Sunday, August 21, 2011
What’s blooming in the area: Hybrid tea roses, rose of Sharon, Russian sage, buddleia, Japanese honeysuckle, trumpet creeper, silver lace vine, red yucca, datura, sweet pea, purple phlox, cultivated sunflowers, Sensation cosmos, alfalfa, brome grass; orange berries on pyracantha; pods reddening on trees of heaven; local grocer roasting green peppers in parking lot.
Beyond the walls and fences: Tamarix, Apache plume, fernleaf and leatherleaf globemallows, scarlet bee blossom, white and yellow evening primroses, whorled milkweed, bindweed, purple mat flower, goat’s head, white sweet and purple clovers, stickleaf, buffalo gourd, silver leaf nightshade, Queen Anne’s lace, toothed spurge, prostrate knotweed, lamb’s quarter, Russian thistle, amaranth, pigweed, ragweed, snake weed, native sunflowers, spiny lettuce, horseweed, paper flower, gumweed, Hopi tea, goldenrod, áñil del muerto, golden hairy and strapleaf spine asters, sandburs, sideoats grama.
In my yard, looking east: Hosta, garlic chives, hollyhock, winecup mallow, sidalcea, baby’s breath, Maltese cross, bouncing Bess, large-leaf soapwort, Jupiter’s beard, pink evening primrose, Shirley poppies, cutleaf coneflower, Maximilian sunflowers; buds on Autumn Joy sedum.
Looking south: Floribunda and rugosa roses, Illinois bundle flower, reseeded and new Crimson Rambler morning glories, sweet alyssum and zinnia from seed.
Looking west: Caryopteris, David phlox, ladybells, catmints, calamintha, flowering spurge, sea lavender, lead plant, perennial four o’clock, Mönch aster.
Looking north: Golden spur columbine, Hartweig evening primrose, Mexican hat, Parker’s Gold yarrow, chocolate flower, blanket flower, yellow cosmos from seed, anthemis, black-eyed Susan, chrysanthemum.
Bedding plants: Sweet alyssum, pansy, snapdragon, moss rose, nicotiana, impatiens.
Inside: Zonal geranium, aptenia, asparagus fern.
Animal sightings: Hummingbirds, hummingbird moth on large leafed soapwort, small bees, hornets, harvester and small black ants, hear crickets.
Weather: Brief downpours have been good for the garden, but haven’t remained in the unirrigated yard long enough to help; last rain 8/21/11; 13:58 hours of daylight today.
Weekly update: The catalpas are in trouble. Their leaves have turned white, with only green veins, much like caladiums.
The problems first appeared last July on trees growing in a town medium. On July 24, I noticed the leaves on some were yellowing. A few days later I noticed others appeared more lime green than usual from the car window.
Catalpa bignonioides and Catalpa speciosa are native to the eastern Mississippi valley where they’re warm season plants. The trees don’t leaf until late April. Their leaves begin turning yellow early, usually the first part of October here.
This winter was unusually cold and dry, much colder than they like. On May 1, just after the leaves began emerging, it snowed. The broad, horizontal leaves caught flakes that would have melted quickly into the warm ground. Within days, the leaves turned black and fell.
When new leaves appeared a week or so later, they emerged from buds a bit back from the branch tips. Leaves on branches nearer the ground, that also were protected by shrubs, grew larger and denser than those on higher, more exposed limbs which never formed a canopy to provide normal levels of chlorophyll. Trees like mine and those along the highway, up and away from the comforting winter river, never recovered from the effects of the cold.
I first noticed the caladium effect on leaves on the west side of my tree on June 29. Some in town were yellowing. In the village there now are trees that are completely white, some that are green and sparse, and some that are normal. They may be across the road from each other, they may be near a ditch, they may be tall or young.
I began watering my tree in late June, but nothing stopped the march of white leaves. There now seems to be two toward the end of each branch, sometimes with another slightly discolored one below them. Some on the west, the first to fade, are turning brown.
Kim Coder says chlorosis is a sign that trees growing in soils with a high pH are unable to absorb minerals, especially iron, from dry soil. Since the trees have been growing here for years, this suggests at least part of the problem is there’s not enough water many feet down to dissolve minerals.
However, I suspect more is involved. Unlike this year, the winter before was wet and followed another wet winter which would have replenished soil waters after a decade of dry years that hadn’t affected the trees in town. Mid-July of last year was simply too soon for deep soil to be so dry.
The alternative is that somehow the soils have become more alkaline. Certainly, over time, irrigation from the aquifer would have that effect. When my well was tested in September of 2002, the water had a pH of 8.6, where 7 is neutral. It also contained detectable quantities of dissolved iron.
