Wednesday, April 23, 2014

Oca: Seedling transplant perils

We have over 1000 oca seedlings this year and have been planting them out for several weeks.  Most are about six inches tall with a single stem, but there is quite a considerable range from spindly plants that are still less than two inches tall to 18 inch tall multiple stemmed plants.  We can't manage this many plants indoors, so the plan has been to grow them in the field.

So far, we have hardened off plants for two weeks, then planted them out in the field slightly deeper than they were in the pots.  This has generally worked well for oca from tubers and cuttings.  It appeared to work well for the seedlings at first.  Then the wind arrived.

We live on the coast, where our dominant spring/summer weather pattern is created by inland warming.  As inland air rises, cool winds flow inland off the Pacific.  That means that any time the weather is clear inland, we have winds that start in mid-morning and last until evening.  They are not particularly strong, but may blow at 15-20MPH all day long.

Oca is generally pretty resistant to wind, although it sometimes causes us problems with flowers and seed pods dropping.  So, I wasn't too worried when we got a week of such winds after planting out the first bed of oca seedlings.  That was a mistake.

Oca seedlings have much less tolerance to wind than tuber-grown plants or even minimally rooted cuttings.  Two days of steady wind badly damaged about 400 seedlings, to the point that I am not sure that more than a small percentage of them will survive.  That is certainly a disappointment, although the sting is relieved somewhat by remaining seedlings that had not been planted out and the promise of more seed this year.

The question is: what should I try next?  I could harden the seedlings off for a longer period, although  moving a thousand plants in trays in and out of shelter every day for weeks may not be possible.  I'm considering two possibilities and may try both.

The first option is to wait and start seeds outdoors.  We get volunteer seedlings here, so I know it is possible.  They are very slow growing compared to plants started indoors, but they also are able to withstand the rigors of the environment.  So, perhaps starting batches of seed outdoors in April may provide hardy, transplant-ready plants by July or August.  There is definitely an appeal to the labor savings.

The second option is to grow the seedling generation entirely indoors.  Even a plant only four inches tall is capable of making mini-tubers.  I could start plants indoors and put them in total darkness once they reach a certain size.  The mini-tubers could then be planted out to the field with the greater hardiness of tuber-grown plants.  The additional advantage is that multiple tubers will often be produced, which provides some backup.  I think four months should be sufficient to produce mini-tubers.

Of course, neither option solves the immediate problem, which is the remaining seedlings that I have to plant out this year.  As I am limited by time (although our success with the store has raised the possibility of doing this full time eventually, it remains a hobby for now) I'm just going to have to harden them off a little more and keep planting them out.  Some will survive, but more will not.  I think that I will try planting them deeper and at an angle in order to put more of the stem underground.  This will reduce wind exposure and provide more opportunities for the plants to resprout if the topgrowth is damaged.

On the up side, this year will definitely select for hardier varieties.  Even if only a tenth of the plants survive, that is a lot of new oca to evaluate and the education that I've received in raising so many plants to this point will certainly pay off in future years.

Hopefully some of you who are growing from seed this year will read this before you repeat my mistake.  I would be interested to hear what you try and how it works for you.


Tuesday, March 25, 2014

Oca: Mini tubers from 2013 seedlings

A side note to start with: Northwest Edible Life invited me to do an introduction to Andean root vegetables, which has gone up today:

http://www.nwedible.com/2014/03/andean-root-vegetables.html

I'm really pleased with how it turned out.  Northwest Edible Life is a great blog and definitely worth checking out if you're reading here.

-----

This will be just a quick post to give you a peek at some tubers from 2013 August-sown oca seedlings.  These plants, for whatever reason (ahem... neglect), died over the winter and I just got around to digging them.  The tubers will be replanted shortly (very shortly in the cases of those that are already sprouting).

It is hard to draw any conclusions from mini tubers about the ultimate size and yield of an adult plant, but they do give a preview of the tuber colors at least.  These were all out of the Hopin x Sunset cross and their parentage is obvious in some cases; the top right and top left look a lot like Sunset, while the second from top right looks a lot like Hopin.  White tubers seem common and I imagine this is probably the color of the tubers of oca's ancestors; a lot of tuber-forming Oxalis appear to have white tubers.

Some mini tubers from 2013 oca seedlings

Wednesday, March 5, 2014

Oca: Lifespan of cuttings

We overwintered quite a few seedling oca plants this year.  These plants were started from seed in August and only a few produced tubers before the end of the season.  I wasn't sure what to expect - if the plants would form tubers indoors, if they would grow through the winter, or if they would just suddently hit their expiration date and die off.  Our results indicate a combination of the above.

