If you have tubers in winter storage you are probably getting ready to move them back into the garden. But is it too early? Late spring temperatures can fluctuate, leaving some gardeners pondering if this is the week for planting tubers, such as dahlias, in the garden, or if next week would be better. Easy rule—when the garden soil is warm, then you can plant. Soil temperatures should beat least 55 to 60˚F before you plant tubers in the garden.
Any tuber or root you have stored during the winter was provided with the ideal conditions. Transplanting them to a cold, wet garden negates all your hard work.
Soil should be warm, as mentioned before, but also well draining. If you are adding plants to new locations of the garden, take the time to test for pooling water. If water does not drain or the soil remains soggy for 8 hours, the spot may be too wet for tubers and bulbs. Amend the soil, raise the bed or if the work is not appealing or this simply is not an option, pick a new spot.