Seed saving 101: Isolation distances and planning your garden

My last real post began to explore isolation distances and their role in seed saving. This is a big and complicated topic. I find that sometimes, the best way to grasp an expansive topic is to try to apply it to a more particular situation.

Applying isolation distances to the sub/urban home garden

Let’s start, for simplicity’s sake, with five major summer vegetables you may want to try to save, and we’ll assume you want to try heritage or heirloom varieties:

  1. Beans (‘Kentucky Wonder’ pole bean)
  2. Corn (‘Golden Bantam‘)
  3. Melons (‘Minnesota Midget’ cantaloupe)
  4. Tomatoes (‘Brandywine‘)
  5. Zucchini (‘Black Beauty’ zucchini)

All of these are open-pollinated varieties.

Common name

Scientific name

Variety name

Isolation distance

Population size

Pollinators

Beans Phaseolus vulgaris ‘Kentucky Wonder’ 20’ 10-20 Self
Corn Zea mays ‘Golden Bantam’ 1600’ 200 Wind
Melons, cantaloupe Cucumis melo ‘Minnesota Midget’ 1600’ 10-20 Insects
Tomato Solanum lycopersicum ‘Brandywine’ 40’ 10-20 Self, insects
Zucchini Cucurbita pepo ‘Black Beauty’ 1600’ 10-20 Insects

Table is adapted from A Seed Saving Guide for Gardeners and Farmers by the Organic Seed Alliance, www.seedalliance.org.

The immediate issue visible for most sub/urban home gardeners is that we have nowhere near the space to grow 20 tomato plants and 200 corn plants, so maintaining a population size to ensure good genetic diversity may not be an option. You can still grow enough plants to feed your family, and save your seed and even share it.

Beans:

This, perhaps, is the most reasonable plant of the five for the home gardener to both maintain a population size suitable for maintaining genetic diversity, and also maintain appropriate isolation distances from other bean crops.

Using a square-foot gardening technique, a row of beans 15-20 feet long × 1 foot wide or a double row 10 feet long × 2 feet wide will yield enough to permit attrition due to deer, disease, and occasional errant basketballs, and still have a viable population. And unless you and your neighbor are both trying to grow beans in the only sunny part of land in your neighborhood, which just happens to fall directly on your property line, you’ll probably be able to keep your plants 20’ from another variety of bean plant.

Urban patio gardeners: Beans may be grown in containers, using cage-type trellises to support the vines as they grow. Grow as many plants as your space permits, but do not overcrowd your containers. Plan on one plant per 8″ of container diameter. Spacing from other plants may be more challenging for you. Can you tell what your neighbors are growing?

Seed saving technique:

Enjoy some of your beans, and leave some on the vine until they turn leathery and yellow, tan, or brown in color. Then remove the pods from the vine, and dry them out of direct sunlight for a week. When the beans rattle in the pods, they are ready.

Corn

Corn is tricky. Let’s come back to it in another post.

Melons

Melons likewise are challenging. We’ll address those in a separate post.

Tomatoes

The trouble with tomatoes, from my perspective, is that there are only 200 interesting varieties. How can one possibly pick just one variety to grow in the home garden? I have no discipline: If I have the space to grow 10 to 20 plants such as would be recommended for a good seed-saving population, I will grow 10 to 20 different tomatoes.

Brandywine tomatoes by rsgreen89, via Creative Commons 2.0.

Brandywine tomatoes by rsgreen, via Creative Commons 2.0

It helps that tomatoes are primarily self-pollinating. If it is possible in your garden to grow multiple varieties and observe the 40’ planting distance from other tomato varieties, by all means do so.  But the popularity of home-grown tomatoes means you would do well to pay attention to what your neighbors are growing if your sunniest spot happens to be near your property line.

Acknowledging these challenges for the sub/urban gardener, my best advice from a seed stewardship perspective is to grow as many plants as you can of the variety you love best, say, ‘Brandywine.’ Cluster them together, tend them well, and select appropriately. If you cannot resist growing 15 other varieties, consider growing those well apart from the best-loved variety. Knowing that the other 15 may mix between themselves, if you save seeds from those varieties, keep those seeds for yourself. Keep detailed notes on how those plants behave from year to year, select them as you will for the Brandywines, and if they appear to be quite stable, then you may share them.

