Conclusion aka What I Learnt this Year

So, another year of growing sweet potatoes under my belt. And what have I learnt this year?

I think the main conclusions to draw this year is the confirmation that some varieties are more suited to my soil and weather conditions. The darker fleshed varieties probably like somewhere a bit warmer as both Burgundy last year and now Evangeline have struggled to produce a decent harvest.

My top three last year were:

Orleans (3kg)

Murasaki (2.5kg)

Bonita (2.25kg)

This was from five plants of each variety don't forget.

This year my top three were:

Bonita (2.5kg)

Orleans (2.1kg)

Belle Vue (1.3kg)

The actual harvests were less but I then only had three plants of each variety. Looking at the overall yield (calculating the total weight of the tubers harvested divided by the area of ground the crop took up on the plot) was less too; 2.23kg/sqm vs 1.6kg/sqm. But again this may purely have been because I had less plants in effectively the same area i.e. three plants per tunnel instead of five so a better comparison may be made next year if I only have three plants per variety again, which I think I will as even 7kg of sweet potatoes is enough for me!

So I think I can safely assume I should get about 2kg of tubers per row going forwards. Is it worth the effort and amount of space they take up on the plot? Possibly not, but I do enjoy growing them. They provide a talking point and now that I have a full plot, it's not like I'm struggling for space anymore!

Last year I had problems with a soil borne fungus called scurf that affected the skin of some of the tubers. The flesh of the potatoes underneath was ok, they just didn't look very nice as the skin was all dry and black. I chose healthy looking tubers to grow my slips for this year and luckily all the tubers I've harvested are ok.

This year's problems have been something eating at a couple of the varieties while still in the ground, probably slugs and possibly because I left them in the ground too long.

 

Indeed, I found most of the skin of one huge Murasaki tuber that had been eaten away!

And the other thing to note is some of the vines rooted themselves.

When I dug them up it looked like these new plants had been trying to produce tubers.

I think in trying to do so, this took away a lot of strength from the main plant so its tubers were smaller. These were from Murasaki which didn't produce as good a harvest as I was expecting. A possible solution, if it happens again, might be to cut these rooted plants off from the main plant and see if these new plants produce any decent tubers.

I'm going to see if I can source another variety to try for 2018, there's a couple more I have seen from seed companies here; Carolina Ruby and the delightfully named T65 are a couple.

In fact the 2018 growing season is already underway as one of the tubers decided to produce a slip whilst still in the ground!

So I have broken this off and put it in a water to encourage it to grow a few roots before potting it on.

And the cycle continues......

Joanna

The 2017 Harvest - part 1

We had the first frost of the winter a couple of days ago which was an excellent reminder that I really ought to dig the sweet potatoes up now! I've usually dug them up by about the third week of October in the past but a busy few weeks have meant I just haven't had the time, plus luckily until last Sunday we've had really warm weather for autumn so the plants have been quite happy in their little polytunnels.

This coming weekend is also showing a couple of very cold nights with temperatures hovering just above freezing so this week is the week they are getting harvested.

I've been weeding the sweet potatoes recently anyway so had a inkling there might be a few tubers just under the surface. In fact, they really are clustered below the main head of the plant and are peeping through and pushing the ground up at that point.

The first row I dug up were Orleans. This was a new to me variety last year and it was quite productive with a yield of 3kg from five plants. This year I decided to limit the number of plants I had of each variety to three but even so, the yield this year is 2.1kg from those three plants and the biggest tuber weighs 450g.

Orleans

I'm quite happy with that harvest.

I dug up two further rows this afternoon but both were disappointing. I knew the first one, Evangeline, wasn't going to amount to much as the plants never really got going with very little vine growth. A measly 220g from three small plants.

Evangeline

And what's more, look at those two bigger tubers; something has been eating at them! I guess they must be sweeter?

The next row, Beauregard, was little better; 600g from two plants.

Beauregard

At least there are some potential tubers here that I can use to grow next year's slips. I have a feeling that I'll struggle to use any of those Evangeline tubers for next year.

So, it would appear that my experiments so far are running true to form; that the white tubers are the highest yielding for me rather than the darker fleshed ones. I have yet to harvest the Bonita and Murasaki but they both had so much vine growth again, I'm sure there are plenty of decent sized tubers down there. I have struggled with Evangeline each year so it may be time to say goodbye to this variety.

And lastly, a couple of little anomalies; firstly a couple of the vines have rooted themselves.

Not quite sure what that means. Will them form separate plants? Would tubers form underneath them amongst the roots? Can I cut the vines and treat them as new plants?

And finally....why are some of my tubers so twisted and contorted? Just the ground conditions? I can grow straight carrots, so why not sweet potatoes?!

I'm hoping to dig up the last three rows before the next frosts are due at the weekend so will do a final update then.

Joanna

The 2017 growing season

Just a quick update on how the sweet potatoes are fairing this year.

I tried growing slips as usual from tubers I grew last year. All produced a good number of slips with the exception of Burgundy. The tuber I'd saved just stubbornly refused to grow any shoots. It made a half-hearted attempt to put out some roots but even these were pretty feeble. As I've done previously, I wondered if I'd got the wrong end of the tuber in the water. So I turned it upside down and tried again, with no joy. So I'm afraid it's farewell to growing Burgundy sweet potatoes. They just don't like it here.

This year I put my mini polytunnels out on the allotment before I was ready to plant out each set of slips. Thought it might help to warm the soil for them. They were planted out during May.

The photo below was taken at the end of August.

From the bottom of the image up, the first row is Evangeline. These slips weren't particularly big when I planted them out and there isn't a huge amount of vine growth yet. Likewise with the next row up, which is Beauregard. Next comes Belle Vue followed by the very healthy rows of Bonita and Murasaki. Just about in view at the top of the image is Orleans.

So it looks again that the white tubered plants of Bonita and Murasaki are going to produced the best crop. I'll find out in a couple of months!

Already I'm thinking I might try and source a couple of new varieties to replace the poor performers. I don't know why, especially as they taste pretty much the same, but I still prefer the 'usual' coloured tubers....

2016 - And a New Plan

I had a new plan for growing my sweet potatoes this year; if I started growing the slips earlier then surely the plants would be bigger and stronger when it came to planting them out! If they were bigger and stronger then they would fend off frost attack better and just generally be ahead of where they were in 2015?

So instead of waiting until early 2016 before starting off my slip growing, I started them off towards the end of 2015, in November/December. I followed the same method as before, selecting a decent sized tuber and putting into a jar of water to encourage it to start growing roots and slips.

I had managed to save tubers from all of the varieties I grew in 2015 with the exception of Burgundy. The tubers I harvested from that variety were just too small to produce any growth.

The remaining tubers produced slips as expected and I potted on the first ones towards the end of December 2015.

I started planting out the plants towards the end of May this year. All the plants were bigger and more healthy looking than the previous years.

My other part of this year's plan was to cover the plants in plastic for the whole time they were planted out. Sweet potatoes need a long warm growing season. I can give them a long season but the warmth is something that can't be guaranteed in the UK so I bought a bunch of mini polytunnels from Marshalls Seeds, figuring that should keep them nice and warm all year and would also extend the growing season each end.

This year I've also been lucky enough to trial a few more varieties, one was Burgundy and the others were Orleans and Belle Vue. These all came from a wholesale grower in Ireland, Fiztgerald Nurseries, these were all planted out in June.

The new to me varieties:

Orleans - a light rose skin with orange flesh

Belle Vue - a light orange skin with orange flesh.

I was quite excited to try these new ones as well as have another chance to grow Burgundy which is supposed to have the best taste.

Joanna