Fall cutting from an oca plant that formed tubers
Notice that the main stem has died and that it
has formed no roots.
Cuttings that we took from plants that had not yet set tubers grew through the winter.  They have rooted and appear to be growing like any other oca plant.  I've been planting them out this week and I anticipate that they will grow through the season like any plant started at this time of year.

The cuttings that we took from plants that had formed tubers are the more interesting case.  Until recently, they looked as healthy as the other group of cuttings and they continued to grow indoors through the winter.  About a month ago, I noticed that many of them were forming aerial tubers.  The new growth branches began to thicken.  Over the past couple of weeks, it has become obvious that the old stems are dying.  On pulling them from the soil, the cause is clear: none of them formed roots.

The division between the two groups is very clear.  Every cutting from the plants that had not formed tubers has well developed roots.  Every cutting from the plants that had formed tubers has no roots.  In addition, the stumps of the original plants, which obviously had roots, died back as well.  So, it is not just a failure to form new roots; the roots on the original plants appear to die off after tuber formation.

The new growth thickens into aerial tubers
These can be plucked from the dying stem or
will eventually fall off on their own.
Each can be planted and forms a new plant.
So, it appears to me that oca is only perennial through the formation of new plants from tubers.  Even in a mild climate where the plant is not killed by frost, the mother plant eventually dies off to make room for its tubers to start the next generation.  The sample size is pretty small here and this doesn't remotely resemble a controlled experiement, so there may be other factors at work, but the limited evidence seems to point in a pretty clear direction.

This is an important consideration for the oca propagator.  Plants can probably be continued from cuttings indefinitely as long as the plant is not allowed to form tubers.  Cuttings taken from a plant that has formed tubers will be an intermediate step toward the production of sprouted aerial tubers which can be separated and replanted.

This may also provide interesting fodder for future experiments.  It appears that oca produces a chemical signal that probably both starts tuber formation and triggers senescense in the existing growth.  Either the signal persists for such a short time that the new growth (tubers) is not affected by it or the new growth produces a chemical that counters the signal.  The safe assumption is that this signal is produced when daylegth falls below a certain threshold, although it appears that it also requires plants of a certain size before this can happen.  That may be an indication that the new growth produces a countering signal and that the tuberization signal may actually be a long-lived event.  Is it possible to force a plant to produce this chemical signal by moving it into dark conditions and then transfer the chemical, perhaps by sap inoculation, into another plant to force tuberization?  If I have time to play around this year, I will do a few experiments.

Wednesday, February 26, 2014

Sea Kale: Forcing time has arrived

Sea Kale (Crambe maritima) is an excellent vegetable for the perennial garden.  All parts are edible, but some are tastier and require more work than others.  For my palate, there is a tie for best tasting part between the flower buds (like broccoli) and the blanched shoots.  Shoots come early in the year, anywhere between February and April here, depending on the weather.  This year, we're getting them right on the average.

Ideally, you want to get the new shoots covered up as soon as they emerge.  If you're smarter than I am (or have fewer plants), you might mark them all the prior year so that you know where they are.  If you are lazy like me, you just wait until you see them coming up and then cover them.  You may pay the price in a little extra bitterness if you wait too long.


Here is what you are looking for.  This one is actually several days past when I would normally want to get it covered, but it will still be OK.


Just cover the emerging shoots with something that blocks light and check on them in about two weeks.  You can continue this process profitably for up to two weeks per year of age on the plant, up to four weeks.  If you continue too long, you can kill the plant.

In the absence of light, the plant will produce long, pale shoots that you can use just like asparagus.

Some people use lovely ceramic forcing pots for this job.  I use paint buckets and bricks.  If you do use a bucket, make sure it is a dark color.  I found that white buckets didn't block enough light.  I recommend drilling some holes on the north side of the bucket for ventilation.

Friday, January 31, 2014

So, you want to grow ulluco...

Interest in ulluco has taken a big jump the past couple of days, with the giant Baker Creek Seed company doing a bit of blogging about it on Facebook.

Half a dozen varieties of ulluco grown at the coast of Washington state
We're excited that they are taking an interest, because their ability to reach people and educate them about ulluco far exceeds ours.  The more people who know about ulluco, the more people who will be interested in growing it, and that is a rising tide that lifts all ships.  Baker Creek hasn't come right out and said whether or not they will be selling ulluco, but reading between the lines of this and some other recent announcements, I assume that they will soon be in the tuber business as well. Hopefully they will make good use of their power to import more varieties!