And if you live in an apartment and can only grow 1 tomato plant, grow it and enjoy it. If the plant is healthy, save seed from it to use next year. It’s your treasure.

Seed saving technique:

To save tomato seeds, use a wet processing method:

  • Squeeze the pulp and seeds from several saved fruits into a glass jar, and top it off with tap water.
  • Leave it on the kitchen counter for a few days, stirring occasionally. (It will begin to mold, so this may not be the time to have your mother-in-law over for dinner.) The white mold can be stirred back into the mixture with no ill effects.

How to know when they’re finished fermenting? There are several indicators that may be used, but I have had fine luck simply waiting 48 hours. You may want to try the different methods described here and find the method that works best for you.

  • Rinse the seeds several times using a metal mesh strainer. You may need to rub some residue off the seeds if they won’t come clean by a simple rinse. I find the spray attachment that comes on many kitchen faucets works well, as long as the spray doesn’t hit the seeds with full force.
  • Spread the seeds on a cookie sheet and let them dry for a week (it may take up to three weeks for the seeds to fully dry), and store them in a labeled paper envelope placed in a glass jar in the refrigerator.  You may put a packet of silica gel, such as you find tucked into a box of new shoes, in the bottom of the jar to absorb extra moisture, provided the packet is intact and the seeds are well secured in their envelopes.

Zucchini

Good heavens. I can barely keep up with the produce from 1 zucchini plant, let alone the 10 recommended for selection purposes. I should like to see the freezer big enough to hold all the zucchini bread one could make from 20 zucchini plants.zucchini copy

But perhaps your next door neighbor, or one across the street, or both, wants to grow zucchini as well. If you all are concerned about genetic diversity, you can all grow the same variety, splitting the seed packet between you. You might then be able to each select your best plants, save those seeds, and perhaps share a few seeds between each of you to spread the risk.  What are their neighbors growing? If they’re growing a variety of yellow summer squash, you might have an isolation issue. Fortunately, squash are easy to hand-pollinate. You could take this route, and use floating row covers to isolate the plants from the neighbor’s yellow squash.

Urban gardeners: I’m guessing that, due to the plant’s enormous size, heirloom zucchini may not be high on the list of plants to grow on a balcony. If you want fresh zucchini, you may need to go with an F1 variety developed to grow compactly. You can still have grow such plants organically, but heirlooms may simply not be practical for you.

Squash and zucchini are cucurbits, which are notorious cross-pollinators. I’ll get to this in more detail when we explore growing melons.

Seed saving technique:
  • Allow some fruits from the best plants to grow very big and to harden.
  • Harvest them, then allow them to cure at room temperature for four weeks.
  • Remove the seeds, cleaning the pulp from them, and rinse them well.
  • Spread the seeds on a cookie sheet and allow them to dry for several weeks.
  • Store them in a labeled paper envelope in a glass jar in the refrigerator.

Seed saving 101: Understanding isolation distances

In order to save seed and, more to the point, be a good steward of the health and success of open-pollinated varieties, it’s important to take a few precautions.

Perhaps the most challenging one, particularly for (sub)urban gardeners, is that of observing some isolation distances. Isolating plants is a way of preventing the pollen of two closely related varieties from mixing, thus ensuring a relatively stable and pure strain of seed.

A pure strain of seed? Didn’t we want genetic diversity? Well, yes, but not too much. There is a balance to be struck: We want enough diversity to maintain a healthy and well adapted variety, but not so much that the heirloom cabbage you love doesn’t resemble that same cabbage anymore. Seed saving and seed stewardship are a blend of art and science, but don’t be terrified or put off by that. You alone will not irrevocably destroy your favorite variety of cabbage.

Of course, if your whole ambition is to produce a totally different variety by throwing everything into the pot and seeing what comes out, plant with abandon, but please don’t share your resulting seed and promise it’s going to be the original. And be considerate of your neighbors, and any plans they may have for their own gardens.

