Category Archives: Isolation Distances

Seed Webinar today

I’m excited to be part of a seed webinar this afternoon at 4PM Eastern.  I’ll be talking about how we approach selecting seed plants on our farm. I’ve got some pictures lined up!


If you’re interested in listening in all the details are below. (Or you can just register here: There is no fee to participate.




“The People’s Choice” Webinar: Seed Questions across Canada!

Hosted by: The Bauta Family Initiative on Canadian Seed Security


Designed according to feedback collected from across Canada, the webinar will start with a presentation on “On-farm Roguing, Selection, and Adaptation” by Dan Brisebois of Tourne-Sol Farm (QC). Part 2 of the webinar will feature a seed panel of experts from across the country who will address YOUR most important questions about seed. The panel will speak to both pre-submitted questions and live questions from webinar participants. Please come prepared to engage!

You can get more info and register here:



Selecting/Breeding Hot Peppers

Seven or eight years ago I planted some Bulgarian Carrot Hot Pepper seeds from Fedco. Most of the plants had elongated orange fruit similar to Cayenne peppers but with more flesh. One plant was covered with fruit that were round and squat though equally orange and spicy. This rogue pepper plant was likely due to an accidental cross in the seed growers garden.

Of course, I saved the seed from this rogue hot pepper – essentially a F1 cross. This is where things got messy. When you save F1 seed from, you get a lot of variation in subsequent generations.  Only by consistently saving seed from plants that look similar over a number of generations do varieties start to stabilize.

The impact and diversity from my carrot pepper selections each generation have brought me to pay more attention to each plant in a population and try to find ways to easily record the changes (essentially accurate labeling and taking pictures.)

(For more crossed up plant, you can read my post on crossed-up lettuces

Growing Out Crossed-Up Peppers

Nowadays, in the early generations after a cross I save the seeds from each selected hot pepper plant separately. The next year I grow 10-20 plants of each selection in the garden.

I grow each selection in a row divided from the previous selection with a stake.

Over the season, I evaluate each plant in each selection to see how uniform the selection is and whether any individual plants stand out. If the selection is very uniform I might mix the seed from the best plants together. If there is still quite a bit of diversity, I keep the seed from individual plants separate.

Let’s see what that looked like in 2011 and 2012

2011 Carrot Pepper CrosseS

In 2011, I selected 6 different plants.  Each plant is labeled in the picture. The first plant labeled F3 6-1. F3 means the plants is from the F3 generation. 6-1 means the plant is the first plant selected in 2011 from the 6th plant in 2010. These 6 plants were all from 6th or 7th selection  made in 2010.

Plants 6-1, 6-2, 6-3 and 6-4 are therefore siblings. These plants are cousins with 7-1 and 7-2.

2012 Carrot Pepper CrosseS

In 2012, due to space constraints I only grew 5 plants of each selection. For each strain I first took a picture of the plants:

This gave me a quick idea of the relative yield, color variations, pod shape, and whether the fruits grows upwards or hangs down.

Next I pulled the fruit off of each plant and took another picture:

This let me see how fruit variation was still present. Pods pointing down indicated hanging fruits, pods pointing up indicated upwards fruit.

This also lets me compare the 2012 fruits with my 2011 picture above. In general you can see there’s less variation within each of the following 2012 selections than in 2011.

At this point I’ve selected different plants to save fruit from based on pod characteristics, plant structure, yield, and earliness (I’d previously tagged the first plants with mature fruit.)

I put the fruits from each of my selection into a separate quart to later extract the seed.

This picture is actually from another set of selections in the F6 generation.

The culled fruit go into a bin…

and then head to market or CSA!

One Other Selection Consideration

Before extracting seed from each selection, I taste each fruit. I start with the fruit bottom, then the side wall, and finally the core to see how hot these peppers are.

I started doing this after I realized a Jalapeno I was working with had lost almost all of its heat. After selecting by taste for a future generations, most peppers are consistently and adequately hot.

