How To Condition a Straw Bale for Gardening – Straw Bale Gardening Guide

Straw bale gardening – is there a gardening method that sounds easier? All you need to do is buy a straw bale, place it in a sunny position, condition it for 10 days, and plant your favorite plants in it. Let’s find out how to condition a straw bale for gardening!

Why Straw Bale Gardening?

I live in a bus on my son’s property in a tropical climate, surrounded by cane fields. A true garden paradise, except there are a few challenges in the garden I have to deal with. Our climate experiences very high temperates, causing rapid evaporation of water from the soil. We have a huge array of insects and wildlife, all wanting to share the food we grow. 

At night, many animals visit the gardens looking for tasty treats and they’ll dig up the plants. We need to put rocks or other materials around the base of the plants to stop them from being dug up. We also need to apply a thick layer of mulch to protect the soil and the plants’ roots from the hot sun. My gardens are chock full of mulch, not always my favorite look!


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Starting Straw Bale Gardening

Not long ago, I came across Joel Karsten’s book, Straw Bale Gardens Complete. I actually wrote a review on it a while ago as it made a big impression on me. It proclaims to be a breakthrough vegetable gardening method, with a lot of information on gardening in small spaces, organically growing vegetables, and saving water.

Where to put the straw bale for gardening?

My first consideration was where to place my straw bale garden. I wanted partial shade, close to my house, and conveniently placed so I can keep a close eye on progress, yet keeping in mind that it is a “bale of straw” in my garden.

My son, who knows quite a bit about gardening and had his own plant nursery, was quite skeptical about growing plants in a bale of straw. He suggested I would never be able to keep enough moisture in a bale above-ground. 

Note from editor: The ‘son’ is Dan – you can read about Dan on our About page!

He has not read the book ‘Straw Bale Gardens Complete‘, but…..

Sandy stated in Joel’s book:

“Hi Joel, I’ve been doing small straw bale gardens for my tomatoes, peppers, and squash since 2008 and the bales have worked great. For the last couple of summers, when we had drought…. The bales stayed moist and required very little water. I watered weekly using a gallon of water (that’s about half a bucket) per bale during that time.

I can’t say enough good about the process, it’s so easy and practically takes care of itself. Thanks for the info on Straw Bale Gardening.”

So, he grudgingly placed my bale near a tree for partial shade and some afternoon sun.

How To Condition a Straw Bale for Gardening

I got straight to work conditioning my bale of sugar cane straw, and I’ll show you how to condition a straw bale for gardening with photo’s here. 

The straw bale conditioning process is to encourage the bale to begin composting internally so that it can support root growth. I’m rather impatient and Joel said: “It will take 10 days to get the fertilizer and water deep down inside so they can start to “cook”. ” 

Conditioning My Straw Bale Garden

Day one


  • Thoroughly soak the bale with water.
  • Pour on half a cup of all-purpose soluble fertilizer. 
  • I made up half a gallon in a bottle to use every second day.
  • Alternatively, you can use 3 cups of organic fertilizer.
  • Notice that the bale is a cut-side up – this is important to let the water soak in properly.

Straw bales and hay bales have two distinctly different sides. One side is the cut side and it looks like the ends of the straw are aligned and have been sliced off with a knife. The other side of the bale is the folded side and appears as if the straw stems have been folded over in the baling process.

Make sure that the strings are around the sides of the bale and not on the top or bottom. String is important for keeping the straw bale compressed which will help it to decompose quicker. 

Day 2

Finger test for moisture and warmth

As soon as the sun warmed up the water in the hose this morning (free warm water to kick-start the conditioning process!), I saturated the bale with water again. A finger test (poke your finger in to test the moisture) told me the straw bale garden was moist positive.

Joel states that no one likes a cold shower, and warm water stimulates bacteria to grow, that’s what I wanted, and quickly!

Cut-side up   

Day 3

Day 3 of how to condition a straw bale for gardening is fertilizer day again! Pour on half a cup of fertilizer and water in with some warm water from the sun-soaked garden hose to wash in the fertilizer. 

At this point, I was a little worried about the position of my straw bale garden. Joel mentioned that a straw garden must have 6 to 8 hours of full sun every day. However, my son said that we live in the tropics with temperatures over 35 degrees and plants would be better off in partial shade.

I am following my son’s advice at the moment, leaving the bale near a tree. The straw bale gets partial shade there with a few good hours of sun each day. My son grows his vegetables in a shade house, so there is possibly good reasoning behind his advice, let’s see what happens.

Day 4


Day 4 of conditioning the straw bale garden is warm water only. Apply 1-2 gallons and the water should be running out the bottom of the bale. 

The good thing about straw bale gardening is that you can shift your bale to another position if you don’t like where it is. That’s exactly what I did on day 4. I moved it around the other side of the tree so it gets a few more hours of sun.

Try the finger test on day 4 (see image further up). Push your finger down into the bale to check the temperature. My bale is indeed getting a bit of warmth inside, and the straw is starting to change color slightly. Conditioning the straw bale for gardening is going well – the bale is starting to cook. 

Day 5

We are now half way through how to condition a straw bale for gardening. The whole conditioning process takes 10 days, after which we’re ready to plant. 

Pour on half cup of fertilizer again, and wash it in with some warm water. The straw bale should be feeling a bit warmer today.

Day 6


Day 6 is another water-only day. Apply some warm water. 

Some people set up water sprinklers in their straw bale garden but I like to water them manually. I like to see what’s happening and I‘m never in a hurry these days. The bale is slightly warm today. Fingers crossed it starts to cook better tomorrow. 


