It’s time to dispel the myth that only people with “green thumbs” can start seeds. Reflect back to your school days: Did you ever start marigold or grass seed in an old milk carton? Chances are your first lesson in seed starting was in grade school. And wasn’t it like watching a miracle unfold right before your eyes? (Heck, I’m still amazed that a tiny seed can produce a beautiful flower or provide food to eat!)

Seedling in milk carton

Your early lessons in seed starting probably included sowing marigolds in milk cartons!

Photo Credit: Donna W. Moramarco

Racks of seeds

Garden centers offer many types of seeds for purchase – from vegetables and herbs to annuals and perennials.

Photo Credit: Donna W. Moramarco

Marigold seedlings

These marigold seedlings appeared just seven days after sowing.

Photo Credit: Donna W. Moramarco

Repotting Marigold

When it’s time to repot young seedlings, handle by the stem, not the leaves!

Photo Credit: Donna W. Moramarco

The hardest part about starting seeds for your garden is determining when to do it. The key is to know when your safe planting and last frost dates are. (Your safe planting date means just that: It’s the time when all danger of frost has passed and it’s safe to plant tender crops in the garden.) Fortunately, most seed packets can help you find your answer as to when you can start planting. But as a general rule, most annual and vegetable seeds can be started indoors 6-7 weeks before the outside planting time. (Of course, there are always exceptions, so do read the seed packet for particulars. Seed packets also include a wealth of useful information, including how many days it takes for seeds to germinate, as well as spacing and planting measurements.)

That said, seed starting is a fun hobby for any age, and you don’t need an arsenal of supplies to do it – just a few essentials:

  • clean containers, pots or flats
  • viable (or fresh) seed
  • sunlight or artificial light
  • temperatures between 60-75 degrees F
  • soilless seed-starting mix (readily available at most garden centers and nurseries)
  • dibble, pencil or the trusty finger
  • water
  • starter fertilizer

Ready to start? Let’s get sowing!

Fill flats, trays or packs with your soilless mix (level to remove any excess) and lightly water so the mix settles. (Note: If you’re using peat pots, wet them before you fill them with soil.) If you’re sowing your seed in flats or trays, use a dibble, pencil or finger to carefully make depressions in the mix in rows. If you’re using pots or cell packs, make a depression in the center of each little container. How deep your depressions are depends on the size and type of your seed. Very fine seed may need to be scattered along the top, while larger seed will need to be more scattered in the depression. Your best bet is to follow the directions on the packet for proper planting depth and covering. (Whatever you do, don’t bury your seeds too deeply!) After sowing, water lightly.

Congratulations, you’ve got your seeds planted – but you’re not done yet! Believe it or not, soil temperature plays a key role for most seeds to germinate. As a general rule, soil temperatures of 60-75 degrees F are preferred. (Luckily, if you’re starting seeds in your home, chances are the inside temperatures are adequate for germination.)

Light is a key part in your success, too. While not all seeds need light to germinate, once they do, light becomes critical to the development of young seedlings. The most important thing to remember is that most seedlings need 15-18 hours of light each day. If you’ve just started counting on your fingers, yes – finding a sunny window that provides that much daily light is impossible. So what’s the best way to provide your seedlings with the light they need? There are a couple options:

Cool fluorescent lights make the job easy and rewarding, and the setup can be simple or elaborate. Hanging a fluorescent light fixture 6-8 inches over seedlings can work nicely. As the seedlings grow, just raise the fixture, maintaining that 6- to 8-inch distance. Seed-starting racks with built-in trays and light fixtures work, too (and can be considered an investment for the serious gardener). With proper planning, you can use this rack year-round for growing other plants under lights.

And of course, seedlings, like all living things, need water to grow and thrive. Emerging young seedlings should never go dry. Keep the growing medium moist – not soggy – at all times. How you water is also important. Never open the floodgates! Instead, invest in a watering can with a rosette at the end. The rosette breaks the strong flow of water and gently distributes it evenly over the soil.

Seedlings that are growing in individual pots (plastic, peat or other) don’t need to be transplanted. But if you’re growing your seedlings in flats or trays, you’ll need to move them to new homes once the tiny plants have one or more sets of true leaves. Using a spoon or fork, carefully work the seedling out of the soil. When it’s free, lift the seedling by its stem, not the leaves. Place it in its new pot (filled with soilless mix) and carefully firm the mix around the stem. Water carefully to settle, then place your transplants back under the fluorescent lights. (Remember to raise the lights as they continue to grow, keeping that distance of 6-8 inches between the tops of the plants and the lights.) Young transplants can be fertilized with a starter solution according to label directions.

A week or two before it’s time to plant in the garden, begin to harden your little guys off to outside conditions. This means bringing your plants outside each day for a couple of hours, gradually increasing the amount of time they spend outdoors. Do this during the warm hours of the day, returning them to a cool (about 50 degrees F) and protected location at night. (If you’re so inclined, adding a cold frame to your garden is a great way to harden off transplants.)

Remember, you don’t have to be a green thumb to germinate seeds! Revisit an old school lesson and try growing some plants from seed. Before you know it, you’ll be hooked!