Dahlia Growing Guide

Planting Instructions

Wait until the soil is 55-60 degrees before planting. Usually in Minnesota that is after Mother’s Day weekend or when you see the lilacs blooming. Keep your tubers in a cool, dark place like a garage or basement until then. All tubers are different shapes and sizes, but if they have an eye (sprout) they are viable. All your tubers should be viable, because we check to ensure they have eyes while packing the orders.

Planting:
Find a sunny spot in your yard—the more sun the better, although they can handle partial shade. Loosen up the soil with a shovel or pitchfork, and adding some compost to your soil sets you up for success. Dig a hole or trench 6" deep and plant your tubers on their side with the sprout facing up, 12-24" apart, and then cover with soil. Once you have planted, do not water until you see sprouts popping up out of the soil. Tubers rot very easily, and there is usually enough moisture in the soil to get them started. Once the green sprouts have emerged, you want to keep your dahlias watered all summer. If it doesn't rain, I like to give them a deep water at the base of the plant to saturate the soil every week.

Mulching:
Once the sprouts have emerged from the soil, mulching with straw or dried leaves is a good idea to suppress weeds and hold in moisture.

Pinching:
This is an optional step, but very common in flower growing. Once the plant is 1 foot tall, you can snip off the top 3-4 inches of the plant. This is encourages the plant to branch out and produce more blooms. I pinch all of my dahlias to get the most production as possible and to prevent them from getting too tall and toppling over.

Staking:
Dahlias need support or they will fall over. If you only have a couple of plants then tomato cages work beautifully. However, if you're growing a whole row, you may consider using t-post stakes on both ends and tying twine around to corral them.

Harvesting:
If you want your dahlia plants to produce as many flowers as possible, you have to harvest them! Cut the stems bouquet length every time (about 12-18"). You will end up sacrificing buds, but you'll encourage the plant to keep sending up nice long stems.

Overwintering:
This is one of the trickiest steps to get right. Dahlias in Minnesota have to be lifted out of the ground and stored inside to live through the winter. They will freeze and turn to mush if left in the ground. Ideal storing conditions are 40-50 degrees with medium humidity. Click here for additional info on digging/storing your dahlias.