When I'm working on a wedding, I go through a number of steps to condition and take care of the flowers so that they're in the best shape possible for your wedding day. This includes proper cleaning of the stems, making sure everything is in water, using floral preservatives to help the flowers take in as much water as possible and eliminate bacterial growth, and keeping everything refrigerated. But once the flowers are delivered to you, it's your job to take care of them so that they continue to look great. And let's face it, in Manitoba, that can be hard. 

SUMMER WEDDINGS
With the heat of summer, there are a few varieties of flowers and foliage that I'll probably warn you about. Some flowers just don't hold up well in heat, and there's really nothing that be done about that. But for everything else, there are a few things that I'm always going to recommend that you do: 
-Keep your bouquets in water as much as possible. I always deliver each bouquet with a glass vase with just enough water. When you're driving around on the wedding day, when you're taking pictures without the flowers, and even when you're at the reception, be sure to pop them back into those vases.
-Keep your flowers out of the sun as much as possible. When my girlfriend got married a few years ago, the humidity made the temperature reach over 45 degrees. We melted...and my phone shut off because it reached "dangerous temperatures!" I did my best to put those bouquets in the shade when we were taking pictures and keep them in the air conditioned vehicle whenever we could, as well!

WINTER WEDDINGS
Winter temperatures are another thing altogether. Just as your skin can get frostbite, so can flowers. When I'm talking about winter temperatures, I really mean anything below zero degrees celcius.
-Order a second boutonniere for your groom. If you're taking any pictures outside at all, that boutonniere will freeze (aka it will end up browned). Plus, he will inevitably put his parka on over top of his suit, and the boutonniere will be crushed.
-Keep your bouquets wrapped and covered at all times when out of doors. They will be delivered wrapped in plastic, and it's up to you to make sure that the covering is tightly secured every time you move the bouquet boxes from place to place. If the cold air gets at them, guess what's going to happen?
-Don't leave your flowers in an unheated car or building. This might mean that you plan to take some indoor pictures with your flowers, and some outdoor pictures without your flowers. Given that you're spending a lot of money on your flowers, you want to make sure that they're going to last for you!