It may be frigid out there but there are lots of dreams of summer's heat manifest in sweet potato seedlings from last year. Below you'll see sweet potatoes that you have NEVER seen before. Never unless you saw some of my pictures on Facebook that is. Why? Because these are from true botanical sweet potato seed. Each seed contains its own jumbled genes of a unique individual rather than clones of a particular variety (I've got lots of those growing too).
Seedling Sweet Potato Selection
My seedlings from last year (from three seed sources which included seed produced minimally here) were cut. I didn't do it last fall as I wanted to test them for storability under my conditions first. Sweet potatoes are stored warm, by the way, and mine are stored in a wooden chest by a wood stove.
White is apparently semi-dominant, which was certainly the case for my seedlings. White and purple made up the majority of my plants. Purple ones tended toward being longer season or spindly - both of which aren't interesting to me but I did get a few that were exceptional purples/reds with shorter, stouter tubers. I also got a few bronze skinned-white fleshed ones that might be worth growing as I get requests for these sort of starchier sweets quite often.
Most were smooth skinned but as you can see on the right, there were a few that were bumpier. Perhaps this is more common in wild types. White and purple, by the way, tend to be drier and less moist making them better for certain types of recipes like chipping and stewing. I did get two oranges within 2017's seedlings. The pale orange that you can see here and a stouter, shorter darker orange.
I sorted the sweet potato seedlings by form, colour and podding ability first then tasted some of the more interesting ones. The best seedlings were put in a tray for slipping.
One of my favourites was a red skinned, red-purple fleshed one with good yield. We'll see how it does this year!
Last year, I instructed two partner farmers as part of the West Carleton Calorie Project to look for and gather seeds for me. Myself and Our Farm had success so these seeds have been started for this year's trials!
I look forward to comparing yields with 2017's seedling tubers and common short season cultivars like Covington, Beauregard and so forth.
Hoping for a little luck and summer sun to keep this project rolling into 2018.
Given how wet it was this year, I was not expecting particularly good yields but maybe that one or two weeks of warmth late in the season made up for the near absence of direct sunlight most of the year? Probably not but sweet potato shows that it is adaptable once again. The above picture is of one of my non seedling rows.
Here is a compilation of various tubers from seed. Some look quite promising. There was a large variation in colour, texture, vining and leafing habit. The best yielding and flowering varieties were saved separately for seed production next year where the rest will most likely be eaten.
I had a terrible problem with June beetle grubs this year as well meaning that almost all my Yacon in one part of the property were destroyed. I had to rescue the true seed seedlings, meaning now I have to baby them all winter - grumble. I'd be without Yacon if it weren't for my family plot in another part of the property. Diversity (of planting locations) wins again.
Plans for 2018
* I have quite a few true seed to grow out.
* The best yielding, florific plants with good tuber characteristics will be used as seed parents.
* I'm looking for 2 more farms to participate in the West Carelton Calorie Project. This includes getting to grow out some unique varieties of sweet potatoes!
There was quite a bit of variation in growth habit, leaf form and colour. Early tuberization was found in all three seed sources which surprised me as I was expecting it to be pretty much non existent in the tropical source. However, it is possible that they are growing shorter or more 'day neutral' varieties in the tropics as well. That said, there was more of a tendency toward longer vining and later flowering in the tropical seed source than in the Swedish short season derived one.
Some of the short season seedlings were very florific! These also tended to set the most pods. I'm looking forward to what that means in coming years. I did get flowers and seeds off of my short season slips as well though less.
The best pod forming row was the one with the seedlings and short season slips by far! The two other plots that contained no seedlings set seed minimally. Our Farm had a decent seed set though said that one end of their row produced seeds much better than the other. This is almost certainly because the right 'parents' were there. Purple seems to be a good pollen parent. The other farm site suffered more from flooding and hail than the other two locations so didn't get any seed set.
I did some minimal pollen transfer at the beginning of the flowering season but mostly left it up to the plentiful bee population. There were bumble bees, various native bees and honey bees visiting the flowers. They were often frustrated by how quickly the flowers closed. You could see them trying to enter the flowers that were already twisting shut by mid to late morning. The lack of sunny weather meant there were probably less opportunities for pollination but still I managed to get a fair number of ripe pods and seeds.
Most pods contained 1-2 seeds though the occasionally one had more. I inspected frequently so as not to lose ripe pods in the abundant leaf cover and litter below. Once the stem connecting the pod started to yellow, the pod was ready so I tended to harvest at this point.
This year, I had three sources of true botanical sweet potato (Ipomoea batatas) seed: 2016 produced seed from short season sweet potatoes from Sweden, tropical seed and minimal seed produced here at ALE.
All seed germinated readily. Generally I scarify then soak for a few hours before sowing but this might not even be necessary. The Swedish and ALE seed was started perhaps a week before the tropical seed source, near the beginning of March. I wanted hefty seedlings at planting out time. You can read more about the seedlings here.
