Saturday, April 26, 2008

Spring Rolls on in Fern Valley...Yellow Lady's Slipper

Cypripedium parviflorum, the Yellow Lady's Slipper is the easiest of the "showy" native orchids to grow in the garden. When we moved into our house a long time ago, I noticed a few plants growing near the play equipment at our neighborhood park. I am proud to say that they are still there. I didn't dig any and as far as I can tell no one else has either. Many of our native orchids have had and continue to have their populations ravaged by collecting. Don't collect and don''t buy collected plants.

You don''t have to! Every year there are more suppliers on line that sell nursery propagated plants. Don't be fooled by the phrase,"Nursery grown". It can mean, and usually does mean, that the plants were ripped out of wild populations, potted up, spent a little time in the nursery, and then on to market! Disingenuity at its finest.Out of Carversville, Pennsylvania, The Wild Orchid Company, owned and operated by William Mathis, publishes a small list of both native and non-native orchids that are not wild collected; they are largely sold out now, but, buy his book, The Gardener's Guide to Growing HardyPerennial Orchids, build some of those specialty beds, and you'll be ready to plant next year.

Timber Press has also published a useful book on growing hardy terrestrial orchids, Growing Hardy Orchids, by John Tullock. I haven't written anything about Timber Press yet. Wow. There are two things that I love particularly; plants and books. I am thankful every day that Timber Press exists.If I was omnipotent and could invent a lineup of books, and control the subject matter, the quality of writing, the illustration, and the layout, I couldn't do any better than they do. Sitting here at my keyboard I can look up and see, oh about 200 of their titles. And there are more I need.

Thursday, April 24, 2008

Plenty of Rain in Washington...Not so much in Florida

We had almost 3" of rain in Washington last week. That's great. It hasn't rained in Wildwood since we left. It is a sort of helpless feeling knowing you have a garden 900 miles away with newly planted plants and no water. The internet makes it easy towatch the weather anywhere. I monitor Wildwood, Florida and I haven't seen any rain since we left. And there is no rain in the 15 day forecase.

I did realize at some point that we had to use xeric plants. We killed a few Tibouchinas and the Hibiscus suffer mightily during the dry winters. Florida scrub plants work well and we lhave a lot of them, This time we planted specimens from dry lands all around the world. Plants from Australia, South Africa. SW US. There is no rain in the winter, I am not there to water, and the soil is sand and holds no moisture. These plants need to be self sufficient. I am not worried. The Bismarckia will be fine, as will the Xanthorhoea and the Dasylirion. I'll only lose plants that oughtn't to have been there anyway.

Gardeners are beginning to look for plants that are more heat and drought tolerant as Global Warming surges forward. I have always had an interest in "Mediterranean plants", from those areas in Chile, Australia, S. Africa, S. Califonia, and S. and E. of the Mediterranean Sea. Traditionally xeric plants have come from these area. The climate is characterized, broadly, by cool wet winters and dry summers. In Washington we have sometimes cold winters and that eliminates a subset of these plants. Summers while often dry can occasionally be quite wet further limiting the usefulness of some Mediterraneans. Finally our high humidity is the kiss-of-death to more. Still some are adaptable.

The plants that really look promising for us though are the non-wetland plants of the SE Coastal Plain. They expect high humidity to go with summer's heat. As Global Warming nudges average temperatures up, most of these plants, excepting the sub-tropicals of peninsular Florida, move into our range. We should all thank Woodlanders, an excellent Nursery in Aiken, South Carolina for tirelessly discovering, propagating, and retailing many of these plants. They are an incredible resource.

Oklahoma State Tree...Eastern???Redbud

The garden that I am primarily responsible for is Fern Valley, but I work 2 days a week in the National Grove of State Trees. The Grove is a collection of state trees. We can't do Hawaii, and predictably have a lot of trouble with Alaska and not so understandably with Washington state. We, I would love to say I, do a good job with Oklahoma. The Eastern Redbud, Cercis canadensis, is the state tree of Oklahoma. These trees pictured are the Oklahoma display in the NGST. Most of the state trees don't put on this kind of a show. They're may be majestic, stately, or grand, but not showy. Virginia and Missouri have the flowering dogwood as their tree and they are small but beautiful too. when they bloom.

Redbuds are showy and are native pretty much everywhere from the tall grass prairie to the Atlantic Ocean. They are happy in deciduous shade, full sun, or anywhere in between. They don't always, or even usually live a long time as they are plagued by a variety of fungal diseases. But hey, they grow fast. They reseed around themselves. They are tolerant of a wide range of conditions. They flower together before the deciduous canopy has filled in; driving through Rock Creek Park when they are in bloom, you can pick out every tree from your car going 35 or 40 mph, whatever is legal on the parkway. There are selected cultivars, white flowered or weeping, or variegated, and they are nice, but the species is nice too.

