Long before the last frost melts and the rest of us are gearing up for spring, Martha Stewart is already thinking ahead and tending to her garden. Although winter is still lingering, she’s already getting started on one important task inside her greenhouse: starting onion seeds ahead of the planting season.
In a recent The Martha Blog post, Stewart explains that every year around January, her head gardener, Ryan McCallister, sows vegetable seeds indoors to ensure they’ll have strong and healthy plants that are ready to be moved outside when the weather shifts into gardening territory.
The first crop to be planted is onions, which, according to Martha, rewards early preparation with an abundant mid-summer harvest.
Martha lives on a 153-acre farm in Bedford, New York, and knows, just as any northern gardener, that the summer season is short. But she doesn’t let that hold her back from having an abundant garden, and early preparation is key to making the most out of gardening season.
Photo by Coolpicture on Getty Images
(Photo by Coolpicture on Getty Images)
Keen to copy Martha’s season-extending hack? Starting onions from seeds is actually a whole lot easier than many gardeners might think.
“Starting onions from seed isn’t difficult,” Martha explains in her blog post. “They can be planted closely together in seed starting trays and, because they are shallow-rooted, they can be pulled apart easily when ready for transplanting outdoors.”
How to Start Onions From Seeds, According to Martha Stewart
This efficient method allows dozens of onions to begin growing in a relatively small space (see: no farm greenhouse necessary). Martha uses seeds from Johnny’s Selected Seeds—her favorite source for high-quality seeds and equipment. She starts by sowing seeds in shallow, 20-row flats to keep each onion variety separate.
Photo by Mint Images on Getty Images
(Photo by Mint Images on Getty Images)
Martha and Ryan then fill each tray with a pre-made seed-starting mix, which helps ensure it contains the right balance of vermiculite, perlite and peat moss for drainage and moisture retention. Martha also noted that she prefers Miracle-Gro Seed Starting Potting Mix to give the seeds the best possible start.
After leveling the soil to the top of each tray, Martha suggests taking the edge of a wooden ruler to create quarter-inch-deep furrows. Each tray is then carefully marked with the onion variety and color, making it easy to track performance throughout the season. She adds that clear labeling is essential for tracking what grows well and what doesn’t.
In a few weeks, the seedlings should be ready to be selectively thinned to eliminate weak sprouts and prevent overcrowding. Martha says that this allows the strongest plants to thrive without competition.
Photo by Albany Times Union/Hearst Newspapers on Getty Images
(Photo by Albany Times Union/Hearst Newspapers on Getty Images)
Once covered lightly with soil and gently tamped down, Martha’s trays are thoroughly watered in the greenhouse (but your kitchen windowsill would do just fine). She then adds a thin layer of fine vermiculite over the top to aid germination.
And that’s really all it takes! Martha says that seeds are typically started about two months before the last expected frost, ensuring sturdy transplants when spring planting begins.
Related: Martha Stewart Reveals She Feeds Her 7 Cats This Luxurious Treat
This story was originally published by Parade on Mar 5, 2026, where it first appeared in the Life section. Add Parade as a Preferred Source by clicking here.
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