Straw Bale Garden Conditioning

This entry is part [part not set] of 28 in the series Straw Bale Gardening

I embarrassingly admit that last year when I first saw straw bale gardening I thought the plants were just planted in straw. What actually happens it that the straw decomposes and the virgin dirt that is created is what feeds the plants. According to Joel’s book Straw Bale Gardening, this process helps protect the plants from disease that comes from soil and helps prevent pests. You can read his book to learn about why. The rest of this post is about how I did my straw bale garden conditioning.

Here’s the video transcript. The post continues below.

Hi this is Chris from We are following Joel Karsten’s book Straw Bale Gardening. This is the first straw bale garden I have ever done, so we are going let you know how it goes. We are doing a series on our blog. You can look it up by going to and searching straw bale gardens. Um, otherwise, you are probably watching this in a post. Either way that is great. Today we are talking about conditioning your bales. The reasons straw bales garden work is because they decompose and that fresh virgin soil that is being created in the decomposition process of the hay bales. … Iam sorry, the straw bales, not hay um, is producing just this nutrient rich really good soil for the roots of these plants. It serves a couple of purposes. As it decomposes, it produces a little bit of heat, so early in the spring, it gives your plants an advantage because as the bales are warm and it cools outside you are giving it just an ideal condition for the plants. You can see right here I’ve got a speghetti squash and it is looking awfuly healthy. Um, we are also watering at the moment. You might be able to see that trickling out of the hose. When you condition the bales I recommend you buy Joel’s Karsten’s book because he has a very specific process that he follows. We followed that. It worked wonderfully for us. Um, basically it’s a combination of watering and putting on nitrogen. So you want to find a nitrogen rich fertilizer or an organic means of producing the nitrogen. And ah you spread it out on your bales. It is about a two week process. In the end of that you use a balanced fertilizer for 10-10-10. Um, you will have an idea when you are ready. I have this little thermometer here. It’s about 70 degrees outside right now. You can see in the thermometer, we are reading 85 to 90 degrees. So we are still producing a little bit of heat. During the peak of the conditioning, the bales got up to 140 degrees. I’ll send put a couple of pictures at the end of this video so you can see what that looked like. Alright, before you plant, you know the temperature is going to get really hot, you want to make sure the bales cool down. You don’t want to burn your plants. So let all that bacteria break that stuff down and it will be great. you are going to see a spike in your temperature for a little period and it is going to trail off. Once it gets below about 100 degrees you should be good to plant again.

straw bale gardening

Decomposition is a natural process that has been working for millions of years. When organic matter, in our case straw bales, are exposed to Nitrogen the decomposition begins. I don’t think it is a complicated matter to get nitrogen into the bales, but Joel Karsten has a proven method that will set your bales up for success. You can buy his book Straw Bale Gardening to learn more of how he does it. His process is very simple and takes 10 to 12 days to complete.

So how do you get Nitrogen? I purchased a standard lawn fertilizer that was 42-0-10. The first number is Nitrogen, the second is Phosphorus, and the last is Potassium. These are three major nutrients that plants need to grow. The bales’ decomposition needs to be jump started to get the bales ready for planting. That is why I chose a high Nitrogen fertilizer. For obvious reasons, do not buy any fertilizer with herbicide.


It is now day 4 of preparation and just getting close to the bales, I can smell quite a bit of decomposition happening. It is a very earthy and musty smell. Most of the bales are also warm to the touch so I know we are making great progress.

Today, the bales only needed to be soaked with water. I was able to let the automatic sprinkler system run by itself. It took 9 minutes for the water to seep out the bottom of the bale. Now, I know how long I need to set the daily timer after the garden is planted.

I will update you on the process of conditioning the bales as we get to the end of the conditioning period. Until then, I will be working on building some trellis’ for structure and plant growth.

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Chris Ashbach is one of the founders of Dan330. Chris is a pilot and avid outdoorsman who loves fishing, hunting, camping, and exploring. He loves taking kids (especially his own) on trips to share his passion of the outdoors. Chris is also a gardener, volunteers at Let's Go Fishing, and teaches Sunday school. Chris holds a MA in Organizational Leadership and is faculty at a local university in Minnesota; teaching undergraduate business classes.