Garden Layout for Seed Saving, Part 2: Nightshades

Reader Contribution by Edmund Frost

Just when I thought it couldn’t get any busier with planting the seed gardens, it was time to cut the hay. I’m not really in charge of hay cutting at Twin Oaks, but I am in charge of hayfield fertility and re-seeding. I care about getting the hay in before the rain. It is my job to fill in when needed, to help coordinate people, and to worry. I don’t cut or bale the hay (I’ve carefully avoided learning), but I do rake, deliver fuel, drive the flatbed dump truck, and help load the barn under threat of thunder. We got a really good harvest this time, 206 round bales, and we got it all in the barn before the rain. I credit the good productivity to the re-seeding we did in fall of 2012 with a no-till drill we rented from a neighbor. I also think it helped that we gave the fields a rest last year.

I live at Twin Oaks, which is an income-sharing intentional community of 100 people in Louisa County, Virginia. We use the hay to feed our dairy and beef cows, which we raise for our own food (not to sell).

Anyway, on Monday morning it was time to hit it hard with the final stages of planting the seed gardens, and I’d spent the whole weekend racing around dealing with hay. Not ideal, but I think I’m getting through it ok. Pretty much everything is planted, and we’re now busy with the hoeing, cultivating, staking, caging and irrigating.

This is me with a seed crop of Arkansas Traveler tomatoes.

Garden Planning With Seed Saving in Mind

The focus of this post is garden layout for seed saving of nightshade crops. I know it’s a little late to talk about garden layout. I have a decent excuse though, which is that I only started blogging on this site a month ago. Understanding isolation distances and cross-pollination is an important starting point for seed saving. So although its June, I’m still going to write about it. I hope that readers will be able to use the information I am presenting in two ways:

1)To identify crops already growing in the garden that you can save seed from. Its quite likely there are a couple.

2)To go through this garden season thinking about how to plan next year’s garden for seed saving.

Saving Seeds from Nightshade Crops

The Solanaceae family (nightshades) includes peppers, tomatoes, potatoes, eggplant, tomatillos and ground cherries. These, with the exception of potatoes, are often a good choice and starting point for new seed savers.

Tomatoes need little isolation distance, and many people produce pretty good tomato seed with no isolation at all. Tomato flowers are usually self pollinating, but can be crossed by bees. Jeff McCormack, who has written several excellent pamphlets on seed saving in the Southeast (available at, recommends an isolation of 10 feet for home use and 35 feet for commercial seed production of tomatoes. Cherry tomatoes and potato-leaf varieties may need more isolation: 45 feet and 35 feet respectively for home use. Even if your tomatoes are closer together than this, you could save seeds this year. There probably won’t be much crossing, and if there is, its good information to gather.

Tomatoes (and the other nightshade family crops) are also easy because they don’t exhibit something called Inbreeding Depression. Inbreeding Depression occurs in certain crops when you don’t save seed from a big enough genetic pool. With corn for example, you need to save seed from at least 200 plants or else the future generations will start to be stunted and less vigorous. This doesn’t happen with tomatoes. Just one plant will work, although more plants are better if you want the seeds you save to more fully represent the range of genetics present in a variety.

How to Save Seeds from Tomatoes and Peppers

I’ll cover seed saving techniques in a future blog, but here is a short summary of how to save seed from tomatoes. Mash the entire tomato, or else cut it in half and remove the seeds and gel from the seed cavity. Let the resulting mash ferment for about three days (don’t add water), stirring the mash at least once a day to prevent mold from forming on the top. Then add water. The seeds will sink and the water and pulp can be poured off. Add water again and pour that off to get the seeds cleaner. The seeds can be dried on a screen or on paper, ideally in front of a fan.

Peppers require a larger isolation distance than tomatoes. For sweet peppers, 40 feet may be adequate for home use, and about 125 feet for larger plantings. Hot peppers require more isolation. This is partly because they are more prone to crossing, and partly because its especially important that sweet peppers not be crossed by hots. I wouldn’t plant a sweet pepper within 350 feet of a hot pepper and save the seeds from it unless I wanted a cross.

Simply removing and drying the seeds from a ripe pepper (no green peppers) is one good way to save pepper seeds. Avoid any moldy and discolored seeds, and any thin seeds (that are not fully formed).

One great thing about growing peppers for seed is that you can save the seeds and still eat the whole pepper. Peppers are a major crop for us at the Twin Oaks seed gardens for this reason. We eat a lot of peppers in August, September and October, and also put them up as pepper pesto, pepper jelly, pickled peppers, hot sauce, and frozen in bags.

For small peppers it can be tedious to remove all the seeds. If this is the case, you can mash up the small peppers (do add a little water), let the mixture ferment for about one day, and wash the same as tomato seed. This method also works well for eggplant, ground cherries and tomatillos.

Eggplants need slightly more isolation than peppers – about 75 feet for home use and 150 feet for larger plantings. Tomatillos and ground cherries probably have similar isolation needs to eggplant.

Potatoes are usually propagated from the tubers. The plants also make small fruits which can be processed for seed, but this seed will not necessarily produce plants that resemble the parents. Saving this “true seed” from potatoes is useful if you want to do breeding work. Usually potato tubers that are used for seedstock come from northern areas where there is less incidence and risk of diseases like scab. We don’t grow potatoes in the seed gardens here.

This year in the Twin Oaks seed gardens we are growing seven varieties of peppers and eight tomatoes for seed. Our largest nightshade planting is 1/8 acre of Cherokee Purple tomato; the smallest is five plants of Matt’s Wild Cherry tomato (a sweet cherry tomato with exceptional disease resistance). We’re also doing a pepper observation trial. I’m looking for peppers that are productive, that taste good, that hold up well in the field, and that don’t rot or get spots on them before they get ripe. I’m especially looking for great red bell peppers, and am excited about several varieties from pepper breeder Doug Jones from North Carolina.

There will be lots to report at harvest time! I’ll have more to say about the seed saving part as well.