Spring colors are often either yelllows or in the redbud, pink/purple range. Good companion plants for redbud are native phloxes either Phlox subulata, divaricata, or stolonifera. A non-native that mixes nicely with Redbud is Lunaria annua, moneyplant.

Wednesday, April 23, 2008

Native Azaleas are the Best...Fern Valley 4/23

One of the things that I get sick of reading or hearing is, "it had to go to Europe and they had to develop it before we could appreciate it." Wow. That is so condescending and so wrong. And do we think that, for example, all those Helenium cultivars are so special? I don't think so. And I don't think the European selections of our native grasses are enough to make us give up the species. Hey, the Germans do pick a special plant here and there, but so does Tony Avent. Lets not just concede European sovereignty.

Oh my. For years the only incarnation in which our incredible native azaleas occurred was as a part of the Mollis/Exbury hybrid complex. And while these are good plants, tell me why anyone would not want to grow Rhododendron austrinum (pictured), the Florida Azalea. Intensely fragrant flowers in colors from yellow to orange bedeck this ~7' deciduous shrub in early/mid April. This is a stand alone plant. It doesn't need to have rose highlights, or more subtle color shading. Disease and pest resistant, it has no issues with lacebugs or petal blight. And there are other wonderful native species. Not difficult. Many fragrant. Others that bloom in July and August. Try Rhododendron arborescens, or atlanticum, or cumberlandense, or calendulacea. The commonest azalea in the woods hereabouts is Rhododendron periclymenoides. Its a great plant. just one of a number of great native azaleas. Give them a try. And if you are in the Washington, DC area, come to the Arboretum and visit Fern Vallley or the Azalea Collection and look at what I'm talking about.

Tuesday, April 22, 2008

Deltaic Deposit of Beech Bud Scales

One of the interesting aspects of working under trees is all the different stuff that falls on your head. Everybody sees snow, rain , sleet, hail. Its hard to miss autumn leaves, maple helicopters, or the petals from cherry trees. Sometimes whole trees fall, or branches; that is usually bad. Large populations of caterpillars, gypsy moth or tent, eat and metabolize so fast that there is a constant rain of their fecal exudate. That is gross. When we first moved to the Adelphi house there was a metal awning over the small front stoop, itself under two large cherry trees. Tent caterpillars love cherry trees. At the height of the season you could stand under that roof and listen to the defecation sift down onto the metal. Like fine sand. A lot of it. We cut the trees down in our third year in the house. Sometimes the caterpillars themselves, fall and it doesn't seem to bother them; they just crawl back up the tree and resume eating and pooping. Cankerworms, or loopers (those tiny green or brown inchworms), drift on short lengths of spun silk, riding the wind to new meals. I swear that Blue Jays deliberately drop acorns on my head in the fall but its probably not true. It sure seems that way though. If you look up, keep your mouth closed!

When parts of trees (petals, flowers, seeds, bracts, sepals, bud scales) fall, they usually do so over a short period; sometimes less than a day, almost always less than a week. They fall always at a particular season and often as the result of a particular stimulus, usually a weather phenomenon. Plant parts falling out of trees were often "pushed off" by a sudden increase of turgor pressure. White Oaks hold their leaves all winter and often the stimulus to lose them is a rain that swells up twigs and pushes the leaves off.

The beech tree bud scales in this picture fell a week and a half ago. Joan and Jeanna were there. I missed it I am sorry to say. Maybe next year, though I don't remember ever seeing them all fall at once before; this may have been a once in a lifetime chance. Oh well. Last year was the first time I ever remember hearing/feeling the rain of tiny seeds from gumballs, the fruit of Liquidambar styraciflua. Since they fall in the autumn they make a distinctive sound as they cascade onto dry leaves on the forest floor. Theres always something exciting going on in Fern Valley.

Monday, April 21, 2008

Trilliums are not the only flowers with parts in 3's (in Fern Valley)

Pawpaws, Asimina triloba, are known more for their tasty custardy fruits than these curious pendulous blooms. The flowers are nice though. I guess its just that so much more spectacle is happening in the garden now (azaleas, lilacs, crabapples, etal.) that Pawpaw flowers just fade into the background. They are handsome enough, interesting, curious, even maybe endearing, but not spectacular. The tree itself is pleasantly attractive though and grows well in the shade. If you have ever grown an avocado from seed you will have some idea of what a pawpaw looks like. The leaves are up to a foot long and so this is a way to add a bit of coarse, or bold texture to a shady part of the garden. The fruits are tasty; I like them. I have heard people claim that the flavor is insipidly bland. The fruit has the consistency of soft custard and tastes a bit like banana Turkish taffy. For fruit set you need 2 plants that are genetically different as the flowers are self-incompatible. Of course as a design element 3 would work better!

