In my opinion, no coastal Pacific NW garden is complete without moss softening the edges of a rock garden or nestling between paving stones. Now that the rains have returned, mosses are lush green sponges, absorbing sound as well as water. They are the finishing touches to our native landscapes.
A few months ago, however, mosses looked quite different. With our particularly hot and droughty summer, mosses were brown, dry and brittle just like our lawns. But unlike those dead blades of grass, the mosses were only in a state of environmental dormancy. All it took to revive them was water.
Here’s a patch of moss in our home landscape during a hot dry spell. It’s dry and brown:
Here’s the same patch of moss 20 minutes after I watered it:
How can mosses recover so quickly? Well, mosses are one of the most primitive groups of land plants still in existence. They lack a true vascular system, so their “roots” are only anchoring structures – they don’t absorb water. Instead, water and nutrients are taken up over the leaf surface. As soon as water hits the leaves, it’s absorbed and literally throws the switch to turn everything back on. Leaves expand, chloroplasts start to absorb sunlight, and the photosynthetic machine is humming along.
In fact, my undergraduate major advisor was a bryologist (one who studies mosses). Jack Lyford’s lab was stacked ceiling-high with shoe boxes. Each box contained a different species of moss – completely dried out of course. All he had to do was take out a piece and place it in a dish of water. Within minutes it was fully functional and ready for study.
So make room for some moss in your garden. It’s a tough and fascinating little survivor.
It’s October. Fall is such an underrated time in the garden, and much pink can be found. In fact, flashes of pink are everywhere!! Got my ma’ams grammed last week; thanks for the reminder, NFL.
Muhlenbergia ‘Pink Flamingo’. Aye yi yi. Alleged hybrid between M. capillaris and M. lindheimeri. Five feet tall and as wide, huge plumes of pink. Looks like nothing important the rest of the year, then, blammo!!! Sorry, folks north of Zone 6. Actually, it only works here (Z. 6a) because of outstanding drainage; it’s planted in a pile of gravel. Mine has lived through two winters with -20 F days. Place where the sun will rise or set behind it for maximum effect. Bunny the Whippet not included.
Salvia involucrata – Rosebud Salvia
Big ol’ gal that will not favor you with blossoms until September. Absolutely not hardy here, or anywhere north of Zone 8. Take cuttings, ’cause baby she’s worth it. The furry, hot pink flowers will thrill any hummingbirds left zipping around (I read ours the riot act this weekend, they have GOT to hit the road soon). Note there is some hullabaloo as to S. puberula vs. S. involucrata vs. some hybrid amongst the two. Will report back.
Chrysanthemum x whatever ‘Venus’ .
Am so tired of the taxonomic uncertainty. Chrysanthemum…Dendranthemum… Whatever you call her, ‘Venus’ is a wonderful “real” garden mum (not those heinous meatball things) that brings the pink blooms in September, then fades to palest of pink, but not before every bee in the neighborhood visits. Fairly compact (2-3’) and pretty darn hardy (Zone 5). Tuck Venus amongst things you know will be done before fall – bee balm, phlox, etc. to keep the show going!
So there you have it, some pink for our October gardens. In loving memory of my sister Carlene.
As promised in my Sept. 9 post of “The Science Behind Fall Color”, I would address trees and shrubs with outstanding fall color. It was hard limiting it to only ten trees and ten shrubs, since I found 5 common shrub species of maples alone, so I cheated a bit and grouped the maples, oaks, etc. into one group so that my list was not entirely all maples.
I have seen the below plants with reliable fall color in northern, southern and eastern landscapes. These plants “light” up the landscape in autumn. For outstanding, long lasting autumn color, plant the below trees and shrubs with herbaceous plants which bloom in fall such as asters, mums, sedums, monkshood, toad lilies, and Japanese anemones. Do not forget ornamental grasses with their showy seed heads extending the season of color and texture.
We used to recommend ash for fall color, but not any more due to emerald ash borer. Japanese barberry and burningbush are tops for fall color, but both species are highly invasive and not recommended. There are more plants with great fall color than the ones below. I would love to hear your favorites!
