Sunday, 5 November 2017

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......


Friday, 3 November 2017

The 2017 Harvest - part 2

With rain forecast for the first part of the weekend followed by about five cold looking days and nights, I decided to dig up the remainder of my sweet potatoes whilst the sun was shining this afternoon.

Mixed results again with the last three varieties. The big surprise was Murasaki which was one of the better performers last year. Only a kilo of tubers, several had been eaten and a couple, for reasons only known to them, had started sprouting!


So that slip has been broken off and put into water to start next year's plants...

Next up was Belle Vue. I like this variety as I like the colour of the skin; it's quite a bright orange. It's a steady performer this one; not outstanding but plenty of good sized tubers and a decent yield of 1.3kg.

Belle Vue

And last but not least, consistently the best performer, Bonita. I wish I could love it but with it's pale tan skin and white flesh, to me, it's just not a sweet potato!


A couple of these tubers had been eaten too so my next job is to google (aka ask an expert on Twitter) what's likely to have been doing that and why. I suspect it's slugs and probably because I've left them in the ground later than usual.

So a total harvest of 7.7kg which is quite a bit down on last year's of about 12kg but factoring in 40% less plants, I think that's a similar yield.

Next up in a day or so, what I've learnt from this year!


Wednesday, 1 November 2017

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.


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.


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.


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.


Monday, 4 September 2017

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....

Thursday, 20 April 2017

The 2016 Harvest

Better late than never? That's how the saying goes, doesn't it? As usual I've been meaning to do a post about the result of last year's harvest. And as usual, several months have gone by with no update.

I seem to have a spare half hour or so at 6.30am on a Friday morning, so here goes!

Last year's harvest was a HUGE improvement on the previous years and I think that was due to both starting the slips off earlier AND keeping the plants nice and warm in their polytunnels. The weather in 2016 wasn't particularly warm until later in the year so giving them that added warmth definitely helped. I guess there would only be one way to prove that and grow some plants without cover. Hmmm.... maybe that can be this year's experiment?!

Back to the harvest. I had a decent crop from each of the varieties, with the exception of Burgundy (again). The highest cropping varieties for me seem to be Bonita and Murasaki. Both produced over 2.5kg of tubers from five plants. Both are white fleshed sweet potatoes.

One thing that was hugely different this year was the amount of vine growth, with some of them trailing several metres!

The best cropping variety last year was one of the new ones Orleans. This produced over 3kg of tubers. Once again, Burgundy was quite pitiful with only about 600g of tubers from five plants and they were small ones at that.

It was good to see I had some decent sized tubers this year. There were plenty of skinny ones still but they are still quite useable.

Whilst I seem to have grown slips for each of the varieties for 2017, I may thin out the number next year and stick to the ones that I know are going to produce a harvest for me. I'll probably choose ones which look different too. For instance, I love the skin colour of Belle Vue which has a lighter orange colour to it.

And so on to 2017......

Thursday, 22 December 2016

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.


The 2015 Harvest

I had planted out my first Beauregard slips in the first week of May 2015, having assumed the risk of frost had passed. They were planted in open ground on my allotment. 

I was wrong. 

We had a patchy air frost the first week of June which obviously set the plants back a bit. I did think I was going to lose the plants for a time, but thankfully they survived.

At the end of June I planted out my remaining Beauregard slips together with the Evangeline plant from my friend, Jenny. The Murasaki, Bonita and Burgundy slips were planted out in the first week of July that year. They were all quite late going in the ground as Jenny had received them very late. All were planted in open ground on my allotment. 

It was a difficult growing year in 2015, with that late frost setting things back plus it was never particularly warm apart from one short period. So I had a feeling the sweet potato harvest wasn't going to be the best. As late summer turned to early autumn, it was clear the plants were still behind schedule so I covered them with plastic to make a polytunnel of sorts to give them a bit of warmth for longer

I dug the plants up towards the end of October 2015. The harvest wasn't the best, but it wasn't a complete disaster as I had tubers of each variety that could be used to grow slips for the following year. 

So here goes....the 2015 harvest!

Beauregard. The first plants yielded a few decent sized tubers but only about a kilo in total. 

The ones I planted a bit later were all skinny

The remaining plants from Jenny had little chance of success really as they arrived so late from Suttons Seeds.




And finally Burgundy which was a failure 

So what did I learn this year?

For starters sweet potatoes need their long growing season and they need warmth if the summer isn't a scorcher like 2014. So I think going forwards l'll cover them early on. Covering them will also protect them from a rogue late frost!