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How Deep to Plant Seeds That Are Being Sown Indoors

I am sowing seeds in pots indoors this winter and I will transplant them outdoors this spring. How deep should I plant the seeds in my pots?

hollyhock seeds alcea rosea

Answer: Sowing seeds indoors is a great way to enhance certain plants’ chances of success as well as give you a head start on growing a beautiful garden. When starting seeds there are a few general steps that you must take in order to ensure your seeds are off to a healthy start.

One of these crucial steps is to make sure you are planting your seeds at the right depth. The correct soil depth improves your seeds’ chances of developing into flourishing seedlings to transplant to your garden. The precise depth varies depending on the type of seed being sowed; in general you should sow seeds twice as deep as the seeds are wide. This is a good guideline to follow if your seed packet lacks planting instructions or you’re planting seeds you harvested yourself from your mature garden plants.

It’s also key to use sanitized containers with proper drainage as well as sterile soil mixes that are designed specifically for starting seeds. For most seeds, you must also provide sufficient water as well as tons of light for the seedlings—typically 12 to 16 hours a day—and adequate warmth, typically keeping the seedlings in a location with constant temperatures around 65 to 75˚F.

For more helpful tips on starting seeds, browse our propagation articles or check out these popular links:

Image: Hollyhock seeds by Frank Vincentz
The Horticulture Smart Gardening Techniques: Seeds is an easy-to-follow download filled with insightful articles for various seed-related techniques.

The Joy of Seeds is an affordable guide with information specifically for starting seeds.

Download the Horticulture Smart Gardening Guides: Q&A for Every Season for an abundance of gardening advice and techniques.

Grow your favorite plants from seed easily and joyfully with the resources in the You Can Start from Seed Value Pack.

The Fabulous & Unusual Annuals Collection contains seeds of beautiful, old fashioned cottage-garden favorites: Marble Arch Salvia, Bells of Ireland, Monarda Bergamo, Pride of Gibraltar Cerinthe and Pink & Purple Agrostemma.