Dahlias originally come from Mexico so they really love a sunny spot and they need good drainage. If it is hot, water regularly but never overwater.
Cut regularly flowers from your dahlia plant and enjoy them in a vase. The more flowers you cut, the more new buds will start to bloom. Also removing dead heads helps new buds to develop.
Beware of frost! When planting dahlias make sure the risk of frost is past and remove the plants after the first sever frost in Autumn. Store the dahlias in a cool, dry and frost-free place.
You can also choose to leave dahlias in the ground during winter, mulched deeply to protect them from the frost. Very low-maintenance but you risk losing your plants by a hard winter. However to replace them is cheap and easy.
Only pick dahlias in full flower, best in morning or evening and put them in a clean vase with a drop of chlorine.
Dahlia plants are so thankfull, they are easy to grow and they keep on giving flowers from July until October or even November.