The other dogwoods

The dogwood that is native to the eastern United States (Cornus florida, in bloom below) is a wonderful tree with beautiful large white flowers in early spring (actually white bracts that surround the small, undistinguished flowers), excellent autumn foliage color, and clusters of red berries that persist into early winter when birds pick them clean. Unfortunately, even improved selections of the native dogwood are susceptible to a variety of maladies that can disfigure or kill the tree. In my garden I’ve planted several dogwoods that suffer from moderate to severe leaf spotting (anthracnose) in wet springs, and powdery mildew in hot, muggy summers. While this is hardly cause for concern, two large dogwoods have various small and large cankers that will eventually spell their doom, though they’ve survived for twenty years so far, and I don’t regret planting them for a moment.

A variegated leaf selection of the native dogwood, ‘Cherokee Sunset’ (below) has splendid yellow and green foliage and red blooms, though it hasn’t flowered in my garden for the past five years (at least). Plants with colored and variegated foliage are often slower growing and less vigorous than the green leafed versions (due to less chlorophyll), and with dogwoods I believe this makes the tree less tolerant of foliar diseases. Though its foliage is beautiful through the spring, by mid summer I take for granted that ‘Cherokee Sunset’ will be covered in mildew, and I’m guessing this disturbs the tree in forming flower buds for the following spring.

Last year I planted several dogwoods with similar green and yellow variegation that are vigorous growers, and are resistant to the disease problems of the native. ‘Celestial Shadow’ (Cornus x ‘Celestial Shadow’, below) is a selection from the Rutgers University introduced hybrid dogwood ‘Celestial’, which is a cross between the native Cornus florida and the disease resistant Chinese dogwood (Cornus kousa). The native Cornus florida typically flowers in mid April in my garden (though it started in late March this year), and Cornus kousa usually begins to flower in late May, though sometimes it’s delayed into early June. The Rutgers’ hybrids flower right in the middle of the two parents, typically mid May, but this year the flowers are evident late in April.

The Chinese dogwoods (Cornus kousa) add vigor and disease resistance to the early flowering genetics of the native dogwood, but their form is often shrub like, and only a few selections grow taller than wide. Chinese dogwoods are usually low branched or multi trunked, and along with late spring flowers this helps explain why they are not more popular in American gardens. The Rutgers’ hybrids are fast growing, but their growth is more upright and tree like, and only after a number of years do they spread to be as wide as their height.

The flowers of Rutgers’ hybrids are commonly larger than the native dogwoods’, and the blooms of ‘Venus’ (Cornus x ‘Venus, above) are huge by comparison. ‘Venus’ is a cross between Chinese dogwood and the tall growing Pacific dogwood (Cornus nutalli). It grows quite upright at a young age, and on an eight or nine foot tall tree the flowers look oddly out of scale. After a few more years the tree grows to balance the blooms, but the salad plate sized white flowers still attract considerable attention.

The first of the Rutgers’ dogwoods I planted was ‘Stellar Pink’ (Cornus x ‘Stellar Pink’, above), and in early years after planting it was quite a disappointment. I concluded at the time that it would flower sparsely, since young trees did not flower as heavily as either the native or Chinese dogwoods. My mind was changed in a couple years, and I noticed last spring that it was difficult to see foliage behind the flowers of ‘Stellar Pink’ until they faded several weeks later. When I first saw ‘Stellar Pink’ in an Oregon tree nursery the flowers were a full and deep pink, but I’ve discovered that with warmer early spring temperatures in Virginia the flowers are mostly white, with just a blush of pink.

The foliage of the Rutgers’ hybrids remains clean and vigorous through the hottest and most humid summers, performing better even than the Chinese dogwoods. I will always treasure my small collection of native dogwoods, but I’ve also learned to love the hybrids. For many gardens they will be a superior, long lived, and low maintenance tree.

Japanese maples in bloom

There are dozens of flowering plants in the garden today, but I couldn’t let this week pass without showing off the emerging foliage and flowers of some of the garden’s Japanese maples. Most people don’t think of Japanese maples as flowering, but in fact most trees have flowers of some sort, it’s just that many aren’t very ornamental so they’re barely noticed. Some Japanese maples have flowers that are tucked beneath the foliage, some match the color of the leaves so they blend in, but others are more obvious. None are ornamental enough to be seen at a distance of twenty feet, but I enjoy them in any case. I make a point to visit them frequently through the spring, and I particularly favor several maples that have flowers that contrast with the new foliage.

