Category Archives: Harvest

Cleaning Lettuce Seed

Lettuce is the other seeed crop that took me years to learn how to clean well (radishes being the first).

The basics are like other dry seeded crops (thresh, screen and winnow ad nauseam) but to do a good job I’ve had to pay a lot of attention to the threshing and final screening.

(If you want to read more about growing lettuce for seed : growing lettuce seed under field tunnels  and growing out crossed-up lettuce seed)

Harvesting Lettuce Seed

I keep a regular eye on the lettuce plants to catch them as they flower.

After flowering, the lettuce blooms close up.

A couple of weeks later, the flowers open again to reveal little fluffies at the end of mature seed (kind of like dandelions).

Since the seed doesn’t all mature at once, some folks walk their lettuce patch every couple days and shake the plants into bins or paper backets to collect the seed. I’ve tried this approach but don’t have the time to handle the plants this regularly.

Instead, when about 1/2 the flowers are mature, I harvest the whole plant.

I cut the plants above the roots (keeping dirt in the garden!), pile them in bins, and bring them back to the barn.

Drying Lettuce Seed Plants

I spread the lettuce plants out on tarps with a fan blowing air over them. I rotate the plants at least once a day so that the leaves dry down rather than rot.

If I have a little lots, I dry them upside down in a bucket.

The lettuce plants usually dry for 1-2 months before I process the seed. By this time the plants are completely dry and most of the seed has matured.

Threshing Lettuce Seed

Whereas we now stomp most seed crops to thresh them, we put on kid gloves to handle lettuce.

We rub the plants vigorously between our hands so the flowers fall apart dropping the seed and fluff.

This leaves the stems bare. I try not to break many stem pieces into the mix as they can be tough to later extract.

Screening Lettuce Seed (First Time)

I usually skip the 1/2″ screen and move right to the 1/4″ screen.

I separate the seed and chaff into the bin below and leave any stem on the screen. This is where cleaning lettuce seed gets tricky because the chaff is similar in weight to the seed and the fluff doesn’t seem to want to let go.

At this point I turn to more specialized equipment.

Screening Lettuce Seed (SeconD Time)

This is my favorite colander. The size of the holes are perfect for little oblong seeds (such as lettuce).

I rub the chaff-seed mix through.

This extracts the coarse material. I use this screen a few times and wind up with seed and a bit of fluff.

Winnowing Lettuce Seed

At this point I winnow delicately. If the seed is still dirty. I winnow again a bit more aggressively and perhaps run the seed through my colander another time.

One of the biggest tricks I’ve learned is to not try to save every last seed. When I accept losing a bit of seed, I can get the remaining seed much cleaner.

This is about as clean as I can get most lots with screens and fans. I pick out some of the remaining bits but have to live with the rest.

I apologize for the delay in getting this post up (Brian Creelman has been asking me to post about lettuce for nearly a year.)

Some of the delay is because I’m not much of a lettuce seed man – I’ve often had trouble getting lettuce seed crops to maturity and even though I’ve been cleaning lettuce seed 10 years, I still can’t get it as clean as most other seed. I’m currently looking into some seed screens from Hoffman Manufacturing. If these work out maybe I’ll become a lettuce seed cleaning maniac. I’ll keep you posted!

The rest of the delay is that I’ve been conference and workshop hopping this past month and any my spare time has been going into our new website. I’ll tell you guys more about all that soon …


10 Steps For Getting Seed As Clean As Possible

In my early seed-saving days, I’d thresh and I’d winnow but I just couldn’t get my seeds as clean as when those that came from a seed packet.

Over the next dozen years, meeting experienced seed growers, reading piles of seed production books,  and attending whatever seed workshops I could find; I gleaned many pearls of wisdom that I then fine-tuned cleaning hundreds, if not thousands, of seed lots.

Here are the steps and lessons that have had the biggest impact in my seed saving career:

