Seed Starting

Although seed starting may seem a little daunting, there are many reasons to give it a try. If you are a new veggie gardener, do start with transplants from the store or mail order to get your feet wet.

Starting your own seeds has many advantages.

  • Varieties are endless when purchasing seed versus the small selections available as transplants.
  • Although organic seeds are limited, any seeds started organically are better than conventionally grown transplants that may have already been treated with pesticides.
  • Chance of disease is greater from transplants purchased. The New York area had a bad blight outbreak a few years ago that spread through the transplants from one of the home improvement stores.
  • Price, price, price! Seeds are much cheaper than transplants if you wish to garden for the purpose of saving money by growing your own.
  • If you have a failure with your own transplants, you should still have seed left to try again.

Basically there are 2 methods of seed starting:

  • Direct sowing in the garden, usually after the last frost date.
  • Indoor seed starting 6-10 weeks before the last frost date, depending on seed.

Seedlings environment must be properly prepared and monitored just like a baby. I say this with many years of failures due to laziness, neglect & not paying attention to details of environment. Of all my shortcuts in gardening, my seed starting shortcuts never seemed to pan out.

Necessary elements to good seed starting with either method:

  • Good quality, viable seed
  • Loose soil medium
  • Warmth
  • Regular water
  • Adequate light

Outdoor Seed Starting

Many seeds may be started directly outdoors. Although it seems much easier, because you don’t have to transplant, you lose a lot of control when seed is started outdoors.

What you will need

  • Good quality seed that is fresh for good germination. Seeds all have a shelf life whereas they will have a good germination rate; their viability. Some seeds have longer viability times than others, check the chart below. That doesn’t mean you can’t try old seeds, they just won’t have a high germination rate; if any. There are many good seed companies offering a wide selection of seeds and many organic. There are also companies that specialize in heirloom and non-GMO(genetically modified seed) for the purist of organic gardeners. A list of seed companies you will find in RESOURCES at the end of this article. Seed selection is the same regardless if you start them inside or outside.
  • Soil may be any good garden soil, light & friable with organic matter such as compost or dried manure, preferably applied a couple weeks prior to planting. If using wet fresh manure, apply the season before planting.
  • Warmth in the soil is necessary for germination, soil temp., not air, should be 70° except for some seeds, like peas can handle a little cooler. Also, if the temps are too high, germination may not occur, as in the case of lettuce with 90° & higher.
  • Water the seedlings twice a day to keep moist. Avoid late evening watering in early spring when cool temps can breed disease or wet soil. Use a gentle sprayer head so as not to dislodge the seeds.
  • Labels are absolutely necessary, especially if growing different varieties of the same plant. I make labels from cut up old slats of vinyl Venetian blinds. Use a permanent marker, but I still put clear tape over the writing due to water & sun exposure, they won’t last by the time you get to harvest.
  • Light outdoors is up to Mother Nature, but plant in a sunny spot!

What to Do

  1. Loosen up bed or area to be seeded.
  2. Add a sprinkle of organic fertilizer.
  3. Add organic matter in the form of peat, compost, or manure
  4. If planting in rows, mark out the row with a trowel making a narrow trench.
  5. Or just broadcast seeds lightly over an area to be thinned after they germinate.(for very small seeds, mix with peat or sand first and then broadcast.
  6. Cover lightly with coconut coir, peat or compost & tamp down.
  7. Water gently with sprinkling head.Cover with burlap or landscape fabric if you have critter problems that may want to eat the seeds, like birds.
  8. Keep moist & do not mulch till seedlings are 4-6” tall.

Seeds that start easy outdoors are beans, corn, carrots, lettuce, peas, squash, corn, peanuts, dill, coriander and melons.

Others, do much better with a little pampering indoors and may need a long growing season. Such as tomatoes, peppers, eggplant and many herbs.

Indoor Seed Starting

What you will need

  • Good quality seed.
  • Soil-less medium such as: Peat, coconut coir fiber, peat with perlite, vermiculite, or premix bags of seed starting mix. It must be sterile, lightweight, water retentive, and drain well. Garden soil is not a good medium unless loaded with humus and sterilized in your oven on 125° for at least an hour.
  • CLEAN containers. Seedlings are very vulnerable to bacterial & virus so containers must be cleaned with bleach solution or other antibacterial cleanser. You can use:
    • Any plastic container with drainage holes in the bottom
    • Small pots & flats from other nursery purchases
    • Seed starting flats & trays.
    • Self-watering seed starting “system”, for the really serious home gardener, that consists of a multi-cell tray that sits on top of a reservoir of water with a gauge to let you know when to add (to dummy proof the watering- my personal favorite). The water is then wicked up underneath the tray of cells. It also has a clear dome for optimum humidity. This seems to be the best method as you only need to fill the reservoir once a week!
    • A soil blocker system; uses a mold to make blocks of firm soil, multiples at a time. The blocks are then placed in a flat with ¼ inch air space between each block. The roots grow just to the outside of block and do not intertwine with each other.. You must use a fibrous soil mix that is wetter than usual so that the blocks will stay together. Soil blocks make for easy transplanting without stressing the roots.