Needless to say this tasting happens over a few days. As it takes me 10-15 minutes after each “winner” before I can taste another pepper’s heat.

A Word About Isolation Distance

Most of the peppers we grow are destined for eating. As such we grow these varieties side by side with no isolation distance. Though peppers are predominantly self-pollinating, there can still be low amounts of cross-pollination with plants grown this close together. Still I save seed from these peppers for our own farm use. Most of the time I don’t see any crossing, but when I do I get excited!

I should mention that I always grow hot peppers a good 200′-600′ away from our sweet peppers. This ensures our sweet peppers stay sweet and our hot peppers stay hot. Also, any hot peppers we grow to sell as seed are grown with 200′-600′ isolation distance since we want to keep these varieties pure.

What Else Has Been Going on In Dan’s Life?

You may have noticed I haven’t been posting much lately. Part of that of course is due to the growing season, and playing with hot peppers; and of course planning for the Nov 9-10-11 Seed Connections conference in Montreal; but mainly (and most importantly) Emily and I now have a little daughter named Stella in our life! You can see some pictures in the recent Tourne-Sol newsletter.

What Is Seed Quality?

Seed quality was one of the big topics at USC Canada’s Train the Seed Trainer sessions. All the participants had a lot to say on the topic. And though we had many conflicting opinions on other seed issues, we had consensus making a list of seed quality concerns.

I’ve taken that list and broken it into a few categories and elaborated on each of them:

  • Basic seed concerns
  • Physical handling concerns
  • Genetic concerns
  • Traceability concerns

Basic Seed Concerns

These are some of the first things that folks thing of in terms of good seed:

  • Germination rate: Does the seed germinate well?
  • Seedling vigor: Do the seedlings grow vigorously?
  • Seedborne diseases: Is the seed free of problematic diseases?

Physical Handling Concerns

  • Cleanliness: How much chaff, dirt, or dust is present?
  • Presence of weed seeds
  • Handling mistakes: Was the variety mislabeled? Was there an accidental mixing of another variety of the same species during cleaning or packing?

Genetic Concerns

  • Varietal purity: Has the variety cross-pollinated?
  • Population size: Was seed saved from a large enough population to maintain a wide genetic breadth?

Traceability Concerns

Where is the variety strain from originally? Is it simply another variety that’s been renamed? How were previous generations handled? Does the variety perform/appear different from what it once did?

What Is Seed Quality?

You might notice that I have highlighted all of the above as concerns. In the end we did not put forward a list that defines quality seed as each of these concerns is not all or nothing. They depend greatly on the end use of the seed.

Beets with a 55% germination are fine for a home garden though none of us would want to sell those beets seeds. Slightly crossed up tomato seed is probably good for the vegetable grower who saved it though again none of us would want to sell the seed.

Generally speaking if the seed is for sale, then high standards need to be met, but seed saved for personal garden and farm use needs to meet the standards the seed saver can tolerate.

Do you think we’ve missed anything in this seed quality discussion?

What are your seed quality concerns?

One comment one seed growers made was that he doesn’t often hear back from his clients after they’ve ordered seeds until their next seed order. He  would love to hear their complaints about the seeds (if they have any.) And of course he loves to hear from thrilled clients too!

So, go  and write your seed sources a letter to tell them what you don’t like so much and what you love!

My trip to the OSA Organic Seed Growers Conference

On Jan 19-21, 2012, I attended the 6th Organic Seed Growers Conference in organized by the Organic Seed Alliance (OSA). The event started off with a one-day tour of the Skagit Vally seed region and then two days of conferences in Port Towsnend, WA.

If you missed the event, you can download the conference proceedings or view videos of the plant breeding sessions through eOrganic.

Though I did participate in a panel on marketing and growing seed profitably with Maud Powell and Steve Peters, today I won’t be posting about that but about the rest of my experience.

