With careful selection and planning, the same space can easily be used for bulbs and bedding plants.
I dont dig up the bulbs. Since they are often 4 to 6ins deep, I plant the greenhouse grown annuals over them on a good heavy layer of compost.
A light loosening of the top soil with a small fork is all thats needed to get them planted.
The plan is to have the plants ready for planting out by the time the bulbs have died off.
Its easy with crocuses. They fade away quicker than Daffs and Tulips. If Daffs are still green leaf, I cut them just enough to make them look tidy, and plant the annuals in the gaps.
Annuals I find are good for this purpose are Stock, Asters, Nemesia etc.
Another 2 tier layer tip which works for me, discoverd by accident of course.
Ive been lucky this past few years and havent lost any Dahlias over winter. The Dahlia spots were becoming naturalised by crocuses, and they seem to co-habitate happily.
When Crocuses die off, I clear the area, and look for the Dahlias emerging. I have to be quick to apply a sprinkling of slug pellets for protection.