First steps in planning your summer gardening and seed-saving activities:

  1. Assess your site. Understand the space you have available to grow your crops and the light the site receives.
  2. Identify the crops you want to grow.
  3. Learn your plants’ scientific names, and which other plants share that scientific name. That means both parts of the name: the genus and the species (not the part in single quotation marks). It’s especially important if you wish to grow cucurbits (squash, cucumbers, melons, pumpkins) or brassicas (broccoli, cauliflower, cabbage, collards, kale, to name a few).
  4. Depending on the size of your property and your proximity to your neighbors (especially critical if you grow in a community garden), learn:
    1. What your neighbors’ plans are for their summer gardens, if any.
    2. Whether anyone in your vicinity is a beekeeper.

The topic is a big one to grasp (bigger than I realized when I set out to research the issue), so I’ll break down an example in my next post.

Seed saving 101: The lowdown on hybrids

(Part 3 in a series in honor of the Durham County Seed Library)

Yesterday, we looked at the differences between open-pollinated plants and heirloom varieties. Today, we’ll explore the basics of their agricultural counterparts, the hybrid varieties.

What is a hybrid?

Hybrids are created when individuals of two different genera, species, or varieties mate. Hybrids occur in nature: Leyland cypress (Cupressus × leylandii), peppermint (Mentha × piperita), and wheat are well known naturally occurring hybrids.  Next time you shop for plants at the garden center or nursery, if you see a multiplication sign (×) in the plant’s name, you’ll know the plant is a hybrid.

In agriculture, hybrids are often created by controlled pollination, a process in which the pollen of one parent is applied to the stigma of the other parent, and the flowers of the “mother” plant (the pollen recipient) are isolated (for example, securely enclosed in paper or fabric) to prevent further pollination.

F1 hybrids

F1 usually refers to the first generation produced from a specific cross of two distinct, uniform varieties (two “pure lines”). If seeds are saved from the fruits of these F1 hybrid plants, they will not be “true to type;” that is, they won’t reliably resemble the parent plant.  To get a similar plant to the one that produced those fruits, a gardener would have to cross the original parents again. When it comes to vegetables and flowers, F1 hybrids are typically vigorous plants and good producers, but new seeds must be purchased year after year.

What would happen if I planted those seeds from the F1 fruit?

Unless the hybrid is sterile, plants will grow from those seeds from F1 fruits. These F2 plants (second generation) won’t look like their parent, though, and they may not look much like each other. But if you have an appetite for a long-term project (say, close to a decade), you might be able to select for good traits, save those seeds and grow out successive generations, and over time bring that variety to stability. Then you’ll have created your own open-pollinated variety, and you can name it whatever you like.

There’s so much talk about growing open-pollinated plants. Are hybrids bad?

No, hybrids aren’t bad. They fulfill an important role in agriculture, whether it’s for the backyard gardener or the large-scale industrial farmer.

Truckload of corn

Truckload of corn, Wikipedia photo released to public domain.

The problem in modern agriculture, for which hybrids receive the lion’s share of the blame, is the widespread loss of genetic diversity. We all remember from biology class that variety in a species’ gene pool enhances that population’s ability to adapt to changing conditions and survive over the long term. When farmers plant F1s heavily or exclusively, their fields are filled with identical genetic copies of one another. There is no evolution; favorable traits are not selected and propagated. And when an open-pollinated variety is not planted, it does not have the opportunity to grow and adapt to changing conditions, and over time the variety deteriorates.

Meanwhile, insects and diseases are evolving, changing, and adapting. Restricting genetic diversity in the plants we grow means that over time we’re effectively building better bugs and blights.

The long-term prospects of planting monocultures of F1 varieties include massive crop failures and famines, and/or the heavy use of pesticides and herbicides and whatever residual impacts on human health those products may have.

So hybrids themselves aren’t bad. Exclusive planting of hybrids, however, is very short-sighted.

