing over that 32 degree water).

Pete October 24, 2013, 10:30 am

It’s not just the water temp, It’s the rate of change that some fish can’t tolerate. Koi can only adapt to a 3 degree change in temp per hour. Since the rate of change in water temp is dependent on the volume of water, a smaller pond has less of a buffer for the extreme temperature swings that we experience in “the mitten state”. My goldfish did great outside for 5 years, but it looks like my Koi will be history before they see another spring.
Also, any variety of hibernating fish will need to be on a low-protein diet under 50F and NO FEEDING at all below 40F. Too much exertion for their decreased metabolism (I’ve been told overfeeding in the fall could cause a fish to EXPLODE but haven’t seen this first hand- THANK GOD)

Ted B July 24, 2007, 8:36 am

From Wisconsin, the pond will need a heater but should be fine. Also may need protection from all the great wildlife you’ll see – I wonder if loons like koi!

All the plants you list will grow well with the possible exception of the Japanese maple but it’s worth a shot.

The main things you’ll notice is much longer days in summer. Reliably cool nights. Lots of winter snow and good winter humidity. The growing season will be shorter, but more intense. Flowers last longer in the cool weather and colors are often more vibrant. I’ve always thought the UP would be a good place to garden.

I just got back from northern Wisconsin, about 20 miles from the UP. The soil there is very sandy and acidic, maybe a good place for Finnish rhododendrons?

Mel Rimmer July 22, 2007, 2:58 pm

I’m glad to hear Amy can have her fishpond in her new home. How nice that she was able to get advice from this blog.

Dan Eskelson July 22, 2007, 10:38 am

Our winter temps here in north Idaho often go down to minus 20F. Our Koi and goldfish do just fine in our two foot deep pond. The only requirement is to keep a small hole in the ice (with a 100 watt pond heater) so any potentially harmful gases can escape. We keep the falls and stream running all winter…the ever changing ice “sculptures” are beautiful…some folks will remove the pump during the coldest months.

Our aquatic plants also do fine right where they grow, the marginals in 4″-6″ of water, the water lilies down about 16″.

Carolyn July 20, 2007, 10:30 pm

As a former Yooper born and bred, I would suggest planning on housing your koi indoors during the winter. One of my friends kept koi. She overwintered them in a tank in her heated garage.

I think a heater would cost a fortune to run all winter and it sure would be hard to maintain in the winter. They have 3 feet of snow on the ground most of the winter (Lake Effect Snows). Its not unheard of to have snow on the ground on Halloween and still have snow piles the first week of May.

~~Melissa July 20, 2007, 7:08 pm

I’m in Ontario Canada zone 5a. I keep goldfish year round in my shallow pond. Common advice says pond must be a few feet deep but mine is just 20″ and the fish all survive fine. I don’t have a heater. I just make sure the pump runs all winter long (and I keep a spare on hand). I overwinter the pond plants the same way: leave everything as is.

Jane July 20, 2007, 5:00 pm

From Edmonton, latitude 53, zone 3a: I do not have koi or a pond but my next-door neighbours do and they overwinter their koi in a tank in the basement. In very large ponds (like at the Kurimoto Garden – I think the fish overwinter in the pond. Assuming they still have fish. There seemed to be dozens last time I was there but that was years ago.