Growing Dahlias
with Kim Magee
Dahlia Tuber Winter
Check Up
Propagating Dahlias
Coming Soon!
Planting Dahlias
Coming Soon
Digging & Storing Tubers
Coming Soon
Dahlias are gorgeous flowers, grown from tubers, that come in every colour, except blue.
They range in size from 1" pom poms to 15" fluffy petalled varieties, known as ‘dinner plate dahlias’.
Most varieties grow 4 to 5 feet tall. There are many different forms of dahlias, from tightly petalled
ball types, to peony & waterlily, cactus, collarette and more. You can never be bored with dahlias.
Tubers can be planted outside after last frost. Expect blooms mid-August to Frost. For earlier blooms,
start tubers inside 6-8 weeks before last frost and plant outside after last frost. Expect blooms early July.
Dahlias grown from cuttings will often bloom before a tuber, as they have a head start.
Rooted cuttings are identical to the mother plant and will produce flowers and tubers in the same
season, just as it would from a tuber. Cuttings are a great way to increase your stock at no expense.
Dahlias require at least 6 hours of sun. Ideally 8+ hours with a bit of shade midday.
Plant tubers 5” deep and water lightly. No need to water again till you start to see sprouting.
Dahlias are sensitive to rot, so plant in well drained soil.
If planting from a cutting, bury down 2-3 sets of leaves. (Strip off leaves first.)
Be sure to stake your dahlia when planting.
Dahlias are heavy feeders and thirsty plants. They need lots of nitrogen, so mix in well-rotted
manure or compost to soil when planting and fertilize weekly. I also add a handful of alfalfa
pellets, and bone meal to the hole when planting. I use seaweed fertilizer throughout the
season, till mid-August, but any type of fertilizer will do. Look for something with a higher
phosphorus level, such as a 10-15-10 to encourage blooming.
Dahlias don’t like soggy soil, or the tubers can rot, but they don’t like to dry out either.
The best way to test your soil is to stick your finger down a couple inches. If it is cool and damp,
don’t water. It’s always best to water deeply, less often, then frequently in small amounts.
To get a stronger, bushier plant with more stems and blooms, pinch your plant back
when it is approximately 12” tall. Pinch off the top 2-3 sets of leaves.
I know this sounds scary to do, but you’ll never regret it!
Dahlias are a “cut & come again” flower. Make yourself a bouquet! Take time to cut off
dead flowers so they don’t go to seed. The more you cut, the more you get!
Tubers must be dug up in the fall and stored for winter. They are best stored in
plastic bins with peat or vermiculate in a cool environment.
Follow me online for more tips & tricks throughout the season.
I hope I’ve made a dahlia addict out of you!
Kim Magee
Follow me online
Facebook curlygirlgardening
Instagram curlygirlgardens
Check on your dahlia tubers in storage monthly!
It’s not always easy to get your dahlia tubers to survive winter storage.
There are many methods, and it all comes down to YOUR space. What works
for one person may not work for you because of the temperature, humidity
and storage medium used. Ideally, dahlias love temperatures of 4-8c
& humidity 75-80%. They store well in plastic bins or bags, with peat moss or
vermiculite. Generally, storing in paper or cardboard will dry out your
tubers, though some people do have success with this method.
My first couple years growing dahlias I stored in cardboard boxes and newspaper.
Guess what? They shrivelled & rotted. The next year I did a test of a few in
vermiculite, some in peat moss, all in plastic bins or bags. I had almost NO loss!
For environmental reasons, I choose to use vermiculite as my primary storage
medium. It can be re-used and does not spread rot, as peat can. It is however,
very expensive. This year I tried a new method to me, where I cure my tubers
for several weeks in wood shavings, outside. When they were no longer
cool to the touch, meaning the skins were tough and they were dry, then I moved
them into their storage space. All is going well and I am quite liking this method.
I am also lucky to have a cold room which stay between 2-6c all winter,
with ideal humidity as well.
This is why you check on your tubers!
Problems can happen over winter storage, sometimes can’t even be
explained, but with regular checkups, we can hopefully stop the
problem and prevent further loss.
Depending on your storage space, there may be too much humidity and
you will find drops off moisture on your lids. Wipe off the moisture and
crack the lid open for a week or so.
-If you find mold on tubers, wipe it off, apply some cinnamon,
again, keep the lid cracked a bit.
- If your tubers are in cardboard and you notice them shrivelling up & drying out,
then you should change your storage medium or container to
something like peat & plastic. In a pinch, you could use dry potting mix.
-keep cardboard off the floor, as concrete sucks the moisture quickly
-If already in peat or vermiculite, and you find them drying out, add just a
little spritz of water. It will not re-hydrate them, but it will help prevent further loss.
-The drying up is also a sign of too high of a temperature. Move to the coldest
area of your home. Close to the floor in a heated garage, or possibly,
higher on a shelf, next to the house in an unheated garage. But you must
monitor your temperatures. If the temperature drops to freezing, you will lose them
-if you notice squishy tuber, they are rotting. Remove them completely and
check on tubers close by, as the rot can pass along through peat
-rot may have already been present in the tuber when you dug it up, or
you may have too much moisture in your storage area