Top 10 Trees for Fall Color
1) Black gum, sour gum, tupelo (Nyssa sylvatica), orange-red, scarlet to purple, outstanding
2) Maples, especially:
Sugar maple (Acer saccharum), bright yellow to orange-red
Red maple (A. rubrum), yellow, orange-red to bright red
Freeman maple (A. × freemanii), yellow, orange-red, red to reddish-purple
Paperbark maple (A. griseum), dark red to bronze
Japanese maple (A. palmatum), orange, red to purplish-red
Korean maple (A. pseudosieboldianum), deep orange to reddish-purple
Three-flower maple (A. triflorum), orange
Full moon maple (A. japonicum), yellow-orange to scarlet-red
Moosewood, striped-bark maple (A. pensylvanicum), bright yellow
3) Ginkgo (Ginkgo biloba), bright golden-yellow
4) Thornless honeylocust (Gleditsia triacanthos f. inermis), bright golden-yellow
I’ve written previously of my adoration for ornamental grasses. A few of you folks in the mid-Atlantic might have heard my “Grasses for the Masses!” presentation complete with lots of arm-waving. As with most of my talks, there’s usually some sort of interpretive dance involved.
Most of our warm-season ornamental grasses are in full gloriousness at the moment. Because it’s autumn! ‘Tis the season to purchase, plant, and enjoy ornamental grasses!
Well, not really. If you’d have purchased and planted them in April or May, you’d only have to do the “enjoy” part now. And your local grower/garden center would LOVE you for it. But most gardeners overlook containers full of 6″ tall Fescue – which is what a LOT of our best grasses resemble in the spring. It’s always been challenging to sell “green” in the spring – consumers want to see and buy plants in flower – so nurseries and greenhouses that supply garden centers do their darnedest to provide said blossoms.
So we pass over pots full of green grassy things in favor of enticing blooms. Nurseries have picked up on this – many include grasses in their summer/early fall production schedule, making full, fluffy pots for the autumn gardener. This works o.k. for shorter, compact things like fountain grass, little bluestem, etc. But by September, majestic switchgrass, big bluestem, and the like rarely look that fabulous in a one or two gallon pot – the proportions aren’t right; a bit of wind and rain and the situation is ripe for floppage (closely related to splayage). So you’ll probably pass them over. Again. Or maybe…take a second look? Just cut them back and plant away – you’ll enjoy them NEXT fall.
Doubling of flowers — the development of extra petals — is a common mutation, and often beloved by gardeners. Sometimes double forms of flowers become so popular that gardeners hardly recognize the single flowered, wild-type. Wild roses, for example, have just 5 (or, in once case, 4) petals and look totally different than the extra petal flaunting varieties familiar from gardens.
Doubling usually happens when gene expression gets mixed up and bits of cells that were destined to develop into anthers develop into extra petals instead. Sometimes a single mutation makes a dramatic change all in a go, but more often, the path to a double flowered cultivar starts with something like this:
Here we have a flower of Iris xnorrisii (formerly known as x Pardancanda norrisii) with the usual six petals, and three “petaloids” — anthers that are stuck in an ugly transition between anther and petal. This is a seedling in my garden this year, and I’m going to grow out lots of seeds from it — hopefully some of them will get past the petaloid stage to full on extra petals and hey presto, a double flowered variety will be born!
Salvia azurea (maybe my favorite salvia in the world — sky blue flowers in late summer/fall, hardy to zone 5) is blooming in the garden, and the bees are all over the flowers. But while some are poking their heads into the flowers to drink nectar and transferring pollen as they do so, others are up to something more sinister.
The evidence of what they are up to is clear if you look closely at the side of the flowers after they leave.
See the little hole in the base of the flower? That is where the carpenter bee bit a hole in the flower to get access to the nectar instead of going in the front of the flower as one would expect.