Only one of my seeds managed to make it to the end because of a series of calamities! The other two sources both did very well. There was lots of variation evident from cotyledon onwards.
I grew them in cups because of their deep root systems. If I were feeling more confident about their ability to thrive at planting out, I would have started later and set out younger seedlings. They were grown under lights.
2017 was a very wet growing season. Rivers, creeks, ditches and even fields were at spring melt levels repeatedly, basements flooded, roads were washed out and the rain kept coming. Late spring was marked by hail storms AFTER planting.
I had two other farmers growing out mix of short seasons sweet potato slips as part of the West Carleton Calorie Project. Below are Kate and Katie from Our Farm braving the endless rains. Sweet potato row is in the foreground. They also grew out sea beet, moschata landrace and true potato seed along with some eggplant, pepper and cabbage crosses that weren't officially part of the WCCP.
I've had excellent germination on seeds sent to me by a fellow sweet potato enthusiast in Sweden, some seeds sent to me from a warmer local and from my own (albeit limited) seeds grown out from short season sweet potatoes here.
Germinating Sweet Potato Seeds:
They seem to germinate easily after scarifying by clipping carefully with a nail clipper away from the root and soaking. You can continually soak until you see roots or soak until seed coat starts to swell and crack. At this point, they could be direct sown into deep containers - they have quickly growing and long ranging roots - or you could monitor them in the baggie method somewhere warm. Took 1-2 days for most seeds with swollen seed coats to germinate fully. The rest took up to a week.
Seedlings start off slowly raising out of the soil, shedding their seed coats and setting out roots. The cotyledons (seed leaves), that look like butterfly wings and betray their morning glory relations, grow quickly in vigorous seedlings.
What I've learned about growing seedlings so far:
1. Make sure you bury the germinating seeds so that the seed coat properly softens and is easily discarded by the unfolding seed leaves. Soaking slightly longer may also help with this process. The seedling should be pulling itself out of the soil.
2. Slow and struggling seeds have not improved much several weeks in. I have about three seedlings that had damaged seed leaves at emergence and now have undersized true leaves. These will be discarded shortly.
3. Seedlings benefit from warmth.
Cotyledon shape varied slightly in shape and colour. The Purple Selfed emerged unsurprisingly as purple though the true leaves are so far light in colour. Most seedlings have emerged with yellow to bronze to purple baby leaves that have greened up afterwards.
I started one set quite early in order to set out robust seedling (because of an issue last year) and started another set recently. Plan to grow on inside and then in the lean to greenhouse before setting out to see what treasures they may grown beneath!
I had several Allium projects going this year, one was a biennial bulb onion, Allium cepa trial which managed to be massacred by a voracious legion of cutworms, leading to several replantings with heavy losses and a vow to try again next year.
The other was multiplier onion, Allium cepa aggregatum. Unfortunately, I lost a lot of shallot type to the same voracious cutworms forcing me to collar (protect each seedling) the replanting. Finally the darn things subsided and I got some growth, including regrowth of some that had, had their tops toppled. Like 2015, and all the years before, the multiplier onions were significantly more robust for me than the biennial bulbing onions, even those bulb onions that made it through the cursed cutworms with extra wide spacing (since all their neighbours had been eaten).
I'm pretty sure that the lesson here is to focus on multipliers though the stubborn streak in me means I have some promising biennial onion seeds, that I've been collecting, to try again.
Back to multipliers. My goals are two-fold. Firstly, I'd like a nest of four or more mid sized bulb onion with an easy to use shape that stores well over winter and has a pungent, pleasant taste. I'd like to maintain good seeding on top of nesting in order to continue to select. Secondly, and more fancifully, I'd like to mix up the colours a bit more with some reds, whites, roses and whatever else comes along.
I've been receiving a wide array of multiplier seeds for a number of years now. Included are seeds from Kelly Winterton's project, any seeds I could get from the usual potato onions floating around, seed grown (Allium cepa) shallots and a number of other more mysterious ones just labelled 'multiplier.'
Though I did have a few that had white skins and a few others with a touch of rose, most of mine are golden like these below. More variation was seen in the shape and orientation of the bulbs in the nest.
I had a good harvest this year considering the drought. Seed set was adequate. All the best candidates were fall in some large rows with wide spacing in order to maximize harvest of both bulbs and seeds for 2017. I am planning on adding more variety in the base population, especially to replace material lost to those nocturnal chewers.
I suppose if there is one thing about drought, it is that it usually comes with heat, and since sweet potatoes like heat, this year's harvest was AWESOME. Some of my field mate's sweet taters were the size of her forearm. Well performing Georgia Jets were the size of bowling balls! In fact, it was somewhat challenging to find mid-sized bakers to sell to a local CSA that didn't manage to get their sweet potato slip order in on time.