There are not so many fruits that will grow in the shade. When clients who have no sun ask me for fruit trees in their designs, pawpaws are often the answer. Of course blueberries are good too, but they aren't "fruit trees." For a long time though a few cultivars did exist, they were almost never available. Now that pawpaw is being looked at by commercial, usually organic, growers, cultivars are appearing. We are fortunate, in this area, to have Neal Peterson, owner of the nursery, Peterson's Pawpaws. Neal is an ardent devotee of and advocate for Pawpaws, and has produced a number of cultivars selected for their outstanding attributes.

Sunday, April 20, 2008

Sometimes Trillium flexipes can be Red or Pink

Some groups of plants have more natural variability than others. If you look at a large population of genetically diverse individuals of a single species sometimes they are almost homogeneous and sometimes there is a lot of variability. Trilliums belong to the latter camp. One of the easiest to spot, least subtle variations is flower color. Someone spotted this red Trillium flexipes at Shenk's Ferry. It was a considerable distance up a quite steep slope, but that didn't seem to deter anyone from climbing up to see and photograph it.

When we arrived at the plant in the picture, the one visible from the trail, we discovered that there were other non-white individuals growing together in a relatively small area. There were various shades of pinks ranging from quite light to rose. Tony Avent spoke at the Symposium and a large part of his talk detailed plant collecting trips and the wide ranging variability of this genus. I have to wonder if the extreme variability of some taxa isn't sometimes as much an element in our attraction to them as their appearance. It is fun to know you will, or might anyway, find a surprise when you look at a population.

12 Miles From Longwood...A Large Native Plant Nursery

Because it was close to the Trillium symposium and because we needed to pick up an order of plants and because we Like Jim Plyler and his wife Bethany, we visited Natural Landscapes Nursery in West Grove, Pennsylvania. This is a wonderful nursery, old school. They grow almost everything in the ground and dig all the rootballs by hand. Some of the balls were more than 3' across! Jim amends the soil and root prunes! To look at most B&B stock you would not think anyone root-pruned anymore. He tells me that most summers they can dig many things all through the summer. Because Jim is too modest to say it, I will explain that that is because they do things the right way.

They grow exclusively woody native plants and many are grown from seed that they collect themselves from locations up and down the East Coast. This picture is a bed of Azaleas that came from seed collected on Gregory Bald in the Great Smokey Mountains. That makes this a pretty exciting group of plants! Though they have a fairly wide range of material taxonomically speaking, I detect a fondness for the Ericaceae.

Because he is such a zealous supporter of the use of native plants in landscaping, Jim goes, as a vendor, to a number of "garden sales" around the area. Get the plants out there! I first met him at the Lahr Symposium, at the National Arboretum. I was overjoyed to see that he was offering so many of the native azaleas for sale. They are such wonderful landscape plants but so difficult to find. I was overwhelmed to discover that at his nursery he had large plants suitable for major landscaping. That is a remarkable resource that too few people are aware of. And that includes professionals who ought to be using these plants. This is large, healthy, sourced, native material. Availability of good material is the limiting factor in design/installation of high-end landscapes. It is hard not to salivate when you look at this list!

Shenk's Ferry Wildflower Preserve Field Trip

Certainly we went to Shenk's Ferry looking for Trilliums, and we found them, but there was so much more. This slope, like much of the steep terrain alongside the stream valley was enveloped in a haze of Virginia Bluebells. Other species bloomed in mass quantities; spectacular drifts of Phlox, Dicentra, Saxifraga, Trillium colorfully graced the slopes. We saw smaller populations of a number of exciting less commonly encountered plants including Walking fern, White Trout Lily, a senescing Puttyroot, and Showy Orchis (not yet flowering), among others. It was good to be there at the perfect time of year on a spectacular day.

Shenk's Ferry is a fascinating site. Apparently there is a core of Ordovician limestone with schist at either end. I'll look at the geology later and maybe revise this paragraph, but this is what I got from the local experts. Obviously there is a lot of seeping going on (even young limestone is porous and this limestone isn't young!) that provides enough moisture on those slopes to allow large populations of non-xeric wildflowers. There are a good number of limestone ferns on the fern list available at the head of the trail.

Pennsylvania Power and Light Company owns the land and allows visitation year round from 8:00 to sunset. There was a rumor at this field trip that they are going to turn iit over to a local Conservancy. That could only be a good thing as it will allow for more/any invasive control. There are some invasive issues, predictably worse at the periphery. Garlic mustard abounds; there are quantities of Japanese honeysuckle, Daylilies, Ornithogalum, a monstrously large Oriental bittersweet and more. Still it is a nice site inside and a little work would go a long way.