Hello Dahlia Gardeners,
I thought I would share how I wake up tubers. This is especially relevant to those of us who dig up tubers in late fall and store them inside a cool, dark room. This pertains to growing zones which have freezing temperatures and/or snow! If you are new to growing dahlias, it is important to know what growing zone you are in. You can find your growing zone by visiting the USDA Plant Hardiness Zone Map. Lakeshore Dahlias LLC is located in West Michigan zone 5b, where we get freezing temps and lots of snow. Our dahlia tubers have been sleeping since mid November in our cool, dark basement, where we check on their condition monthly.
We can begin “waking up” tubers about 6 weeks (before our last frost date) before they are planted outside. Find out when your growing zone’s last frost date will be, then subtract 6 weeks to begin waking up your tubers inside. An early start means you can enjoy more dahlia blooms two weeks earlier in the growing season! What does “waking up” mean regarding dahlia tubers? Well, we bring them out of cold storage (not freezing) and into temps of 70 degrees. During the process of “waking up”, they will develop eyes and then shoots around the crown of the dahlia tuber. This is also known as the collar. Some dahlia tubers get eyes in 2 weeks while others can take 5 weeks!
When you take them out of storage, inspect them! If mold has been an issue, it is easily treatable by spraying them with Lysol Disinfectant Spray (blue can) or using a Lysol Disinfectant wipe. Let them dry to touch. If any rotting occurred, you can cut the rotting piece off, let the tuber dry and cure, then dust with cinnamon. This prevents mold from developing. Remember, as long as the crown has eyes and feels firm you can still plant that part and it will likely grow, even though the soft rotten part was removed! Shriveled up tubers will likely be okay, they just dried a little in storage. Remember to never soak tubers in water as they haven’t developed root systems yet and there is no way for them to take up water. We will talk about this more in a few minutes! Make sure all of your tubers are labeled with names. Personally I use a black sharpie but you can also use an “Indelible Ink Pencil” available on the Swan Island Dahlias website. With necessary preparations in place, let’s talk about walking up tubers step by step!
Supplies We Recommend
- Seed starting tray or trays – available at Home Depot, Lowes, Meijers, or any other hardware store. Amazon sells them in packages of 5 trays. They are reusable!
- Potting soil – Avoid Miracle Grow as it is known to burn tubers with their fertilizer already added!
- Spray bottle of water
Please note there are several methods to wake up tubers but here is the method we use.
Make sure to begin this process 6 weeks before your last frost date!
Step 1 – Preparing a Tray
Using a seed tray, spread about 1″ of potting soil evenly across the bottom. Newly opened bags of potting soil may have enough moisture, but if it feels dry, lightly mist the potting soil and mix it up. Remember we are not soaking the potting soil, just a very light mist from the spray bottle. This will also be beneficial to any shriveled tubers!
Step 2 – Laying the Tubers Horizontal
Lay the labeled tubers horizontal. I lay them in 2 long rows.
Step 3 – Cover Them With Potting Soil
Cover them with potting soil, so they are just covered. I like to leave the crowns exposed so I can keep an “eye” on the “eyes” and shoots.
Step 4 – Set Them In Sunlight
Set the trays by a sunny window or sliding glass door to get heat from the sun and light. Heat pads are not necessary!
Step 5 – Check Them Daily
Check the tubers daily. You may mist the potting soil sparingly as needed, but do not water the tubers! I begin watering them outside when they are about 3″ tall. I water them sparingly about every 10 days and increase watering as they grow taller.
I hope this helps! Feel free to email me any of your dahlia questions at paula [at] lakeshoredahlias.com.