I won't go on and on about it, since every year I mention this plant, but Clematis paniculata is now in bloom and will be a great ornament through Labor Day, and after that its white starry small scented flowers will be succeeded by feathery seed clusters. These are handsome till Thanksgiving, or until the birds eat them all.
This is almost the only garden flower of first-class beauty that grows like a weed and gives no trouble to anybody. It surpasses most clematis in grace, and virtually all of them in scent. It does not get bugs, blights, spots or other miseries; it is iron-hardy yet easy to control if it gets too big to suit the gardener.
On a fence, up the bole of a dying tree, on posts and pillars, on trellises, any place a vine of good foliage is required, this one does admirably, provided you don't try to keep it trimmed to knee height. It is equally handsome spilling down a bank by an alley. It was introduced by the Arnold Arboretum from Japan, and is the most valuable plant ever introduced by that famous garden, as far as I am concerned.
It is particularly astonishing that a vine of the highest beauty and most placid disposition should bloom at the dullest and weariest season of the garden year. It is hardly worth growing in England, by the way, and is rarely seen in good gardens there, since Britain lacks our fine summers.
I am not much interested in bugs, except as ornaments like the jet and vermilion grasshoppers of northern Alabama, the various dragonflies, rhinoceros beetles and gold bugs, but I had always assumed that the various bark beetles that damage pine trees were fully understood by all plant biologists dealing with forests.
It was surprising, therefore, to read a paper recently written by Herman J. Heikkenen and Stephen E. Scheckler of Virginia Polytechnic Institute.
Apparently there have long been two schools of thought about how the beetles descend on pines -- that they hit pines at random and then emit pheromones that attract other beetles, so that soon you have a damaging mass of them. The other view has been that the beetles target certain trees, and since the beetles are worse in drought years it was suspected weakened trees were attacked first.
Heikkenen told me of an experiment in which a pine was sawed off, but kept propped up on its stump and carefully watched. After some days -- the tree getting no water, of course, and dying as promptly as a pine can -- there was a virtual rain of resin, to which great numbers of bark beetles were attracted.
Normally when old needles fall (a needle lives one to three years, depending on various conditions) the abscission layers heal over, sealing the resin. A healthy pine is no more likely to leak resin than we are to leak blood.
The traumatic injury to this tree, however, accounted for the failure of the scars to heal over and seal.
Work at VPI strongly suggests the beetles are attracted to the resins of the wounded tree, while other pines monitored as controls showed no beetles.
Possibly beetles attack only stressed trees. If so, then the beetles are more like coyotes cleaning up carrion than like leopards killing lambs.
The fact that beetles attacked the dying pine does not in itself demonstrate that beetles do not attack healthy pines, though the healthy pines at Blacksburg were not bothered. Heikkenen said the pheromones by which additional beetles are attracted to beetles already ensconced on a pine are "quite similar" to fermented plant products such as you find when the tree rains resins.
The fact that beetles swarm to the resins of a wounded tree does not preclude their swarming to beetles that have hit a healthy tree at random, but the paper does strongly suggest it is the wounded tree that draws the beetles, and if so, the trick would be to keep the tree in health, more than to spray healthy trees against beetles. You would have thought that by now, considering the economic importance of timber, everything in the world would be known about pines and beetles, but here as in every other field the knowledge is far from complete.
In the garden, to get back to less grand things than forests, I shall try sowing some poppy seeds in the next week. I have sowed them at various times of the year without any good results. The best way to have good poppies is to have some already, letting them seed themselves since they are better at it than I am. This is not comforting advice, however, if you don't already have them.
A nice plant of the silvery mullein (Verbascum bombyciferum) has showed up as a volunteer near some chrysanthemums. It has been several years since I last had this splendid mullein. Always in the past it seeded itself about, so I took no care, but one year there were no seedlings at all. I have delayed writing for more seeds from Park's and you see how wise it is not to be hasty. For now a seed that has just been sitting about in the earth for three or four years has sprouted, formed its little rosette and should bloom next summer, saving me 75 cents.