Yes. You can keep lots of flowers in your garden if you want to have bees in your yard. Bees attract to pollen and they will go after it in order for them to survive. If you want to move to the next step then you should buy a beehive. Beehives can be sold on BeeMax, they offer a variety of durable products.I suggest you get a wooden beehive, which is thicker, stronger and last longer. Remember to always wear protective clothing if you decide to buy a beehive. 

Flowers are not necessary for beekeeping. The hive will flourish in many places including rooftops in major cities or just about anywhere else if you take care of it. However, if you do choose to plant flowers or other nectar producing plants near your hive, they will most likely thrive. Bees are excellent pollinators and will help to not only maintain what ever it is you are growing, but can also help restore native species in the area through pollination. Have fun with your bees!