Monday, March 30, 2015

Cheekwood Botanical Garden in Spring - Flowering Quince, Cornelian Cherry, Hyacinths, Tulips, Winter Honeysuckle and More!

Chaenomeles x superba (C. japonica x speciosa) 'Jet Trail', flowering quince

'Jet Trail' quince looks like a good bee plant. I've never tried it, but I've read that ornamental quince (Chaenomeles spp.) produces a very hard fruit that can be used to perfume a room or even cooked to make jam.

The foliage emerges early (mid-March) on Heptacodium miconioides (seven-son flower), a Chinese tree that reportedly has fragrant late-summer flowers that attract bees and butterflies.

Beautiful peeling bark on the Heptacodium miconioides adds a lot of character and texture to the garden.

I confess I haven't had the courage to do much with bulbs (other than daffodils). I'm nervous that winter rains and heavy clay soil would be a death sentence for most bulbs. But since my wife was enamored with this hyacinth display, I guess I'll be digging holes and popping in hyacinth bulbs next autumn. Perhaps if I plant them on a hill they'll be OK?

There was something about these thick, twisting wisteria vines curled around a metal arbor that reminded me of the Elvish kingdom in Lord of the Rings. (FYI, Asian wisteria vines (Wisteria sinensis and Wisteria floribunda) are considered invasive in Eastern U.S. forests. And as you can see here, they can get massive over time. If you live in the Eastern U.S. and must have a wisteria, perhaps consider the American wisteria - W. frutescens - which is native primarily from Texas to Florida and Missouri to Kentucky.)

What a nice moss-covered rock. Gardeners in shady moist regions awash in moss would probably find this photo laughable, but in my moss-deprived garden, this would be a handsome sight. I have a few small patches of moss (including one shown in my last post) and am trying to encourage them to proliferate.

Cornus mas (cornelian cherry) flowers

Ribes odoratum (clove currant) leafed out nicely already in mid-March. Could the foliage withstand temperatures in the 20s? I'll have to make a return trip to find out... Primarily native to Western and Central North America from California to Arkansas and Washington to North Dakota, I think clove currant is supposed to be the only currant capable of surviving (or perhaps thriving?) in the heat and humidity of the Southeast.
There were bees (honeybees, I think) all over this blooming Lonicera fragrantissima (winter honeysuckle). Although some other exotic bush honeysuckles are considered highly invasive, winter honeysuckle apparently is much less of a problem from an invasiveness standpoint. For example, it has the lowest level rating (Alert) from the Tennessee Exotic Pest Plant Council (TNEPPC). By contrast, the TNEPPC considers Japanese honeysucke - L. japonica - to be a Severe Threat to native plant communities. Given this relatively well-behaved reputation and its clear appeal for bees, I may have to consider adding L. frangrantissima to my garden. As the common name suggests, the flowers have a marvelous scent that can be detected from some distance away when the shrub is in full bloom.

Cheekwood has a remarkable tulip festival in the Spring. We visited too early to see most of the tulips, but these precocious 'Rosy Delight' bulbs were putting on a good show! :)

Wednesday, March 25, 2015

Enjoy It While It Lasts - Winter Jasmine, Hellebores, Daffodils, 'Georgia Blue' Speedwell, Boxwood Flowers and More!

After a harsh winter (especially last month - 8th coldest February on record in Tennessee) we have been basking in above-average temperatures for the past couple of weeks.

Yesterday's high temperature was 77 (Fahrenheit). The previous day was 73. Last week, we hit 80.

As a result, leaves, buds and flowers have been bursting out all over, making for a lot of pretty pictures (see below).

Unfortunately, temperatures are supposed to take a nose dive later this week. We're expecting lows in the 20s (perhaps as low as 23) on Friday night and Saturday night.

Usually, I am what you'd call a Darwinian gardener - I let plans thrive or die with minimal intervention. (Well, I water them for a season to get them established, but I don't spray or coddle after that.) But in this case, I'm tempted to try throwing a sheet over the crabapple tree. It's loaded with buds and I'm worried that many of them will be killed in the cold snap.

For now, enjoy these signs of Spring!

'Honey Bee Blue' Agastache (I believe A. rugosa). Purchased three from a local nursery last year, they all seem to be coming back nicely.

