I just bought Purple Sensation and Gladiator Alliums along with oriental lilies. I have posted a similar question on the lily forum since the same problem applies. I planted some Sphaerocephalon Drumstick alliums last fall and was not impressed: they grew about 3 feet tall and the stems were so weak they just flopped. I'm hoping these others will have stronger stems.

However, the garden is currently STUFFED. I have some dahlias and annuals in there to give me fall color. It's a new garden and I had space to fill temporarily. Most are smack dab where I want those alliums and lilies. I was planning to buy in spring but I succumbed to temptation (the price was right!).

I consider myself pretty tough but I cannot willfully kill a dahlia (not when they're blooming their heads off like that...!). Can I wait to plant the bulbs until first frost, then dig the dahlias? Or will they have insufficient time to make roots? I'm in Zone 5, Chicago north suburbs.

In a pinch can I hold some til spring? In case the weather becomes too horrible to be outside after the frost. I do have space in a holding bed if that is a better option.

Also, what kind of width does the foliage take up for these? I want them in thick clusters. I assume the leaves can overlap each other. I have 4 Gladiators and 10 Purple sensation (these PS probably I will split up into 2-3 different clusters.) Do the bloom times overlap on these or are they different? That will make a difference in where I plant them.

Thanks!