Waking Up Your Dahlias and Gladiolus
Dahlias
For anyone living in an area with a short growing season it is a very good idea to pre sprout your dahlias and gladiolus to ensure you get blooms before the end of the growing season. Both dahlias and glads take about 90 days to bloom once they are planted in the ground but they are very sensitive to frost so if you wait until the risk of frost has passed your flowers may not get the opportunity to bloom before the end of our 100-120 day growing season.
Gladiolus
How to Pre Sprout Gladiolus
Supplies:
A tray such as the bottom of a seed tray, old plastic food containers or aluminum pie plates.
Water
Directions:
Pull your glads out of storage and examine them to be sure they don’t have mold growing on the bulbs or that they are soft or rotting in anyway.
Place the corms on the tray so that the pointed part is at the top and the flatter side is on the bottom.
Fill with water just enough so the bottom 1 or 2 cm of the corms are in water. Keep an eye on the water level and refill as needed.
Leave on a windowsill or under a grow light or in your heated greenhouse and wait for the corms to sprout.
Once all risk of frost has passed plant your corms into the garden. Digging deep enough so the white of the sprout in covered as well.
Pre sprout only a portion of all your corms each week so you can extend the bloom time throughout the summer. This is known as successive planting. I will presprout once a week for the month of April and possibly even the first week of May so I can get blooms from July to September.
How to Pre sprout Dahlias
Supplies:
Spray Bottle
Light source such as a greenhouse, windowsill or grow lights.
Directions:
Pull out the dahlia tubers out of storage.
Examine the tubers and discard any ones that look like it’s rotting. The tuber should be solid. If it looks a little shriveled you can still try to sprout it, It may just need some extra spritzing and soaking.
Clean up the tubers by soaking in water for a few minutes. If the tuber looks shriveled I will soak it longer. Up to 15 to 30 minutes so it will rehydrate.
Dip the tubers in a weak solution of 1 part chlorine and 10 parts water to kill of any mold or thrip eggs. You don’t want little bugs hatching and taking over your house or greenhouse so this step in very important to prevent disease in the future.
Lay out the tubers under sun or under grow lights, spritzing with water daily as needed. Rotate the tubers as needed if you have the tubers by a window to prevent the sprout from growing sideways. You will see the sprouts starting in a few weeks. Just keep spritzing the tubers as needed so it doesn’t dry out then plant out once risk of frost is over.
I leave the tubers as one whole plant when I store it and cut the tubers after I sprout them so I can easily see how many tubers have intact body, neck and eyes. See photos below. The sprouts grow from the eyes. As long as you have an intact tuber with a body, neck and eye it will grow into a flowering dahlia plant that season. So once you can identify the parts, cut the main tuber into several for even more plants. Some growers divide their tubers in the early spring, fall or winter but it is a little hard to see the eyes and figure out the parts of the tuber. So I find this the easiest for beginners.
Note: You do not have to pre sprout the tubers if you live in a warmer climate with a longer growing season.
Dahlia Tuber Parts: The Body
Dahlia Tuber Parts: The Neck
Dahlia Tuber Parts: The Eyes
This is where the tuber will grow sprouts.
That’s all there is to it, now you can watch your sprouts grow until any risk of frost is over then get them in the ground. This will give you at least 2 months head start so you will be able to enjoy blooms in July and August.