When I hand pull to get rid of buttercups, some white fibrous root fragments broke off. I would like to know if it will regrow from the root fragments. I have completely removed the crown/rosette and the runners. It is difficult to remove all the root fragments. Thanks.
They can, but if you keep an eye out for new plants and remove them as soon as you spot them, this will exhaust the energy reserves of the remaining root portions and they will die (and be unable to grow anymore new plants).
Buttercups are very dense between raspberry plants and it is very hard to get them out by the roots. What should we try to control them?
For selective control of Buttercups, use a contact herbicide like glyphosphate plus a wetting agent. READ AND FOLLOW ALL LABELS. Two or three treatments may be necessary to control Buttercups due to the ability of mature plants to recover.
I want to store bulbs of ranunculus.
This article will help you with that:
http://www.extension.org/pages/42111/how-do-i-store-ranunculus-tubers-rununculus-asiaticus#.UwuNazaYbIU
If I plant Ranunculus asiaticus now, would they be in flower by mid June? I would love to use them for my wedding or is this too risky? Are they difficult to grow?
Mid June would be the tail end of their potential blooming time. You may have blooms, but you may not. They are pretty easy to grow.
What is the life cycle of the buttercup? Are they like zinnas when you look for seed? Maybe I should dig up the whole plant to move it. They have just finished blooming. Is it a good time?
Not sure which plant you mean, as there are several known by the name buttercup, so I can't say much about seeds. I can give you some information on transplanting wildflowers: https://www.doityourself.com/stry/transplanting-wildflowers-from-the-wild-into-your-garden
My ranunculus became wilted in day time and regained its turgidity at night. Why?
You may want to check to see if they need to be watered, if they are in a pot you could water from below.
Many plants do get sun wilt during the day, then recover in the evening, this is perfectly normal.
https://www.gardeningknowhow.com/special/containers/container-plant-watering.htm
What pesticide can I use to get rid of creeping in British Columbia? Thanks
Here are links that will help you with Buttercup control.
http://www.kingcounty.gov/environment/animals-and-plants/noxious-weeds/weed-identification/creeping-buttercup.aspx
https://www.gardeningknowhow.com/plant-problems/weeds/how-to-kill-buttercup-weeds.htm