Saturday, May 31, 2008

Mulch 'Mators

The perfect tomato is the Holy Grail of many gardeners. Especially in the coastal, marine-influenced climate where I live. I’ve watched neighbors plant tomatoes where the summer fogs are frequent and nurture, worry, persist and try every way they read in the books and magazine articles to eke out a handful of tomatoes. Probably at a real cost of $10 per tomato, or more. Whereas just 2 miles east, over the high hump of the land that captures so much summer fog, tomatoes thrive. So, I buy them at the farmer’s markets and save lots of money and elbow grease.

Back in the ‘30s a man named John Weaver had the patience to excavate entire root systems. He dug a trench along side of the base of each plant and proceeded to excavate, scrape, and dust his way through soil – much like an archeologist at work - to reveal in exquisite detail the full extent of a plants root system. He (or someone else – the book makes no comment as to who did the drawings that resemble etchings) mapped mostly economic vegetable crops. Weaver must have been the Saint of Patience. I often wondered if he had a wife (no search found any clue) who could understand his work and have the same patience he must have had.

In Weaver’s experience, a tomato seed planted in ideal outdoor soil, with no transplanting involved, can grow a taproot to the depth of 22 inches at a rate of one inch per day. The tomato is yet another vegetable that prefers to grow a taproot, which is often damaged during transplanting. Young seedlings transplanted several times into increasingly large pots before their final move into the garden will probably end up with a root system more fibrous than that of tomato plants planted by seed in the garden which are allowed to grow a conventional taproot. However, transplanting tomato-plant stems deep into the soil will produce many adventitious roots along the length of its stem (See Weaver’s illustration.), creating a great root system early in the life of the plant, more advantageous than seed grown in the garden.

The illustration is drawn on a one-square foot grid (Taken from my book Roots Demystified, change your gardening habits to help roots thrive.) and shows how massive the root system is for one plant. At seven feet wide it changes one’s perspective of how much mulch is required to keep all the roots happy. In cool climates you might experiment with paper from an office or home shedder to help reflect light into the canopy of the plant. Turn all those shredded unsolicited checks from your credit company into wonderful tomatoes!

I don’t know of anyone planting tomatoes by direct seeding in the ground. Do you?

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A Gardener's Repast - sometimes

I've often observed that many garden fanatics don't have place to sit and relax and enjoy the view and soak up the fragrances and sunlight. I gardened for seven years as a fanatic vegetable and fruit gardener before I put in some places to sit.

They are large rounds of a tree with half of the back chained sawed off. After 25 years they still allow visitor to sit and enjoy two views of the garden. Now I’ve added two proper seats - Adirondack chairs - for visitors as I still don't sit in my garden that much. But when I have guests over we all relax in various chairs and benches. I like to let plants wander around my garden. If two people sit in these chairs, they must be careful to avoid the foxglove for one season - as it will soon go to seed.

Then there’s chairs as art. The overgrown-white chairs pictured here are from the eccentric garden of Maxine and Jeff. Mostly found objects fill their whimsical garden and the white chairs are for look only. The bench, however, is one of several that allow them to rest and enjoy the garden with friends. (Notice the seats to the right-for "show" only.)

As with all my posts, click on an image to get a larger view.

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Thursday, May 29, 2008

Roots Grow Up!

Surprisingly, many of a tree’s feeding (not “structural” roots) roots grow up, not down. In a paper published in The Landscape Below Ground (International Society of Arboriculture, 1994. pg. 3), Professor Thomas O. Perry states “Most tree roots range in diameter [from that of] of a lead pencil to the size of a hair. These smaller roots…grow upward into the surface inches of soil and the litter layer.”

The significance of the importance of the most aerobic layers of the soil and duff can be seen in a simple study using potted tree seedlings. You can see the dramatic difference in the illustration of growth between the three soil depths. The seedlings in the pot on the left are growing in soil collected from the top two inches. The middle pot has soil only from the 2-4 inch depth of a forest floor. The pot on the right is trying to grow in subsoil.

The top two inches is so vital to a tree’s health, whether it’s native or ornamental. This is also the favorite two inches for all the plants in a humid climate with periodic rains. Take away that top two inches by planting it to lawn, raking the duff up for “a cleaner look” or allowing so much foot traffic that the roots are exposed, and you have a disaster in the making. This is perhaps the most important illustration in Roots Demystified because it so graphically reveals where tree and shrub roots prefer to grow and feed.

The photo is of a cross-section of three feet of soil beneath a vineyard. Most of the roots are in the top foot or so of the soil. Below that level it gets increasingly more like clay subsoil. (If you click on the image to enlarge it, you will see a few roots below the first foot and even a few that found the lens of gravel.)

