We are normally not huge fans of annuals, as they simply evoke extra WORK. Having to plant them every spring and tend to them until they get established rarely seems worth it, particularly when so many perennials, grasses, and shrubs can provide just as much visual appeal at a fraction of the effort. In any case, one annual in particular we have fallen in love with, and this is Brazilian verbena. While the springtime planting of them takes a bit of doing, they become established quickly and begin blooming early. Blooming virtually all summer long, they attract countless monarchs, honeybees, and other pollinators to their electric purple flowers. Form-wise, they provide a feathery but pronounced vertical accent within a landscape. When planted in drifts, they create a glowing purple screen that seems to float over the lower-growing plants nearby. Add high drought-tolerance to the list of pluses and you have what amounts to a perfect annual to mix in with your existing perennials and grasses. The butterflies will thank you for planting them, and your neighbors might too.
We are always on the lookout for plants whose foliage can provide visual and structural interest long after its flowers have faded. Add in good drought-tolerance and some wildlife value, and it should fit comfortably within our botanical arsenal. Penstemon grandiflorus (or, large-flowered beardtongue) is such a plant. Its waxy grey-green leaves can provide a shot of color contrast and coarser texture within a landscape of deeper greens and fine foliage. Its purple-pink flowers shoot up in vertical spikes in June and work well as companions within large plantings of grasses or other plants with feathery foliage, such as little bluestem. Once established, the plant likes no supplemental water, content to survive and thrive on its own in crummy gravely or sandy soil. Avoid clay soils for this plant, however, as it resents poor drainage.
Blue Queen Sage embodies everything we love in a plant: textured, hardy, tidy, structured, and that evokes the mood and feeling of a place we’d like to be. Give it full sun and not much water, and you will have a tough, showy plant, whose grey-tinged foliage contrasts well with the typical kelly green of many a native prairie perennial. Additionally, it blooms in June, a month when the full flush of spring flowers has faded and little is in bloom. We like it best planted in rows or lines, to create swaths of electric purple gracefully cutting through the landscape.
Amorpha nana (aka dwarf false indigo, or fragrant wild indigo, or some variation thereof) is a feathery-leafed, compact shrub native to the central and northern prairie of the US. Growing to about two feet by two feet, it looks its best in groupings, drifts, or masses, for a swath of grey-tinged-but-still-fresh-green color and a detailed, but soft texture. Like many flowering shrubs, the plant blooms in early summer. In its case, it sends out reddish-purple spikes that give off the smell of honey and attract pollinators to boot. The plant likes moderate to very dry conditions, so it moves to the top of our list for its ability to withstand those summer periods where it may rain less than an inch over a three-week period. Additionally, the feathery nature of its foliage can offset and contrast with the coarser foliage of some other dry-landscape plants. The plant can get top-heavy and leggy if you don’t pay attention, so a good pruning annually in spring can help keep the plant compact and full.
On the subject of pruning, we love this book for its dogma-free approach to pruning: The Well-Tended Perennial Garden.
For those who are not familiar with the sights and colors of Minnesota in summer, we will tell you that it is an explosion of Kelly green, including in gardens and landscapes. Perhaps because we spend so many months of the year blanketed in snow and darkness, all anyone wants come spring is green, and nothing but green, in their gardens. While we understand the sentiment, this swath of green quickly becomes flat and monotonous come July, and every landscape starts to look like every other. For those who are looking to start playing with foliage color in the landscape, Shepherdia argentea is a good candidate. Its fine-textured silvery grey-green leaves give the appearance of an olive tree, and offer some much-needed color contrast against brighter greens and coarser textures. Planted in the back of a landscape it offers a sturdy but flowing grey-green screen of height and form. Once established it can survive on its own without supplemental water, and birds appreciate the large shrub for the food it provides. As with many shrubs, be sure and fence it in for the first couple of winters or so, so as to ensure the rabbits don’t make a meal out of it. In any case, we love being able to invite those mellow grey-green tones of a Mediterranean landscape in to a Minnesota one; the color contrast could not be more welcomed.