I hope that I haven't lost you in that long introduction, because the main purpose of this post is to share a little information with those of you who are new to ulluco and interested in growing it.  We had a big burst in orders yesterday and I am now in the process of reversing some of them because people were a bit too quick to click the buy button.  Ulluco is not a crop that will grow just anywhere; it has unique requirements that you should be aware of before parting with your hard-earned coin.

What is ulluco?

Ulluco (Ullucus tuberosus) is a tuber crop that was developed in the Andes mountains of South America, a process begun by the pre-Incan peoples of that region.  It is found primarily in Peru, Bolivia, Ecuador, and to a lesser extent in Colombia, Venezuela, Argentina, and Chile.  It is very similar to the potato, but is not a close relative, botanically speaking.  It is still a popular crop in its native region, but has not spread to the outside world due both to difficulties with cultivation and the fact that the potato arrived in Europe first.

Ulluco plants form hundreds of small, starlike flowers through the summer
It is grown very much like potatoes, but requires a more specific environment (which we'll get into below).  The plant is similar in size, although more sprawling than potato.  Whole or cut tubers are planted in spring.  Planting occurs at about the same time as for main crop potatoes, although harvest takes place later than for most potatoes.

The flavor is akin to beet and the texture, when cooked, is dense and somewhat like boiled peanut.  It remains firm even after long cooking times that would cause a potato to disintegrate.  Ulluco can also be eaten raw, but is mucilaginous (slimy) when uncooked.  All parts of the plant are edible at all stages of growth.  Tubers will become green when exposed to light, but this does not alter flavor and they do not become toxic as potatoes do.  The tubers are the primary part used as food, but the leaves are similar to spinach when cooked.  Tubers can be cooked according to almost any root vegetable recipe and are nearly interchangeable with potatoes, although they don't mash or fry as well.

The ulluco growing environment

Ulluco plant about 1 month after sprouting
Ulluco grows at high elevation in the tropics, where the uplift of clouds against the mountains creates cool and wet weather conditions.  Mild conditions are constant throughout the year, without well defined seasons, due to the proximity to the equator.  The temperature falls mostly between 40 and 70 degrees Farenheit, rarely reaching either the freezing point or exceeding 80 degrees, regardless of season.

Ulluco in the hot zone: Midwest and east

If you live in the United States, odds are very good that your climate is not much like this.  Most of us have much hotter summers and pronounced seasons.  Where summers don't get very hot, the growing season is often short and cold weather closes in relatively early in the fall.  Ulluco is not very adaptable to either condition.  Plants will survive temperatures into the 80s and possibly even the 90s, but they appear to yield almost nothing when they have been exposed to that kind of heat.  The typical yield under hot summer conditions is less than 1/10th of a pound of very small tubers and sometimes nothing at all.  In the UK, which is relatively cool in the summer compared to the US, and where ulluco is a more popular crop, people still often struggle to get a reasonable yield away from the northern coasts.

Ulluco in the cold zone: Up north and up high

Pica de Pulga ulluco, a common type with many varieties
You might be tempted to think that ulluco would be a good candidate to grow in the northern states, which have relatively cool summers, or at high elevations, like the Rockies, since it is a high elevation crop in South America.  Unfortunately, ulluco is grown at high elevation in the tropics, so while the weather is cool, it doesn't get cold.  Ulluco won't survive a frost and, unfortunately, it doesn't begin to form tubers until after the autumn equinox (about September 22).  It takes about two months from that point to form good, eating size tubers, which puts harvest at about the end of November at the earliest.  It is even better if you can delay harvest until December or January.  If you live at high elevation in the US, odds are that you will begin experiencing frosts long before ulluco has matured its tubers.

Bottom line: you need a long frost-free autumn in order to get a good crop of ulluco.

Ulluco oases in North America

A Peruvian ulluco with long, banana-shaped tubers
So, where can you grow ulluco?  We're still working to answer that question with the help of some of our more adventurous customers.  One good bet is anywhere along the west coast where you experience coastal fog in the summer.  So, a five mile wide strip along the coast, running from the northwest tip of Washington state down to about the San Francisco Bay area is a good bet for growing ulluco.  There are many people growing the crop successfully in this "ulluco belt."  By the way, the belt continues on up in Canada to at least Courtenay, BC.  Growers in Vancouver and Victoria have reported good results.

Some people are also having success in the same zone in Southern California, but others have reported failure.  It may depend on the year and how much you water the plants in that region.  The inland Pacific Northwest, west of the Cascade Mountains is another good area.  You will have some difficulties with summer weather and the ulluco may get cooked in some years, but will be fine in others.  In Seattle, you can probably get an ulluco crop in most years; in Portland, the odds are not so good.  We have mixed reports from Oregon's major agricultural region, the Willamette Valley, where there will often be a sufficient frost-free season, but also a bit too much summer heat.

