What is the best mulch for no dig potatoes? Back in April 2018, I started a no dig potato trial and what I wanted to see is whether the mulch or the covering over the seed potatoes and therefore the growing medium would make a difference to the yield of the potatoes. Obviously this is not a highly scientific experiment, this was done in my garden as a home trial.
What is No Dig Gardening?
No dig or no till gardening is a method that minimizes soil disturbance and uses mulch on top of the soil surface rather than digging it into the soil. There are so many advantages to no dig gardening including
- less weeding
- better soil structure
- less damage to micro organism life
- improved yields
- less work
I’ve been using no dig gardening for a few years and moved to the whole garden being no dig in 2016. I’ve been getting great results, for less effort and that has to be a good thing! While I don’t shy away from hard work, I am so pleased that I made the change. I chose no dig after a disaster in creating a new flower border, you can read more about why I chose this gardening technique in my book Grounded.
If the method is new to you, I recommend you start by reading Charles Dowding’s beginners guide to no dig gardening (link in Further Reading below).
Best mulch no dig potatoes trial method
I planted a row of one variety of potatoes by putting down a narrow row of shop bought compost (all from the same bag). It was split it into four sections, I marked the areas with bamboo canes pushed into the ground. I planted three potatoes, evenly spaced into each section of shop bought compost. Each section was then covered with a different mulch –
- used bedding from the chicken house that had been sitting in a heap quietly rotting down for about six months or so,
- wood chips that had been sitting around for a while, but not an awfully long time so they hadn’t broken down a huge amount,
- leaf mold that was about eighteen months old and
- garden compost that was several months old and was looking pretty good.
I anticipated that the highest yield would be from the seed potatoes grown in the garden compost, because they would have a more rounded balance of nutrients available to them. I thought that the other mulches for the no dig potatoes would provide a suitable growing environment, but probably not enough nutrients for a good yield.
Plant care during growing season
Throughout the growing season I treated all entire row of potatoes in the same way. Water was measured in watering cans to ensure an even amount of water was provided, not only to each section, but to each plant within the sections. When I added additional mulch to ‘earth up’ the growing potato plants, I measured it by the bucketful, so that similar amounts of new mulch were being added. I hoped to minimize the risk of the results being skewed by different treatment of the growing potato plants and tubers.
Harvesting the no dig potato trial crop
I harvested the potatoes in three separate batches. One plant from each section after a few weeks, one from each section about three weeks later. There was a really long gap until I harvested the last of them. These potatoes were early potatoes. Harvesting can take place after about 70 days. But for the final harvest it was more like a hundred days or more. I recorded the weights of each harvest and then added the weights of those three harvests together, in other words, I got a grand total for the three seed potatoes for each section.
Total Yield over 3 harvests
Wood chips = 2206g
Garden Compost = 2910g
Chicken Bedding = 3354g
Leaf Mold = 3706g
The thing that’s absolutely stood out for me with this Best Mulch for No Dig Potatoes experiment is how little slug damage there was to the potato tubers.
Last year I tried growing potatoes under a permeable weed suppressing membrane. It was a black sheeting that allowed the water to go through it. I disliked the number of really huge slugs that that lived underneath the plastic! And also disappointed by the number of potatoes ruined by slug damage. As a result of that experience, I was really pleased to see minimal slug damage to those potatoes.
Taste Test (boiled)
Wood chips – Nice flavor
Garden Compost – Earthy, not much flavor
Chicken Bedding – Not much flavor
Leaf Mold – Flowery, a nice spud
Wood chips and Leaf Mold Mulch won the taste test, how much that’s got to do with the growing medium, I have no idea. I hope our highly unscientific and particularly subjective taste test was of interest. I will continue to experiment to find the best mulch for no dig potatoes using other mulches and coverings.
Further reading, videos and information
How to minimize slug damage in your garden. My thoughts about how to deal with slugs and snails.
Growing potatoes in containers. A step by step guide.
How to reduce plastic use in your home. A look at simple ways to have less plastic in your everyday life.