Michigan Department of Natural Resources:

Autumn olive is native to Asia and was introduced into the US in the 1830s. It was commonly planted for wildlife food and cover until its invasive traits became apparent. It produces abundant fruits that are widely distributed by birds and mammals. Like many non-native shrubs, it leafs out early and retains its leaves late in fall, shading out desirable native species and reducing species diversity. It is able to germinate and survive in shade as well as sun.

Autumn olive has root nodules that fix atmospheric nitrogen. As a result, it has the potential to degrade native plant communities that are adapted to low nutrient levels such as barrens and prairies. The resulting increase in nitrogen can promote the growth and spread of weedy species at the expense of low-nutrient adapted natives. In addition, it can increase stream water nitrate concentrations when it comprises a large portion of the stream bank vegetation.

Autumn olive does not appear to suffer significantly from herbivory by deer. In one study, it grew as tall outside of exclosures as it did within, while natives growing in the same places were much smaller when browsed by deer.

To learn more about Autumn Olive, download the DNR Best Control Practice Guide…

MSU Extension:

Everyone in Michigan is anxiously awaiting spring and warmer temperatures to arrive. Few of us are as patient as the woody plants around us. They have been patiently waiting since mid-January for warm weather. Last fall, as the days got shorter and temperatures fell, perennial plants got ready for winter. Sugars were stored as starch in the shoots and roots. Proteins in the leaves were broken down and reassembled as storage proteins in the shoots and roots. These materials were stored for the explosive growth we often see in spring as trees and shrubs leaf out rapidly under warm conditions.

Read the rest of the article…

A common gardening question each spring is, “When will the last frost occur in my area?” As anyone in Michigan knows, the weather here is difficult to predict and our state has diverse climates with wide variation from the upper peninsula down to the Ohio border. But, we do have historical averages which is where you want to start. The MSU Extension has created a helpful table based on last frost data from 78 weather reporting stations throughout Michigan.

Check it out here…

NPR:

Despite the cold and snow, some signs of spring are starting to break through in Colorado. The public library in the small town of Basalt is trying an experiment: In addition to borrowing books, residents can now check out seeds.

In a corner of the library, Stephanie Syson and her 4-year-old daughter, Gray, are just finishing a book with a white rabbit on the cover.

When Gray approaches the knee-high shelves filled with seed packets, she zeroes in on a pack labeled “rainbow carrots.”

Read the full story here…

The Salt Blog at NPR:

Though we hear about them every holiday season in that famous song, chestnuts – whether roasting on an open fire or otherwise – have been noticeably absent from many American tables for decades, thanks to a deadly fungus that decimated the species near half a century ago. But a small army of determined growers have been on a seemingly quixotic quest to put chestnuts back on the American table, and they’re just starting to see results.

Read the full story…

This website extra complements Janet’s article entitled, “Remarkable, unusual plants on my wish list,” from the Nov/Dec 2012 issue. Check out the digital edition here.

Classic combination for form and sequence of bloom

Four plants on my list mesh without any special arranging, because one is large, coarse textured and mounded; another is a medium height, fine mound; a third is tall, columnar, coarse and gray; and the fourth has a horizontally spreading shape, medium height and texture, and gray-green foliage. All are long-blooming at varied times of the year or offer multiple seasons of interest. So even when none of the four are blooming, there will be visual interest in the garden because the shapes, textures, and foliage colors contrast.

Plus-season peonies
Few plants take charge in a garden like peonies do. Although the bloom season may be short, if the peony is one that can resist its species’ leaf diseases, then its neat form and substantial foliage serve all the other plants all summer. If it’s a peony that can develop nice fall color at least some years, that makes for a grand finale.

For years I’ve been watching peonies looking for that great bloom, good health, and at least a fair record of significant fall color, all in the same plant. Many of the tree peonies and intersectional hybrids (such as the ‘Itoh’ types) can qualify, including the ‘Bartzella’ yellow-blooming intersectional I already have. When it comes to more traditional peonies, there are just two on my list. One is the rather late-blooming, single white-flowered ‘Krinkled White,’ that can be a showy yellow in autumn. The other is a very early double pink, ‘Estafette.’ This heirloom plant can develop a good burgundy tone in fall.

‘Krinkled White’ will probably have to go to bat this time, because a retail source for the pink continues to elude me. I’ll have to beg a piece from one of the gardeners who tend the plants I watch.

Ornamental mullein (Verbascum hybrids)
Gray-green foliage can add to a garden if you design for it, and spike-like flowers contribute in form well before bloom time until cut back. Ornamental mulleins offer both for sunny dry places, but have been underused. That’s a shame that plant breeders seem ready to correct, with varieties such as ‘Clementine,’ quite foxglove-like at 48-inches but like no other spike for its apricot flowers. Also on our list with good if not stellar ratings is the 12-inch dwarf hybrid ‘Blue Pixie.’ This last is actually purple (don’t we hate it when breeders pick such names?!) and it blooms its heart out and seems to pay for it in shortened life.

