Planting Dahlia

Tubers

 Planting

Plant your dahlia tubers after all danger of frost has passed, when the soil is about 15°C.  Choose a spot that receives full sun (at least 8 hrs/day) and well drained soil.  We recommend amending the soil with well aged compost or manure before planting.  Dig a hole 4-6 inches deep and place the tuber on its side with the eye facing upward. Refill the hole making sure there is approximately 2 inches of soil above the tuber.

Space dahlias at least 12-18” apart and consider staking each plant.  The varieties of dahlias we grow reach 3 feet (or taller) so they’ll appreciate some support.  You can use a tomato or peony cage, or a pole/stake and use twine, string or tomato clips to steady the main stem.  Here at the farm we grow so many dahlias that we simply corral them with stakes and two levels of twine.

If you grow in containers, make sure the container is a minimum of 12” deep and 12” wide.  Your container must have a drainage hole and remember that potted plants sometimes dry out faster than plants grown in the ground, so water accordingly.

Watering

Do NOT water your dahlia until you see shoots appear above the soil.  Dahlias are notorious for rotting if watered before this point.  Once the shoots/leaves appear, the tuber will also have set down a healthy network of roots below, so you can begin to water lightly.  As your plant becomes bigger and puts on more foliage you can increase your watering time and frequency.  We tend to water our dahlias deeply 1-2 times per week when they are fully grown, but every garden is different so watch your soil to see what is required. 

Want to encourage more flowers?

This is going to feel wrong, but it will pay off big time!  Once your dahlia plant is 12 inches tall, use a pair of clean snips to cut out the centre growing tip just above a set of leaves (this results in cutting about 3-4 inches off your plant).  This is called “pinching” your plant.  This encourages your plant to start growing new branches lower on the stem and you’ll end up with lots more flowers.  Bite the bullet and do it!  If you have any questions about this, feel free to ask us for guidance.  We are happy to help!

Cutting flowers from your plant

Here’s where it really gets fun!  The more flowers you cut from your dahlia plant, the more flowers it will produce.  Don’t be shy to cut flowers with LONG STEMS (1 - 2 feet).  If you cut a flower from your plant and the stem is hollow this is good!  This means you’ve given your flowers nice long stems and your plant will reward you with even more long stemmed flowers.  Also this gives you lots of stem length to work with in your vase.  Wait until the bloom you want to cut is almost all the way open before cutting to get it looking its best.