Most of the area trees, if they’re tended at all, are watered from ditches supplied by the Santa Cruz reservoir. The snow fed lake is probably less alkaline than groundwater, but its primary fish are still rainbow and German brown trout. The Pacific coast species should have water with a pH between 6.5 and 8.5. The European import does best with it between 6.8 and 7.8.
A high pH is usually associated with limestone, but it’s been a great many years since we’ve been under water. The last time was before the Cretaceous Seaway that covered much of the west receded some 70 million years ago While calcium carbonate is eroded from outcrops and transported by rain, we haven’t had enough precipitation this year to add anything to the surface.
Neither missing iron nor additional lime fully explains this year’s etiolated leaves, perhaps because each is only a symbol we use to denote chemical reactions we never question. We’re quite happy to accept the possibility that tests for pH levels are magical divinations of soil qualities, when, in fact, they’re measures of hydrogen ions found in solutions.
In 1884, Svante Arrhenius suggested two molecules of water (H2O) often recombine to form one hydroxide molecule (OH-) and one hydronium one (H3O+). The first is missing an electron the second has absorbed. The first thus has a positive charge; the other is negative.
If either ion is absorbed into another molecule before they can recombine into two molecules of water, the chemistry changes. A base condition results when the number of positive ions increases.
The question becomes what chemical could have created a hostile environment for the catalpas last summer and this. I’ve been pondering the ash from the Las Conchas fire ever since I noticed sun beams crossing the Jemez were highlighting fine ash in updrafts that delineated the ridges and canyons. This effect occurs around eight in the evening, just before the sun colors the clouds, when the land is cooling and the air has begun rising.
Burned wood is alkaline. Some recommend using wood ashes to sweeten acidic soils. Early settlers in this country made caustic lye soap by mixing ashes with water. Most people this year have been concerned with the heavier black fragments which have threatened to clog the water treatment equipment in Santa Fe and Albuquerque, or which may have smothered fish on July 31.
My thought is that when the finer invisible dust lands on a leaf, some base molecule reacts with the naturally occurring negative hydronium, and leaves a positive hydroxide. When that occurs enough times, the tree’s surface water turns alkaline. We know leaves absorb that water because Coder says it’s possible to temporarily green a catalpa by spraying the leaves with chelated iron.
We’ve certainly had enough dry ash the past two years. Last year the South Fork fire was started in the Santa Fe National Forest by lightening on June 10 about 25 miles west of Española and maybe 10 miles north, in the Jemez between the Santa Clara and Abique land grants. By the time it finally rained with hurricane Alex on July 3, it had charred 17,086 acres and was only 80% contained.
This year we haven’t just had the Las Conchas fire that raged across the river from June 26. We also had smoke and ash from Arizona fires in early June, followed by the Pacheco fire which started north of Tesuque on June 18.
Both years the monsoons were delayed. There were no rains last June, and the next major rainfall after Alex came with Bonnie on July 23, a twenty day pause between hurricanes. This year, while the burned areas in the Jemez have seen rain, there’s been little here in the valley. No hurricane has yet been serious.
Last July and this, after the fire fighters were less active and ashes had a chance to dry, my nose itched or dripped, my eyes were gummy or burned. I’m not a tree. Unlike the catalpa which lets surface water seep through, my skin and nasal passages act as barriers to prevent irritants from entering my body.
I don’t know if ash is the problem, but like any superstitious being facing an unknown I’m open to any explanation that might help the tree. I followed the standard operating procedures, watered the roots. When that failed, I consulted the oracles, laid down Ironrite and watered it in. When that achieved nothing, I turned to folk science, washed the dust off the leaves in the morning.
And lo, no sooner did I begin spraying the tree, than we started getting brief downpours, either in the afternoon or middle of the night. A belief in sympathetic magic is easily reinforced.
Notes: See entry for 25 November 2007 on why catalpas were introduced into the arid west.
Coder, Kim D. “Southern Catalpa: ‘The Fish Bait Tree’,” University of Georgia, Warnell School of Forest Resources website.
Cowx, Ian G. “Oncorhynchus mykiss (Walbaum, 1792),” FAO Fisheries and Aquaculture Department, Cultured Aquatic Species Information Programme website, 15 June 2005.
Raleigh, Robert F.. Laurence D. Zuckerman and Patrick C. Nelson. Habitat Suitability Index Models and Instream Flow Suitability Curves: Brown Trout, 1986 revision.
Wikipedia. Entries on “Acid” and “Hydrogen Ion,” retrieved 14 August 2011.
Photograph: Catalpa with full-sized, discolored leaves growing in Española medium; Jemez in far background; 20 August 2011.