Sea lavender (Limonium latifolium)
Its foliage is large, entirely basal, but completely hidden from bloom season until fall cut back time by the flowering stems which create a dense, fine dome. A relative of statice, in bloom it has been described as “like a lilac-pink baby’s breath.” It’s not new to me but has been news to most garden centers and growers I’ve contacted. Finally this year, Specialty Growers in Howell, Michigan decided to grow it. Give it a try. Pair it with Liatris spicata to create synchronized bloom of two different shapes and textures.

Dwarf butterfly bushes (Buddleia davidii hybrids and selections)
We’ve grown the ‘Nanho’ dwarf butterfly bush for some time and been glad for its better fit with moderate and small perennials. Now we have choices in even smaller butterfly bushes, such as the Lo and Behold series in blue-violet, lilac, white and purple, and the Flutterby Petite series that includes the best blue we’ve seen in ‘Blue Heaven.’ We’ll include one of these even though we’re only two years into watching them, because they’re worth the cost even as an annual addition for the flowers it produces and the butterflies and hummingbirds it brings.

Wanted: A good-sized sunny space for “new” natives

“New” and “Native” may seem contradictory, but what’s been around since before civilization can still be new when it’s first brought into garden cultivation, and again when a plantsperson hybridizes or selects for special characteristics among seedlings. It’s very good to see a lot of that going on recently. For too long before this, natives were overlooked and left standing in the field with names that draw snickers: ____weed, beardtongue, papoose root.

All in this group should have full sun (6-plus hours of cast-a-shadow-light each day) and very well-drained soil, plus enough water to keep it from ever drying down all the way.

This group doesn’t include all the native species on my current wish list. In other groups are Coreopsis, Gaillardia, Gaura, Heuchera, marsh mallow Hibiscus, and mountain mint, which all hail from North America, and all except Heuchera and Gaura occur naturally in Michigan.

Selections and hybrids from false indigo (Twilite Prairieblues baptisia)
False indigo is a big plant, five feet tall and wide. Most gardens have room for only one. So some garden I work in that doesn’t yet feature baptisia will have it soon because this bicolor-flowered hybrid deserves attention. The plant itself is a good anchor for any combination, with clean blue-green foliage and sturdy stems. The bloom is icing on the cake, as each blossom on the tall spike is blue-violet with a yellow streak.

Plenty of other false indigo hybrids are breaking on the garden scene. If purple and yellow aren’t right for your color scheme, check the creams, yellows, and blue-plus-white varieties that preceded Twilight Prairieblues.

‘Crimson Butterflies’ gaura (G. lindheimeri ‘Crimson Butterflies’)
Gaura’s floppiness always put me off, even more than its tendency to come and go in northern hardiness zones. (Who can blame a Texas native for preferring the South?) Then I saw ‘Crimson Butterflies,’ just 18 inches at the tips of its dark pink flower stems. The maroon foliage is gorgeous. It’s a good front-edge, fine texture, and long-bloomer.

Culver’s root (Veronicastrum species including V. sibiricum ‘Red Arrows’)

Veronicastrum virginicum is a Michigan native with neatly whorled foliage and thin white candelabras held at eye level in July. It’s a welcome fresh face with clean lines as a perennial garden is making its annual transition to more-things-done-than-still-to-come. Once in a while you see a bit of pink in the flower of this or that veronicastrum seedling, so it’s not surprising that someone found a dark-leaved, pink-blooming type in the Asian counterpart, Veronicastrum sibiricum, and propagated it as ‘Red Arrows.’

Showy goldenrod (Solidago speciosa)
This five-foot plant is native just about everywhere east of the Rockies. It’s showy in golden bloom in August and continues to glow into October as yellow seedheads. Its dense flower head attracts me as a welcome switch from all the feathery explosion-type goldenrods that have already stepped from wildflower to mainstream ornamental perennial. This is a plant that spreads by rhizomes (root-like underground stems), but its vigor, speed and controllability track more closely with black-eyed Susan and daisy than the “weed” goldenrods.

‘Iron Butterfly’ threadleaf ironweed (Vernonia lettermanii ‘Iron Butterfly’)
The trouble with many sunny Midwest native plantings is that so few of the plants are short, or even mid-sized. Most vernonia species (I say we ditch the name ironweed) are so tall that gardeners seeing one for the first time will find bloom time, color and height equally remarkable, as in, “What is that very tall plant with dark purple flowers in August?”

However, the selection of threadleaf vernonia called ‘Iron Butterfly’ is only about three feet tall at maturity. Long-lived like peonies, these plants take some time to bulk up below ground before they hit their full height. Those pictured here are in their first year and still under 18 inches as they begin bloom in late September, offering nectar for the last flight of Monarchs. As the plants age we’ll probably pinch them once or twice in late spring and early summer, or forgo rabbit protection until Independence Day, so they’ll bloom short and late. This species may be at the edge of its hardiness in USDA zone 6; the jury’s still out.