10 Steps For Getting Seed As Clean As Possible

  1. Make sure plant material is dry, dry, dry before threshing. In Eastern Canada, it can be hard to get a crop to dry in the field. Harvest whole plants when they are 3/4 dry. Spread them on tarps in a greenhouse with fans to increase ventilation and turn them periodically to ensure even drying.
  2. Leave dirt in the field. Leave dirty plant roots in the field when you harvest seed crops. It is much easier to not add dirt to your seed than to remove it later.
  3. Clean seeds on a dry day. Even if your seed crops are very dry, ambient humidity on an overcast or rainy will make seeds stick to the chaff.
  4. Thresh aggressively if seeds don’t easily shatter. Use boots, sticks,  rakes, tractors, and trucks to shatter seeds from pods.
  5. Alternate screening and winnowing to blow away the light chaff and separate plant material into 2 groups:
    • Threshed seed and small bits of stem, pods, and rocks.
    • Larger plant material that contains unthreshed seed.
  6. Repeat steps 4 and 5 with larger plant material until you only have bins of threshed seed with small bits of stem, pods, and rocks that are the same size and weight.
  7. Winnow threshed seed aggressively to remove other material of similar size and weight.
  8. Screen seed carefully. Seed usually falls through first. Stop screening when most of the seed has fallen through.
  9. Be willing to sacrifice seed as you repeat steps 7 and 8. If you focus on getting seed clean rather than on saving every last seed, you can get seed a lot cleaner.
  10. Remove any remaining unwanted elements by hand. I usually spread seeds on a baking tray and do a final triage to remove broken and damaged seed, and any other remaining bits.

Seed saving examples

You can see all these principles in action in these two posts:

And in the next couple of posts I’ll demonstrate these principles for two crops that used to really give me a headache: radishes and lettuce.

Are there any tricks or lessons that really improved your seed saving?

Season Update

Here is some of what we’ve been doing during the last 2 months.

Building Things

We’ve put up a second caterpillar tunnel.You can find  more construction photos on Tourne-Sol cooperative farm’s Facebook page.

We’re almost finished a 35′ x 150′ unheated greenhouse for more season extension.

Dealing With The Rain

Most of May was muddy with water pooling in the fields. We couldn’t use our tractor-pulled transplanter and planted by hand whenever a sunny day or two came by.

However even on the wettest days, conditions inside the caterpillar tunnels were mostly dry. We were glad for these warm covered spaces to plant our heat loving crops in.

Working In The Field

We’ve harvested the first overwintered Brassica rapa seed crops.

We’ve been snapping garlic scapes.

The boys have arrived. (This year’s pigs are a Tamworth Berkshire cross though they look more Berkshire than Tam.)

The Kildeer eggs that were laid in the middle of our tractor path have finally hatched!

Working Out Of the Field

Our weekly CSA vegetable baskets have started.

Our market stall is getting more and more diversified. In addition to the Saturday Ste-Anne farmers market, we’re now attending  the new île-Perrot market  on Wednesday evenings.

Open House

And finally, if you’re in the neighborhood this weekend you can come to our annual open house.

  • Sunday July 3rd from 1 p.m. to 3:30 p.m.
  • Guided visits at 1:15 p.m and 2:30pm
  • 1025 ch. St-Dominique, Les Cèdres, QC, J7T 1P5


At Tourne-Sol farm, we drill our apprentices in the importance of efficiency, profitability and priority setting. So it’s understandable that our apprentices  thought it was a hoot when we spent part of an afternoon on hands and knees riffling through the soil for bean-sized chufa tubers.

Still, I love these nuts and make a point of growing them for our seed catalogue and especially to snack on.


Chufa nuts are also called tiger nuts or earth almonds. They have a nutty taste similar to coconuts that gets sweeter as they dry.

They are sometimes mistaken for yellow nutsedge (an invasive weed on many farms). In fact, chufa and yellow nutsedge are both varieties of Cyperus esculentus but with a couple key differences:

  • chufa tubers are a touch bigger than yellow nutsedge
  • chufa plants (and tubers) frost kill and therefore don’t overwinter in our Quebec climate

I’ll repeat that, chufa nuts are NOT invasive where the ground freezes heavily. Of course, before planting any chufa, make sure you aren’t buying mislabelled yellow nutsedge.

Chufa look like this (though a bit smaller):


Chufa nuts are usually propagated vegetatively. That means you plant a chufa nut to grow a chufa plant. (They don’t seem to set seed on our farm.)

This is how we plant chufa

  • Wait till after last spring frost (end of May for us)
  • Soak chufa nuts in water for 24 hours
  • Plant one inch deep
  • Space plants one foot apart from each other
  • Wait 1-2 to weeks to see first shoots emerge

After a few years of wrestling with weedy chufa plots, I now place a stick upright beside each planted chufa nut.  This way I know where to weed (and not to weed) as I wait to see the chufa plants.

A month or so later, the chufa plants are about 4″ tall. (This year, I tried intercropping a row of Korean shiso between two chufa rows.)

Mid summer, the chufa is nearing full height though the plants will keep growing in width. (At this point, I started to suspect that the Korean shiso’s growth habits might overcome the chufa.)

