Seven Summers of Flower Boxes at Our Northern Wisconsin Cabin
Every morning up here starts the same way: breakfast and a walk around the cabin to see how the flowers look. Seven summers in now, and the flower boxes are still the thing I look forward to most once the snow’s finally gone. Not only are the flowers beautiful, but they bring in so many pollinators! Hummingbirds circle our house all day long.
We bought this cabin in 2019 and pretty much touched every surface, inside and out. On the exterior, we painted the log siding a solid dark stain (black with blue undertones) and wanted something on the windows to soften all that dark and give the place a little more charm. The flower boxes were actually Jeremy’s idea. He built them out of cedar, one for every window, partly because cedar would age well against the siding and partly because that’s just what he reaches for. We lined them with plastic to slow down the wood breaking down, drilled drainage holes through both the box and the liner, and every spring I swap out the top third of the potting soil. That’s the whole system, and it’s held up for seven years.
Everything that’s in the boxes and pots this year came from Green Handel North, our local greenhouse. If you’re up here, I hope you’re buying flowers there because they are seriously the best. She starts everything from seed, has the coolest variety, and ensures that the flowers are super healthy and robust.
I plant around Memorial Day because anything sooner is too risky where we are (zone 4a - the last average spring frost is May 26). I split the job into two days, so on day 1, I will swap out the top layer of potting soil in all the boxes and pots. The next day, I’ll plant the flowers.
Three sides of our cabin are primarily in the shade, so I use mostly impatiens in those boxes, but each year I experiment with a little something different. I did try mixing in Torenia this year, Suntory’s Summer Wave in Large Silver, just for a little variety. I wouldn’t do it again because the impatiens filled in so fast you couldn’t even see the Torenia by midsummer. Next summer I might play around with some new greenery in addition to the impatiens.
The sun boxes and pots on the deck and the dock are where I had a lot of fun this year:
Geranium, Calliope Large Lavender — I can’t get enough of the pink-lavender color. I deadhead the spent stems as they go and that’s it. I also learned my lesson to skip the fertilizer. I fed mine early in the season and got all leaves and almost no blooms. Turns out that’s a known thing with geraniums: too much nitrogen tells the plant to put its energy into foliage instead of flowers. If you’re going to feed them at all, look for something with higher phosphorus, which is what actually drives blooms.
Angelonia, Alonia Big Bicolor Purple — These are the delicate, tall purple and white blooms. They need real pruning to keep the new shoots active. Once most of the spike bloomed, I snipped it back at the base.
Lobelia, Magadi White Basket — I loved these whimsical little white flowers. They dry out fast when it’s warm, so I watered them almost every day. I gave them a haircut in June when they got leggy, which promoted more growth and kept it bushy the rest of the summer. Otherwise I left it alone.
Spider Flower / Cleome — These tall spidery pink/magenta blooms were so fun. Jeremy called them Dr. Seuss flowers. Honestly though, I probably won’t use them again because they got a little crispy and brown towards the end of summer.
Scaevola, White — These are a cute trailing daisy shape, and I loved them in pots. They required zero pruning. They also love the heat and seemed pretty tough on the warm days.
Generally I watered every day or sometimes every other day. The different varieties seemed to enjoy the same amount of water, so that was convenient.
One more thing I’ll save you the trial and error on: the deer up here will absolutely eat their way through every box and pot if you let them. I learned my lesson the first year. I’ve tried many types of deer repellent, and most of them smell terrible. I found one (link here) that is pleasant, and I’ll never try another brand again. I dilute it in a pump sprayer and spray it every week or so, ensuring there isn’t rain in the forecast that day.
Is this a lot of work? Sure, but we have a long winter. The short flower season brings me so much joy. That’s exactly why I don’t skimp on any of this.
If you’re in a similar zone, I’d love to hear what has worked and not worked for you.