This phenomenon is called nectar robbing because it is an evolutionary betrayal of sorts. Flowers have evolved nectar to lure bees and other pollinators into the flower, so the bees will pollinate while getting their sugar fix. When the bees nectar rob, they’re getting the payment without doing the actual pollinating.
So why bite a hole in the side of the flower instead of just going in the front? Well, many flowers have evolved flower forms that make the nectar hard to reach by anything but their preferred pollinator, the species that most effectively moves pollen from plant to plant. In the case of this salvia, the nectar is down at the base of the flower, and only accessible to bees with long tongues, like whatever species normally pollinates it in its native range in the US plains. In other words, it is out of reach of the carpenter bees to save it for another bee, probably a bumble bee. Which works great to avoid wasting nectar on sub-optimal pollinators… unless, of course, those bees become robbers.
So next time you see bees on your flowers, take a look… they might just be robbers, not pollinators.
I’m going to keep posting about perennials that deserve more attention until somebody makes me stop. The fact that my subject is, once again, yellow… is merely coincidental
Definitely was a crowd favorite during the Perennial Plant Association annual Symposium’s grower tour (mentioned in my previous post). These photos were taken at Emory Knoll Farms north of Baltimore; I believe that they were trialing and/or including it in their plant selection for green roof use.
Thanks to Mary Vaananen, Jelitto’s North American operations manager (and goddess of perennial plant knowledge), who just happened to be standing next to it, full of 411, when I squealed “WHAT the (blankety blank) is THAT?!” My compadre Paul Westervelt added more info, as he’s also a plant geek deluxe (and manager of the annuals and perennials section of Saunder Brothers Nursery). D’oh. Plus you rock gardening fanatics probably know this cutie as well (I may have first seen this in one of Joseph T.’s talks, now that I think about it).
Eriogonum allenii, shale barren buckwheat, is native to counties that comprise the Virginia Highlands plus those on the West Virginia side of the line in the same region. Within these counties, the scattered populations reside in the botanical wonderlands called the shale barrens.
This floriferous selection ‘Little Rascal’ is indeed from Jelitto, so you too can obtain seeds of this rarity (along with detailed germination/growing instructions). Jelitto lists hardiness to USDA zone 5. As with most species from the barrens, it requires plenty of sun and excellent drainage.
Stocky and slightly shrubby in habit, the coarse grey-green green foliage was, when I saw it at the end of July, completely smothered in deep gold flowers. Simply gorgeous. It was abuzz with bees of all sorts, including insanely happy honey bees that could barely attain lift-off. I have a plot of regular-old-buckwheat (same family, Polygonaceae), but our spoiled-rotten bees always seem underwhelmed. Wait till they get a load of this!
I thought today’s post would feature two awesome plants that are relatively new or unheard of in the industry. Both of these plants have performed well in my own garden and survived our two hardest winters recorded since the 1970’s. Many plants suffered severe winterburn or even death due to extremely low temperatures, but not these two plants. They may be harder to find in the nursery/garden center, but are well worth it and have huge ornamental impact all growing season.
The first is variegated fiveleaf aralia, Eleutherococcus sieboldianus ‘Variegatus’ (formerly Acanthopanax sieboldianus ‘Variegatus’). I know, a really horrible, long scientific name for such a great plant. Now before I go on about this particular cultivar, I need to let everyone know that this is the cultivar you want, NOT the species that has all green leaves. The straight species is weedy, grows too large for most landscapes and is not colorful. The variegated cultivar is a real showstopper! It is low maintenance, grows slowly and rarely needs pruning. This medium-sized shrub grows about 5-6’ tall and wide in the northern U.S. growing larger in the south. The natural form is upright, rounded with long, arching branches. Suckering at the base of the shrub is slow, hence the plant does not become a nuisance in the garden. Variegated fiveleaf aralia is adaptable to most soils and pH, tolerates sandy and poor, dry, clay-based soils, will stay variegated in shade and will not scorch in full sun. It is quite drought tolerant with no pest problems. Deer and rabbits seem to leave it alone.
