My Background
As with the taro, I'm pretty much a new comer to growing sweet
potatoes. I started growing them about a year ago. As with
the taro, I got my start with a potato given to me by Andy and Joy
(they are my gardening heroes!). Andy gave me an Okinawan sweet
potato, the kind that are purple on the inside. And so it began...
Note: a sweet potato is not really a potato, but I'm going to call it that anyway.
I started with a single sweet potato. I'm pretty sure that anybody can
do this. I took the potato, put it in container of dirt, added water
every now and then, but mostly left it alone. Eventually vines started
growing out of the potato, so I transplanted it into a small section of
a raised bed. The vine grew very, VERY quickly, and before long, it
was just pretty darn big, and starting to take over.
Lacking
anything resembling patience, within a couple of months I was digging
around, checking to see if any little potatoes had been started.
Not
knowing what I was looking for, at, or how to look for it, I didn't
find anything, and was discouraged. But I left it alone for a few
months, then me and the Shin-meister (my oldest boy) went out and
started digging. And were pretty happy. Within the few
square feet dedicated to the sweet potatoes, we probably got about five
pounds worth. Nice.
After that I built up a raised bed dedicated to sweet potatoes, and
grew out another batch, giving them a bit longer, and in that raised
bed, which I started from slips and plant leftovers, we got a pretty
good take of purple goodness ;o)
The Problem With Sweet Potatoes In Hawai'i
Nah, just kidding. There's no real problem. The closest
thing I had to a problem was finding out accurate information about
growing them, information that was applicable to Hawai'i. Most of
the information I found, both in print and on the web, was oriented
towards the mainland. But sweet potatoes are tropical! Go
figure.
Starting Out
You can start with a single sweet potato. Just get one, put it in
some dirt, water it, and eventually vines will start to grow out of it.
Not a real challenge.
Propagating
Sweet potato can be propagated in a few different ways. One is to
just take small sweet potatoes and bury them (just like when starting
out). Another way is to grow slips. Take a length of sweet
potato vine, and cut it into sections, with a shoot (leaf)/vine combo
making up each section. Put the sections in a glass of water, and
within a couple of days roots will start coming out of the piece of
vine.
I have this theory that if you were having a problem related to leaves,
disease, bug infestation, something like that, you could take potatoes
to a new place and start over and maybe escape from that problem.
If you were having a problem related to the potatoes, you could
start slips and plant those in a new place, and escape that problem.
That might work. Or maybe you'd just be spreading the
problem all over your yard, it ain't rocket science, and I'm no rocket
scientist.
Now, let me talk about re-use. After harvesting my first batch of
sweet potatoes, I was all set to cut up the old vines and make slips
and start all over again in the new raised bed. Then my wife
asked me why. Her theory was that the plant had already gone to
all that work to make this huge vine/leaf mass, why not just replant
it. I didn't have an answer against replanting it, so that's what
I did. And as far as I can tell, I haven't had any problems at
all, nada, zilch. All I did was take that mass of leaves and
vine, throw it on the ground, toss a couple shovel fulls of dirt on
top, then walk away.
When To Harvest
This was a confusing part for me. Most of what I read indicated
that you'd grow the plants all Summer, and when they died, it was time
to harvest. This are apparently mainland U.S. info, because if I
understand correctly, the plants there die when Winter comes. So
basically you grow them out as long as you can, and once they quit
growing (because winter comes...), you dig up the potatoes.
I think in Hawai'i it's reasonable to let them go for about six months.
I think much more than that and the potatoes start splitting.
I had several that were the size of my forearm and hand combined,
and they had experienced some splittage. This is mostly not a big
deal, but it does make the potatoes uglier.
Pests
I don't really understand it. The root is edible. The
leaves/shoots are supposedly edible. And everything I've read has
indicated that the plant is non-toxic (no solanine, no oxalic acid,
nothing). And yet, slugs don't seem to eat it. Other bugs
pretty much leave it alone. I can't figure it out.
The only bug I've seen mess with the sweet potatoes in my yard were
some kind of vine borer. I've had problems with vine borers
destroying my cucumbers, melons, and squash, so I was pretty worried
when I started finding them, they can destroy a plant and the crop
pretty thoroughly. But with the sweet potato vines, it was a
different story. They'd burrow in, dig out some of the inside,
and that was about it. A section of the vine would get fat, and
the surface would become kind of "barky", but the plant would just keep
on trucking.
Soil Or Something Like It
I'd read that you need to plant sweet potatoes in "medium" ground.
Too sandy and the potatoes get all long and spindly. Too
rich, and they have other weird problems.
I didn't have a lot of dirt for my sweet potato bed, so I threw what I
did have, added some compost, added some shredded up cardboard, and
called it good. And that seemed fine. Another interesting
factoid, I'm pretty lazy, so at one point I'd planted all my stuff in
half of the raised bed (the raised bed being eight feet by four feet),
ran out of stuff to plant, and decided I was done with it. I
tossed a couple of chunks of really heavy duty cardboard, whole sheets,
on top of the unplanted area (basically the other half of the raised
bed), and quit right there.
Well, forgot about the cardboard, then the vines overgrew it and
covered it completely. Later when I remembered, I saw the huge
plant mass and just assumed that the cardboard had broken down. I
was wrong. When I went to harvest, I found the sheets of
cardboard still there, still whole. And under the sheets of
cardboard were about nine or ten REALLY BIG potatoes. Right under
the cardboard, on top of the dirt. How weird is that?
I would say that it doesn't take much to grow sweet potatoes. My
next batch I'm going to try using about 25% dirt, 25% compost, 50%
shredded newspaper and shredded cardboard, and just see what happens.
Eating the Leaves
I have read that the shoots/leaves are edible, similar to vine spinach.
I've only ever found one recipe that actually said use sweet
potato leaves, it was a Chinese recipe that had you steam the
leaves/shoots, then pour a mix of a little shoyu, rice wine vinegar,
and sesame seed oil over the top. I would love to find out ways
to eat the leaves, so if you know of any, please email me at
zachary@zone11.org.
Sweet potato recipes.