How To Start Dahlias Indoors
Dahlias are a magnificent flower and beloved amongst gardeners everywhere due to their vibrant colors and stunning blooms. Starting dahlia tubers indoors is an excellent option for those looking to get a head start on the growing season. But, when should you start dahlias indoors?
The ideal time to start dahlias indoors is in early April, about six to eight weeks before the last frost date in your area. This gives your dahlias enough time to grow and develop before they are transplanted outdoors. To begin, fill a 4-inch-diameter pot or larger about one-half full with a potting mix.
Place your dahlia tuber vertically in the potting mix so that you can see the neck, and cover the rest of the pot with potting soil. Be careful not to water the soil immediately, wait until you see eye development (see below) before watering. Tubers left in cool, damp soil can rot, so make sure the area you have it in is at least 65F consistently. Using a heat mat is best to keep the soil temperature up.
Once your dahlias start to grow, place them in a sunny window or under artificial lighting. Dahlias require at least six hours of sunlight each day, so ensure they receive enough light. Keep the lights on for about 14-16 hours a day and turn them off at night if you're using artificial lighting.
As your dahlias continue to grow, keep the soil evenly moist but not waterlogged. When the sprouts reach about 4-6 inches in height, pinch off the top growth to encourage bushier growth.
When the weather warms up, and the threat of frost has passed, transplant your dahlias outdoors into well-draining soil. Plant them so that you bury the neck under the soil and space them at least 12 inches apart. Only the green sprout should be visible above the soil line. Our rule of thumb is that when it’s time to plant tomatoes, it’s time to plant dahlias!
Starting dahlias indoors is an excellent way to get a head start on the growing season and ensure that your plants are healthy and strong before transplanting them outdoors. Planting tubers directly outside can be risky, especially when there is a sudden downpour of rain. Getting your dahlias started indoors ensures beautiful blooms all season long.
Do you have any tips for starting dahlias indoors that have worked well for you? Share your thoughts and experiences in the comments below!
To learn more about what we offer and the next sale, check out our Dahlia Tuber Collection.
6 Responses
If your comment doesn’t show up right away, don't fret! We have a spam filter that requires we approve most comments before they are published.
Unable to post at this time.
Also in Farm Journal
Growing With Intention: How We Celebrate Earth Day Every Day at Rooted Flowers
At Rooted Flowers, we’re not following a traditional model. We’re building something entirely different—a way of working and living that reflects the rhythm of the seasons, honors the land, and keeps family, beauty, and sustainability at its core.
Hellebores for Cut Flowers
Before there were flowers and our farm in Agawam, I was growing asparagus in Hadley. This time of year, locals would start stopping by my little roadside stand, asking if it was time yet for the first spears. For many, the arrival of Hadley’s famous asparagus meant spring had truly begun—so tender you could eat it right out of the field.
Hope & Light Return
Our family farm turns five this season, making this spring even more joyful around the farm! Although accustomed to seasonal cycles on the farm, there’s always one surprising morning when the scritch crunch of my muck boots on frosty grass transitions into soft, squishy footfalls on matted grass clumps the texture of pudding.
Rebeccca Sadlowski
October 09, 2023
Franziska — Sluggo works well for slug problems and isn’t a problem for all growers.