Martha Stewart Swears by This Flower Seed-Starting Method – Here’s What Gardening Pros Have to Say About It

One of my favorite parts about spring is planting new things. It's just so exciting knowing that in those simple steps of care – the digging, the watering, the nurturing – you're at the start of something new and alive.

There isn't any set, exact way to plant seeds, though Martha Stewart swears by a particular method when it comes to starting off her flowers. She posted some behind-the-scenes snaps of filling up her seed trays on Instagram, and she talked about it on her blog.

To put her technique to the test, I asked gardening pros what they think of Martha's flower seed-starting method, as well as whether they would do anything differently. Read up on what they had to say before you dive into planting your own seeds.

Martha's Seed-Starting Method Explained

Martha and her team of gardeners sow thousands of seeds per year, but she follows a particular method when it comes to starting flower seeds in her greenhouse.

She starts by choosing the seeds she'd like to sow and gathering up seedling trays, just like these Apipi Seed Starter Trays on Amazon. She chooses this type because they have deeper cells at the bottom, thanks to their more cone-like shape. Then the fun part begins!

Martha begins by filling her trays almost to the top with Miracle-Gro Seed Starting Potting Mix, which is formulated to promote fast root development.

Once filled, Martha then stacks two trays on top of each other, perfectly in line, and pushes them into one another to create indents in the soil. This creates small holes that are ideal for dropping seeds in quickly.

After popping the seeds in, Martha finishes off her planting by adding a layer of vermiculite over the top of each segment and watering. Vermiculite is great when starting seeds, as it absorbs and retains water while also helping to promote air circulation within the soil. You can purchase vermiculite on Amazon.

Shop Martha's Seed-Starting Essentials

What the Plant Pros Say

A major plus point, according to the pros I spoke to, is the way Martha is creating a highly controlled environment to both monitor and nurture her flower seeds.

As Staci Hill, co-author of The Preserver’s Garden, explains: "Martha’s seed-starting method is effective because it creates a simple, controlled environment for germination. Starting seeds indoors in trays allows gardeners to manage moisture, temperature, and light much more reliably than direct sowing outdoors early in the season."

Staci also thought using vermiculite was a great addition to an already robust seed-starting mix. She noted: "Martha’s use of vermiculite on the surface is particularly helpful because it holds moisture while still allowing airflow, which can improve germination and keep the soil surface from drying out too quickly."

Gardening Know How's Editor in Chief, Melanie Griffiths, highlighted the clever way Martha makes indentations in the potting mix. "Using a second tray to make the indentations is a quick and easy way to ensure consistency of seed depth, helping seeds germinate more evenly," she says. "However, before doing this, it's important to check the correct seed sowing depth for your variety – a good rule of thumb is to sow seeds at roughly twice their height in depth. Planting them too deeply is a common mistake that can prevent germination or healthy growth."

What Would They Do Differently?

While the experts wouldn't change much about the process, Staci did encourage gardeners to consider whether a different kind of tray might work better in their planting space – especially if they're placing their trays of planted seeds underneath grow lights or heat lamps.

She explained: "The one thing I would do differently is save space and seeds by starting seeds in small open trays (think a reused lunchmeat container) and then transferring the germinated seedlings into individual pots when they have one set of true leaves.

"Yes, this adds a step, but it saves space on the heat mats and under grow lights early in the season – and it keeps you from needing to thin seedlings later on. Seedlings also grow better, in my experience, in smaller containers, being bumped up as they need to, versus having all the space they need from the beginning."

Something like these Plant Growing Trays from Amazon would do the trick.