    🙁 I am not a big fan of peat pots or pellets that are available. They dry out easily & even though they say they will breakdown in the soil after transplanting, after many attempts with different types, they were pretty much intact at the end of the season.

  • Warmth will make seeds germinate & grow faster if soil temp is 70-80°. That’s not to say your seeds won’t germinate with cool nites and a sunny window warming them up in the day, but they can rot if it’s too cold & wet. Placing your flat on top of the frig is usually a warm place, but the radiator or heat vent are usually too hot and drying. If you want to get serious, you can buy a heating mat that goes under your flat and will maintain optimum temps. . I have coiled up a set of Christmas lights, covered with a trash bag and put a seedling flat on top, keeping the lights on at all times, there is enough heat to germinate seeds quicker.
  • Labels are necessary for each cell or at least every other if growing multiples. As your plants get transplanted, hardened of & then set in a pot or ground, they tend to get split up, so each needs a label. I make labels from cut up old slats of vinyl Venetian blinds. Use a permanent marker, but I still put clear tape over the writing due to water & sun exposure, they won’t last by the time you get to harvest.
  • Light is needed after germination. Without enough light, natural or artificial, your seedlings will be weak and spindly. 12 hours a day is ideal, which is next to impossible to get just from a sunny window. If starting indoors, your best bet is to supplement with artificial lights, kept 2-4” above the seedlings. Plant lights are best, but expensive. Shop lights with regular fluorescent tubes will work. They do lose their strength after a couple of years. Even with added lighting, do place your flats in a sunny window. Check out our plans for a DIY lighting set-up. Or you could buy a set-up; they run anyway from $70 & up!

What to Do

  1. Fill containers with moistened soil-less medium. A ½” layer of chopped sphagnum moss keeps the surface moist & helps to prevent dampening off, a disease of seedlings that causes them to keel over & drop dead.
  2. Set containers on a tray or flat so you can bottom water if possible.
  3. Poke holes in surface of medium of each cell for 2-3 seeds. Use a set of tweezers or a BBQ skewer to make small holes.
    Drop 1 seed in each hole and stir the medium around it to barely cover if seeds are small, large seeds should be pushed down into the medium at least ½ inch. Cover with plastic dome or plastic wrap.
  4. Set in warm spot and leave covered til they start to germinate, then uncover and put in the light immediately. Best to try to plant seeds with the same germination time. Some seeds actually need light to germinate, like lettuce & basil.
  5. Keep surface barely moist to prevent molds & disease. If the surface of the medium gets crusty or green, gently loosen with a fork around the seedlings.

  6. Try to keep the dome on the plants as long as possible while growing to supply optimum humidity, at least at night. Remove during the day to get air circulation. A little ceiling fan action will simulate a breeze which helps strengthen stems.
    When the first true leaves appear, it’s time to transplant into a larger container or to the garden. It’s also the time when you should water with a diluted solution of compost tea, kelp or fish emulsion. If plants are in the house with cats or dogs, fish emulsion may not be a good idea, they may not eat the plants, but they can do some damage digging for that fish.

Viability of Seeds

Seeds are only good for germination for a measured period in which the embryo is alive within the seed coat. This is called viability. Seeds may be grouped by their viability as such:

  • 1-2 years: sweet corn, leek, onion, parsley, parsnip
  • 3-5 years: asparagus, bean, Brussels sprouts, cabbage, carrot, cauliflower, celery, chicory, cress, endive, kale, kohlrabi, lettuce, okra, peas, pepper, radish, spinach, turnip, & watermelon
  • More than 5 years: beets, cucumber, muskmelon, mustard, & tomato

This is of course if seed is stored in cool & dry environment. NOT in the greenhouse.


Seed Companies

Seed Starting Kits

  • ohnny’s Selected Seeds / – soil blocker molds, seed tray & lighting systems
  • Lee Valle y/ – trays with reservoir & wicking mat, soil blocker molds
  • Gardener’s Supply / – seed trays and lighting systems

Send us your comments or tips with seed starting through our Contact Page.