Later in the spring I’ll take a longer look at the Japanese maples in the garden, but for today, here’s a sampling of flowers and foliage.

The leaves of Golden Full Moon maple (above) emerge a few weeks later than other maples, but it’s worth the wait. It is often recommended to plant to shelter the tree from the late afternoon summer sun, but mine is planted in nearly full sun with no problem.

Fernleaf maple (above) is one of my favorites. The flowers are the largest and showiest of any of the Japanese maples. The common name perfectly describes the foliage, and for six weeks in the autumn this is the most spectacular tree in the garden. 

The foliage of Scolopendrifolium Japanese maple (above) is a mid green, but the deeply cut lobes and graceful form earn this fast growing tree a spot in the garden.

For the smallest garden ‘Shaina’ (above) is the perfect Japanese maple. After five years ‘Shaina’ is barely three feet tall.

‘Viridis’ (above) is a low mounding, wide spreading green leafed dissectum Japanese maple. Its branches arch over the first of five ponds that I built in the garden, so that it has to be carefully pruned each year to keep its graceful form without allowing it to overwhelm the small pond.  

‘Gwen’s Rose Delight’ (above) is sold under the trade name ‘Shirazz’. In spring the red leaves are bordered by a thin pink edge that fades by mid summer.

The variegated leaf ‘Butterfly’ (above) emerges early, and new leaves often feature a bit of pink that fades as the leaves mature. 

‘Bloodgood’ (above) is the standard of red leafed, upright growing Japanese maples. The newly emerged foliage in the photo will flatten out after a few weeks.

Black locust in bloom

Bordering my garden is a thicket predominated by black locusts (Robinia pseudoacacia, flowering below), willow seedlings, mulberry, and pernicious vines. Long ago I aspired to keep this area cleaned up to claim as part of the garden, though it’s outside my property. I’ve been mostly successful managing the long stretch of forest that borders the garden, but the area with the locusts and willows is constantly damp, and the wild seedlings and tangled vines have proven more than I can handle.

My goals have shifted to tolerate this weedy patch of trees, but to try to prevent them from encroaching further into the garden. A few times a year I chop back vines and stray mulberry branches, but I steer clear of the thorny locusts. For a few weeks in late April and early May my caution is rewarded with intensely fragrant, white wisteria like blooms that nearly make the black locust tolerable.

Years ago I was seduced by these splendid flowers to plant a somewhat domesticated cultivar of the locust, the yellow leafed ‘Frisia’. It grew vigorously, though it flowered more sparsely than the nearby natives. Finally, it proved too wild, seeding and suckering, and growing wide to occupy space reserved for a more precious Japanese maple. So, it was chopped out. Left behind were roots that suckered for several years until I dug and chopped out every remnant, and seeds that sprout ten years later.

When I read overzealous native plant enthusiasts lauding all plants native as mild mannered, low care, disease and pest resistant I chuckle over my battles with the locust. The woodline beside the garden is littered with trunks of locusts that have succumbed to disease, but not before seeding and suckering to spread this thorny thicket. So, the black locust is beautiful in flower, but has little ornamental value when not blooming, and is aggressive and short lived. Enjoy it in flower today along the roadside, but be cautioned against planting one in your garden. 

A considerably gentler native tree is the fringetree (Chionanthus virginicus, above) that flowers a week or two later than the black locust. It has no thorns, and doesn’t spread uncontrollably by seed or sucker. I’m quite certain that its only fault is that it flowers too briefly. At every other time of the year fringetree is unremarkable, but for a week in early May (late April this year) the small tree is covered in magnificent white, fringe-like blooms.

Fringetree is usually grown as a multi trunked tree or as a large shrub. Even when purchased as a single trunk tree it will annually grow a sucker trunk until you give up and let the tree have its way. Once an additional trunk or two is allowed the suckering ceases, so there is no danger that fringetree will spread itself through the garden. It is mild mannered, and other than a mild case of leaf spotting in a rainy spring, I’ve seen no pest or disease problems. If planted in a prominent location (and there’s no reason to plant fringetree elsewhere), this is the kind of tree that brings the neighbors over to ask “what is it”, and “will it live in my yard”?

