Yikes! Monster dahlias eating my garden!
I've been researching here on division because my lovely garden, of which dahlias were meant to only be a part, has now, in year 3, become dominated by 5'-6' monsters which flop beyond my staking/support resources, and obscure roses & many other things near them. While I love dahlias, I need them to be neighborly companions to my roses & perennials. To this end, I have some questions.
After reading the great 'splitting dahlia tubers - photos' thread, I'm realizing I should have been dividing them every year. Some questions:
1. How would the set of procedures outlined in that thread differ for those living in z 9, California, where you don't have to take tubers out of the ground to overwinter them? Would spring or fall division make more sense? Or even winter here, before the rains, but after I've cut down the flowers to stalks? [That might give them a little time to develop new eyes?]
2. Is there a way to estimate how many tuber 'bulbettes' to re-plant if I still want that dahlia next season, but not monsters? The 'offending' ones I have are mostly dinner plates, spider & cactus'.
3. Given my zone, would I just re-plant right after dividing, or, is there some benefit to storing & waiting to plant them?