Now I feel guilty for liking my ‘Silver Queen’ corn, ‘Packman’ broccoli, and ‘Big Beef’ tomatoes. Will I be a bad citizen if I grow them this year?

No, but try growing some open-pollinated varieties as well. You’ll need to maintain isolation distances for some crops, but that’s a matter I’ll write about later this week.

Seed saving 101: What’s the difference between open-pollinated and heirloom?

Continuing with the homage to Durham County’s new seed library, let’s examine the difference between open-pollinated seeds and heirloom seeds.

What’s the difference between an open-pollinated seed and an heirloom seed?

Heirlooms are seeds of plants that have been tended, selected, shared, and handed down for generations within a particular location or community. Some seed companies categorize heirlooms by the age of the variety (e.g., if seeds of a particular plant have been recorded as being handed down for 100 years or more). Seed Savers Exchange classifies heirlooms by tracing a plant’s documented history of preservation, emphasizing the plant’s ties to a particular group of people.

Grandpa Ott's morning glory

Grandpa Ott’s morning glory. Photo by Seed Savers Exchange. http://www.seedsavers.org/onlinestore/Flower-Seeds/Flower-Grandpa-Otts.html

For example, Seed Savers Exchange founder Diane Ott Whealey’s great-grandparents brought some morning glory seeds from Bavaria to Iowa in the 1800s. Upon her grandfather’s death, Diane Ott Whealey founded the Seed Savers Exchange to continue this hand-me-down tradition of conservation, and Grandpa Ott’s morning glories are found in gardens across the country, including mine.

Seed Savers Exchange further differentiates between heirlooms and “heritage” varieties, which are “old-timey” plants that may have no particular connection to a particular people.  And there are “modern heirlooms,” or modern open-pollinated varieties in various stages of emerging tradition, being bred and selected by a handful of seed companies who care deeply about plant genetic diversity and stewardship.

radishesSo to summarize:

  • Open-pollinated seeds, as we learned yesterday, are pollinated by insects, birds, wind, or other means, whose offspring closely resemble their parents from generation to generation. OPs may be of any age or tradition.
  • Heritage varieties are old, traditional open-pollinated plants, that may or may not be connected to a group of people. Heritage varieties are open-pollinated, but not all OPs are heritage varieties.
  • Heirloom varieties are old, traditional open-pollinated plants that are variously defined as being handed down by generations in a particular location or context, and/or which may be greater than 100 years old. Heirlooms are open-pollinated, but not all OPs are heirlooms. Heirlooms are heritage varieties.
  • “Modern heirlooms” is another name for open-pollinated plants bred more recently (say, post-advent of commercial agriculture, up until today), whose tradition among groups of people or locations is emerging. They’re neither heirlooms in the traditional sense, nor are they heritage varieties, but they are being bred in the same tradition and may become heirlooms or heritage varieties in years to come.

Study hard. The exam will be tomorrow.

Seed saving 101: Differentiating between open-pollinated and hybrid plants.

My local public library is starting a seed library. In honor of its launch, this week I’ll be exploring the basics of seed starting and saving, learning about which plants are best for particular applications, and how to plan and prepare for a successful growing season.

Successful seed saving begins with choosing seeds that have the potential to be saved (not in the religious sense).  Seeds of any plant—herb, vegetable, or flower—are either open-pollinated (OP) or hybrids. Only open-pollinated seeds can be saved successfully.

bee in flight

What is an open-pollinated plant?

Open-pollinated plants are plants that are allowed to cross-pollinate by wind, insects, birds, and other means, or they may self-pollinate. Over time and with careful selection, open-pollinated varieties can stabilize, meaning that the parents and offspring naturally share similar traits, closely resemble one another, and are easily distinguished from others in its species (e.g., one variety of tomato, like ‘Brandywine,’ is clearly distinguished from another, like ‘Cherokee Purple’ or ‘Green Zebra’).

tomatoes and squash

What is an F1 hybrid?

Hybrids are made by specifically crossing two different species or varieties. Growers breed commercial hybrids to produce a specific trait, like uniform appearance, concise ripening periods (useful for large-scale machine harvesting), resistance to bruising, or long shelf life. Many of the traits found in modern hybrids were selected with large-scale commercial agriculture in mind.