Too much moisture, too little, and just right

The dwarf crested iris (Iris cristata ‘Tennessee White’, below) is a vigorously spreading native to woodlands and along streams in the eastern and southeastern United States, so the gardener would suspect that it grows best with abundant moisture, and perhaps some shade. But, the iris grows best in nearly full sun, and I’m afraid that I’ve surpassed its tolerance for soil dampness. In the prolonged rainfall in September last year the soil in the lower garden remained saturated for a month or longer, and I was afraid that ‘Tennessee White’ had disappeared.

For a few years the low growing iris clump doubled in size annually, but by October last year the foliage had faded, and I feared that it had rotted in the wet soil. There was no sign of the iris until a few weeks ago, and now the clump has diminished substantially. There was one flower, but I’m happy at least that it survived, and I don’t figure that we’ll have another September with twelve inches of rain to worry about for awhile.

The flowers of ‘Tennessee White’ are supposed to persist longer than other dwarf crested irises, but this single bloom only stayed around for a few days, so it was disappointing. If there was another spot that had ideal conditions for the iris I would move it, but there are few areas with enough sun to please it, so I’ll take my chances on leaving it where it is. Sometimes a plant is left in unfavorable conditions to eventually perish because it is too much work to move it, but the tiny irises would be scooped up with a single swipe of the trowel.

In nearby soil that is waterlogged through much of the year the clump of Spanish bluebells (Hyacinthoides hispanica, above) merrily increases in size each year. This spring has been quite dry, but the bulbs sprouted and flowered without a care in shallow standing water in last year’s wet early spring. I’ve read that they can be a bit invasive in damp conditions, but I’d be happy if they were to spread far beyond the small patch where they are now. There’s a hundred feet of low lying, wet ground to cover before the back end of the garden, and the bluebells are welcome to cover every inch before I’ll be concerned about them being too invasive.

I occasionally read that bugleweed (Ajuga reptans ‘Chocolate Chip’, above) can become too aggressive, but I’ve had trouble with it surviving, probably because I’ve tried to push it into dry shade when it prefers more moisture. A few years ago I planted a variegated leaf bugleweed in the shade of the large purple leafed beech in the front garden, but it didn’t survive the year, even with soil that was heavily amended with compost. Under the beech the soil remained dry, no matter how much compost was worked in. Now, I’ve planted the small purple leafed ‘Chocolate Chip’ across the stone path, only a few feet away, and with a bit of sun, and less competition from roots to rob moisture, the bugleweed is content and spreading quickly. If it grows well enough to be just a bit of a problem, I’ll be satisfied since it’s a wonderfully colorful groundcover with superb blooms in April.

I’ve discovered countless times that native plants are just as likely as any other plant to fail if planted in the wrong conditions, and I’m happy to report that I’ve finally succeeded with large-flower bellwort (Uvularia grandiflora, above) after a few failed tries. In the past I think it’s been too dry, and then too wet, but the latest plants have settled in for a third spring now, so I think the bellworts are here to stay. The spot is a little shadier than I’d like, so perhaps they won’t grow as quickly as I’d prefer, but I’m not arguing with success. Bellworts are susceptible to grazing by deer, but I’ve planted them alongside a small bluestone that is bordered by hostas and hellebores, and the deer seem reluctant to walk on the slick stone surface so I don’t have to spray a repellent in this area.

I don’t know that spurges (Euphorbia) as a whole prefer bone dry ground, but whenever I’ve failed with them the soil was slightly damp, though not close to what I would consider wet. There are numerous varieties available, and in dry shade or sun they flourish in my garden. The fifteen inch tall Robb’s spurge (Euphorbia amygdaloides var. robbiae, above) spreads vigorously through root infested shade beneath tall maples and tulip poplars, though it is easily controlled when it pops up through the stone path. I don’t know how the rhizomes can pass under and around the large roots that prevent me from planting anything else in this area, but I’m happy to fill the space with such a long blooming and carefree perennial.

In full sun at the other end of the garden threadleaf spurge (Euphorbia cyparissias, above) meanders contentedly through granite boulders and river gravel that border the large swimming pond. This spurge can be quite aggressive (I’ve read), but here it is bordered by larger evergreens and a stone patio that keep it within bounds. In late March through April the yellow flowers contrast nicely with slightly reddish foliage, and even when the blooms fade the foliage is effective through the heat of summer.

Beside the spurge in the dry shade variegated Solomon’s Seal (Polygonatum falcatum ‘Variegatum’, below) has spread slowly into a nice clump. By mid April the arching stems are lined with tiny white bells for a few weeks, and then the white striped foliage looks fresh through the driest periods of the summer. I don’t know how Solomon’s Seal would fare if given more favorable soil and a bit more moisture, but in dry shade it performs admirably. 