Wild ulluco has small tubers, but long vines with
edible, sort of spinach-like leaves.  You can grow
ulluco for its leaves in climates where tuber
production is poor.
Along the east coast, there are some reports of success along parts of the coast, from North Carolina to Maine, but also some reports of failure.  You need to take a close look at your microclimate to see if you can supply a long enough frost-free season while staying under the 80 degree mark in the summer.

We also have some reports of good results along the shores of the Great Lakes.  If you are very close to a large body of water, you might be in a good place to try ulluco.

Growing outside the oases

You can grow ulluco almost anywhere if you are willing to take steps to protect the plants and supply the growing conditions that they need.  In cold zones, you can extend the season in a greenhouse.  In hot zones, you can grow the plants in containers and move them into heavy shade or indoors when the weather gets hot.  You won't harvest a huge crop this way, but if you just want to grow a few plants, it's certainly manageable.  Ulluco makes a nice houseplant, but won't get enough sun to produce a heavy crop of tubers indoors.

You can also experiment with blacking out your ulluco.  It doesn't produce tubers until after the equinox, because that is when day length falls below 12 hours.  You can possibly stimulate tuber formation earlier in the year by blocking light from reaching your plants.  Blacking them out beginning two or three weeks before the equinox may get you tubers that much sooner.

If you try to grow ulluco in a difficult climate, you may actually discover ways to get better yields.  We're in a rather ideal ulluco climate, so in a way, I'm the worst person to give you growing advice for different climates.  I've collected a lot of information from people who have tried growing ulluco in a warm climate, but I've never done it myself.  So, if you are feeling adventurous and flush with cash, give it a shot and let us know if you discover better ways to grow ulluco in your climate.

Some of the incredible ulluco diversity already available in North America

Future possibilities for ulluco

Ulluco has a couple of problems that limit its adaptability and we're working on both of them, so we hope to eventually expand the North American ulluco growing region by at least a little bit.

Viruses

Meristem culture is one technique for reducing
viral infections in plants
Most ulluco on the market is heavily infected with viruses.  This is the easier of the two problems to solve, but still a time-consuming process.  Like the potato, ulluco is propagated by replanting tubers, which are clones of the original plant.  The tubers carry on every virus that the previous generations of the plant have been infected with, so over many years and generations of ulluco crops, they have become burdened with these viruses.  There is good reason to think that the viruses make ulluco more vulnerable to environmental stress and probably limit its ability to grow outside of ideal climates.  In 2012, we began tissue culturing our ulluco plants using virus elimination protocols to test whether or not we will get more robust plants once they are virus-free (or at least freer; some of the viruses that infect ulluco are difficult to eradicate).  Results have not been conclusive in our climate, but as mentioned above, our climate puts little stress on the plant, so it is not easy to evaluate the results ourselves.  This project will take several more years to complete, but we hope that the end result will be some stronger, healthier plants that are somewhat more adaptable.

Breeding

Ulluco has been reproduced asexually (from tubers) for so long that it has lost almost all of its ability to reproduce sexually and produce true seeds.  (The burden of viruses that they carry may be partly responsible for this as well.)  When plants cannot be grown from seed, they adapt only by relatively uncommon mutation events.  Selecting better plants involves growing large numbers of plants and hoping to find a chance mutation among them that happens to be valuable.  There is no doubt that ulluco varieties have been selected this way, but the process took generations.  Human generations, that is.

An ulluco seed obtained in 2013
(Possibly the first ulluco seed in North America)
A little sexual reproduction could go a long way to mixing up all of those ulluco genes to give us large numbers of new plants with new traits.  That is the key to breeding new, better adapted varieties for North America and the rest of the temperate world.  Unfortunately, ulluco has been observed to set seed very rarely - on the order of decades between reported events.  Fortunately, we got some seed last year!  We are now attempting to grow out some of that seed and working to figure out how to produce more.  In fact, we're going to have so much ulluco to sell not just because we want to share it with the world (which we do!) but because we need to grow very large numbers of plants in order to maximize our chances of producing more seed.

Summary

Ulluco is a crop with a future as bright as its colorful tubers.  It has good potential today for parts of the US and Canada with maritime climates and late frosts.  It will need some breeding work and a bit of luck before it becomes a crop that can be grown outdoors in the warmer continental climates of North America.  The more people who are aware of ulluco, who grow and preserve varieties, who help the people of the Andes steward this crop, and who make it available to the world at large, the better the odds that we can find ways to overcome ulluco's limitations and put it alongside the potato (which once faced similar difficulties) as a staple crop for the temperate world.

