How to Grow Dahlias
Growing dahlias is such a joy!
It takes time, patience and some work. And I know it pays off when blooms start to fill your garden with gorgeous color.
I’m here to walk you through how I grow my dahlias - from starting the tuber to growing-on in the garden.
starting your tubers
Start your tubers inside in mid to late March.
Fill a gallon pot half full of potting mix (I use the organic Pro-Mix from Southside Garden Supply) and lie your tuber in there. Be sure to orient the eye of the tuber toward the top, as that’s where the shoot will come up and turn into your dahlia plant! Unsure what an “eye” looks like? Click Here for a good view of one. You won’t need lights until the shoot pops through. You can keep your pots somewhere out of the way but warmish: 50-70 degrees.
It’ll take about a week or two (sometimes longer) for the shoot to pop through the soil.
Until then, keep your soil dry. Maybe just drizzle water on it if it’s looking super dry or dusty. Too much water will rot your tuber before it sprouts up.
Once the shoot pops through the soil, get your plants under lights!
A simple full spectrum florescent or LED shop light will do. Now you can start watering as needed. Keep soil moist and well drained.
planting out
Wait until after the danger of the last frost has passed before planting your dahlia out in the garden. Historically this means Memorial Day but since our northern climate is changing so fast, I think you can safely plant out around Mother’s Day.
The Merril Field weather station hasn’t recorded a last frost after May 5th for 10 years!
When selecting your planting site, choose a sunny or mostly sunny location. You can opt for a large pot (5 gallons or more) or a place in your garden (raised bed or in-ground).
soil requirements
Be sure to do some soil prep before planting your dahlias to ensure that you get your plants off to a good start. Dig a large hole and mix in some compost and some general fertilizer. I like to use the all purpose fertilizer mix from Down to Earth.
After you’ve planted be sure to schedule a monthly side-dress of a more bloom-specific fertilizer like the bone meal from Down to Earth. To do this, dig a shallow trench next to the plant, add your fertilizer, cover fertilizer with soil and water well.
growing on
Once your dahlias are planted be sure to immediately stake them. You can either use a large tomato cage or a stake (2x2 or long bamboo stick). If using the stake, loosely tie the plant to the stake every now and then to keep the plant supported.
As your dahlia begins to bloom, either cut the blooms for your enjoyment in a vase or dead-head them once they start to fade. This will keep ample energy available for creating new blossoms!
Dahlias will keep blooming until the first frost. Once the dahlia is killed by the frost it is time to save your tubers!
If you have any questions now or as you get growing be sure to comment here or send me an email at turnstonefarm@gmail.com.
Happy growing!!