From Boerner to Your Backyard

From Boerner to Your Backyard
2010 Garden Walks with Melinda Myers
Sponsored by Summer Sizzlers
1. Horstman’s Silberlocke Fir -­‐ Abies koreana ‘Horstman’s Silberlocke’ The upward curving needles reveal the silver undersides of the needles. The purple/blue cones are quite
attractive. This irregular shaped fir is a bit more heat tolerant than other species. A slow grower that
can reach 10 feet in ten years and eventually 15 to 20 ft in height. It grows best in zone 5 through 7.
2. Swamp Milkweed – Asclepias incarnata This plant is a butterfly magnet that works well in a sunny perennial border or rain garden. Spread by seed and some find it a bit too “weedy” for them. The key is keeping up with weeding out of the unwanted seedlings. (Zones 3 to 9) 3. Fringeleaf Wild Petunia -­‐ Ruella humilis It’s native in Wisconsin, the Midwest and much of the Eastern and Plains states. The beautiful lavender-­‐blue flowers appear early summer through fall. I am not sure of the fringeleaf reference since this plant has hairy lance shaped leaves. It can spread– in fact I keep weeding it out of my alley bed, though it seems to be a bit more contained in the front bed. Prefers full sun to part shade and tolerates dry soils once established. (Zones 4 to 8) 4. Cardoon – Cynara cardunculus ‘Plein Blanc’ A look at these flowers reveals its close relationship to the artichoke. Hardy in zones 7 through 9 it is often grown in the north for its ornamental foliage. An early start indoors or overwintered plants will bloom in the northern garden. Flowers can be used in dried flower arrangements. The leaf stalks and midribs are edible as are the unopened flowerheads that can be eaten like an artichoke. 5. Sawara Falsecypress – Chamaecyparis pisifera ‘Mops’ The Chamaecyparis are relatively new evergreens in the northern, Midwestern and southern landscapes. They have long been used on the east and west coast where the climate is more suitable. But we are finding more and more species and cultivars that work in the central and southern areas of the US. Grow in full sun with rich moist soils for best results. Northern gardeners should protect these plants from winter winds and winter sun that can be drying. Eventually grows to 6 feet tall and 4 ft wide (Hardy zones 5 to 7) 6. Flat Sea Holly – Eryngium planum ‘Blaukappe’ You either love or hate this one. The flowers are great for cutting and used fresh or dried. Butterflies like the plant and it tolerates heat, drought and salt. Plant a mass and surround with grass for an informal look or combine with more refined perennials for a formal design. This particular sea holly grows to 28 inches and tends to be more upright and sturdy than others. Dr. Duncan Himmelman, on the www.perennials.com website says “…. Plan to use Sea Holly and its kin in those surly and malicious borders designed to keep cats and small dogs at bay. As a bonus, cut them, dry them and use them in your favorite Halloween bouquets!” I think I will give it a try this Halloween. (Zones 4 to 8) 7. Combo Alert #1 Sculpture, Agave & Dallas Blues Switchgrass Mountain Face by Jim Malkowski, Agave spp., Panicum virgatum ‘Dallas Blues’ The Agave (donated to the Domes by a home gardener and lent to Boerner) complements the look and feel of the statue. The Dallas Blues switchgrass makes a nice backdrop and its blue-­‐green foliage echoes the foliage of the agave pulling it all together. This switchgrass grows 4 to 6 feet tall and the large flower heads look like a cloud hovering over the foliage in the fall. (Zones 4 to 9) 8. Creeping Thyme – Thymus spp. A great groundcover or edge in the sunny perennial garden. It is tolerant of hot dry conditions once established. Winter dieback is common in poorly drained soils. It’s very attractive to bees. 9. Combo Alert #2 – Diamond Frost Euphorbia, Cosmos & Pink Castor Bean Euphorbia hypericifolia ‘Inneuphe’, Cosmos ‘Cutesy Mix’ & ‘Pied Piper Blush White’ & Ricinus communis ‘Carmencita Pink’ The bold leaves of the castor bean (the seeds are very toxic) create a nice backdrop and contrast to the fine foliage of the cosmos and diamond frost euphorbia. 10. Smokebush – Cotinus coggygria ‘Golden Spirit’ Smokebush (Smoketree) can be grown as a large shrub or small tree. It may die back to the ground in extremely cold winters in its northern limits (zones 4 to 8). Green, gold (in this case) or purple leaves are topped with ineffective flowers that give way to hairy flower stems that create a “smoky” cloud. Great fall color as well. Note how the Golden Spirit echoes the blooms of the panicle hydrangea bringing it into view. 11. Peacock Lily – Gladiolus callianthus (Acidanthera bicolor var. murielae, Acidanthera murielae) Beautiful fragrant flowers nod above sword shaped leaves on this heirloom plant (1896). It grows 18 to 24 inches tall and prefers full sun and slightly dry soils. This flower is a nice surprise amongst more common perennials. Hardy in zones 7 to 10. Northern gardeners may want to start these indoors for earlier bloom outside. 12. Combo Alert #3– Elephant Ears & Canna Colocasia spp., Xanthosoma ‘Lime Zinger’ & Canna ‘Australia WOW! We had to just stop and enjoy the display of these bold leaf plants that lined the back walk. Note the sun shining through the leaves of the Lime Zinger. These tropicals are not hardy in northern gardens and the rhizomes need to be overwintered indoors. Elephant ear and Lime zinger can be grown as houseplants or the rhizomes stored in a cool dark location like cannas. * Note: Pink Chablis Deadnettle still in bloom Bottlebrush Buckeye in bloom Japanese Kerria still in bloom 13. Combo Alert #4 – Henna Coleus, Fanflower & Coral Nymph Salvia Solenostemon scutellarioides ‘Henna’, Scaevola & Salvia coccinea ‘Coral Nymph’ Mary Braunreiter (Gardener responsible for Perennial Garden and gardens surrounding the Visitor and Education Center) has created many wonderful combinations, including this one, that we are enjoying this season. This combination started with the Henna coleus and coral nymph salvia. She had some left over fanflower that needed a home and decided to add it to the combination. The blue added just the right impact and she plans on looking for more opportunities to expand her combinations. Like all gardeners she feels some of her best combinations are a result of happenstance. 