Saturday, 18 February 2017

Growing Sweet Potatoes

Growing Sweet Potatoes

Something that I had not thought about before was the Sweet Potato. I had no idea what you needed to do in order to grow them until I read Mary's Veggie Garden post about the subject. Her post said:

 "I placed this potato into the glass jar 3/1/2008.  A week later I spotted its first root and by 3/17 it had several 1/4″ roots. Around 4/12 the first slip slowed as a tiny bump near the top."

It looked like it would be a process that needed months and I started mid January, pleased with myself that I had started on  time. Of course I miss read the date, the month is first, and so I've started at least 2 months early!

The process looked straight forward, firstly put a Sweet Potato, up the right way, in a glass of water. After a few weeks when you have roots, place it into a pot of compost so that it doesn't rot, then wait for the shoots, called slips, to start growing.

Secondly, when the slips are big enough cut them off and place them in a glass of water, when they start rooting, pot them up. 

Lastly, after the chance of frost has gone plant out.
1st Step
2nd step

It all looked easy but the first step of putting the potato in a glass up the right way caused a bit of a problem. Which end is the top? My potato was rather pointed at both ends. The end where the stem had been removed looked identical to the end where the end of the root had been cut.

Eeny, Meeny, Miny, Moe sorted it out. 

No problems so far, until the roots started. A few days after the roots came the first slip. In fact loads of roots and loads of slips started, all at the bottom! There were about 10 slips starting right at the very bottom and one at the top.

You'll notice that the 1st step photo shows the potato up the other way compared to the 2nd step photo. This is because I forgot to take photos when I started and I have started a 2nd potato off. (Actually I also started a 3rd).
3rd step
I wasn't sure that all the little slips at the bottom (which was really the top) would grow and survive as they were about to be under the compost for the 2nd stage but I did have one slip at the top so I continued just expecting 1 slip to work.

A few weeks later that one slip had grown to 8 or 10 inches so I placed it into a glass of water (step 3) and am waiting for roots to start. The slip grew very fast.

After removing the slip I left the potato in its pot hoping another slip or several slips would now grow.

We went away for a few days and when I returned was surprised to see that not only a few other slips had started but most of the slips that started at the bottom had now grown through the compost.

Rather then the odd one or 2 slips that I had expected, (because it was upside down), and Mary's post explained that depending on how she grew them she got between 3 and 9 slips, I have so far got 21 slips showing and I don't think that all of the ones that started at the bottom have broken through the compost yet.

This photo doesn't do it justice and it's hard to see all the slips but there are 20 slips left on this potato.

So far I've learnt that it doesn't seem to matter about being up the correct way (although being up the right way may be better) but the bigger problem is going to be keeping them warm enough until the end of the frosts considering how quick they are growing and it's only mid February. These slips are going to be my experiment but I have a feeling that I may have to start again mid March although I'm sure that 1 or 2 can go into the Poly Tunnel and maybe another 2 can go into large pots in the green house but there just won't be room for the others to be nurtured for another 3 months.

If you are thinking about growing Sweet Potato I would suggest you don't start until Mid March and give Mary's post using the link above a good read.

For now I will let the slips get to about 8 inches, remove them, and then see just how many slips can be started from one potato.

Update 2nd March
In no time at all the slips have grown massively. 5 taken off already, with 2 of them having roots of their own (in the glass). There will be at least 20 slips coming from this one potato!

The 2nd potato also now has a few slips starting although these are only from the top. I'm beginning to think the potato should be started upside down as the one in the pot. The one in the glass is the so called right way up.

Click on the photos to enlarge.


  1. Where did you get the sweet potato from? Was it just a supermarket one, or a special variety? I know people have been trying to breed ones that do better in the UK climate. Here's an article from the Guardian that suggests a combination of selective breeding and mulching for frost resistance:

  2. I bought it from the local market fruit and veg lady. I forgot to ask the variety but I will do on Friday. I texted her and asked her to bring 3 good ones with her because I knew she wouldnt have any so she went out of her way to get them for me.

    It probably came from Lincolnshire as she tries to get the local produce when price and quality is right.

    1. Did you find out the variety?

    2. No, I forgot. Next week may be. I would like to know, it's just a matter of remembering to ask :)

  3. The lady didn't know the variety apart from they were called "American"...I didn't ask "from America" or "is the variety called 'American'" as I didn't think she knew.