Starting Seeds

Growing plants from seeds offers significant advantages in terms of cost-savings. For the price of a single plant, you can potentially buy 100 seeds, greatly reducing your gardening expenses. Starting from seeds also allows you to carefully time and control the growth process, ensuring your plants reach the ideal size at precisely the right moment.

While local nurseries typically have a limited plant selection, the selection of seeds that can be ordered is vast. You can order seeds for plants you'd never find in retail outlets, and seeds for varieties closely adapted to your growing conditions. I look for seed suppliers in the southwest US to get varieties adapted to my dry, high elevation conditions.

starting seeds for biointensive

Seeding for Biointensive

Starting seeds for a biointensive garden normally is done by indirect seeding. Seeds are started in flats or cells, as opposed to direct seeding into the garden beds. Then the seedlings are transplanted into the garden.

This is done for a some good reasons. Trays of starts are much easier to keep watered than whole garden beds, making them very water efficient. Close spacing in the bed is important and seeds planted directly don't always come up, leaving a gap in the grid that is hard to replant. Starting plants first allows you to put out only vigorous seedlings in the right spacing with no gaps.

In addition to being part of the biointensive system, I have just had more success with starting seeds in pots or flats first. It's physically easier to manage working with plants at table level. I also suspect my soil has tiny, seed-eating critters and my germination outdoors tends to be very low.

Selecting Seeds

Wherever you are, pick seeds and varieties that are going to thrive in your conditions. How long is your growing season? What are daily conditions like in the summer? What is your elevation? The right plants for your climate will use less water, be easier to grow and will yield more consistent harvests.

In the search for the best varieties, talk to your neighbors who garden. Local county extension offices will generally have information about local conditions and the plants that are best suited. Master Gardener volunteers may also offer good recommendations. Of course, you'll also want to select crops that you and your family like to eat.

Buy seeds only from reputable suppliers. Many stores put up cheap seed displays in the spring, but the selection and quality are usually low. Most seeds should readily sprout and if they don't, it could be that the source did not provide quality seeds. Buying open-pollinated seeds ensures that you'll be able to save your own, high quality seeds for the future.

Seeds & Viability

Viable seeds are those that sprout easily and produce healthy seedlings. Older seeds generally become less viable over time, and most seeds have less than 100% viability. Some conditions can result in lowered viability. Seeds that were improperly stored, diseased or poorly pollinated won't start or produce vigorous seedlings. Plant extra and choose the healthiest seedlings to plant in the garden.

You can test seed viability by spreading 10 seeds on a damp paper towel. Place the paper towel in a plastic bag and in a warm place, checking daily for a few days. Count the sprouted seeds and multiply by 10 to get the percent viability. So if 7/10 sprout, that would be 70% germination. To get the right number of plants, more than 30% extra seeds will needed for seeding.

Some seeds, especially those from perennials and wildflowers, are very hard to start even though they are viable. Parsley, for example, makes anti-sprout compounds in its seed coat to ensure the seeds won't sprout in poor conditions. These sprout much quicker after 2-3 days of soaking in water which is changed a couple of times. For plants whose seeds have a tough outer coat, nicking or sanding holes in the seed coat can improve sprouting. Others may need a prolonged period of cold before they can be started.

Getting Started

Indirect Seeding

For small gardens, single containers work well for starting seeds, as do single-cell trays. If you grow lots of the same plant, it may help to use flats (deep, undivided trays) because you can plant many seeds in one container. I have used many different containers with success.

These days, I often use a small flat or 4" pot to start many seeds and pot them into individual cells or transplant into the garden, once they have one set of true leaves. Tomatoes in particular seem to love being transplanted and do well this way.

When deciding how much seed to plant, it's a combination of how much you want to eat or grow plus an extra amount to ensure you have plenty of seedlings. Close spacing in the biointensive beds means that a lot of plants can fit in the bed. Think about how many plants are needed and add 10% to arrive at the number of seeds to plant, and more than that if the viability is low.

What Seeds Need

Regardless of the pot or method, seeds need consistent conditions to see them through to mature plant. They especially need consistent moisture to sprout, but also aeration. Nutrients will become important after roots and true leaves form. For these reasons, I use a good potting soil or seed mixture with some sifted compost. This may not work for others if damping off is a problem, but I do not experience much of this in my dry climate.

Some seeds need a little light to sprout, usually very small seeds. But otherwise all seedlings will need light after they emerge from the soil, and they will get stretchy or leggy without sufficient light. Indoors, a grow light or flourescent light source work fine, but natural light in a window can be fine too. Outdoors, seedlings benefit from natural light but should be protected from the elements such as wind or excessive heat.

Planting Starts Into the Bed

When seedlings are big enough but not root bound, start preparing them to go into the garden bed. Plants should still be actively growing and have developed at least a couple of true leaves. The advantage of using deep flats for seed starting is that the roots haven't hit bottom before transplant time, which can prevent excess transplant shock.

Hardening off seedlings also reduces transplant shock. I try to harden off with increasing exposure times outside for at least 4 days, longer if needed. Tomatoes I will transplant into a larger pot or 2 before hardening off to keep the plant healthy and actively growing.

With seedlings prepared this way, I can evenly fill my garden bed with healthy, growing plants. I'll need to water them in and protect them if you have pests or wildlife issues. They should adapt within a few days and resume active growing. Be sure to keep them moist. I start watering deeply when I see growth to encourage deep root growth, which will make them a little more drought tolerant.

Direct Seeding

There are circumstances when I start seeds directly in the garden beds. For compost and cover crops, direct seeding is easiest. I also sometimes direct seed plants that don't transplant well, like carrots. For direct seeding, I make sure to keep things moist and often cover the seedbed with newspaper or boards, something to hold the moisture in. Those covers need removed immediately once the seeds poke through the soil though so the seedlings get light.

Sometimes, soaking or presprouting seeds will help to improve germination outdoors. For soaking, I'll just cover with water in a bowl overnight, but for presprouting I'll spread on a damp paper towel and roll up in a bag like for a viability test. Then I'll just plant the soaked seed or sproutlet just as I would have the seeds out of the packet. I have had good success with presprouting beets and soaking peas.