I mostly slip my own plants from those with good storage, yield and eating qualities that were also good at flowering and setting seed from 2015. More slips were planted from two suppliers: Mapple Farms and Burt's Greenhouse - this was part of a large group order for my Facebook group Edible Ottawa Gardens Group (thank you to some industrious members who did the heavy lifting on this one). We planted around the end of May.
Plants established and grew well in the newly cleared field and existing beds. Though we did get an excellent harvest, flowering was delayed compared to 2015 and seed set was minimal. And by minimal, I mean I think I got three seeds or maybe four. At any rate, not stellar. Thankfully, I have been sent a nice batch of seeds to try from a couple fellow plant breeders, including some produced in a shorter season European climate. I am exploring options to help stimulate seed set for 2017 especially as it is slated as one of my super-crops for a longterm project.
I plant in approximately two foot diamonds (all the way around) and water only for establishing. I don't believe I gave them any rescue watering even in the worst of the drought as they recovered in the evening. If I did, it was maybe once or twice. They were dug in the third week of September as temperatures started to fall. Below left, you can see one of my rows and below right is Farmview's Gardens harvest from the shared field here. He uses a pitchfork like you are supposed to. I tend to dig immediately around the plant with a slicing spade (I don't slice on purpose) as I find that, at least short season varieties, cluster just beneath the plant (My favourite shovel's name is Sherman). The purple that we grew this year did have quite a few far flung tubers though I suspect it's a longer season variety. Yield was 0.5lb per square foot.
I also tried a tuber planting experiment as I've often heard people telling me they just put the whole seed-tuber in the ground. They did pretty much nothing for me except produce greens so I wouldn't recommend it as a technique at least in this climate.
You would not believe how giddy this makes me but growing under my lights right now are five precious sweet potato babies. Now before you wonder why this is exciting or that you've heard all about this sort of thing before, let me do my common name security check in the form of questions.
1. Did you know that Solanum tuberosum - potato - is not in the same family as Ipomoea batatas - sweet potatoes? True Potato Seeds (TPS) is also a thing and it is arguably easier to get potato berries than sweet potato seed.
2. Did you know Sweet Potato is generally vegetatively propagated by slips?
3. Did you know that each seedling represents a new variety?
4. Lastly, do you have a bunch of TSWPs? You do? Really? Are you a giant research station? No? Wanna chat? Yes?!?
Okay, so last year, I got lucky. Or to be more accurate, my sweet potato flowers did...courtesy of bees and my own pollen transference. I got a very small quantity of seed. I wasn't sure if they'd sprout. I used the warm baggie method and waited and waited. A few rotted. I was getting a little disappointed but always the hopeless plant optimist, I scarified, soaked and roots!
Each sprout is a new variety. Probably all five little guys are nothing special BUT small steps. I'm hoping to get a much higher seed set (weather etc... cooperating) this year in order to do a larger sowing with selection.
Well, exploration is its own reward no? Other than that, I have a hankering for a zonally purple-orange sweet potato. The above cross is Purple x Georgia Jet so maybe? I'm also adding some other flowering types to the mix this year. Ultimately, my goal is a short season variety with a nice shape, good storage capacity, nice taste along with being highly nutritious (using colour as a proxy for vitamin content). An increased ability to flower and set seed would be a bonus allowing for further selection
Fascinating article about the nitty gritty of sweet potoates
One of my favourite storage crops is the sweet potato and despite what you may have heard, they do grow well in the Ottawa area assuming you choose a short season variety and you remember that they are heat divas.
I've grown various ones in the past including Covington, Beauregard, Fraiser White, Georgia Jet, Japanese Yam, Cuban Red, Purple, Tainung 65 and Mystery. Generally speaking Georgia Jet is not only the highest yielding plant in my gardens but also most likely to flower.
Flower? Why should I care about that? Sweet potatoes are obligate out crossers meaning they require at least two genetically distinct individuals to produce seeds. As sweet potatoes are normally grown by slips, each new plant is a clone of its parent tuber. Not all sweet potatoes flower at the same time or with the same fervor. So assuming you have two different types of sweet potatoes in flower and that they are pollinated and that they have enough time to grow then - fingers crossed - you'll get seeds.
As they contain recombined genes from both parents, each seed is a surprise package.
Most of these new sweet potatoes are likely to be nothing special but… BUT… occasionally they will create a new important variety. So when both Georgia Jet and Purple started to flower, I started doing the plant breeding happy dance.
I watched. Bees visited. I waited. Flower upon flower fell off. Potential seed pod upon potential seed pod dried up. I obsessively checked every day. And...
A few started to swell with promise. We had seeds!
Cold weather loomed and I was forced to harvest but I protected my potential plant parents and their precious seed pods. Harvesting as they started to dry down.
The bare minimum of success. Next up, will any of them sprout.
All about growing, selecting and using edible plants in the Ottawa valley.