Still something of a wildflower even in its tamed versions, purple loosestrife clumps lend an informal tone to the yard. Use them along fences and walls, toward the back of perennial borders, and as colorful highlights in areas of the property where soggy soil discourages other plantings. They are perfect for undeveloped areas of the property also.
Cutting/Displaying Indoors: Purple loosestrife stems add height and color to indoor flower displays. In the early morning, cut stems with only partially opened flowers. Strip the leaves off of the lower part of the stems so that they will not foul the water. Plunge the newly cut stems in warm water and let them sit for several hours. Later arrange them and other blooms in a container filled with tepid water and an equal amount of citrus based (not diet) carbonated drink to prolong flower freshness.
For more information see the files on Keeping Cut Flowers and Cut Flower Supplies