The aerobic-loving soil life – where you find the most soluble nutrients - needs to breathe. The deeper you go, the less aerobic you get, and the number of “good guys” (beneficial soil flora) will rapidly diminish. Studies done with agricultural plants provide a lot of useful information. One example is alfalfa, it can grow roots much deeper than peach trees can, yet both get most of their moisture (along with nutrients) in the top one to two feet of the soil.

But trees still need “dirt”. Perry puts it quite succinctly when he says that trees on soils as little as five inches thick produce only poor tree and shrub growth. (one can then imagine how far the roots must grow laterally in the shallow soils to gather sufficient moisture and nutrients.) You can get fair growth with a ten-inch depth, good growth at 16 inches and excellent growth with 20-30 inches of topsoil. Most remarkably, according to Perry, the tree vigor is likely to gradually decrease with soil deeper than 30 inches. (The Landscape Below Ground, International Society of Arboriculture, 1994. pg. 9)

As I’ve often said: mulch, mulch, mulch. Replicate the duff that forms in a natural forest. Establish as many permanent pathways as possible. Try to let the pathways “breathe”—allowing the air to flow into the roots and the carbon monoxide to be expelled. You can use chipped bark, chipped tree trimmings, gravel or whatever local material suits you.

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Wednesday, May 28, 2008

Bee Kind to My Foxglove

I love foxgloves even though they are not native plants. Each deep-throated foxglove flower stimulates my spirit. The color cascading from each blossom engages my eyes. This photo of a special creamy-white foxglove is the first one with this color to show up in the 25 years I’ve lived here.

While considered an exotic “invader” I like to have it in my garden as a form of controlled chaos. Each year I let the tall flower stalks go to seed and spread their fine, brown seeds where ever they may. This means leaving the flower stalks to mature to an earthy brown. No dead-heading here. No place in my garden for Martha Stewart. These sentinels of future generations remain for weeks until the tiny up-turned cups of the remaining flower parts fill with mature seed and begin to spill with each gust of wind. Sometime I scatter a few seeds myself. (The tallest flower stalks seem to be those growing from seed they have cast asunder, not the seed I plant.)

All this makes for a very kinetic garden as the years go by. One year I had a glorious stand of foxgloves at the end of the main path into my garden. More than two dozen plants reaching four- to six-feet in the air. Each a different shade from hot rose to pale pink to creamy white. The next year they popped up in the soil surrounding the small swale that drains water away from water-sensitive plants on the adjacent berm. This year they have appeared in the soil and mulch left behind after grinding a dead tree stump into oblivion. How they got there, some 20 feet from last years stand, I’ll never know.

The seed needs to fall where there isn’t too much competition. Yet it will grow above some of the grasses. But in the end, it really prefers open soil, my mulched areas or I’ll find clusters of plants will thrive at the edge where mowing meets the more rangy parts of the garden. For the first year the dark-green leaves flourish as they gather the photosynthetic momentum for the flower stalk to thrust skyward. The handful of leaves at the tip of the plant are a pleasure to look at, with a subtle display of the Fibonacci pattern. (The Fibonacci series is the mathematical form portrayed in the cross section of a nautilus shell or the pattern of seeds on a sunflower head.)

Our eyes see delightful beauty in our gardens. Yet, some of the splendor in garden flower remains unseen. Each foxglove blossom has a different set of splotches all the way into its throat, like little runway guides leading to the sweet nectar. These are intriguing enough. But there’s more. Pollinating bumble bees (as seen in the above photo) see something beyond our vision. Bumble bees have a pair of six-sided, compound eyes and three simple eyes. Even with such complex eyes, their sight is accurate for only about three feet. A special light guides bumble bees on their lusty journeys for pure nectar. Bumble bees see ultraviolet light. A pattern of ultraviolet coloration lures a bumble bee into the foxglove flower’s throat. These patterns unseen by our eyes act like the signals of an airport’s landing strip. And the ultraviolet splotches of color don’t match the random splotches we see in the sunshine.

The earth’s protective atmosphere shields us from much of the sun’s ultraviolet light (radiation). Enough ultraviolet radiation filters through to aid bumble bees in their daily journeys. Even on a cloudy day, the bumble bees see the ultraviolet spectrum by cloud-penetrating ultraviolet light. What assists bumble bees on their quest for pollen and nectar can cause us to sunburn—part of the two-sided tapestry of life.

In each blossom the pollen is in the roof of the flower so the upper body of the bumble bee is brushed with the pollen as the bumble bee goes deeper into the blossom to seek out the sweet nectar. After flying to another flower, the pollens are mixed and seed formation begins. The pollination process leads to a plant with a mixture of colors. Yet an isolated stand with creamy flowers will remain shades of cream until a seedling of a rose-colored blossom pops up nearby. Then things get interesting as different blends of color appear.

