How to Harvest and Store Dahlia Tubers
Dahlias are not cold-hardy, mainly because the tubers cannot freeze. Dahlia tubers begin dormancy at 0.5°C and suffer freeze damage below 0°C, so they cannot overwinter outdoors in North China, and tubers should be harvested everywhere before the first early frost arrives.
After a frost, the plants and leaves wither and die. At this point, the stems and leaves of the above-ground part should be cut off immediately and the tubers dug up; for potted plants, they can be removed from the pots or stored in the pots in a greenhouse. Before harvesting, check the varieties and select the best while discarding the inferior ones to ensure varietal purity. Before storage, all withered stems and leaves should be cut off about 15 cm from the crown (root neck). To prevent twisting and injuring the crown (the part that will sprout in the future), the tubers should be dug out as a whole clump. After digging up the tubers, dry them in the sun for 2—3 days before storing. At night, to prevent frost, cover the tubers with reed blinds, straw or similar coverings. Once the soil on the tubers has dried, shake off the dirt, sort them by variety, attach labels, and place them in a greenhouse at a temperature not exceeding about 5°C. At this time, maintaining a constant temperature of about 3-5°C and preventing excessively high temperatures is the key to preserving the tubers, because too high a temperature will cause the adventitious buds at the crown to sprout prematurely, consuming water and nutrients and affecting the tubers, while too low a temperature will cause the tubers to freeze and rot.
In addition, the storage site should be sterilized and disinfected. When arranging them, place the tubers with the crown facing up on the greenhouse floor. To prevent premature sprouting and overheating that causes root rot, it is generally best to stack them in 3-5 layers, buried in slightly moist sandy soil.
After a frost, the plants and leaves wither and die. At this point, the stems and leaves of the above-ground part should be cut off immediately and the tubers dug up; for potted plants, they can be removed from the pots or stored in the pots in a greenhouse. Before harvesting, check the varieties and select the best while discarding the inferior ones to ensure varietal purity. Before storage, all withered stems and leaves should be cut off about 15 cm from the crown (root neck). To prevent twisting and injuring the crown (the part that will sprout in the future), the tubers should be dug out as a whole clump. After digging up the tubers, dry them in the sun for 2-3 days before storing. At night, to prevent frost, cover the tubers with reed blinds, straw or similar coverings. Once the soil on the tubers has dried, shake off the dirt, sort them by variety, attach labels, and place them in a greenhouse at a temperature not exceeding about 5°C. At this time, maintaining a constant temperature of about 3-5°C and preventing excessively high temperatures is the key to preserving the tubers, because too high a temperature will cause the adventitious buds at the crown to sprout prematurely, consuming water and nutrients and affecting the tubers, while too low a temperature will cause the tubers to freeze and rot.
In addition, the storage site should be sterilized and disinfected. When arranging them, place the tubers with the crown facing up on the greenhouse floor. To prevent premature sprouting and overheating that causes root rot, it is generally best to stack them in 3-5 layers, buried in slightly moist sandy soil.
During winter storage, check frequently and promptly cut off rotting and useless roots. If the burying sand is found to be too dry, never water it directly; instead, take out the tubers, spray the sand with water until it is merely moist, and then rebury the tubers.
In addition, you can also cut off the withered stems and leaves of potted plants and place the original pots in a greenhouse at a temperature not exceeding 3-5°C, stack the pots up, and avoid direct strong light. During storage, if the potting soil is too dry, water a little (never too much), keeping the soil only slightly moist to avoid tuber rot. This method is relatively simple, but it takes up a large storage area. Yet another storage method is to divide the dried tubers together with the adventitious buds growing on the crown. After dividing, coat the cut surfaces with plant ash, place them in wooden troughs or wooden boxes, and fill the gaps with dry sand or wood shavings. Then place the wooden troughs or boxes under conditions of 3-5°C, good ventilation and no direct light for storage. During storage, there is no need to turn them. This method is easy to manage, convenient to take from, and can save storage space.
