With the last frost imminent in most parts of the country, you can begin working on your garden today. Instead of buying young plants this year, try to start seeds indoors. It’s cheaper than the alternative (particularly for plants you might choose to grow in great quantities) and accommodates a larger variety than your local nursery does. Seed sources like Burpee.com and SelectSeeds.com specialize in high-quality heirloom seeds and make available a wide range of species.
Of course, buying the seeds is only the beginning. When it comes to successfully growing seeds indoors, Chelsey Fields, Vegetable Product Manager at Burpee.com, has four expert pointers.
1. Seeds with a long growing season that are tolerant of root disturbances are the best seeds to sow indoors. “Tomatoes, basil and petunias are all great candidates,” says Chelsey. Most seeds need to be started 4-8 weeks in advance of the last frost; check individual packages for specifics.
2. Go with a high-quality growing medium that is light and fluffy enough to hold moisture. “If the growing medium is too wet or not sterile, disease can strike. If it is too heavy or sticky, fine new roots won’t be able to push through it,” Chelsey points out. Compressed pellets of peat that expand when wet usually work well (to ensure freshness, purchase from a reliable source). You can use recycled (and sterilized) plastic containers—like an empty yogurt cup with holes poked in the bottom for drainage—or make it easy on yourself by purchasing an all-inclusive growing kit, such as Burpee’s XL Ultimate Growing System.
3. Seeds need lots of light. A sunny south-facing window might be enough, but consider supplementing with a T-12 or T-8 fluorescent shop light (available at most hardware stores) to ensure that your seeds receive 12-16 hours of light each day. Shift the containers a quarter-turn every day to keep all the seedlings even. “To maximize success during the two stages (germination and growing), gentle warmth is needed,” says Chelsey. “If your room temperature isn’t between 60 and 70 degrees, use a special seed-starting heating mat.” Finally, keep the soil moist but don’t over-water.
4. When the seedlings have their first set of true leaves (about four weeks after germination), begin slowly acclimating your plants to the outdoors. The first two days, put the seedlings outside in a shady location for 3-4 hours, adding an hour each successive day. On the third day, put the plants in the morning sun before returning them to full shade. Increase the amount of intense sun the seedlings experience each day until, on days 7-9, you allow them to stay outside overnight. By following this schedule, they should be ready to transplant on day ten, according to Chelsey.
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