The Dahlia Guide - Planting
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What/How
So you have a tuber - now what?
Prep work
Clear the space you’re going to put your dahlias of any weeds or debris
Plan out how you intend to manage your weeds & watering. I have a full time job that is sadly not just tending to my dahlias. So, I use a weed barrier fabric to plant my dahlias in and I set up my dahlias with an automated watering system. I use drip tape & a battery powered hose splitter and controller.
Spacing
I plant the tuber 6” deep and approximately 1 ft apart. Mine are spaced using the lines on my weed barrier fabric.
Planting
I dig my 6” deep hole, put my stake in, mix my tablespoon (ish) of fertilizer into the hole, and then place my tuber in the hole flat with the eye (active growth point) is facing up.
Cover your plant back up with dirt, and then what I do because the varieties and where they are growing maters to me, I pop a label in the ground next to the stake. Labels can be found at most any garden store and the writing implement with the best odds of holding up the whole season is a pencil.
Then what?
Leave them alone until you see greenery peaking up out of the soil!
The common advice is to not water them at all until they are out of the ground. If you’re not getting any rain (re: my growing season of 2023) you may need to go out and give them a good soaking of water. No hydrophobic soil for the dahlias.
When
Mid May - Early June. My zone is 6A (just north of Grand Rapids, MI). Some people plant based on current soil temperature, I aim based off timing as that has been convenient for me.
Pro tips
You’re not likely to have 100% success with your tubers coming up. Plan for failure. I potted up 10 extra dahlias to fill in for ‘duds’. I did not need all of them which was lucky - but it can happen.
I’ll say it in other sections but if you’re really serious about your dahlias succeeding - get a soil test. They’ll help you to avoid just guessing about what your soil needs and you can amend your soil based on the recommendations from the lab.
Tools
Below are the tools I use for planting. Some are generic - some have links.
Trowel
6’ Stakes
Fertilizer
Weed fabric