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Seed starting indoors gives your plants ideal conditions for growing.
Growing a plant from seed to harvest is a rewarding challenge. Really! If you begin indoors, you can jumpstart the season while ensuring your seeds have the best possible growing conditions.
Follow these steps to start your seeds off right.
One of the benefits of starting seeds indoors is that you can sneak in a longer season. This is fulfilling for eager gardeners but also ideal for certain plants that need an extended growing period to reach their full potential.
There is a sweet spot, however. If you begin too early, your seeds may outgrow their starter containers before you're able to transplant them. Most seeds can be sown indoors around 6 weeks before you plan to plant them outdoors. Check your seeds' packet, which should have information on when to plant based on frost dates. You'll also need to know your planting zone and watch your local weather forecasts to learn when the final frost of spring is in your area.
Keep in mind that not all seeds are suited to indoor growing, no matter when you start. Pumpkins, winter squash, cucumbers, corn, and root vegetables like beets, turnips, potatoes, and carrots are a few plants that prefer to stay where they're planted. Check the information that comes on the back of the packet or with the seed supplier you buy them from to know how your region matches up with your seeds’ needs.
Seeds. It's what you're here for, so make sure you bring the seeds! Whether you're planting veggies, herbs, or flowers, seed starting offers you tons of planting options. Some suppliers offer a wide variety of seeds while others specialize in organics or heirlooms. Just make sure to buy a few more than you plan to grow. Not all of them will germinate (or sprout), so less is not more in this situation.
Containers for growing seeds. You have plenty of options here. Whatever you choose to plant your seeds in, make sure your containers are at least 2 inches deep, and you'll want to clean them out thoroughly and poke drainage holes in the bottom (if they don't have drainage already).
Seed Starting Soil. Seeds need a soil that's light and fine so those baby roots can poke through. A good seed starting "soil" doesn't have much soil or dirt in it, if any at all. Instead, seed starting mixes contain lightweight ingredients like peat moss and perlite that allow for airflow and retain a uniform amount of moisture. Miracle-Gro® Seed Starting Potting Mix is a great option that's designed to nurture your seedlings.
Labels. You know exactly what you planted…until you realize that seedlings all look the same. Save yourself a headache and use tape with permanent marker, colored labels, or small plant tags to remind you what you planted where.
Cover. Using a plastic cover over newly planted seeds helps keep the moisture in the soil and humidity levels high. Most seed starting trays come with a cover, but you can also use plastic wrap, bags, or domes to cover containers. Just be sure your cover doesn't touch the soil and gives seedlings room to sprout. You'll also need to be able to access the soil to check moisture and water as needed.
Light. While most seeds don't need light to germinate, some plants including lettuce, petunias, and begonias do need light to encourage them to sprout. Once any plant germinates, it needs plenty of light—-usually between 12 and 16 hours per day depending on the plant. Rooms with south-facing windows in your home are a great option, but even this may not be enough. Your seedlings may take on a leggy or spindly look as they're trying to reach the light. It's best to use LED lights, such as a shop light or grow lights designed for seed starting. Place your light above your seed containers to give your plants an even amount of light. You'll make your work easier if you find a light you can easily move up or down as your seedlings grow and use a timer to automatically switch the light off when it's bedtime.
Once you've got your supplies, it's time to start planting. Follow these steps:
Some seeds are perfectly happy inside their protective coat and aren’t keen to change it up. However, with a little prodding and careful encouragement, most will eventually join the seed-starting party. Whether they need to be scratched, chilled, or soaked, here are a few tips and techniques to get them stimulated. Check the seed packet to make sure it hasn't already been done for you.
Scarification. Certain species are harder to germinate than others because their seed coats are resistant to water and oxygen, two of the essentials needed for sprouting. Give stubborn seeds—morning glory, lupines, milkweed—a boost by scratching them with a metal file or fine-grit sandpaper right before planting. This process, known as seed scarification, makes the seed's protective coating more porous. But now that it's been compromised, you'll want to plant it as soon as possible.
Stratification. Seeds from plants that are native to temperate zones—regions that see mild winters—actually need a cold spell to germinate (strawberries, primrose, wild geraniums). You can simulate the season by chilling these seeds, or stratifying them. One common stratification method is to put protective peat moss in a plastic bag along with your seeds, and store them in the refrigerator at 39 to 41°F—make sure they don't freeze. Another way is to store the seeds in the freezer and pull them out to thaw a day before planting. How long you keep them chilled depends on the variety, but typically this is 4 to 5 weeks, or according to the directions on the seed packet label.
Soaking. Another technique to speed up the germination process is seed soaking. This is popular for seeds like edible peas, sweet peas, parsley, beets, and chard, whose internal clocks rely on the moisture levels of spring to let them know it's time to grow. The process is simple: place your seeds in tepid water, generally for more than 4 hours but fewer than 24 (check the packet for instructions). Discard those that float to the top; they're usually considered bad for planting. Once their time is up, plant the seeds as soon as possible.
So, your seedlings have sprouted, and you're a proud plant parent…now what? Next, you get to transplant them to their permanent homes. Follow this guide to transplanting seedlings to give your new plants the best chance at success.
While sowing seeds indoors requires a commitment, the process is worth it. You'll have more bonding time and greater control over your plants’ happiness. Most of all, though, it's fun to discover and grow plants that you might not find at your local nursery. So dream big, and go for it!