Foxglove (Digitalis purpurea) is the source of digitalis—a heart medication. According to the American Heart Association: “Digitalis is a drug that strengthens the contraction of the heart muscle, slows the heart rate and helps eliminate fluid from body tissues. It's often used to treat congestive heart failure and is also used to treat certain arrhythmias. Digitalis has been described in medical literature for over 200 years.” The extract is taken from the leaves. (Two synthetic mimics of digitalis are Digitoxin and Digoxin.) India supplies most of the cultivated digitalis. Others sources are wild crafted (gathered from wild, un-cultivated areas) in Europe, from Germany, Switzerland, Hungary and Italy. Digitalis is toxic at very low levels.

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Tuesday, May 27, 2008

Taproot Myths Revealed

This is a photograph of a young tan-oak seedling, sometimes called tanbark trees as their bark was stripped off and used to tan animal hides. These trees used to be classified as a species of Quercus (oak), now reclassified by botanists with time on their hands as Lithocarpus densiflorus. Don’t ask me why. This seedling has a stem with a few leaves five inches above ground and seven inches of a taproot, all I could dig out. (Click on the photo to see a much larger image.)

In my book, Roots Demystified, change your gardening habits to help roots thrive, I talk about how few trees actually grow with taproots. Oaks are an exception, for awhile.

Some Californian and western oak trees (including the tanbark oak), begin growing with a taproot, which then naturally atrophies. The loss of the taproot can begin as early as the first or second season. When the young seedling of a blue oak is a mere three inches high the taproot can already extend 40 inches into the soil. After a number of years, the taproot withers, to be replaced by heart roots (which angle down from the base of the tree) and many laterals, with vertical sinker roots. In Spruce (Picea spp.), Hemlock (Tsuga spp.) and Cedar (Cedrus spp.) trees, at less than eight years, the lateral and oblique roots take over the role of support and the taproot declines. (From: “Natural Root Forms of Western Conifers”, S. Eis; From: Proceedings of the Root Form of Planted Trees Symposium, page 24, 1978.) After the taproot atrophies, the new root system grows more horizontal and oblique roots and resembles a fibrous root system.

In my photograph the roots are about as long as the stem and leaves. However, much of the tiny taproot was left in the ground judging by the thickness of the bottom of this seedling as it was dug with a spading fork. The seedling sprouted in deep shade which probably accounts for the extended length of the stem.

Any oak planted from any container or balled-and-burlapped stock has effectively had its taproot destroyed and forms a fibrous (heart roots) root system.

I think the sturdiest oaks are grown like nature, from seed placed where you want a specimen for your grandchildren to climb on.

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Sunday, May 25, 2008

Scatological Blossoms

Scat on my gravel driveway makes me happy.

Scat (the politically-correct way to refer to animal feces – which also masks the street language version) usually means the bobcat or mountain lion (cougar) is back. These animals seem to like pooping on my driveway to mark their territory.

The wonderful result is the deer vanish. They smell the marked territory.

I have not seen any deer for the past week. Today I found a fresh pile of scat on the edge of the driveway.

The beauty of it is that I get more splendor in my garden.

When I first moved here 23 years ago I planted the rockrose ‘Sunset’(Cistus ‘Sunset’) and enjoyed its hot-pink blossoms. The shrub had to be taken out when the stump next to it was ground up into a pile of wood chips. Then three years ago I planted another one. The deer proceeded to eat every flower bud and kept the plant as a half-sphere of foliage. The foliage is nice, but the flowers are spectacular. This week the plant is covered with its crape paper hot-pink petals. Other plants are blooming unlike years before when the deer ate the blossoms and foliage

When I first moved here I put some of those road reflectors that mark highway lanes down the middle of our gravel driveway. (To prove we weren’t entirely country hicks. Of course the two “lanes” would apply only to motorcycles.) The next morning there was a fresh pile of bobcat scat on top of one of the reflectors. A message saying “Hey I was here first. What right do you have to invade my territory?” Just marking its territory, and scaring off the deer.

This winter I found a perfectly intact, fresh deer skeleton with three points. No bobcat could take down such a large buck. It meant the mountain lion was back.

I walk past the scat on my road each day as I take my speedy, aerobic walk. I wear a red shirt and a purple hat so I don’t look like lunch to a mountain lion. Hope it continues to work.

Please post a comment - I want to know what you think.

Visit my web site to learn about my gardening books.

NOTE: The comments section at the bottom of the post has disappeared. Click on the "___ Comments" button or the title under the "Blog Archives". Thanks, Robert