F1 refers to the first generation produced from a specific cross. If seeds are saved from the fruits of F1 hybrid plants, they will not be “true to type;” that is, they won’t reliably resemble the parent plant.  To get a similar plant to the one that produced those fruits, a gardener would have to cross the original parents again. F1 hybrids are typically vigorous plants and good producers, but new seeds must be purchased year after year.

Are hybrids the same as genetically modified organisms (GMOs)?

No. While hybrids are made by crossing distinctly different species or varieties, GMOs are practically defined in the Cartagena Protocol on Biosafety as living organisms that possess “a novel combination of genetic material obtained through the use of modern biotechnology.” (Cartagena Protocol on Biosafety, Article 3, “Living Modified Organism”). (While the Cartagena Protocol does not specifically mention the term “genetically modified organism,” its term “living modified organism” defined in Article 3 is essentially synonymous.)

In practical terms, this means that GMOs are organisms that contain genetic combinations that couldn’t occur in nature. Think back to your grade-school biology classes: Remember learning taxonomy (kingdom, phylum/division, class, order, family, genus, species)? In GMOs, sometimes genes from organisms belonging to different kingdoms are shared, as in the case of Bt corn, corn genetically engineered to produce its own pesticide. To produce Bt corn, bioengineers inserted certain genes of Bacillus thuringiensis, a naturally occurring soil bacterium often used in mosquito controls, into the corn’s genetic material.

If hybrids are vigorous plants and good producers, and seeds are inexpensive to purchase, why should I bother trying to save seed from open-pollinated plants?

Open-pollinated seeds contribute to genetic diversity, which is important to help plants adapt to changing climates and related environmental factors (changing pests and diseases, etc.). Over time, a gardener may improve a variety so that it is particularly well adapted to the local environment, potentially reducing that gardener’s inputs (i.e., saving that gardener time and money!) to a crop, relative to non-adapted varieties.

Plus, it’s a lot of fun.

sed pods of iris tectorum

A quick comparison of open-pollinated vs. hybrid seeds and plants:

Open-pollinated seeds

 

F1 Hybrids

Includes, but are not limited to, heirloom varieties. Are relatively new to the ecological scene, having developed with the advent of commercial agriculture.
Are pollinated by wind, birds, insects, etc., in an uncontrolled way. Are made by human intervention, deliberately crossing two distinct species or varieties.
Are more genetically diverse as a result of this open and uncontrolled pollination. Possess the genetics of the two parents, which may themselves have been crossed back with one of their parents.
Will not all look or perform the same. Are very consistent in performance and appearance. Are typically vigorous and good producers.
Have not been bred for specific traits, but may have been selected over time for taste, resiliency, disease resistance, or other factors. Have almost always been bred by a grower to have specific traits.
Are more likely to be well adapted to their particular region and its challenges. May not be well adapted to a given region and might be susceptible to particular disease or insect problems, potentially requiring more pesticides or active management.

How do I know if I’m growing open-pollinated or hybrid seeds?

If you ordered the seeds from a catalogue, look in the catalogue entry or on the grower’s website. Hybrids types will usually have the words “hybrid” or “F1” in the description. These words may also be on the seed packet.

You may also do an Internet search of your seed variety’s name (what’s enclosed in single parentheses on the packet, like ‘Brandywine’ or ‘Big Beef’) to find out whether it’s open-pollinated or a hybrid.

Cornell University maintains a public, citizen-science database called Vegetable Varieties for Gardeners at http://blogs.cornell.edu/garden/get-activities/signature-projects/veg-varieties/. Home gardeners throughout the United States can search the database to find varieties well suited for their growing areas, including both hybrids and open-pollinated plants. Creating a login allows gardeners to provide their own reviews of the varieties they grow and to help build understanding of regional adaptability of different varieties.

Tomorrow, I’ll write about the differences between open-pollinated plants and heirloom varieties.

For more information on open-pollinated plants, hybrids, and GMOs, see the following resources: