Eek! Mice in the Straw-Bale Garden

bale harvest
The bales produced great potatoes and flowers.

With fall coming on so quickly, I’ve finished with the straw-bale gardens for the year. I had good tomato harvests from the bales, and I can see where in certain circumstances bales would be the way to go with vegetables.

The vegetables grew well, were disease-free (one of the biggest benefits of the bales, in my opinion) and had good harvests.

I did have one of the typical problems with my bales, however — mice!

I had one bale in my main vegetable area that I used to grow potatoes. I harvested the spuds early, broke the bale up and used large chunks of the straw to mulch around some of my tomato plants that were sprawling a bit. A part of the bale (not more than 9-by-9-by-6 inches) was left where it had been. A few weeks later, while working in the garden, I saw three mice emerge from the bale. Eeek!!! I dispatched (what a nice, clinical description) two of the mice with a garden fork I happen to be holding and the third scampered off.

bales decompose
The bales insides turn into compost after several months.

That event prompted some aggressive watering of the remaining bales. If you do straw-bale gardening, you must water the bales regularly to keep them growing and to avoid infestations by mice. I watered my bales every day or every other day, depending on rainfall and how hot it was.

With some trepidation, I approached the remaining four bales this weekend to dismantle them and spread the straw around other parts of my garden. Happily, the watering worked, and there were no signs of mice in the four bales that had grown tomatoes and zinnias.

Will I do straw bales next year? Maybe. They work, especially if you want to give your soil a break. I’m also considering using stock tanks with bales inside or with potting soil.

Straw-Bale Gardens Are Looking Good, Too

I still get a mushroom or 30 in my straw-bale gardens from time to time, but overall, I am really pleased with how they are growing. The four tomato plants I put in two of the bales are getting tall and sturdy. The zinnia seeds I spread across another two bales have all germinated and are putting out leaves, and the potatoes planted in the last bale are growing so tall I’m trying to figure out a way to add more soil around them, so I can get more potatoes.

It probably helps that the bales are watered every day (or at least every other) and that, per the instructions, I poured a weak solution of diluted fish emulsion over all the bales for fertilizer a couple of weeks ago. While I’m not thrilled by the appearance of the bales (and, just to tease you a bit, there will be a great article on how to improve their appearance in the July/August issue of Northern Gardener), I love their productivity. The rabbits haven’t figured out how to get up on them, either. So, go bales!

How are your straw-bale gardens growing?

Something is Growing in the Straw Bales

Inky cap mushroom in straw bale
This one is about to ink-out!

I haven’t planted anything in the straw bales yet, but something is growing! I have a big crop of mushrooms in one bale and a smaller crop of grass popping out of some of the other bales. Both of these are expected events, though still a bit surprising. The mushrooms are “inky cap mushrooms,” which are mushrooms that dissolve into a black goo after a day or so — I noticed the goo pretty heavily on one of the bales.

One bale is covered with mushrooms.

Cornell University’s mushroom blog has an interesting post on inky caps and their tendency to destroy themselves. In addition to sprouting mushrooms and grass, the bales are definitely heating up and I expect to be planting them out within a week or so.

Straw Bales Heating Up

I’m not sure if the warmer temperatures yesterday were the main factor or if decomposition is afoot, but my straw bales are starting to heat up. Yesterday, I detected definite heat from the bales and one of the bales registered nearly 100 degrees F on the old meat thermometer I am using to check the temps. That was a good 30 degrees higher than the air temperature.

According to the straw-bale gardening instructions, it should be time to plant. It’s been more than 12 days since I started. However, I’m going to hold off a few more days. I think the bales are still conditioning. It’s also going to be chilly here for several days.  More updates later!

Taking the Straw Bales’ Temperatures

I have been checking the internal temperature of my straw bales to see if they are starting to decompose inside. According to the information from Joel Karsten at, the bales should start to heat up about now.

thermometer in straw bale
Taking the straw bale’s temperature

I checked yesterday — in the 40-degree cold rain — and found that most of the bales were only about 60 degrees internally. Today, some were even colder. Because we have had a lot of cold rain and weather affects how quickly the bales start decomposing, I decided to put on the recommended plastic sheeting to warm the bales more.

I’m on the seventh day of the 10-day conditioning program, and the bales still need to heat up (they are supposed to go as high as 145 degrees F) and then cool down before I can plant. Hopefully, the slightly warmer weather this weekend and the much warmer temperatures next week will get things cooking.

Have any other straw bale gardeners had similar experiences?

New Straw Bale Garden

Straw bale garden
Bales with espalier for climbing vegetables.

Last week, I attended a presentation on straw bale gardening with my friend, Penny. We both left Joel Karsten’s talk very excited to try this new type of container gardening. So over the weekend, I located a farmer near New Trier who had some big, beautiful bales of wheat straw that I used to set up my straw bale gardens.

The concept behind straw bale gardening is fairly simple. You “condition” the bales by flooding them with water and fertilizer (you can go organic or traditional — I’m trying both ways) for 10 days. During the conditioning, the inside of the bales starts to decompose and within a couple of weeks you have a very fertile medium inside the bales. You can plant seedlings directly into the bales or add potting soil or compost to the top of the bale and use seeds. When the season is over, you harvest your crops, take the twine off the bales and knock them over. Viola! Compost!

That’s the simple explanation, but there is a recommended process for doing this, so check out Karsten’s website or take one of his many classes around Minnesota before you get started.

I had a spot in our meadow area that was very prone to ragweed and other nasty business. I’d already cut the weeds down so I covered the area with a couple of large appliance boxes. I’m hoping that the cardboard will smother the weeds while I grow cutting flowers and vegetables in four of the bales, which are sitting on top of the cardboard with some additional wood mulch surrounding them for paths. I had one additional bale that I put on cardboard on top of one of my regular raised vegetable beds. This bed seemed a little depleted last year, so I’m giving the soil a break. I plan to grow potatoes in this bale, then after the potatoes are harvested, I’ll leave the bale/compost on the bed.

I’ve done a bit of research on straw bale gardening and the only concerns I’ve heard about it are that, if you do not get clean straw, your bales end up looking like chia pets with lots of little weeds sprouting out of them. The farmer I bought my bales from assured me they were “very clean.” I’m trusting him on that. The other concern is aesthetic. As the season progresses, not surprisingly, the bales start to sag and sometime look a little scraggly. Given that the alternative in the location I’ve chosen is a huge stand of ragweed, I’m not that concerned about looks.

We’ll be running an article on one person’s take on straw bale gardening in the July/August issue of Northern Gardener. Have you tried this method yet? Did it work for you?