I'm pretty sure this is Agastache foeniculum 'Golden Jubilee' (anise hyssop), but the leaves should be emerging a chartreuse color. So perhaps the original plant has died and the seedlings have reverted to the species A. foeniculum? (Prairie Nursery does call the species a biennial.)  I'll post an update later in the year as to the foliage color as these seedlings mature.

Shoots and flower buds on Ajuga genevensis (blue bugle, Geneva bugleweed)

Sedum telephium (I believe the 'Autumn Joy' cultivar)

I'll admit it, generally I think boxwoods (Buxus) are boring and overplanted. Yet, the thing I like most about boxwoods is probably what other people overlook - not their bland evergreen foliage, but their sweetly-scented spiky flowers that attract pollinators such as bees and (as you can see here) other insects including flies. Flies don't get much respect, but I'm sure they have a bigger role to play in the world than landing on our picnic lunches.

And here's a bee (honeybee?) buzzing in the boxwood.

Clematis 'Crystal Fountain' -- got to do some judicious pruning here...

Aquilegia (columbine) self sows with abandon here. I love it and encourage it. Originally I planted a few different columbine species including the European A vulgaris and a hybrid called 'Winky', but I've decided to focus on adding and encouraging reseeding by the native species A. canadensis (wild columbine)

Purple coneflowers (Echinacea purpurea) are coming up throughout the garden, both as returning perennials and new seedlings. Again, love and encourage the reseeding. I'm also happy that the new seedlings are easy to spot and identify, unlike some species where you have to wonder for a while whether you're growing a desirable plant or nurturing weeds.

Look closely at the base of these stems and you could spot new growth emerging on Baptisia australis (blue false indigo). Although B. australis reportedly prefers well-drained soil and full sun, it seems to have done pretty well for a couple of years now in our heavy clay soil with a bit of shade from a neighboring crape myrtle tree. Note that the new growth can look a little bit like asparagus, but there is evidence that Baptisia is poisonous (for people) and should not be eaten! So to avoid a potentially dangerous misidentification, don't plant this anywhere near your asparagus patch!

Beautiful foliage and buds on the 'Sugar Tyme' crabapple. This is the one where I don't know whether I should try to provide some protection from the upcoming cold snap or stay true to my Darwinian ethos.

First cheerful blue flowers are appearing on 'Georgia Blue' speedwell (Veronica peduncularis)


Most of the year I'm neutral-to-negative on daylilies (overplanted, high-maintenance, don't seem to have much wildlife value), but I always appreciate the lush, fresh new foliage in March that leaps out of the ground when many other perennials are still snoozing.

Dianthus gratianopolitanus 'Firewitch' (cheddar pink) - I was thinking of planting more cheddar pinks as a groundcover, but I'm a bit concerned that this one could be dying off in the center after a few years, which would not speak well for its potential as a long-term groundcover. I think I'll wait to see how/whether it recovers over the next few weeks...

Geranium sanguineum (bloody cranesbill) - planted three tiny specimens of the 'Vision Violet' cultivar last year. They struggled a bit as they had to compete with a rampant patch of cherry tomatoes, but they all seem to have returned bigger and stronger than last year, so that's a good sign.

Added a couple of hellebores to the garden last month. Of course, I planted them just before our temperatures crashed below average and stayed there for weeks with temperatures dipping into the single digits multiple times. Since these had been growing in an unheated greenhouse and hadn't had a chance to harden off, I assumed they would be goners. I covered them cardboard boxes (weighted down by bricks) that subsequently got soaked by rain and collapsed by ice. When I gathered the courage to remove the boxes after a few weeks, the hellebores looked fit as a fiddle. These are some tough plants!

Alchemilla mollis (lady's mantle)

Stachys byzantina 'Helene von Stein' (lamb's ear)


Philadelphus x virginalis 'Natchez' (mock orange) - Bought this from a sale section in autumn 2013 and got a great bloom last May. Then the plant just say there all last year, not growing an inch. I worried as to whether it had exhausted itself with the bloom and was on the road to ruin. Then late in the season, it sent up a sucker about six inches with fresh new leaves. Was that a good sign or did it mean all the old growth had died off? Well, so far, things look good. I'm seeing all the old growth (and the new sucker) leafing out. I'll remain optimistic on the mock orange.

