Growing Potatoes the No-Dig Way

13 April 2012, written by Helen Gazeley

Growing potatoes must qualify as one of the vegetable gardener’s favorite pursuits. I’d guess that it’s one of the first vegetables that new gardeners go for, even if only in a couple of buckets. Digging for potatoes, however, is less popular, especially among those of us with bad backs. In fact, I gave up growing them altogether at one point, purely because I wanted to stand upright for the rest of the year.

Advantages of No-Dig Potatoes

If you suffer the same problem, then no-dig potatoes are the answer, but the advantages aren’t all back-related.

It’s a great way to clear weedy ground as the mulch blocks out the light
You don’t have to keep earthing up as the potatoes grow - simply add more mulch
Fork damage, when you manage to spear the prize potato through the heart while digging it out, is a thing of the past
If you suffer with potato eelworm, no-dig will lessen its impact on the crop
The potatoes will probably be the best-looking ones you’ve ever grown: smooth, clean and less scabby (if that’s what yours are prone to)
Volunteer potatoes – those tiny (and not so tiny) ones that get left in the soil to sprout next year – virtually disappear
The mulch breaks down to add organic matter to the soil

It’s also easier to judge when the early varieties – those harvested while the plants are still in flower – are ready. Over-enthusiasm used to mean that I had at least one meal with potatoes barely larger than peas.

Possible Problems with No-Dig Potatoes

Disadvantages? Well, it’s not advisable to grow spuds this way too early in the season, as their light covering makes frost more of a threat. Some say that slugs are more of a problem, but it’s worth noting that the mulch encourages predators such as amphibians and beetles. It’s also possible that the potatoes might need a bit more watering, and yield will probably be slightly smaller than it would be from an underground crop. In my experience, though, the difference is small enough not to matter.

Charles Dowding, who’s been using the no-dig method to produce vegetables for market for nearly thirty years, is something of a no-dig guru here in the UK. Potatoes are, in his opinion, the only vegetable that like to grow in, as he says, "mechanically loosened soil" and consequently he tends to put them in after parsnips which need a bit of a hand to help them out of the ground.

Growing Potatoes Without Digging

Hoe off the area where you want to grow your potatoes. Most weeds would die off anyway under the heavy mulch, but this is a good way to ensure that the surface of the soil is loose. You could also add a layer of compost on top.
Water the area well.
"Plant" your potatoes by placing them on the surface. Spacing is the same as normal planting, so early varieties in a bed system should lie 14-16 inches (35-40 cms) apart in every direction (in rows you should allow around 12 inches (30 cms) between plants and 18-20 inches (45-50 cms)). Maincrop varieties need around 18 inches (45 cms) in every direction in a bed, or 14 inches (35 cms) between plants in rows 30 inches (75 cms) apart.
Now cover. You could cover with a couple of inches of compost, but I go straight to the straw. Some people like to top it up gradually as the shoots grow. Being a lazy gardener, I put on six-inches (15 cms) straight away. After all, they’d be six inches under the ground if you did bury them.
Water the straw well. One thing about growing potatoes this way is that they tend to dry out more easily, so getting everything damp now is a good start.
Of course, straw being straw, and the wind being a pain, you can’t just leave it. Either tether it down by covering with mesh or fleece, or cover with grass clippings. I tend to use the mesh to begin with. The plants make their way pretty easily through the straw and then I can see them pushing up against the material.

Remove the mesh when the plants emerge and, if any plants are being held back by the mulch, help them through it. You could continue to add straw but grass clippings are better. They mat together in a way that solves the wind-blown straw problem and a thick layer excludes the light very effectively. If they’re fresh clippings don’t cosy them right up to the stems immediately, in case the heat of decomposition burns the stems.
Now all you have to do is water when necessary and top up with grass clippings if the mulch looks a bit thin.
Harvest when ready. Here’s where no-dig is really useful, as you can check the crop without wasting a plant. Just draw back the mulch. If the potatoes are too small, replace the covering carefully and let them grow on a bit longer. You can even harvest some potatoes from a plant and leave the others to grow on.

Happy harvest!

By Helen Gazeley