Starting Dahlia Flower Seeds Indoors - The Martha Stewart Blog (2024)

FAQs

Starting Dahlia Flower Seeds Indoors - The Martha Stewart Blog? ›

Seeds are usually started about two months before the last frost in the area. Markers are placed in the trays to indicate what seeds are in each row. Seedlings should start to appear within 10 to 14 days. Once the entire tray has been seeded, Ryan adds a light layer of soil to cover the seeds.

Try the paper towel method of germination. Place your seeds on a damp paper towel, fold the towel over and place inside a plastic bag. Check regularly to see if the seeds have begun to germinate and transfer any that do to cell trays. Try starting your dahlia seeds in individual small ¾” soil blocks.

The main growing season is from March to June. Seeds need to be sown in early March or April. Start your seeds indoors for a higher rate of success. Germinate your seeds indoors in seedling cups in a mix of cocopeat and compost and place it in a well-ventilated area.

Dahlia seedlings are extremely cold sensitive, so don't plant them outside until the weather has sufficiently warmed. We typically transplant them 3 to 4 weeks after our last spring frost. Seeds should be started indoors at least 4 to 8 weeks before you want to plant them out.

A greenhouse, hoop house, or sunny windowsill are great places. It typically takes about two to four weeks for dahlias to begin to sprout up out of the soil. So start this process between five and seven weeks before when you expect to be able to plant them outside.

Dahlia seeds do not require any treatment (eg soaking, stratification) before sowing.

The paper towel method creates prime conditions for seeds to germinate in less time. Depending on the type of seed, the controlled moisture and heat conditions within the bag can enable seeds to germinate in a few days. You'll have a home or garden filled with bright new leaves in no time!

It can speed up the seed sprouting process, with roots appearing in a matter of days in some cases. It works for flowers as well as vegetables and fruits.

Raising dahlias from seed is not a difficult business although they do need a fairly high temperature for germination followed by frost protection until planting out.

Not all fully double dahlia varieties are good seed parents so dahlia germination rates can be between 30% to 50%. Also, dahlia seeds do not all sprout at the same time. They can begin sprouting in 2 to 10 days; however, some seeds will take 14 to 21 days.

Is it too late to plant dahlia seeds? ›

In many regions, the perfect time to plant dahlia bulbs falls between mid-April and early June. You can check your region's specific last frost date to be sure. As a general rule, stop planting dahlia tubers after mid-June. When you plant dahlia bulbs, the ground temperature should be at least 60 degrees F.

Do You Soak Dahlia Tubers Before Planting? Generally, dahlia tubers do not need to soak before planting. However, if they appear dried out and shriveled, you may want to soak them in a bucket of tepid water for one hour before planting.

I place the trays in a warm, sunny location like a south facing window, a greenhouse or cold frame. The warmth and sun will tell the tuber it's time to start growing.

Simply plant dahlia tubers in large pots filled with peat-free multi-purpose potting compost in March or early April, and then keep them on a windowsill or in a frost-free greenhouse until late May, when it's safe to plant them outside.