I have my plants ready to go. I bought some parsley, basil, tomato, and capsicum (red pepper) plants. I’m keeping them in a shady place until day 11. Can’t wait to plant!

It’s important that your vegetable seedlings are happy growing close together, so it’s worth taking a look at companion planting. As the Farmer’s Almanac states: tomatoes and basil were made to go together, not only in sauces but in the garden too. Basil is a good friend to peppers too. Check out their handy reference:

Companion planting reference by Farmer’s Almanac

Mother Earth News offers an in-depth companion planting guide, with nearly every variety of vegetable and herb known to man. It certainly makes gardening a lot of fun when you think about planting different types of plants that actually like each other. The ones that promise to get on well together and be good neighbours. My choice of plants will be OK, although general companion-planting rules do mention not to plant parsley and tomatoes too close together.

Day 7

On day 7, we apply  ¼ cup of fertilizer and some warm water to wet the bale. 

At this stage I am, once again, worried that my bale is not getting hot enough. I’ve shifted the straw bale garden again, out from the shade of the tree into full morning sunlight. (I think that Joel was right all along, sorry Dan!) That’s the best part of this garden–you can reposition it anytime with a hand truck.

Today, I see 2 tiny sprouts of weeds on top of my bale. Life-sustaining signs I guess….

Day 8

Apply ¼ cup of fertilizer and a small amount of warm water. My bale feels quite wet today, and it is heavy and smells a bit musty.  

Day 9


Apply ¼ cup of fertilizer and a small amount of warm water.

I turned my straw bale up-side-down today as it seemed to be too wet on the bottom. I may have been too generous with the water these last few days, you only really need enough water to wash in the fertilizer. 

Day 10

On day 10, we need to apply one cup of soluble fertilizer that has both potassium and phosphorus. I used a small amount of warm water to wash in the fertilizer, all over the bale. The fertilizer needs to contain potassium and phosphorus because these minerals penetrate into the root zone of the bale. 

My bale smells sweet at last!  Well, “compost sweet”. Using the finger test, it definitely feels warm to hot inside my bale, I can feel that my strawbale is “cooking”. Be patient…

Our conditioned straw bale garden is almost ready to plant, two more days and it will be ready to go.

Day 11

Day 11 is our rest day. We don’t do anything to condition the straw bale for gardening today. Today is a good day to check for worms in the straw bale; I did check my bale for worms but so far haven’t spotted any. Worms are great in the garden as they help break down the complex organic material back into food that can easily be taken up by the plants’ roots.

I hope that the worms, insects, and bacteria have all been at work eating, digesting, and decomposing organic matter inside my straw bale garden, go hard little critters, I appreciate you.

Day 12


Finally, it’s planting day! How to condition a straw bale for gardening is now done, and we’re onto the next stage.

My straw bale garden was moist, warm, and some obvious decomposition is happening. It is slightly brownish with tiny black flecks everywhere which are the first sign of straw decomposing to make soil. The straw bale won’t look much different on the outside, but bacteria have begun digesting the straw and giving back nitrogen.

I carefully removed the basil, tomato, parsley, and pepper plants from their trays so as not to disturb their small fragile roots, parted the straw with my hands, and placed each seedling well down into the moist bale. Squeeze the straw around each plant and press down firmly.


Unfortunately, the parsley seedlings looked a bit wilted and yellow. I think I left them too long sitting in water in my garden shed with wet feet. I planted them anyway, so hopefully, they will recover in the sunlight.

Don’t forget to water all the seedlings lightly with warm water.

Day 13

We had a cold night but all seedlings look very good. The parsley even looks better this morning. I also pushed in some bamboo stakes beside the tomato plants for support later on.

Day 14

One parsley plant made it through to today, unfortunately, the others didn’t make it. The rest of the plants look strong and healthy.

I moved my straw bale back into semi-shade to its final resting place. It will still receive a few hours of full morning sun but our temperatures are starting to climb and I feel will be too hot for most of the plants in full sun all day.

Day 15 and 16

We’ve had very high temperatures during the last two days. The plants remained strong and did not wilt like the lettuce plants in the garden did. I am impressed with the way my straw bale garden retains moisture and sustains my seedlings. 

The straw bale garden should retain moisture much better than normal soil so it will need less watering, no weeding, no bending, no digging….. But, I will keep an eye on how things are going and water on a regular basis.


Joel suggests a bit over a gallon of water per week in most moderate climates, but on the first sign of wilt, apply water. I will plant some petunias around the sides of the bale to make it look nice and also as a wilt test. If I see any part of the petunias wilt, I’ll know that water is required immediately.

Have a go at making your own straw bale garden! It’s been a great experiment and I’ve thoroughly enjoyed the process. We covered how to condition a straw bale for gardening, and the plants seem to enjoy their straw bale garden. I’m now a straw bale garden convert. Can’t wait to start my next one!


Joel Karsten’s book “Straw Bale Gardens Complete

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I like gardening but I don’t have much space in my place. I love that straw bale gardening is a breakthrough vegetable gardening method for small spaces. Thank you for all the pictures, it really shows how easy the conditioning process is. I will definitely start by soaking the bale in water and an all-purpose soluble fertilizer. I will look forward to purchasing the straw bale to kickstart my vegetable gardening.

I learned new information from your article, you are doing a great job.
King regards,

Great article. I am doing eight straw bales for my gardening this year. My two kiddos are really enjoying it as well. My straw bales are on day three of conditioning. I will be setting up drip irrigation watering system for them this coming weekend. Ready for day twelve to get here so I we can start planting. Look forward to reading about your success with straw bale gardening.

Thank you so much. At last, I discovered an article which I am looking for quite a
long time. I hope that it will help me.
Best regards,
Balle Raahauge

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