To dig or leave your tuberoses in the ground... That is the question.

Tuberoses multiply rapidly from bulblets, which grow out from the base of a larger one. You need to plan on digging them at least every third year to divide them and replant them with the room they need in order to produce nice strong flower stems.

An individual tuberose bulb will only bloom once.  After blooming, it splits into two or more smaller bulbs that almost never bloom the next year. And the smaller bulblets grow larger and larger and will bloom the second year. 

If you don’t dig and divide them, after about three years they will cease to flower, because the clumps have so many small bulbs crowded so closely together that none of the individual bulbs in the clump can get big enough to flower.

If Tuberoses freeze, they die. So, depending on your climate zone, you must decide whether to let them overwinter in the ground, or whether to dig them.

If you’re in zones 3-6, we strongly recommend that you dig them every year.  You most likely cannot mulch them heavily enough to keep the ground they are in from freezing and killing them when there is a protracted cold snap.

If you’re in zone 7-8, you can decide.  If you leave them in the ground, you should put at least six inches of wood chips, leaves or mulch on them to ensure that the ground doesn’t freeze deeply enough to get to your bulbs. In our zone 7a, we leave some in the ground each year to save a little labor, but we dig and store most of them.

If you’re in zone 9-10, you can just leave them in the ground until you need to divide them or move them.