Dahlia Care

Each dahlia variety is unique and has slightly different needs, but they all generally require the same conditions to produce lovely, full plants with lots of blooms

Starting Inside

Potting Up

After bringing your tuber home, plan to pot it up into a larger container. Choose a container with plenty of drainage holes, deep enough to be able to plant the entire tuber just below the top of the surface. You may need to repeat this step again later if your plant really takes off before you can plant it outside

Location

Keep your dahlias in plenty of light, a south-facing window or under grow lights is great!

Water

Water your tuber after potting it up, and 1-2 times per week after that

Pinching

Pinch/cut 3-4" off the main stem when they reach 12" tall with at least 3 sets of leaves. This will push back blooms by about 2 weeks, but give you a much bushier plant with plentiful blooms

Planting Outside

Transplanting

Plant your dahlias outside after the last spring frost (early June for us in Thunder Bay). Loosen the soil and add compost or fertilizer, then plant the tuber about 3" below the soil surface with the sprouts upright. Press the soil firmly around the tuber and water well. Dahlias do best planted directly in the ground or raised beds, but do not thrive in a pot

Sun Requirements

Most dahlias need full sun to produce a bushy plant with lots of blooms, but they can manage in part shade

Water Requirements

Water deeply 2-3 times a week, or whenever the top 2" of soil is dry to the touch (just use your finger to check)

Plant Spacing

12 - 18" is recommended between dahlias, although we have successfully planted them a bit tighter and still had large, full plants

Maintenance

Deadhead (remove wilted blooms) regularly to encourage blooming all season long

Support

There is a wide range of plant heights, but almost all dahlias benefit from some type of support. Some of our favourite options are staking, coralling, and tomato cages work great too! It's easiest to install your support when the plants are still small

Harvesting

Cut dahlias when they are 3/4 of the way open, but not completely open to the center. Dahlias don't unfurl much once cut, so catching them at the right time is important. Cut the flowers just above a leaf, as deep (low) into the plant as you dare (18" is great) so you have nice, long stems for arranging. This also encourages the plant to grow blooms with longer stems for the rest of the season!

Vase Life

Each variety is different, but expect blooms to last 3-7 days