Many gardeners purchase "starts", young plants in plastic containers or flats, not because they want a jump-start on their season, but because they've been unsuccessful getting seeds to grow into healthy plants.
While transplanting purchased starts is definitely an option, one plant generally costs as much as a packet of seeds, and purchased starts are no guarantee that you'll have a harvest at the end of summer.
Root shock and poor transplanting techniques are two of the main issues that wipe out plant starts, putting the gardener back at square one with no other option than to shell out more cash to buy even older (and more expensive) plants to catch up with the season.
Knowing how to select and take advantage of purchased starts is a useful skill for gardeners, but growing from seed is the best way to save money and, with basic seeding techniques and surplus plantings, increase your chances for a bountiful harvest.
The most common mistakes gardeners make when planting from seed include:
- Improper seed depth
- Overwatering, underwatering, or using the wrong watering tools
- Using old or low-quality seeds
- Ignoring special seed preparation needs
- Sowing in the wrong temperatures
Now, before you chuck your trowel or head out to the store to blow your garden budget on box wine, take a deep breath and read on. We've got easy solutions and tips for all of these problems.
Seed Sowing Basics
Imagine for a moment that you're at a post-apocalyptic swap meet, shopping for seeds to augment your dwindling supply of creamed corn, marinated artichoke hearts, and cocktail onions. Someone's divided their surplus seeds into tiny bits of folded paper, and you gratefully hand over a few rolls of toilet paper in exchange.
There are no planting instructions on the seed packets, so what do you do now?
Most seeds have simple planting requirements with a reasonable margin for error. Even the most difficult-to-germinate plant varieties will produce a few starts if you follow these basic guidelines.
Plant Healthy Seeds
Seeds contain the energy a young plant needs to germinate, emerge and establish its roots and first leaves. Choose the plumpest seeds in your packet to plant first. If you don't like to let anything go to waste (a good philosophy when civilization is taking a nosedive) double up the less-favorable or shriveled seeds in the same planting space.
As a general rule, plant each seed about two times the depth of its widest measurement. In loose, fine soils, you can go a bit deeper, but in heavier, clay soils, you'll want to plant your seeds on the shallower end of this range. Avoid planting seeds deeper than 2.5 times their length.
Always defer to your seed packet instructions. Offer to throw in a couple bars of hotel soap to persuade wasteland peddlers to give you a copy of the seed packet information, as you should always defer to the instructions on the back. No joy? Then here are the basics:
- Seeds planted too deep will cause the seedling to expend all its energy getting to the surface.
- Seeds planted too close to the soil surface won't have enough root depth to keep the young plant in place.
- Seeds planted a smidge on the shallow end of the acceptable range will germinate faster than those planted deeper in the soil.
- Older, less plump seeds should be planted on the shallower end of the planting depth range.
- If a seed is no bigger than this --> . then it should be seeded on the surface of fine soil.
Some seeds require sunlight to germinate, while others need darkness. Since those that require sunlight are generally the smallest, it's likely that surface planting extra seeds will even your odds; even light watering and air disturbance will cover or uncover surface-strewn seeds.
Best Watering Practices
What plants usually emerge during heavy, torrential spring rains? If you think of tulips, crocus, and other bulb-type plants, you're right on the money. Long, rigid, spearlike leaves cut through soggy, rain-compacted soils. Stored energy in their deep bulbs, tubers or rhizomes gives these early risers the boost they need to make the climb to the surface.
Seed-grown baby plants, however, don't fare so well under these conditions, so it's important to use a hose attachment or spray bottle with a "mist" setting to avoid compacting the soil above the seed.
Once the seedlings emerge, take care not to knock them down or drown them with heavy watering. Deep, gentle watering at soil level is best, applied with soaker hoses or low-pressure drip emitters.
If you're creating your own starts, water your seedlings in peat pots or multi-cell flats by placing their containers in a pan of water. Use only as much water as will be soaked up within about 20 minutes, and discard any remaining moisture. If the soil at the base of the plant isn't slightly moist, give it a few misting squirts.
This wicking, bottom-up approach encourages better deep root growth than only watering from the top.
Commercially-produced starts are usually watered from labor-efficient overhead sprayers. They often spend too much time in their nursery pots, given the period between production, delivery to retailers and final transplanting to their garden spot. These factors hinder healthy, deep root development.
Increasing Your Odds
Once you've overcome the top two obstacles to successful seed germination, you can play with other techniques that further increase your success rates.
Major seed brands now offer "seed tape", extolling its ease of use and reaping the benefits of high price tags and lower seed counts. Seed tape is a fantastic concept, but if you've got some extra time and more common sense than cash, you can make it at home.
Seed tape is a great way to ensure that seeds stay put at the proper depth and spacing until they're established. All you need to make your own is:
- Toilet paper or paper toweling, preferably unbleached, or black and white newsprint (note, toilet paper will be as valuable as gold when the fertilizer hits the fan, so choose your options carefully)
- Paste made from 2 parts flour to 1 part water
- Toothpick (for smaller seeds) or bamboo kebab stick (for larger seeds)
- Ruler or rigid measuring tape
While many garden or DIY guides recommend long strips of paper, we prefer to keep our strips in shorter, more manageable lengths.
- Fold toilet paper or cut paper towels and newspaper into 2" wide strips, creased at the center.