14. Oakleaf Hydrangea – Hydrangea quercifolia ‘Snow Queen’ A great four-­‐season plant with interesting bark, white flowers in summer that turn pink as they fade and beautiful fall color. It is hardy in zones 5 to 9 and grows 4 to 6 feet tall and wide or wider. These plants tolerate shade and prefer moist well-­‐drained soils. Mulch to keep roots cool and moist in full sun situations. Snow Queen has survived -­‐22° F and has more and larger sterile (showy) florets and flowers that are more upright and less likely to flag. 15. Rock Garden Part of the joy of gardening is the stress relief. The rock garden is a great retreat during the hot summer weather. Plus a walk on the path through the Bugbane (Cimicifuga racemosa now Actea racemosa) flowers can’t be beat. 16. Daylilies – Hemerocallis spp. Boerner Botanical Gardens like many Botanical Gardens and Arboreta work closely with Plant Societies to build their collections. The Daylily path is filled with some of the most popular and many of the Award Winning Daylilies. Visit http://www.daylilies.org/ for more information on daylilies, winners and breeding efforts. 17. Giant Coneflower – Rudbeckia maxima This is a North American native with impressive foliage and flowers. The large blue-­‐green leaves can reach 12 to 18” in length. The 6 to 7ft tall plants topped with yellow flowers in summer make quite a statement in the garden. Grow in full sun with moist well-­‐drained soils for best results. (Zones 4 to 9). 18. Balloon Flower – Platycodon grandiflorus A close look at the flower buds reveal the source of this plants common name. The balloon shaped buds open to a wide bell-­‐shaped flower. Flowers are usually blue but pink and white varieties are also available. It grows well in sun or partial shade and well-­‐drained soils. Mark its location as it is late to emerge in spring. Deadhead much like daylilies – removing individual florets and eventually the whole flower scape for a neater and tidier appearance. (Zones 3 to 8) 19. Korean Yellow Waxbells – Kirengeshoma koreana An underused shade perennial with bold foliage and attractive yellow bell-­‐shaped flowers summer through fall. Grows to 36 inches and prefers moist soil and partial shade. Rated hardy in zones 5 to 8 though I have seen it growing successfully in several zone 4 locations in Minnesota. 20. Carpathian Harebell – Campanula carpatica ‘Deep Blue Clips’ One of my favorite bellflowers. The small (6 to 8”) plants are covered with blooms for most of the growing season. Great at the edge of a perennial bed or in a rock garden. 21. Rocket Ligularia – Ligularia ‘The Rocket’ Moist shade is the key to keeping these plants happy. The tall flower spires may reach for the sun in shady locations and the plants will wilt in midday when grown in full sun for straighter bloom. Keep soil moist for best results. Ligularia have attractive foliage and flowers and are suited for moist shade gardens. (Zones 5 to 8) 22. Tennessee Coneflower – Echinacea tennesseensis Native to only certain glades near Nashville, TN (though University of Kentucky says it is native there). It is shorter, about 3 ft tall, than Purple Coneflower. This perennial is hardy in zones 4 to 8 (though some debate on this). The leaves are narrower, as are the purple-­‐pink ray florets, than the Purple Coneflower. The stems are stiff and covered with flowers for much of the summer giving it even more ornamental appeal. This is an endangered plant. 23. White Balloon Flower – Platycodon grandiflorus ‘Apoyama Fairy Snow’ Dwarf white cultivar of balloon flower that grows 6 to 12 inches tall. 24. Garden Phlox – Phlox paniculata A great butterfly and hummingbird plant that looks good in the garden or as a cut flower indoors. Look for mildew resistant varieties such as Brite Eyes, David, Eva Cullum, Fesselballon, Flamingo, Franz Schubert, Katherine, Look Again, Orange Perfection, PAX, Prime Minister, Sandra, Speed Limit 45, Sternhimmel, Tenor and The King (list from The Well-­Tended Perennial Garden by Tracy DiSabato-­‐Aust). 25. Color Guard Yucca – Yucca filamentosa ‘Color Guard’ Evergreen perennial (shrub) grown for its foliage and dramatic flowers in summer. Color Guard has creamy gold centers on long sword shaped green leaves. It grows up to 3 feet tall and wide and the flower spikes rise to 6 ft in height. Yuccas prefer full sun and well-­‐drained to dry soils. (Zones 4 to 10). They are often biennial bloomers. I find the best flowering occurs during hot summers in northern regions. Avoid rich soils and high nitrogen fertilizers that can promote vegetative growth at the expense of flowers. 26. Wild Senna – Cassia hebecarpa Senna is native to parts of Canada and much of the Eastern U.S. It grows to 6 feet tall and prefers full to part sun and moist soils. If it is happy it can encroach on nearby plants unless you restrain its spread. The finely divided compound leaves and butter yellow pea-­‐type flowers give this native a tropical feel. Olbrich Botanical Gardens in Madison, WI uses this as one of their hardy plants (along with Kentucky Coffeetree) to create a tropical garden around their Thai Pavilion. (Zones 3 to 9) For photos and more details on these and other plants visit Ask Melinda and Plant Guide at www.melindamyers.com Enhance your Property Value. Beautify your Neighborhood. Hire a green industry professional, buy their
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