If I could only grow one kind of flower each year, I would choose to grow zinnias. They are easy and beautiful. There are many different varieties of these garden treasures. There are huge zinnias (Giant Zinnias) and small ones (Lilliput), and there are even ruffled zinnias. They are all beautiful and make great cut flowers. The bigger the flower the fewer you need to make a nice full arrangement, but I like to mix and match.
Cosmos are another garden beauty. I don't always bring them in the house to make arrangements because they are a bit more trouble. The green part is beautiful for foliage in the vase, but the flowers don't last very long so you are left with a bunch of greenery. I will use the them for greenery in lots of my other arrangements if needed.
One very important thing to remember when cutting fresh flowers from the garden is to strip the leaves that will be at the bottom of the vase. (Don't take all of the upper leaves off of your flowers because it will make a prettier arrangement if they have some leaves). Removing the leaves helps them stay fresh longer. I always take a large plastic pitcher filled with water to the garden with me. I put my fresh cut flowers with their bottom leaves removed immediately into the water. In times past, I have had flowers wilt before I could even get them to the house so I started bringing down the water to help prevent this. I also try to cut my flowers first thing in the morning or later in the evening.
grace and peace,