By early September, the Shiso was dominating the chufa.

At the end of September, when some of the leaves start browning and weather reports post frost warnings,  it’s harvest time!


We dig the plants out with trowels.

Then pull the tubers off the plant and dig around in the soil for any that might have been missed.

We toss the nuts and a fair amount of soil into a bin.

Then blast them with water in a spaghetti colander.


You can eat the chufa right away, though it gets sweeter as it dries down.

We spread the chufa on screens in front of fans.

Once the chufa is dry, I use seed cleaning screens to sort out the biggest chufa for next year’s seed stock. I also remove the smallest nuts, stones, and dust. After the chufa has dried for another couple week, I screen it again to remove any nuts  that have shrunk since the last screening.

I store  dried chufa in a paper bag at ambient temperature. It holds quite well, I have some nuts that are two years old and looking fine – though I always use the freshest stock for planting.


The easiest way is to pop in mouth and chew.

I have tried making a Spanish beverage called Horchata de Chufa where you soak the nuts for 12  hours with a cinnamon stick, then blend the nuts with water (remove cinnamon), strain the ensuing mixture, add sugar to taste, and drink. I wound up with something rather lumpy though not unpleasant. I’ll have to try it again.

Supposedly, ground chufa flower can also be used for baking though I can’t vouch for that.


These days, we’re pretty much finished in the field. I just got back from giving crop planning workshops in Saskatoon, Saskatchewan and Olds, Alberta and now I’m switching gears to get into my own own crop planning.

The next couple posts, I’ll catch up on more seedy highlights from the last growing season!

This Year’s First Seed Harvest and Volunteers from Previous Years

Last week, we harvested our first Brassica rapa seed crops of the year. As we start this year’s harvest, I have also been watching some of the remnants of previous years’s seed crops.


The brassicas overwintered in a field tunnel and then flowered in April – a bit earlier than usual. I have been walking the brassica patch 2-3 times a week to make sure I notice when they set mature seed.

Walking across the field earlier this week, the yellow brownish plants (on the left and right of the picture) told me it was time time to harvest. The green plants (in the middle of the picture) are B. junceas, B. napuses and some garden cress that flowered later than the B. rapas.

Up close, I could see that the seedpods hadn’t matured and dried uniformily. This might be a consequence of the  mix of genetic material in this population (our winter brassicas have been quite crossed up as we strive for better cold tolerance), but I suspect some of the premature drying is due to structural damage from that heavy early May snowfall.

We cut the dried stalks, piled them in rubbermaids, and drove them to the barn.

We then laid the stalks on tarps in the barn with fans for air circulation. These plants will keep maturing for a couple more weeks before we thresh them.

I am not thrilled with how green some of the material is. We harvested because I could see seed starting to shatter on some branches, and this was the last sunny day in the forecast.


As we go about our normal farming duties, I always watch what’s happening elsewhere on the farm – evaluating crop maturity, considering soil dryness, trying to guess where that Kildeer nest is, or looking at weed pressure and what kind of weeds are in the garden – which in today’s post are volunteers from previous crops.

Some burgundy amaranth amidst a cover crop of oats and vetch. These are from seed that matured in our cut flower beds rather than in the seed garden. If I think about it later this week, and get around to crossing the farm to these beds, and we don’t mow the cover crop first; I’ll harvest some of these for mesclun salad mixes for market.

Strawberry spinach is taking over the oat cover crop in this corner of the seed garden. I am letting it mature in the undercanopy.

I didn’t harvest last year’s Strawberry Spinach seed crop in time, resulting in the current seed bank. This volunteer crop germinated in April and is almost mature – months earlier than my usual planting and harvest dates. For some reason, I thought this Chenopod was more of a heat lover and always waited to plant until the end of May. Seems I was wrong.

In the previous pictures, there are a lot of plants germinating from shattered seed.  In a cover crop, these can be managed by mowing before they set seed themselves. In a vegetable crop, that seed density would be a weedy problem. However …

This lone mustard in a block of onions is the only sign that I grew out spicy mustards, tatsoi, and dill, all for seed, in these same beds in 2006. I have found that the first year after a seed crop, the level of volunteers is significant, the second year is definitely noticeable, but after 3 years the level of most escaped seed from seed crops is minimal. Of course, this is in a context where we plan our cropping practices and ground management to flush out the soil seed bank.

Coming soon

This week is this blog’s half-year birthday. In my next post,  I will step back and look at what I’ve been writing for the last 6 months.