Growing Seeds for Food or Sale

One of the more important items that is likely to be in short supply in case of a major disruption to the commercial food supply is gardening seeds. If you can’t buy food, or if food supplies of many items are limited, or if there is food rationing, or if the commercial food supply simply becomes erratic and unreliable — in all these cases, people will naturally turn to gardening to provide themselves with some portion of the food that they need. (See my previous post on how much land you need to grow your own food.)

Now suppose you are one of these persons, who decides to grow some of your own food, AFTER disaster strikes. You go to a local store to buy seeds and other gardening supplies. There won’t be any. The shelves in that section of the store will be empty. Everyone will have the same idea, and there is not enough seed in the commercial seed production and distribution system to supply a sudden increase in demand. Now what do you do?

To prepare for this eventuality, can you buy and store a large amount of gardening seeds? You can, but seed germination decreases as time passes. The longer the seeds are in storage, the smaller the percent of seeds that will germinate. This germination rate also varies with the type of seeds; some plant seeds do better than others in storage. Ideally, seeds should be stored at a controlled low humidity and just above freezing, as in the “Doomsday” Svalbard Global Seed Vault “located on the Norwegian island of Spitsbergen near the town of Longyearbyen in the remote Arctic Svalbard archipelago, about 1,300 kilometres (810 mi) from the North Pole.” [Wikipedia has its uses]. If you don’t have your own doomsday seed vault located on a remote Arctic island, I’ll suggest a few alterative solutions.

You could store a large enough amount of seeds, so that a low germination rate will not affect you too badly. You could keep the seeds stored in a cool basement, in sealed containers, so as to extend the viability of the seeds as much as possible. Better still, you could start a large garden, plant the seeds that you have, and then save the seeds from that planting. Then every few years (at least), plant that crop again, and save the new seeds. This way, you always have a large amount of fresh seeds on hand, and you develop the skills and experience needed to get the most out of those seeds. (See this post: Seed-Saving for Disaster Prepping)

But not everyone is so well prepared. If you find yourself with a need to grow food, and only a small amount of seed, you can do what is called a “grow out”. You plant the seed, and then at harvest, you use all of the seed from that first crop as seed for planting the next crop. This process can be repeated until you have enough seed for yourself, and enough for friends, neighbors, and sale or bartering to anyone who is interested.

And this raises an interesting question — interesting to me because (as you might know from reading my posts) I like math. So here is some grow-out math for you.

Suppose, first, that you have 100 gardening seeds. You won’t get 100 plants from those seeds, because not all will germinate. A good germination rate is 90%, but 80% is acceptable. So you plant those seeds, and end up with about 80 plants. The amount of seeds produced by each plant will vary greatly from one type of crop to another. A bush variety of soybean might only produce 50 to 100 beans that can be replanted as seeds. Here’s the math:

First crop:
100 seeds, 80% germinate and survive to produce seed, at 75 seeds per plant = 6,000 seeds for replanting
Second crop:
6,000 seeds times 80%, times 75 = 360,000 seeds for replanting
Third crop:
360k x 0.80 x 75 = 21.6 million soybeans (for eating, selling, and replanting at this point)

A soybean crop takes 3 to 4 months from planting to harvest. Let’s say it’s 4 months, including some time to harvest and dry the seeds, and to prepare the soil for the next crop. If you have 12 months of seasonable weather, 3 crops is one year. If you can only get in two crops, you are into the second year before you have a sizeable amount of soybeans for eating and for sale or barter.

How much seed? You can usually look up the number of seeds in a pound of any particular type of plant. You can also look up the recommended “seed rate”, which is the amount of seed you should plant per acre (or per hectare). On soybeans, one source says: “If the seed size of a variety seed lot is 2,400 seeds per pound, and the seeding rate is 160,000 seeds per acre, 66.7 pounds of seed is needed per acre.”

