Deer resistant. There are many ways to care for Dahlias and to store them, this is one method. Dahlias need good draining soil and a soil rich in compost as they are heavy feeders. Dahlia tubers should be planted in the Spring in a full sun location from mid April to end of May, once frost is no longer a danger to growing shoots. Dig a hole and put compost and a handful of bonemeal in the bottom. Place the tuber into the hole and cover with 3 to 4" of soil and compost. No need to water until shoots start emerging. In July and again in August, give each plant a handful of fertilizer high in phosphorous.
Cut Dahlia blooms often and cut them with a long stem to encourage more flowers with long stems continuously over the Summer.
At the end of the season, when one or two frosts have killed off the foliage, cut the stem down to about 6". Carefully dig up the tubers, making sure to account for growth over the season. Hose them off and trim off the hairy roots. They can now be split into several tubers, (making sure they all have a neck and eyes) or you can wait until Spring to do this. Here is a simple site with easy to follow instructions: https://summerdreamsfarm.com/dahlia-tuber-and-splitting-guide
Tubers need two things when they are dormant. Humidity and a cool location. I store my tubers in cardboard boxes with moist peat moss top and bottom. The boxes are then stored in an area with consistent temperatures of 5 to 8 degrees C. Do not store tubers in an area of greater than 10 degrees C. Each month I check on the tubers to ensure that the peat moss remains moist.