The foliage is quite clean with 5-7, bright, cream to yellow variegated leaflets with an emerald green center. There is no fall color to talk about, however, the brightly colored leaves mix well with other yellow, white or purple flowering/foliaged plants. The stems do have 1-2 curved prickles on them at a node, but they are short. Unlike its straight species, ‘Variegatus’ rarely flowers or fruits so the plant does not become invasive.
This plant is native to Japan and was highly promoted as an outstanding urban tolerant plant by my former graduate advisor, the late Dr. J.C. Raulston of North Carolina State University. He tested and evaluated thousands of landscape plants for adaptability to the southeastern U.S. and a few of those plants are actually hardy up in zone 4b.
Another great plant that I am more and more impressed with each day is a relatively new release from Iseli Nursery, Boring, Oregon. It is NORTH WIND® maple (Acer ‘IsINW’). This smaller, 15-20’ tall, ornamental maple is part of Iseli’s Jack Frost® series of hardy, ornamental maples. Through testing across the country, this maple has proven hardy to zone 4a without any dieback, unlike Japanese maple (Acer palmatum). One of the parents of this great hybrid is the Korean maple (Acer pseudosieboldianum), which is also zone 4 hardy.
The beauty of NORTH WIND® maple is that it combines the cold hardiness of Korean maple with the outstanding leaf qualities and deeper leaf lobes of the Japanese maple, one of the suspected parents, but with one exception. NORTH WIND® maple new leaves are bright orange! The color of these leaves lasts longer in the growing season in cooler climates. I have a young tree in my yard and the leaves are still orange, even this late into August. The older leaves gradually fade to green in midsummer. The orange-red fall color is superb and makes a real eyestopper in the autumn landscape. For best color, plant the tree in full sun to partial shade.
NORTH WIND® maple is pH adaptable and grows best in a moist, well-drained soil. I do not know yet how heat or drought tolerant this species is, but if anyone is growing this plant in southern climates, please let me know how it is doing.
Just back from the always-inspirational Perennial Plant Association Symposium, this year held in Baltimore. The theme celebrated the massive influence of German plantsmen and designers on both the mid-Atlantic and the perennial business as a whole. Whether a grower, garden center owner, or landscape designer, the names historically associated with Mid-Atlantic horticulture – Kurt Bluemel, Oehme, van Sweden & Associates, etc. – resonated with all attendees.
The history of the “perennials movement” was recounted – where the Germans (and more than a few Dutch) admired, utilized, and selected cultivars of our fabulous summer and fall-blooming native perennials – long before we North Americans ceased relegating them to ditch weeds. And then they taught us how to use them in “New American Garden” style – sweeping herbaceous plantings (fewer species but larger quantities of each), mixed with ornamental grasses and non-native but pollinator-friendly beauties such as Salvia nemorosa and Perovskia atriplicifolia.
But this was my first encounter with Rudbeckia grandiflora ‘Sundance’. This seed strain was introduced by Jelitto® Staudensamen seven or eight years ago. It has a pretty broad native range… Midwest to South-Central United States. USDA cold hardiness zone ratings listed as 5-8 and 4-9 from various sources. Always full sun. Didn’t see a speck of powdery mildew.
The flower habit is a bit like Ratibida pinnata – the slightly drooping petals give the sensation of movement (even with zero breeze, 90% humidity, and 96° F). The clear yellow color works with just about anything. Around 4’ tall, the sturdy stems showed little sign of flopping. I’m sure the cones will persist, adding texture as the fall progresses.
‘Sundance’ will never impress in a nursery container in May. It’s one of those you-must-see-it-in-the-garden plants. OR or you can take my word for it. And that word is “Yowza!” (Followed by “gimme gimme gimme.”)
Crazy plant of the day is this: Pereskiopsis spathulata! Which, I’ll admit, looks like a fairly generic succulent, but the cool thing is this is actually a cactus. A cactus with leaves. Most cactus have of course lost their leaves to increase their ability to survive in extremely dry conditions and rely on their stem for photosynthesis, but the genus Pereskiopsis is a bit of living evolutionary history with photosynthetic leaves still intact.