I nearly missed the window for foraging for elderflowers entirely! As you can also see the blossoms I did get are almost past their prime, but I'm going for it since elderflower is one of my favourite flavours! Next year I will do better especially since I bought my own little black elder (Sambucus Nigra).
If you live in the Okanagan or the Thompson Nicola valley you should be able to find some elder growing wild (or you might have a neighbour with a shrub in their yard). The two types native to BC are the blue (Sambucus Canadensis) and red (Sambucus Racemosa) elders.
In my hurry to make sure I got some flowers I forgot to take a photo of the elder I was foraging from, but they are easy to google to find out what you're looking for. Blue and black elder have large flat umbels of tiny white flowers, but in red elder the flowers are arranged more like a lilac. Have a care to discard as much of the stem as you can before using the flowers for culinary purposes since it is quite toxic.
There is some controversy about using red elder for food purposes. It seems there are conflicting reports regarding whether or not the berries are poisonous. I have read that Native American groups used them for food, but considered them inferior in taste and would mix them with other berries to make the tastier ones go further. Do your due diligence and research the various sources before deciding if you want to eat red elderberries or flowers. I could find very little evidence about whether or not the flowers were considered at all toxic, but that is probably because using elderflower is mostly foreign in concept in North America.
I am using the tiny amount of flowers I gathered in some elderflower cordial. This is basically a thick syrup used for flavouring drinks. I love to simply splash some in with my soda water or mineral water for a fizzy, refreshing drink. There are many other uses including elderflower champagne and elderflower jelly which I fully intend to try out next year. For now I made up my own cordial recipe based on some others I read. The reason I didn't simply follow another recipe is that most of them are made for larger quantities of flowers. All I did was make a few cups of a 1:1 simple syrup and while it was still boiling I poured it over all my flowers and one sliced lemon. I let that hang out on my counter covered for a couple days, strained, boiled it again and put it in a bottle in my fridge. Next year when I have some in greater quantities I am going to be looking into recipes that are safe for water bath canning.