P. Allen Smith, whose TV series "Garden Home," I enjoyed, has a Facebook page, and he linked to this blog entry a woman wrote about her garden. She starts out recounting a time when some women said that their garden was strictly utilitarian and they didn't waste resources on things that weren't edible. So she wrote a blog about why she gardens and loves her garden, which has both edible and ornamental plants.
In Victor Hugo's Les Misérables, the priest who saves Jean Valjean from going back to prison has a garden in which 3/4s was for vegetables and 1/4 was for flowers. His housekeeper told him that 1/4 plot was useless and that it would be better to grow salads then bouquets. He replied that she was mistaken and said, "The beautiful is as useful as the useful." And after a pause he added, "More so, perhaps."
Beauty is an intrinsic and valuable part of God's creation. When we plant flowers and enjoy them, we honor him.