So our 100 seeds is less than one ounce; the 360k seeds is 150 pounds (that’s the dry weight). And the produce of the third planting, totaling 21.6 million seeds, is 9000 pounds of dry soybeans: enough to supply a small town with seed for planting. Enough to supply a large neighborhood with one source of high-quality protein and dietary fat. And if you are selling your crop, during a time when food is scarce, you will have a good income — but not until the third crop.

How much land do you need for this grow out? The first crop is 80 plants, which is a small to medium-sized garden. The second crop requires 180 square yards (150 sq m) — a backyard-sized garden. For the third crop, you are planting 150 pounds of soybeans in about 2.25 acres of land. At that point, you need help with the planting and harvesting. You might join forces with some prudent and reasonable neighbors for the planting and harvesting. There will be plenty of crop to share.

See how much fun “prepping math” is? One more grow out example, for a very different type of crop: Amaranth. This plant, more than perhaps any other, allows for a rapid increase in seed from a grow out. Usually, if you plant fewer seeds, you not only get fewer plants per acre, but you get less produce in the harvest. But not with Amaranth. The plant adjusts its food output based on how crowded or sparse the planting is. Seeding rates of: 1/4, 1/2, 1, 2, and 4 pounds per acre all produce about the same harvest. This is due in part to “the ability of the plants to compensate in seed production per plant at reduced population levels.” Amaranth has small seeds: about 600,000 seeds per pound. Each plant produces 100,000 seeds or more (a few ounces of seed) per plant. So instead of one seed turning into 75 seeds, one seed turns into 100,000 or more. The low seeding rate, and the high number of seeds per plant allows for a much quicker grow out.

On a small scale, with hand harvesting, the produce can be has high as 3000 pounds per acre. But on a larger commercial scale, it’s about half that (1500 lb./acre). So let’s do the grow out math.

First crop:
100 seeds, 80% success rate, 100k seeds per plant = 8 million seeds from the first crop. Compare this to the 6k seeds from the first crop of soybeans. That 8 million seeds can be planted at a seed rate as low as 0.25 lbs. per acre. But let’s assume a conservative 0.5 pound of seed per acre.

Second crop:
8 million seeds (divided by 600k seeds per lb.) is 13 lbs. of seed, which plants 26 acres for the second crop. The harvest from the second crop is 26 acres times a conservative 1500 lbs. per acre for a result of 39,000 lbs. of grain. This compares to 150 lbs. from the second crop of soybeans.

With amaranth, by the planting of the second crop, you need lots of help with the work. Or, more likely, you are already selling the seed, from the very first crop, to many different customers. Those 8 million seeds, if sold at 1,300 seeds (one gram) per customer could result in well over 5000 sales. If sold at one ounce per customer, it is still over 200 sales.

Third crop:
You can’t even plant a third crop, not even with lots of help from neighbors. But just for comparison, let’s look at the math: 39k pounds of seed plants 78k acres, producing 117 million lbs. of amaranth grain. This compares to 9000 lbs. from the third crop of soybeans.

Start your first crop of amaranth with one pound of seed, and by the third crop, you have 27 billion lbs. of grain. Of course, now we are on the scale of a large nation, or a multi-nation region, using large scale grow outs to replenish the seed supply and the food supply. Amaranth can accomplish those two goals (seed for planting, food for consumption) much sooner than other crops. Wheat is planted at about 50 lbs. per acre, and produces about 2500 lbs. per acre. Start with one pound, and by the third crop, you have 125 thousand lbs. of grain, as compared to 27 billion lbs. of amaranth.

Which seeds should you store for planting in case of disaster? A wide variety of plants would be best, taking into account the dietary need for protein, fat, and carbohydrates. (See: When The Stored Food Is Gone) But I would suggest that a pound of amaranth seed would be one excellent choice. You could plant 2 to 4 acres, and the result would be up to 3000 lbs of grain per acre for a hand harvested crop from the very first planting. Food for everyone.

– Thoreau

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