I don't know much about mosses, but I think they're fantastic from both a visual and tactile standpoint, so I try to encourage them in the garden. I don't know how to identify this moss, but it seems to be entering its reproductive stage where sporophytes will release spores that will hopefully help the moss spread around the garden!

Symphyotrichum oblongifolium 'October Skies' emerging from under a winter blanket of leaves. I'm pleased to see that all three clumps of October Skies aromatic aster seem to have expanded nicely.

Phlox paniculata (garden phlox) 'David' - As with the daylilies, I think the sight of the fresh green foliage emerging in early spring may be my favorite think about garden phlox. The foliage always seems to get pretty tattered (and sometimes mildewed) later in the season. Still, it's a tough plant that has come back reliably year after year, so I should probably learn to appreciate it more. (I think there are some little Agastache seedlings growing alongside it this year.)

Viburnum 'Pragense' (Prague viburnum). I had five of them planted last year. This is the most impressive one of the bunch and I'm still not impressed.

Here are two of the less impressive Prague viburnums (Viburnum 'Pragense')

I'm pretty excited to see that this Salvia greggii (autumn sage) survived the winter. It's only marginally hardy in our zone and supposedly dislikes poorly drained soil (which is a big problem with our heavy clay). Still, it's one tough cookie and I'm pleased to see that it's back for another round. The other autumn sage I planted last spring seems to have died back closer to the ground, but I still see some new leaves near the base of that plant.

Native to the Mediterranean, Teucrium chamaedrys (wall germander) supposedly needs (prefers?) well-drained soil, but it seemed to cope pretty well in lightly amended heavy clay. All three clumps survived the winter and stayed partially evergreen. I cut off some of the damaged foliage to reveal this fresh new growth. The clumps seem to be expanding at a measured, moderate pace.

Myrica cerifera (southern waxmyrtle) not looking good. This is another marginally hardy plant in our zone. It's mainly native to sandy soils in the Coastal Plain of the Deep South. Perhaps I should have planted it in the spring to give it a chance to get established before it had to face near-zero winter temperatures and ice storms? I may have been doing a bit of excessive zone pushing with this one...(To add insult to injury, I walked by yesterday - after this photo was taken - and saw that deer had chomped off most of the branches. They didn't eat it, they just decapitated the plant, said 'Blech!' and moved on.)

Jasminum nudiflorum (winter jasmine). I'd read that winter jasmine might flower as early as December or January, and perhaps it would if we'd had a couple weeks of warm weather, but with temperatures at or below normal, it started flowering around the same time as the forsythia in mid-March. Bloom was sparse this year, with some of the buds frozen before they had a chance to open. The flowers are cheerful and I like the green stems, but the plant has a reputation for being aggressive in the garden. I'm not terribly enthusiastic after the first winter, but I'll take a wait and see approach and hope I'm bowled over next year (in a good way).

Friday, March 13, 2015

What a Creep!

Creeping raspberry not looking its best. Unfortunately, I've found this mass of dead stems to be a common sight in back-to-back Tennessee winters. Would the plant look prettier in a warmer climate? No doubt. But it would also probably expand faster, and that's a somewhat scary thought for a non-native species with few obvious wildlife benefits. I'd be especially wary of planting this next to any wild areas where it could expand and try to outcompete native vegetation. Oh and notice how despite its rampant growth, it has failed to block out all the love-in-a-mist seedlings poking through in the foreground.

I'm not talking about the iconic Radiohead song from the 1990s, but rather the creeping raspberry (Rubus rolfei, a.k.a. R. calycinoides or R. pentalobus).

I've reported on this plant twice before:

- In October 2013, I was over the moon with anticipation that I'd found the perfect groundcover. I waxed rhapsodic about its merits - the scalloped crinkly leaves, its supposed evergreen foliage, its rapid growth rate and its reported wildlife value (flowers for pollinators, berries for birds and mammals - including people).

- By April 2014, I was singing a different tune after the creeping raspberry died back to the ground in the winter of 2013-14 and took a long time to emerge in the spring. My dreams of a trouble-free evergreen groundcover disintegrated as I clipped back tough raspberry stems with dried dead leaves.

