I live in Hawaii and would like to grow turnips or rutabagas. I know I will have to grow them in a container but with the warm temperatures, will I be able to grow them?
Your best bet to grow them will be to do so in the winter when the temps are slightly cooler. Also, keep them in a partly shady place and mulch around them well to keep the ground cooler.
My rutabagas have been growing since the first week in September. How long does it take to fully grow rutabagas?
As far as I know, it shouldn't really make a big difference either way. I think it's a matter of personal choice. To experiment, however, you might want to try cutting the flowers from one plant and leaving them on another to compare the results come harvest time. Here is an article that you may find helpful: https://www.gardeningknowhow.com/edible/vegetables/rutabaga/planting-rutabaga.htm
It's my first time growing rutabagas. Should I cut off flowers to aid root development or let them come?
As far as I know, it shouldn't really make a big difference either way. I think it's a matter of personal choice. To experiment, however, you might want to try cutting the flowers from one plant and leaving them on another to compare the results come harvest time. Here is an article that you may find helpful: https://www.gardeningknowhow.com/edible/vegetables/rutabaga/planting-rutabaga.htm
How do you keep rutabaga? What and how does it have the waxy shell?
The waxy shell you are referring to is simply accomplished by giving the roots a wax bath prior to storing. These articles should help: https://www.gardeningknowhow.com/edible/vegetables/rutabaga/harvesting-rutabaga.htm
https://www.gardeningknowhow.com/edible/vegetables/rutabaga/planting-rutabaga.htm
I am growing rutabagas for the first time. We live in western Washington (state). I planted my garden on May 15 and it's doing very well; however, my rutabagas are starting to go to seed. Should I pinch off the tops or leave them alone?
They have most likely bolted. Here is an article or two that you may find helpful: https://www.gardeningknowhow.com/edible/vegetables/rutabaga/planting-rutabaga.htm
https://www.gardeningknowhow.com/edible/vegetables/rutabaga/harvesting-rutabaga.htm
https://www.gardeningknowhow.com/edible/vegetables/vgen/what-is-bolting-what-it-means-when-a-plant-bolts.htm
What happens when rutabagas turn to seeds?
You can harvest the seed and grow them next year. See this website for more detailed information.
http://countrylivinginacariboovalley.blogspot.com/2009/03/how-to-grow-and-save-rutabaga-seeds.html
Also you may find this article helpful:
https://www.gardeningknowhow.com/edible/vegetables/rutabaga/planting-rutabaga.htm
Undersized root crops usually happen when the ground is too heavy or too weak in phosphorus. These articles will help you:
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/phosphorus-plant-growth.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/how-to-improve-clay-soil.htm
https://www.gardeningknowhow.com/edible/vegetables/rutabaga/planting-rutabaga.htm