You can read our growing instructions here:
http://www.cultivariable.com/?page_id=165

If we haven't scared you off by this point, you can buy ulluco here:
http://www.cultivariable.com/?product_cat=ulluco

Tuesday, January 21, 2014

Ulluco: The tuber that tries my patience

I have been waiting to make this post for ten days.  Waiting because I wanted to get a picture.  A brief look at my stats is enough to know that nobody reads posts that don't have pictures.  Every day I go stare at this tiny green nub just breaking the surface, which looks like nothing when I take a picture.  Every day I expect that it will be much bigger, but if it has grown at all in the past week, it is undetectable.

Anyway, we have an ulluco sprout.  From seed!  This is almost as exciting as getting the seeds in the first place.

Except that this seedling is growing at a glacial pace.  I don't even know what the cotyledons look like after ten days.  That, unfortunately, is probably not a good sign.  When the Finns famously (to ulluco geeks anyway; all seven of them) produced their seedlings, most of them withered away in their infancy.

I am resisting the overwhelming temptation to do something.  I know from experience that when I do something to outsmart nature, it is almost always the wrong choice.  I could pluck out this seedling and grow it on sterile media and perhaps give it a better chance.  But, if it is this weak, I might not really gain anything for my efforts.  So, I am going to leave it alone and hope for the best.

We do know one very important thing now: at least some of the seeds are viable!

The seedling was obtained at 43 days from sowing on a standard peat/soil potting mix on at 70F heat pad.  Surface sowed under fluorescent light.  Soil was kept moist at all times.

There are 39 other seeds in that pot.  Hopefully I'll get a better one.

In the meantime, I'll keep staring at that tiny green nub.

Friday, January 17, 2014

The Safe Seed Pledge is not for me

Yesterday, a prospective customer asked if we have taken the "Safe Seed Pledge."  I vaguely recognized this term, but I don't think that I've ever actually read it before.  It is a short, two paragraph statement that appears to have been produced by the Council for Responsible Genetics.

 If you have never seen it before, here is what it says:

Agriculture and seeds provide the basis upon which our lives depend. We must protect this foundation as a safe and genetically stable source for future generations. For the benefit of all farmers, gardeners and consumers who want an alternative,

We pledge that we do not knowingly buy or sell genetically engineered seeds or plants.

The mechanical transfer of genetic material outside of natural reproductive methods and between genera, families or kingdoms, poses great biological risks as well as economic, political, and cultural threats. We feel that genetically engineered varieties have been insufficiently tested prior to public release. More research and testing is necessary to further assess the potential risks of genetically engineered seeds. Further, we wish to support agricultural progress that leads to healthier soils, genetically diverse agricultural ecosystems and ultimately healthy people and communities.

What follows is from my email response to the customer:

In general, I am kind of allergic to oaths and pledges and anything that requires me to join and drink the Coolaid.

There is a lot of ideological stuff in there that I don't necessarily agree with.  I don't necessarily disagree with it either, but it depends on context.  What does "genetically stable" mean in this context?  As a plant breeder, I am not interested exclusively in stability.  For that matter, a genetic engineer is overwhelmingly interested in stability; as a rule, they want crops that look like they came off an assembly line.  Beyond that, "stability" is a meaningless term in genetics, unless you define it clearly.  At the genetic level, nothing is really all that stable.  Even clones change with every generation.

The second paragraph requires a lot of philosophical alignment that just isn't going to happen.  I can only agree or disagree with those statements on a case by case basis.  I'm not opposed to genetic engineering in all cases, although I am generally dismayed by the fact that the most significant agricultural applications so far have involved making plants less vulnerable to industrial toxins.

Despite that, I can agree with the meat of the pledge, which is this:

We pledge that we do not knowingly buy or sell genetically engineered seeds or plants.

Perhaps they should have left it at that.

Of course, that's an easy one.  It is true of just about every garden seed company that exists.  GM seeds come with a contract.  Nobody slips them to you when Monsanto isn't looking.  There is a lot of fear generated about this in the garden seed industry for marketing purposes.

And, for that matter, I'm not sure that this protects you.  Is a plant that has been unintentionally pollinated by a GM variety "genetically engineered ?"  I'll bet that you could get a number of different opinions on that.

So, I won't be taking this pledge, but I can assure you that we don't sell any genetically engineered varieties and that we're so far away from farming areas that there is basically no possibility of cross-pollination from genetically engineered varieties.  (Not to mention that almost none of the crops that we sell, save potato, have any GM varieties anyway.)  We're doing conventional breeding; that is where our interests lie and that's not going to change.

And, if you want to, you can consider that my pledge.