Some dahlia varieties have tubers that are more difficult to store, such as 'Heju' and 'Huoshu Yinhua'. When storing the tubers of these varieties, do not place them together with other tubers. The dried tubers can be placed in wooden boxes or flower pots, covered with a small amount of dry sand, and stored at 3-5°C. In addition, a few days before the frost period arrives, the potted dahlias mentioned above can be moved into a greenhouse at 5-10°C, with flowers and buds removed, and cultivated for about 15-20 days so that the nutrients are fully concentrated in the tubers; then remove the stems and leaves from the plants and store them in the original pots or after removing them from the pots.
How Do Dahlias Overwinter? Harvesting and Storing Dahlia Tubers
The reason dahlias are called one of the world's famous flowers is mainly their long flowering period, large flower diameter and numerous blooms. In northern regions, the flowering period runs from May to mid-November, and under suitable temperature conditions they can bloom continuously year-round, with the most abundant bloom after autumn. Dahlias are not cold-hardy, mainly because the tubers cannot freeze. Dahlia tubers begin dormancy at 0.5°C and suffer freeze damage below 0°C, so they cannot overwinter outdoors in North China, and tubers should be harvested everywhere before the first early frost arrives.After a frost, the plants and leaves wither and die. At this point, the stems and leaves of the above-ground part should be cut off immediately and the tubers dug up; for potted plants, they can be removed from the pots or stored in the pots in a greenhouse. Before harvesting, check the varieties and select the best while discarding the inferior ones to ensure varietal purity. Before storage, all withered stems and leaves should be cut off about 15 cm from the crown (root neck). To prevent twisting and injuring the crown (the part that will sprout in the future), the tubers should be dug out as a whole clump. After digging up the tubers, dry them in the sun for 2-3 days before storing. At night, to prevent frost, cover the tubers with reed blinds, straw or similar coverings. Once the soil on the tubers has dried, shake off the dirt, sort them by variety, attach labels, and place them in a greenhouse at a temperature not exceeding about 5°C. At this time, maintaining a constant temperature of about 3-5°C and preventing excessively high temperatures is the key to preserving the tubers, because too high a temperature will cause the adventitious buds at the crown to sprout prematurely, consuming water and nutrients and affecting the tubers, while too low a temperature will cause the tubers to freeze and rot.
In addition, the storage site should be sterilized and disinfected. When arranging them, place the tubers with the crown facing up on the greenhouse floor. To prevent premature sprouting and overheating that causes root rot, it is generally best to stack them in 3-5 layers, buried in slightly moist sandy soil.
During winter storage, check frequently and promptly cut off rotting and useless roots. If the burying sand is found to be too dry, never water it directly; instead, take out the tubers, spray the sand with water until it is merely moist, and then rebury the tubers.
In addition, you can also cut off the withered stems and leaves of potted plants and place the original pots in a greenhouse at a temperature not exceeding 3-5°C, stack the pots up, and avoid direct strong light. During storage, if the potting soil is too dry, water a little (never too much), keeping the soil only slightly moist to avoid tuber rot. This method is relatively simple, but it takes up a large storage area. Yet another storage method is to divide the dried tubers together with the adventitious buds growing on the crown. After dividing, coat the cut surfaces with plant ash, place them in wooden troughs or wooden boxes, and fill the gaps with dry sand or wood shavings. Then place the wooden troughs or boxes under conditions of 3-5°C, good ventilation and no direct light for storage. During storage, there is no need to turn them. This method is easy to manage, convenient to take from, and can save storage space.
Some dahlia varieties have tubers that are more difficult to store, such as 'Heju' and 'Huoshu Yinhua'. When storing the tubers of these varieties, do not place them together with other tubers. The dried tubers can be placed in wooden boxes or flower pots, covered with a small amount of dry sand, and stored at 3-5°C. In addition, a few days before the frost period arrives, the potted dahlias mentioned above can be moved into a greenhouse at 5-10°C, with flowers and buds removed, and cultivated for about 15-20 days so that the nutrients are fully concentrated in the tubers; then remove the stems and leaves from the plants and store them in the original pots or after removing them from the pots.