Now it's March 2015 and I've permanently broken up with creeping raspberry. After another colder-than-average winter (8th coldest February on record in Tennessee), creeping raspberry once again had lots of unsightly, dead stems.

After three growing season in the garden, the biggest plant had rooted all along its runners to establish a thick multi-layered patch that spilled out of a bed and onto a sidewalk. All the new plantlets grew so fast that they created maintenance work in the garden as I had to trim back the runners pretty frequently to prevent them from covering the sidewalk. (I'm pretty sure that left on its own, creeping raspberry would have crept right over the sidewalk and rooted into the grass on the other side.)

Creeping raspberry roots all along its nodes. These rooted sections send out their own runners, so the plant self-propagates and expands with ease. Too much ease for my comfort, especially when we're talking about a non-native plant with little obvious wildlife benefit and limited aesthetic appeal.

Those berries and flowers I'd hoped for to give the groundcover wildlife appeal (and provide a handful of fruit now and then for me)? Never saw them. (Well, I saw a single flower the first year I had the plant in the garden, but nothing ever bloomed after that. Perhaps creeping raspberry only blooms on old wood and thus can't flower or fruit in a climate where it keeps getting killed back to the ground?)

Creeping raspberry is a conundrum. Despite its wild and wandering ways, despite its multi-layered foliage, it still doesn't do that great a job of blocking weeds. In fact, I'd say it's least effective at blocking weeds than any of the other groundcovers I'm trialing in my garden (such as lamb's ear, perennial geraniums, creeping veronica, epimediums, ajuga or lady's mantle).

This is a Cambridge geranium (Geranium x cantabrigiense) called Biokovo. So far, I'd say it makes a much better groundcover than the creeping raspberry here in Tennessee. As you can see, it's stayed mostly evergreen through the winter with some nice reddish highlights in the foliage. Unlike the creeping raspberry that forms tough and wiry stems, I've never needed to cut back Biokovo. The last year's foliage slowly fades away and is superseded by fresh new foliage, plus Biokovo gives you weeks of white flowers with pink centers. The dense foliage does an excellent job of blocking weeds and the clump has expanded at a measured pace while staying dense in the center. 

So yesterday I decided it was time to give creeping raspberry the heave-ho. It did not go without a fight. That main clump which had only been in the garden for around three years had set some serious roots. In some ways, it was like trying to dig out a small shrub. To give you an idea, I had a much easier time digging out three (less-established) clumps of Amsonia hubrichtii (Arkansas blue star), no shrinking violet itself, than I did prying creeping raspberry out of the ground.

The trouble I had removing the plant convinced me that I'd made a very good decision to remove it when I did. Given another year or two, I fear this non-native groundcover would have insinuated itself throughout my planting bed, making it much harder to remove it without doing damage to some of the other perennials and shrubs nearby.

So what do I plan to put in its place? I have a couple of ideas. One possibility is Gaillardia x grandiflora (a hybrid between two North American species - G. aristata and G. pulchella - both of which are primarily native to the western United States, although G. pulchella's range does extend naturally into Southeastern coastal regions). Gaillardia x grandiflora has a reputation as being a short-lived perennial, especially on the sort of heavy clay soil that predominates on my property, but I have a few clumps that have fared very well on the other side of the driveway for a couple of years and I like the fact that it flowers profusely for many months during the growing season, attracting bumblebees and other pollinators. It's a very cheerful plant. Even the spent flower stems are attractive, so I leave them up through the winter and then cut the plant back to its basal foliage in early spring.

I may go with gaillardia as a replacement, but I do have a few other options I'm mulling over. Stay tuned!

Thursday, March 12, 2015

Fire and Ice

Well February was a bear -- eighth coldest February on record here in Tennessee, or so they tell me.

The last few days have been a breath of fresh air and I'll soon be posting photos of Spring busting out all over.

But for now, the most interesting garden photo I have on my camera card is from one of the ice storms we got a couple of weeks ago.

Sure ice storms are dangerous, damaging and inconvenient. They do, however, produce some beautiful impromptu ice sculptures...

Salvia greggii 'Flame' not looking so hot.