- Mark strips according to thinning space (as opposed to planting space) suggested on your seed packet.
- Mix paste so that it's the consistency of toothpaste.
- Place seeds in a flat dish, and space them out.
- Dip toothpick or kebab stick in your supply of paste, and dab onto the center of one side of the creased paper surface.
- Pick up seed with pick/stick, and press into the dab of paste on your seed tape.
- Once you have completed a strip, fold both halves together and gently press.
- Label the strips with the seed type, and allow the paste to fully dry before storing the tape rolled or in strips in a cool, dry, dark spot. (We like to use cardboard shoeboxes.)
Planting seed tape is easy; dig and moisten a shallow trench according to recommended planting depth. Place the tape within the trench, and fully moisten it with a spray bottle. Then, cover with soil until the surface is level.
For seeds that require sunlight to germinate, make sure the soil is smooth and level (but not compacted.) Keep the soil and tape moist until germination occurs.
For shallow-sown seeds, use the same steps above but cover seeds with a thin layer of soil. Keep moist until germination occurs.
Decreasing the time between planting and emergence increases the odds that your seed will germinate into a healthy seedling. Proper temperature, moisture, and available oxygen are important to this process. How do you help your seeds along? Well, to put it bluntly, you abuse them a bit. Give them a few cuts, scrapes and bruises, hold 'em underwater, or let them spend some time out in the cold.
Scarification breaks down the seed's outer walls to facilitate the necessary transfer of gases and moisture between the seed and its environment.
Stratification uses temperature to signal the seed's cells that it's the right time to germinate.
Some of the hardest-to-grow plants require at least one of the above steps prior to planting, and almost all seeds benefit from either soaking or light scarification.
Soaking Seeds, a.k.a. Chemical Scarification
Some larger seeds, especially beans, do well with an overnight soak in a container of warm water before planting. Soak smaller seeds inside a folded damp paper towel. Place the seeds and paper towel on a saucer, and add enough water to ensure the towel will stay damp until the next morning.
Studies indicate that seeds soaked in a 15% hydrogen peroxide solution help oxygenate seeds while softening the seed wall, and actually help seed cells signal that its time to break the dormancy period.
When a seed passes through an animal's digestive system, the bile, and bacteria within acts as another form of chemical scarification. (We do not recommend that you try this method at home.)
Never leave seeds submerged more than 24 hours, as they'll begin to rot. Rinsing seeds following the methods used for edible sprouts, however, is an option, though seedlings could become "confused" as to which way to send the roots, and which direction to send stems and leaves.
The following seeds are great candidates for soaking:
Some seeds require that a sharp or abrasive surface breaks down its outer coating, called the testa. In nature, mechanical scarification most often occurs with the grinding of a bird's gizzard or an herbivore's molars. Insects, wind particulates, and spring's freeze-thaw cycle act as other forms of mechanical scarification.
Gardeners can mimic nature by scoring a seed's outer surface with a pin, tack or knife, or using an Emery board or another small file to rough up the coating. Most seeds benefit from mechanical scarification; those that require it include:
Some plants require heat from forest or prairie fires to help expose the seed to air and moisture. Others require a significant period in a cold, moist environment to germinate.
Many hardy perennials and prairie wildflowers do best with cold stratification, which is why they're often planted in the fall.
Artifical cold stratification methods usually involve mixing or placing the seeds in an absorbent, moist substrate (we prefer the folded damp paper towel) sealing in a plastic container, and refrigerating for a period between a few weeks and three months until the seeds begin to germinate.
Stratification periods vary by plant species, so once again, refer to your seed packets or online gardening guides. Plants that require or do best with cold stratification include:
- Butterfly Bush
- Perennial Sweet Pea
Some plants need cooler temperatures for germination. Others like warm soil.
Planting heat-loving plants indoors or in a cold frame a few weeks before the last frost of spring is a fantastic way to get a head start.
Seedling mats are heated pads placed underneath soil containers to mimic sun-warmed earth, and cold cellars or uninsulated outbuildings make great spots for cool-season starts. Use artificial lighting for those that require sunlight to germinate, or place seedling flats in a dim corner for those that prefer darkness.
Transplanting Your Own Starts
We recommend using tall peat pots, deep seedling trays or folded newspaper pots to encourage root growth and reduce transplant shock. Peat pots and newspaper dissolve quickly when the entire plant and container is placed in well-watered soil, but newspaper pots don't hold up well to bottom watering.
Time indoor planting so that your seedlings can go outside as soon as the risk of frost has passed, and growing temperatures suit the particular variety you're growing. The sooner you and your plants get their feet into your garden's spring soil, the better!
Best Seed-Planting Advice Ever
Your best bet for successful germination always begins with fresh, plump, properly-stored seeds. Don't trust your gardening season to dusty seed packets that have sat in stockrooms for years, or discounted seeds that have long passed their expiration date.
We at Seed Needs hand-package our seeds, which are chosen from the most trusted suppliers of fresh, non-GMO stock and kept in optimal storage temperatures. Our seeds' high germination rates, combined with your planting know-how, can provide you with enough seedlings to expand your garden, give to friends, donate to community gardens, or even sell at your local farmer's market.
Don't forget to bookmark our blog for more growing tips!