It's easy to combine flowers that you grow with flowers that you purchase when doing casual centerpieces. For this party at my friend's house, I used mason jars as vases. I used a summery pallette of yellow, green, and lavender and tied it all together with a lavender and green print ribbon around the neck of the jar. My cutting garden was full of "green" eyed Susans which I combined with lavender larkspur, mini sunflowers, lavender mardi gras asters as filler, purple veronica, and green hypericum berries. When you put together an arrangement like this, make sure that you use flowers of different textures. One flower type should be tall (larkspur), one should hang over the rim of the jar (mini sunflowers), and then other flowers to fill in between. Small heads of hydrangea work well in these jars as well. Lots of us grow those. Good luck and I'd be happy to answer any questions.