Sweetshrub and other April flowering shrubs

Sweetshrub (Calycanthus floridus, below) is native to much of the eastern United States. It’s not commonly found in gardens due to its unremarkable form and foliage, but I’m certain that it deserves greater consideration for shrub borders, and particularly for plantings at the partially shaded edge of wooded spaces. Sweetshrub’s April flowers are distinctive, though a bit unusual in color (reddish-brown) and form, but they are notably fragrant and long lasting. Planted in full sun the shrub will form a compact, six foot tall spreading mound, but in a shady situation it will often be considerably taller and open branched.

In my garden I’ve planted several sweetshrubs in the dense shade between a tall blackgum and bigleaf magnolia, so they have grown to nearly eight feet tall. The branching is very open, much as I would expect from any shrub planted in the forest’s understory, but the shade does not deter flowering so that every branch tip carries a flower or two.

Somewhere through the years I saw a photograph of a yellow flowered sweetshrub (Calycanthus floridus ‘Athens’, below), and when my son was in grad school at the University of Georgia my wife and I often visited the gorgeous state botanical garden nearby where several were prominently planted. As often happens, I fell in love at first sight, and kept an eye out to purchase one for my garden. Several years ago I found a couple that I planted in the shade of the bigleaf magnolia, but lazy idiot that I am, one perished within weeks when I failed to water it. Fortunately, the other survived my neglect, and now it gets along without any care at all.

The yellow sweetshrub flowers a few weeks later than the red, even though the yellow gets a bit more sun. I usually figure that more sun will result in earlier flowering, but that’s not the case with the yellow flowered sweetshrub, and whether it is truly later blooming or just in my garden, I don’t know. References say that the yellow flower is more fragrant than the red, but I can’t tell any difference, though my sense of smell is horribly lacking. Some days I can smell one or both, and the next day neither. This lacking I blame on myself, not the sweetshrubs.

In any case, as often happens when love is rushed, the thrill wears thin sooner than later and now I prefer the red flowered sweetshrub. The red has glossier, darker green foliage than the yellow, and though this is likely to be because of where I’ve planted it, the simple fact is that the red looks a bit better.  Both are wonderful, and I don’t mind that they grow with a sparsely branched, open form in the shade. In fact, there is no plant in my woodland area that I favor more. Many shrubs don’t flower at all or grow well in similar circumstances, and for the fragrant and unusual blooms alone sweetshrub is worth growing.

Beside the red flowered sweetshrub I’ve planted a red bottlebrush buckeye (Aesculus pavia, above), and though it was quite open in form when young, now it has filled in considerably. It’s compound leaves are large and glossy, and it has become quite attractive in this wooded area, even when it’s not flowering. The red flowers are superb, but short lived by comparison to the sweetshrub.

Black chokeberry (Aronia melanocarpa, above) is native to much of the eastern United States, but it’s habitat ranges from wetlands to dry hillsides. I’ve planted several in an area of the back garden that is fed by a trickle of a spring so that the subsoil remains damp, even when the surface appears dry. In this difficult area chokeberry and buttonbush (Cepahalanthus occidentalis) thrive. To my thinking, neither plant is well suited to the front of the garden. They tend to be irregularly shaped, and lower branches are often bare with foliage only on the upper half of the shrub. However, irregular shape and bare lower branches don’t mean that the chokeberry is ugly, and its flowers and fruit are also quite nice.

Here comes trouble

My wife took a break from her studies yesterday to take a stroll through the garden. Since she has gone back to school for a mid-life career change she doesn’t spend much time outdoors, which is fine with me since she usually has a few “suggestions” for me. She instructs me to prune this or that to keep the paths open, and threatens that if  I don’t she’ll have to take care of it herself. When I come home with a bunch of perennials, or when a mail order package arrives, she’s horrified that I could be jamming more plants into the garden. I’ve been instructed more than a few times that there’s no more room, and “no more plants”!

Fortunately, she was preoccupied on her cellphone yesterday, so she steered clear of me while I was planting. I think she barely noticed what was going on since she didn’t have any comments for me afterward. The big leafed hostas have just begun to spread out, so they haven’t take over the paths yet, but there are nandinas and spiny mahonias that I have to duck under and around, and I didn’t hear a word about them.

