Monday, March 24, 2014

Boon and Bane

Symphytum azureum is not your grandmother's comfrey. Here it is in bloom on May 9th.

The mass of blue at the top of  the picture is Symphytum azureum on May 4th demonstrating its ability to function as a groundcover and suggesting its potential to spread.
This October 24th picture demonstrates the ability of Symphytum azureum to grow through thick mulch and for its leaves to persist will into the fall.

Symphytum azureum (The common name (comfrey) is very misleading. This is NOT the comfrey that most people know.) It is one of those plants that is both exceptionally useful and a nuisance to get rid of. I am just coming off about a ten year honeymoon with the plant where everything it did pleased me, so I am surprised at how little is seems to be known and offered. Curiously, a Google search brings up mostly sites outside of the U.S. An issue over its proper name may be one reason.

It spreads slowly. It isn't what you would call invasive. Inexorable would be a better description for its slow but relentless spread throughout a suitable growing site. So now after a decade it has reached the boundaries of where I want it to be, but I find it does not come with an off switch.  It would not be very compatible with mixed perennial plantings. I fear it would insinuate itself into most anything herbaceous, although I imagine larger plants could readily grow through it. By the way the web site for the German nursery Lorenz von Ehren says that prompt deadheading will slow its spread.

What has been exciting to me is that it is both attractive and very successful at developing a dense stand under the heavy shade of a sugar maple and a massive Norway spruce. For the very patient or the free spender it makes a great groundcover for the shade. The catch is that it must be contained (or perhaps diligently deadheaded).

On the whole it is a very useful plant that would bring considerable joy to gardeners, especially where an attractive solid stand of a highly shade tolerant groundcover is wanted.

Monday, February 17, 2014

Inverted Growing Season

Cyclamen hederifolia flowers emerging through Carex platyphylla foliage in September

Cyclamen hederifolia in full leaf in mid January, finding plenty of growing room, growing with the dormant Carex platyphylla seen in the previous image

Arum italicum fruiting in August with conspicuously dormant leaves.
Dentaria (Cardamine) diphylla still looking fresh in March after being around all winter and before going dormant in the summer
Sternbergia lutea blooming in the fall as its leaves emerge from dormancy

I grow at least four perennials that emerge in the late summer or fall, remain green all winter and then go dormant as summer approaches (Dentaria (Cardamine) diphylla, Arum italicum, Sternbergia lutea, and Cyclamen hederifolium). Weird. I suppose that makes sense in a Mediterranian climate where the winters are mild and moist and the summers are hot and dry, and that is exactly where three of these four are native.  But somehow they survive in climates with cold winters and relatively moist hot summers.  Dentaria diphylla, on the other hand, is native to the eastern U.S. So where did it acquire this inverted growing season behavior? I bring this up not for botanical reasons but rather horticultural. How do you take advantage of this habit to enhance your garden? I mean, what a gift to have plants that grow when others aren't. They need to be paired up with compatible companions, but there's the rub.

I pride myself in my efforts to orchestrate the sequence of emergence and decline of perennials in my garden and have several combinations that I shamelessly tout as exemplary. But, alas, this growth habit I am calling "inverted" is challenging. I think I found a nice combination for the Cyclamen. I combined it with Carex platyphylla (Silver Sedge). The sedge is low growing enough that when the otherwise dormant Cyclamen sends up its flowers in mid summer they poke through the sedge and make a nice display. As the Cyclamen leaves are emerging late in the growing season the sedge leaves make room for them as they go dormant. It is all very tidy, but I haven't been able to do anything comparable with Arum italicum or especially Dentaria diphylla. (For hardiness reasons I grow Sternbergia in a pot.)  Arum italicum produces stalks with bright red fruit in August when the leaves are gone. It makes an interesting affect on bare ground, so there is a reward for not finding a sort of mirror image growing companion, but I would be more satisfied if I could. I have been growing Dentaria diphylla for six or seven years and only recently realized why it was so unsatisfactory in the summer. I just have to apply myself to this challenge. That (and so much more) is what I love about gardening.