Pre-Conference Skagit Valley Seed Tour

Skagit county produces approximately 8% of the world’s spinach seed, 25% of the world’s cabbage seed, and 50% of the world’s beet seed (from WSU Skagit County Agricultural Statistics 2010) .

Here are some of the highlights of the tour:

Field Tour

A couple of days earlier about a foot of snow had fallen (an exceptionally large volume for this area). The walking part of the tour was subsequently canceled and all the following field pictures were taken through the tour bus window.

Here is a field of overwintered cabbages for hybrid seed production. The tour guide mentioned there were 2 rows of female plants for one row of male plants.

Another shot of a cabbage field. There is a v-ditch every 12 rows for drainage.

This area also produces a lot of raspberries.

Pinning Maps

With so many seed crops grown in one area, isolation distances are a big concern. Seed companies growing seed in the valley meet every year to decide who will grow what crops where using pinning maps.

In the Skagit Valley seed companies meet at WSU Mount Vernon Research Center for this process.

These are the cabbage pinning maps.

This is a chart of minimum isolation distance for different types of Brassica oleracea.

The red lines indicate areas where only one type of Brassica oleracea may be grown.

The pinning order is determined randomly. The first person pins a field for their crop. Then the next person pins a field. Each subsequent person needs to respect the minimum isolation distance from the fields that are already pinned.

This way seed companies cooperate to make sure their seed crops maintain varietal purity.

Soil Testing For Spinach Seed Crops

Spinach seed crops are particularly sensitive to bacterial and fungal disease. A 10- year crop rotation is the minimum to break many of these spinach disease cycles. In some cases this isn’t enough. Prior to pinning, growers can bring soil samples to WSU Mount Vernon Research Center to determine whether their soil is indeed disease-free.

Spinach seeds are planted (with replication) in the soil in a greenhouse in January. Within a month it is possible to evaluate the spinach seedlings to see what degree of disease might be expected.

Dr. Lindsey du Toit runs the vegetable seed pathology program.

The Conference

When I came to the previous Organic Seed Growers Conference in 2008 in Salem, OR, I was bombarded with information about climate appropriate seeds, plant breeding, seed cleaning details,  dynamics of the vegetable seed industry, and more.

Having already had this experience, I wasn’t at the 2012 conference only for seed information. I was here to be inspired (and I was inspired – especially about seed libraries, which I’ll be posting more about soon) and to mingle with the seedy underbelly of the organic farming world. In addition to seeing many old friends, I made some new friends.

Some folks I’d been reading about, or following their blogs, or even ordering/growing their seeds. I got to meet Sarah Kleeger and Andrew Still of Adaptive Seeds (and the Seed Ambassadors Project)  – Sarah was a touch disappointed I didn’t have a French accent.

I was surprised to be talking with Madeline McKeever of Brown Envelope Seeds. She was a long way from Ireland. She told me this wasn’t the first OSA conference she’d gone to either.

With other folks this was the first time I touched base. I spoke with Holli Cederholm of Proud Peasant Farm (who also works for Fedco) about how crop planning books don’t seem to factor in the food that the farmers eat. I was impressed by how much food Holli puts up and I thought Fred and I need to add a homesteading chapter if ever we revise our Crop Planning book.

I chatted with Doug Baty of Wild Plum Farm for quite a while about garlic. He couldn’t believe how big our porcelain garlic grew. I couldn’t believe how big his artichoke garlic were.

Sometimes you have to go a long way to meet someone from close to home. Though she’s now based in California, Rowen White of the Sierra Seeds Coop  grew up a couple of hours from Montreal. She is also the author of the just-published Breeding Organic Vegetables (available through NOFA NY).

I kept running into Chris Hardy of the Village Farm in Ashland, OR. We talked a lot about Tulsi.

And I got to know some folks better that I’d only met briefly at the 2008 conference such as Hanako Myers and Marko Colby of Midori Farm. I think every farmers market needs quality locally-produced kimchi and sauerkraut.