I spent a good part of the day planting, and of course there’s still plenty of clean up to be done, so I was working on a few of the bigger messes. The winter weeds really got out of hand this year since I did nothing through the winter, so I’m slow in catching up. Although the redbud and dogwood blooms are fading, the period from the middle of April to mid May is my favorite time in the garden. Everyday there are new blooms on something, and as the shrubs and perennials burst into leaf they hide much of the garden’s untidiness until the piles of leaves and branches decay and disappear on their own.

The Japanese maples have leafed several weeks early this year, and it’s fortunate that they have escaped injury from the recent freezes. In past years I’ve found that there is a couple day period when the leaves have just emerged when the foliage is particularly vulnerable to damage, but for my garden the timing worked out fine. Other local gardeners were not so fortunate, and I’ve found that Japanese maples are very slow to recover from frost or freeze injury. When new leaves are lost to a freeze the tree will usually leaf again, but very sporadically so that branch tips die back, often severely. The dead branches will require pruning, and probably a few more years before they return to good health.

Most of the Japanese maples in my garden are now flowering, and I’m certain that few people consider for a moment that they flower (above and below). I treasure the dainty blooms, and make a point to visit the maples often just after the new leaves open. 

I hope that I’m a week or two from having the garden back in shape, at least the shape that I’m satisfied to live with. There are some messes that have been around for a few years, and it’s unlikely they’ll be addressed this year (or any other year). If I can keep my wife occupied, and indoors, my work list will be much shorter, and I’ll be much happier, even if the mahonias occasionally draw blood as I squeeze past.

A redbud seedling

In my garden I’ve planted a bunch of redbuds (Cercis canadensis), but none are the standard green leafed variety. I have nothing against green. There is a green leafed weeping variety (‘Lavender Twist’), but the others have variegated foliage (‘Silver Cloud’), or yellow (‘Hearts of Gold’). ‘Forest Pansy’ leaves emerge a glossy reddish-purple (below), and then turn to purple in May. Through the heat of the summer the foliage will often fade to reddish-green, though it remains quite attractive.

The various colored leaf versions of redbud are mostly natural mutations, and not hybrids where the genes of one tree are crossed with another. Whenever a redbud seedling pops up in my garden, it always (almost always) has green leaves, but if there were a thousand seedlings it’s likely that a few would have a different leaf color or other variation of some sort. When an experienced plantsman with a keen eye spots an anomaly he will flag the tree and grow it on to see if the unique characteristics are stable, but also to see if the tree has sufficient vigor to survive in a garden.

If all grows well, the plantsman will nurture the tree for years until he can tell if the tree is significantly different and better than existing varieties. If so, is there a market to sell the tree? If, if if, there are lots of if’s, but for most interesting mutations there are more but’s so that the tree remains a one-of-a-kind. So, now the plantsman has figured that the tree is different, arguably better, and with has some degree of marketability. How do we make more?

This is not so simple. Most seedlings from the tree will look nothing like it, so the tree must be cloned. Some plants are propagated by tissue culture where plant tissue is grown in a laboratory, but a redbud is likely to have a  small cutting taken that will be grafted onto the root stock of a plain green redbud. The process is slow, and it can take a decade to grow the first batch of trees ready for market.

I’ve recently discovered a glossy red leafed redbud seedling (below) growing in my garden. Is it ‘Forest Pansy’? There’s little doubt that part of the new tree’s genetics came from the nearby ‘Forest Pansy’, but there’s another half that contributes to the genes of this tree, so while the seedling might look like a ‘Forest Pansy’, it’s very unlikely that the trees will be identical.

What will I do with this little red leafed redbud? It has sprouted about five feet from a Japanese maple, and I’m not tempted even slightly to move the maple. So, the two are too close together. I suppose I’ll let the redbud gain a bit of strength this spring, then dig it out when the ground is damp and more rain is expected to reduce shock from the transplant. I’ll find a spot to plant it with a little more space that’s partially shaded, and then I’ll wait. After a year or two there might be enough information to decide whether this young tree is just a curiosity, or if it has some value.

Most likely the red will fade (probably worse than ‘Forest Pansy’), or there will be some other defect so that this redbud’s only value will be inspiration for stories that I tell. There are hundreds of Japanese maple seedlings that pop up in the garden every year, and with genetics of the twenty four varieties in the garden a few could turn out to be something of interest. But, other than a few seedlings I’ve given away to friends and family, the others get pulled out and discarded. What am I going to do with a few hundred seedlings each year? The same fate is likely for my little red leafed redbud.