Friday, December 20, 2013

Old Dwarf Conifers

Those cute little balls of evergreen dwarf conifers seem like they will be small forever, but eventually, of course, they get big. It is sad, sometimes to see old dwarf conifers that have never been pruned because many varieties are so dense they form a solid but shallow encasement of foliage that reveals none of the plant's branching architecture. I did a program recently on dwarf conifers and dug up many of my old slides which included pictures of old plants that, because of their dwarf and slow growing nature, had acquired an interested sort of aged look to them. I am eagerly pruning my own dwarf conifers to try to accelerate that look.

An Austrian pine (Pinus nigra 'Nana') seen many years ago growing at the National Arboretum in Washington D.C. had acquired a venerable and distinguished look while remaining within a reasonable scale for most landscapes.

Japanese umbrella pine (Pinus densiflora 'Umbraculifera') is not a dwarf, but it is a fairly small, slow growing tree a with distinctive growth habit. If it isn't pruned it grows into a very uninteresting solid mass of foliage. The plant pictured above, as seen many years ago at the Cincinnati Zoo had been beautifully pruned to show off its many attractive features such as the orange bark, vase shaped growth habit and flat topped branching.

This dwarf eastern white pine (Pinus strobus 'Nana') also seen a number of years ago at the National Arboretum in Washington D.C. has a fascinating form that in a better setting and without the gravel and ring of exposed edging could be the centerpiece of a wonderful garden composition.
My own dwarf eastern white pine is only eight years from the container nursery and already I think it is starting to show some interesting branching habits that will only become more interesting with age if I prune with care. It may be hard to imagine, but shortly before taking this photograph I opened up the interior of this plant and removed a great number of branches.

Thursday, November 21, 2013

Growing Weird Plants

I like to grow weird plants like Ephedra, and they can be considered weird for any number of reasons. Anyone who studied plant taxonomy would have to consider Ephedra weird because it just doesn't fit into the preconceived notion of a cone bearing gymnosperm. It seems like a remnant of evolution. They are also unusual for their essentially leafless habit, although in their typically arid habitats, that trait is shared by many. Finally the alkaloids contained within the plant have a long history of use and abuse which gives the plant special interest. Gardeners are often collectors, and there is great pleasure in being able to say, "Oh yea, I have that."

When I was thinking about whether to include this plant in my blog I checked the Internet for images of Ephedra minima, which is the one I have been growing since 2008. Most pictures show the red fleshy cones, which I also illustrate, but I didn't see any with the interesting growth up a vertical crevice with the leaf-like switches lined up in a similar vertical orientation as if the plant is flowing up the rockery. My weird plant also makes a nice aesthetic contribution to my rock garden.

Thursday, October 17, 2013

My Flat, Rock Garden

I love my tiny garden compositions. Judging by the current enthusiasm for fairy gardens and ongoing enjoyment of gardens for model trains and terrariums diminutive garden compositions seem to be popular. I guess I get my diminutive garden outlet through my rock gardens and in particular, for the sake of this edition of my blog, through my flat, rock gardens. One in particular has proven particularly satisfying, so I am in the midst of expanding and improving it. The photographs below portray a sampling of some of my favorite inhabitants.

I have access to a quarry's scrap sandstone rocks that typically have at least one flat side and are about four to eight inches thick. They are otherwise irregular.  I lay these down like a patio leaving abundant planting gaps where the irregularly shaped rocks don't fit together. I backfill with sandy loam soil.

Above is one of my favorites in this garden, Veronica prostrata 'Wine'. Although the growing conditions are very different from alpine screes, to me this sort of scene reminds me of that rocky, sparsely vegetated landscape.
This tiny clump of Lewisia 'George Henley' (above) is my only surviving Lewisia and it has been growing as this little clump for about seven years. Those sandy cracks between the rocks must be well drained, because I think my Lewisia growing in other sites died from winter wet. Its biggest threat is from encroachment by the neighboring Dianthus. See below.

A dilemma that always seems to loom for me in my rock gardening is what to do with expansive plants such as the above Dianthus gratianopolitanus 'Feuerhexe'. I relish its success in the site but don't want to lose the precious little specimens it engulfs. A balance must be struck and I have been brutally whacking the Dianthus back lately. Notice the above mentioned Veronica prostrata in the lower right hand corner for a size perspective.

I thought I had lost my fall blooming, questionably hardy Leucojum autumnale (above) from this garden, but I was thrilled this fall to find it growing and in bloom.