I did meet a lot of other folks too, including a number of people who’ve been reading Going to Seed. It was great meeting and talking with everybody. Seedy people are an interesting and friendly lot.

If you haven’t been to a OSA conference, you should. The next one will probably  be in 2014. I’ll likely be there.

(P.S.  the just posted Five Books Dan Brisebois thinks new farmers should read)

Seed Production Planning Part 2 – Calculating Seed Needs

This is the second part of a series on crop planning for seed production. Seed production planning part 1 covered growing small trials to evaluate whether a variety was worth growing to seed on your farm in your climate.

Once you’ve decided the varieties for  this year’s seed production, you need to determine how much seed you would like to harvest.


Under good storage conditions most seed will last a number of years. You can grow enough in one year to cover your seed needs for multiple years. This has a few benefits:

  • Growing fewer varieties gives you more space for better isolation distances to avoid cross-pollination.
  • Growing a larger number of plants of on variety provides more plants to observe and you can better select the most fit individuals. Large population also maintain a broader genetic pool that ensures more resilient varieties.
  • Cleaning bigger seed lots is easier than cleaning small seed lots.

For most varieties, I aim to grow enough seed for at least a 3-year supply. (This is not possible for all varieties. I.e. parsnip, leeks and onions lose germination quickly after a year in storage.)

(You can read a previous post about isolation distances and population sizes.)


Consider all the ways you sell or use seed, and estimate the needs for each use. This includes

  • Seed you use on-farm. This is calculated from your crop plan – basically the rowfoot you plan to grow multiplied by a seeding rate. (The crop planning for organic vegetable growers handbook covers this.)
  • Seed sold through a seed catalog (in packets or in bulk). This is projected from the previous year’s sales records.
  • Seed sold to other seed companies. This is based on how much seed they need.

Then make a chart to summarize this information. Here are two examples loosely based on our farm.


Tatsoi is a leafy green from the Brassica rapa species.

At Tourne-Sol farm, we seed a lot of Tatsoi to sell bunching or as part of our salad mixes. We also sell Tatsoi seed as packets to gardeners and in bulk quantities to other farmers.  And our seed company clients purchase regular amounts of our Tatsoi seed.

 Purpose 2012 2013 2014 Total
Farm Use 120g 120g 120g

360 g

Packet Sales 100g(50pkts x 2g) 120g(60pkts x 2g) 140g(70pkts x 2g)

360 g

Bulk Sales 1kg 1kg 1kg

3000 g

For Other Seed Companies 1kg 1kg 1kg

3000 g


6720 g

We’ll need to harvest about 7 kg of Tatsoi seed to meet our projections for the next 3 years.


We need significantly less tomato seeds than Tatsoi seeds. Since we transplant tomatoes, our on-farm needs are low and we only sell packets through our seed catalog. Our seed company clients purchase a significant volume but they usually buy enough seed for multiple years at once.

 Purpose 2012 2013 2014 Total
Farm Use 1g 1g 1g

3 g

Packet Sales 5g(50pkts x 0.1g) 6g(60pkts x 0.1g) 7g(70pkts x 0.1g)

18 g

Bulk Sales

0 g

For Other Seed Companies 300g

300 g


321 g

We’ll need to harvest 321 g of Jaune Flammée tomato seed to meet our projections.


In our next seed production planning installment we’ll figure out how many plants to grow to meet these seed needs.

Planting, roguing, thinning, watering, and pigs

This week we got all the frost sensitive seed crops into the ground: tomatoes, peppers, eggplants, beans, and some more flowers.

Seed crops planted on the same date go into the same beds. This lets us prepare the beds  at the same time and doesn’t leave unused area to grow weeds. We alternate blocks of Solanaceaes (tomatoes and peppers), beans, and flowers to prevent cross pollination between different varieties. Growing in blocks (rather than long rows) also increases the likelihood of pollination within the same variety.

Warm season annuals are the second big seed crop planting on the farm. Frost hardy crops went in a month ago and are now well established.

