Purple loosestrife is evil! This aggressive perennial which grows two to seven feet tall with purple flowers on its long spikes invades wetland areas, literally shading out most other vegetation. Besides threatening plants, loosestrife also reduces populations or leads to the displacement of muskrats and several species of waterfowl. In Wisconsin, it is illegal to sell, distribute, or cultivate the plants or seeds, including any of its cultivars.
But purple loosestrife is beautiful! The purple spikes of loosestrife would be a wonderful accent plant in any perennial bed, especially those near water. Fortunately there are many other plants that look very much like purple loosestrife which can safely be used in the home garden without fear of an invasion.
Three such plants grow in my yard. The first, veronica, also called speedwell, grows next to my pond and the first time my dad saw it he started yelling, “You have purple loosestrife!” before I could tell him what it actually was. Like purple loosestrife, veronica has tall spiky flower clusters. The color varies from white to pink to blue to purple, but the color of the cultivar ‘Red Fox’ exactly matches the color of purple loosestrife. Veronica is a tough, low-maintenance, drought tolerant plant that grows in full sun to part shade and will bloom from early summer until frost.
The second plant I grow that looks similar to purple loosestrife is liatris, also called gayfeather or blazing star, and this one fooled my high school chemistry teacher for a moment when he came by on a detour from the Pond Walk a few weeks back. Although his reaction was much milder than my dad’s, he did say in a slightly accusatory tone, “Is that purple loosestrife?” Liatris is a native American prairie plant with spikes two to five feet tall bearing dozens of small red-violet to purple flowers carried in narrow dense compact clusters. It grows best in average well-drained soil in full sun. Liatris is a popular cut flower and adds a punch to any flower arrangement.
Perovskia, or Russian sage, grows in back of my pond. Russian sage grows up to four feet tall and wide even in poor soil and has cloud-like spires of violet-blue flowers. It grows in full sun and blooms from late July until frost. The foliage is finely dissected and very aromatic.
Other perennial plants that give the impression of purple loosestrife are buddleia or butterfly bush, liriope, delphinium or larkspur, blue vervain, lavender, wild lupine, great lobelia, pickerel weed, and salvia x surperba or violet sage. Some of these plants offer flowers in colors besides purple so if that’s what you’re aiming for, be sure to check the bloom color before you buy.
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