I had also been missing the flowers of my fall blooming crocus (Crocus kotschyanus)(above) from this garden but it appeared in good blooming order this year. I saw the spring leaves but have had problems in other gardens losing track of these little plants in mid summer after the leaves disappear. I think in this case the flowers were obscured by floppy bordering plants such as the Japanese anemone seen here. I have since beaten them back.

And finally, I want to mention this long time survivor of this garden pictured here several years ago before the stones became weathered and moss covered. This year's photographs of the plant don't do it justice. Its Antennaria dioica 'Rubra', a red flowered selection of a common native inhabitant of thin infertile soils around here. My rockery seems to suit it just fine and its another example of how I don't get too hung up on beating my head against a wall trying to grow true alpines in my hot humid climate.

Friday, September 20, 2013

Long Term Investments

These four dwarf confers (Pinus cembra 'Blue Mound') have been growing in my garden for eight years and are now ready to be pruned into something of interest.
This dwarf conifer (Pinus parviflora 'Miyajima') (next to the phlox) has also been growing in my rock wall for eight years. It was difficult to get it established in the thin lines of soil between the rocks, but now it should be perfect for sculpting as it continues to grow.

I have been growing a cluster of four dwarf conifers (Pinus cembra 'Blue Mound') for eight years now (top picture). I planted them with the notion that eventually I would like to make a landscape scale grove similar in concept to bonsai groves that I so admire. Inspiration for exactly what that should look like has not yet hit. Finally, however, they are getting to a size that I can start forming them into something of interest. My long term investment is beginning to pay off. I have the raw materials in hand to make something interesting of this little grove.

I have several other dwarf confers that all represent similar long term investments. Most are in rock walls (such as the bottom picture above) where I hope to make them into something like the wind swept confers (Krummholz) seen at the tree lines of tall mountains or the confers growing out of rock faces hanging on to tiny cracks in the rocks. A couple have been "in training" for a couple of years, but others are so small they can hardly be shaped yet. I lost a few initially that just couldn't get a toe hold on the rocky retaining wall, so it is gratifying to now have some well established plants in a difficult site that are getting to a size that they can be the objects of my artistic ambitions.

Friday, August 23, 2013

Even a Blind Pig...

I am not ready to shout, success!, but I do think this unlikely combination in the top picture looks kind of cool. It is Hibiscus 'Robert Fleming' and Clematis 'Mrs. Robert Brydon' growing at Kingwood Center. As an administrator I don't get many opportunities to garden at work, but I do have a few beds to tend, and I try to do weird things that are unlike what the other gardeners are doing. My efforts fall flat all too often, but I want the gardeners to experiment and try new things. Maybe if they see me doing it, and eventually succeeding, they will be emboldened.

We had Clematis 'Mrs. Robert Brydon'  for sale at the Greenhouse for two years and could hardly give it away. That is one reason I made a point of using it in the garden.

On the other side of the bed I am trying to do something similar, but instead of using 'Mrs. Robert Brydon' as the groundcover I am using Indigofera pseudotinctoria 'Rose Carpet' (Dwarf False Indigo). When I took delivery from our local supplier I noticed that he gave me more than I ordered. He said he couldn't sell them (I see a pattern here.), so he just give me the last of his supply. The first year they looked great and full of flowers as illustrated in the bottom picture, but I discovered they die back hard in the winter. The good news is the Indigo has come back vigorously in year two and has self seeded. I am counting on a robust groundcover eventually.

To me this is the sort of stuff that makes gardening fun.

Wednesday, July 31, 2013

Veratrum nigrum (Black False Hellebore)

Plants can be desired because they are rare, beautiful, fruitful, shade giving, architectural and so forth, but I also love plants that are intriguing. One of those intriguing plants is blooming right now in my garden and I feel a compulsion to share my enthusiasm for it. I can't say it is especially beautiful, although it is striking. Imagine coming across a patch of these in some remote Asian meadow. Who wouldn't be drawn to it? Perhaps I find it intriguing for its deep maroon flowers, pleated leaves and stark inflorescence, but that doesn't seem sufficient. Maybe it is because I have just the one and it has made itself a fixture in my garden since I bought it from Arrowhead Alpines nine years ago. I don't know, but I do relish it and why not? The flowering of my Veratrum nigrum is always a special event. How many other plants can offer that?