I walk the Mizuna patch daily, pulling out early bolters and any less than vigourous plants.

Poppies are also coming along. The bottom row is the density these guys were seeded. The top row has been thinned. Growing your own seed means you can afford heavy seeding since your closets are full of seed.

The poppies and the mizuna enjoyed the drip tape during the previous week’s heat wave.  And speaking of hot and dry …

This week, we irrigated garlic for the first time in my ten years of garlic growing.  Normally, a good mulch keeps the garlic nice and moist. This year though, as we pulled weeds from the straw, the dry soil told me the garlic had depleted the soil moisture. With the garlic already growing faster than usual in the spring heat, I was afraid to stunt the plants by keeping them from drinking.

Of course, the morning after we watered these alliums, the rain came down to our heart’s content. But would it have, if we hadn’t moved sprinklers onto these plants and irrigated for three hours?

And the real big news this week is the arrival of our seasonal guests.

These four brothers arrived on Thursday. They seem to have made the transition here quite smoothly. Now,  they wait for any rogued mizuna plants!

Plant Populations and Isolation Distances

A version of this article I wrote appeared in the August 2009 issue of the Seeds of Diversity magazine. It is a summary of a couple of key points from the March 17,  2009 principles of seed production course held by the Eastern Canadian Organic Seed Growers Network.

John Navazio taught the course. He is the Seed Research and Education Specialist for Organic Seed Alliance and Washington State University. The two aspects of seed production he focused on were


Seed growers need a large enough population of plants to maintain genetic breadth and resiliency. Populations that are too small will gradually result in varieties that no longer perform as well.

In addition, seed growers also need to keep plant populations far enough away from each other to make sure different varieties of a same species do not contaminate each others’ genetic makeup.

Both population size and isolation distance are a function of how a crop pollinates itself – whether it is predominantly self pollinated (selfers) or cross pollinated (crossers).


Selfer flowers have petals that completely cover the plant’s reproductive parts, making it difficult for insects to get to the pollen and carry it elsewhere. Selfers have evolved  to not suffer from inbreeding depression. They do not need large population or isolation distances.

For the highest quality seed, you should save seed from no fewer than 12 to 16 selfer plants, preferably 50 to 80. Since selfers can still cross-pollinate, most need 80 –150 ft of isolation distance.

The main selfer crops are: Solanacea crops (tomatoes, peppers, eggplants), Fabacea crops (beans and peas), lettuce, and many of the staple grains (wheat, oats, barley, rye)


Almost all other crops are crossers. Crossers have evolved to encourage fertilization from different plants, and most suffer from inbreeding depression.

Crossers need much larger populations and isolations. John Navasio recommends saving seed from at least 64 to 80 plants of a crosser variety, preferably 200 plants. Insect pollinated crossers should be separated by 1-2 miles. Wind pollinated crossers should be separated by up to 5 miles.

It is a much bigger undertaking to produce seed from crossers than selfers.


Cucurbit (squash, cucumbers, and melons) fall somewhere between the two groups.  Cucurbits are technically crossers. They need the same large isolation distances. However, Cucurbits are very resistant to inbreeding, so only need population sizes similar to those of selfers.


John Navasio highlighted that the exact population size and isolation distance you use depend on your seed production goals. If you grow mainly for your own use, you can afford to have fewer plants planted in closer proximity to other varieties of the same species. If you intend to maintain and improve a variety, John stood steadfast by his recommendations. Especially for population size – John has found that the best varieties he has seen were developed from large populations.


ECOSGN is hosting a Seed Workshop in Ottawa on April 10-11.

The Eastern Canadian Organic Seed Growers Network (ECOSGN) has been meeting since March 2008. It’s goal is to foster a community of seed growers and seed sellers who can protect and enhance an economically viable and ecologically sustainable organic seed supply for Eastern Canada. ECOSGN strives to do this through education, shared resources, research and a united political voice.