For years I’ve been teaching you how to grow sweet potatoes. Actually, for years I’ve been teaching you everything I know about sweet potatoes. How to produce slips, how to plant them, how to keep them pest free, when to up and down swear at them and when to just give them a sideways glance. I even taught you how to make Guaranteed Crispy Sweet Potato Fries with them even though some people in the comments of that post claim they didn’t work for them, but they aren’t regular readers who know how to follow basic instructions. They’re you know … Pinterest people. And they don’t count.
When I first started learning about growing them there really wasn’t a lot of information out there on the big, bad Internet about how to grow Sweet Potatoes. At that time, which was just 10 years or so ago, growing sweet potato slips was a closely guarded secret in the farming community. It was a mystical, mysterious process much like how to do a card trick. Or apply liquid eyeliner.
But I read little bits here and there, emailed a few loose lipped Sweet Potato growers with my questions and before I knew it my slip was showing.
THE OLD WAY
Growing Sweet Potato Slips the Old Way
1. Early spring take sweet potatoes out of storage
2. Insert toothpicks around top of sweet potato
3. Rest in jar of water and wait for it to root / produce slips in 2 weeks – 2 months.
This is how I’ve grown my Sweet Potato slips for the past 10 years. Around this time every year I bring a couple of sweet potatoes out of storage, stick a few toothpicks around the top of them and rest them over jars of water. Depending on the mood of the sweet potato, slips will start growing out of it in anywhere from a week to two months. Slips are those vines growing out of the sweet potato by the way. They’re what you plant in the ground to produce sweet potato plants.
As you can imagine, this whole maybe I’ll sprout today, maybe I’ll sprout when it’s way too late to plant me, attitude of the sweet potato got old fast. You never know when sweet potatoes are going to actually agree to sprout so you have to start them WAY in advance of when you actually need the slips to be developed on the off chance they’re going to go the “meh …. maybe in 2 months” route.
They are much like Luffah Sponges in that way.
Which got me to thinking. Maybe the trick I used to get my Luffa seeds to sprout consistently and early would work for the sweet potatoes.
And it did. But I had to change one other thing up too.
This year instead of starting my sweet potatoes in jars of water like I normally do, I tried something new. I planted them in a pan of soil. Nothing fancy, just an aluminium roasting pan from the dollar store that I poked holes in the bottom of for drainage. Then I sat it on a seedling heat pad and waited.
THE NEW WAY
Growing Sweet Potato Slips the New Way
1. Place whole sweet potato(s) lengthwise in a pan of soil so the soil comes halfway up the side of potato.
2. Place the pan on a seedling heating mat.
3. Make sure the soil stays moist and wait for it to produce roots / slips in 2 weeks or less.
A few weeks later the sweet potatoes had rooted and produced enough sweet potato slips for my entire garden.
It’s the magic of the heat pad. And also the magic of growing in soil (mixed with compost) that has actual nutrients in it. The slips grown in just water look positively anaemic compared to the soil grown ones. This is also an example of the magic of always, always evolving and trying new things.
Sure I’d already had success growing sweet potatoes slips and I could have stuck with that forever and ever. But I tried something new and my slips are better, stronger and have a way more predicable growing timeline.
If you want to continue growing your slips in water that’s fine. It won’t make one iota of difference in terms of the quality of sweet potatoes you get at the end of the summer. Your plants will be the same size by August and so will your sweet potatoes. Growing in soil on a heating pad just gives you slightly stronger slips (less likely to croak on transplant) and a better guarantee of growing within a few weeks as opposed to a few months.
All the Sweet Potato Information You Need
How to Cure Your Sweet Potatoes so they’re SWEET. (info is near end of this post)
It ain’t that hard. Any of it.