As you guys know, we’ve been growing potatoes exclusively under mulch for about 5 or 6 years
at this point.
We initially took inspiration from the Ruth Stout Method, and have since done some additional
experimenting of our own.
So if you’ve missed any of that, I’ll link to a playlist in the description.
But today, I’d like to focus on one specific part of the potato growing process, because
though we’ve certainly mentioned it in previous videos, we’ve never actually gone into detail
on how and why we hill our potatoes using mulch instead of soil.
So when planting potatoes the traditional way, the seed potatoes are usually buried
in soil and then as the plants begin to grow, they produce foliage above the surface, and
roots and tubers below the surface.
But when using the Ruth Stout method, the seed potatoes are instead simply placed on
top of the soil and then buried under a thick layer of organic plant matter, like grass
clippings, fallen leaves, straw, or in Ruth’s case, and ours, old spoiled hay.
Then, once again, as the plants begin to grow, they produce foliage above the surface, and
roots and tubers below.
However, since the surface in this case, is the mulch, the tubers tend to form just under
the relatively fluffy hay, meaning that compacted soil is far less of a concern.
Now there are plenty of other advantages to this method as well, like water retention,
weed suppression, and even easier harvests, but we’ve gone into all of those details
before.
So again, please check out our previous videos if you’re interested.
But now let’s talk about hilling.
Once again with the more traditional method, after the plants reach about 6 - 12 inches
tall, most people pull some of the soil up around the stems and leaves.
This helps to suppress weeds, provides some insulation from temperature fluctuations,
and protects the potatoes from hungry critters.
But most importantly, it also ensures that the tubers are never exposed to sunlight.
Because sunlight is the potato tuber’s worst enemy.
Or more accurately, sunlight is our worst enemy, when it comes to potato tubers.
You see, despite usually being considered a root crop, potatoes are actually stem tubers,
and so just like the rest of the stem, when exposed to sunlight, they produce chlorophyl
and turn green.
But unfortunately, along with the chlorophyll, they also produce other compounds that give
the potatoes a bitter flavour.
And most importantly, one of those compounds, solanine, is toxic to both people and pets.
So avoiding green potatoes is pretty important, and periodically hilling them with soil has
traditionally been the easiest solution.
But in our case, where the only soil is under the tubers, if we “hill” our plants, we
simply add more mulch.
So I’ll demonstrate that process in a moment, but if you’re already familiar with growing
potatoes the traditional way, then this is honestly pretty much the same thing.
Just use mulch instead of soil.
However, you may have noticed that I said “IF” we hill our potatoes, and that’s
because when using the ruth stout method, it isn’t strictly necessary, as long as
the initial layer of mulch was thick enough.
Because, once again, the main reasons for hilling potatoes are: weed suppression, insulation,
critter control, and shading the tubers from sunlight.
But mulch already takes care of most of those anyway, not to mention providing a whole bunch
of other advantages to boot.
Which is why, in all of Ruth’s books that I’ve read, I don’t recall her ever recommending
hilling potatoes, and instead she consistently stated that she simply threw the seed potatoes
on the grown, often on top of last year’s mulch, covered them with 6-8 inches of hay
and then never looked at them again until it was time to harvest.
And most years, that’s pretty much all we ever do too.
In fact, thanks to the moister retention of the mulch, we’ve even gone entire seasons
without ever watering them, even once.
So when we do hill our potatoes with mulch, we do it exclusively to block the sunlight.
Now luckily, the initial layer of tangled hay already does a pretty good job of keeping
them shaded because it forms a flexible mat that stretches throughout the season.
However, we have had a couple of instances where the sunlight still reached a few of
the tubers below, so now we do tend to hill them once or twice just as an extra insurance
policy.
But as you’ll see, it’s such a quick and easy process that there’s really no reason
not to anyway.
So here’s our potato bed earlier this spring, and by the way, I initially created this bed
by simply pushing aside our mulch pile to expose the natural bare earth below.
No tilling or amending required.
Then I placed the seed potatoes on the ground in rows, and covered them with about 8 inches
of old hay.
I also added some fallen leaves between the rows, but that was just to keep weeds from
growing in the walking paths.
Finally I gave an initial watering just to be safe, and then we never looked at these
again until a few weeks later when the plants were around 8 to 12 inches tall.
At that point, I pulled out some milk weeds that had popped up here and there and then
added some more old hay around the base of the plants.
The idea here is really just to ensure that there is a nice thick layer over top of where
the tubers will eventually grow.
So I don’t put much effort into making it look nice, and try not to over think it.
Sometimes I just press the hay up on either side of the plant, and sometimes I gently
shove it in between the foliage.
And as a general rule, I try to ensure that about 4 to 6 inches of the leaves are still
poking out the top.
Oh, and in this case, I added some more fallen leaves in the paths.
But once each of the rows are covered, that’s it.
And then I just walk away and ignore them again for another couple of weeks.
Now, to be honest, this one hilling is likely enough to get them through the rest of the
season.
But once the plants reach 8 to 12 inches again, we often do a second and final hilling just
in case.
Same as before, I just added more hay around each plant.
Sometimes leaning it up on either side, sometimes fluffing it, and sometimes shoving it in between
the foliage.
Whatever it takes to ensure that no light will make it to the tubers.
And at this point, the paths are doing fine on their own, so I didn’t bother with adding
any more leaves.
That second hilling usually happens right around the time that the first few flowers
begin to appear.
And so afterward, the only other attention they get from us is when we come back to harvest
the spuds.
Speaking of which, here’s yet another advantage to this method.
When harvesting the small new potatoes in mid summer, all you have to do is pull aside
some of the mulch and then pick them off the ground.
Here you can see the original seed potato, still present at the base of the plant.
It sends the roots down into the soil, and then all of these young tubers spread out
around it, connected by stollens.
Then once you’ve collected what you need for dinner, you simply push the mulch back
around the plant and it continues growing like nothing ever happened.
This honestly couldn’t be any easier.
However, I should mention that this ease of harvest is unfortunately a bit of a double
edged sword.
Because easier for us also means easier for critters.
And that’s one of the few disadvantages to this method.
In our case, we had no issues at all for the first few years, but then all of a sudden,
our potato patch was discovered by our very healthy vole population.
And since hay is way easier to tunnel under than soil, they made quick work of what to
them must have seemed like an entire field of buried treasure.
Now, we’ve talked in previous videos about why they may have suddenly become a problem,
and have even been experimenting with alternative methods of protection.
For example, this is our second year using a border of onions, in an attempt to feed
two birds with one scone.
Not only is it an easy and inexpensive option for deterring our fury friends, but it’s
also a pretty convenient place to grow another of our favourite vegetables.
So, if you’re interested, be sure to check out our results of that experiment from last
year, and stay tuned for our second season update later this fall.
But in the meantime, thanks for watching.
And we’ll see you soon.