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Articles by Dr. Francis Gouin

Gardening in bales of straw

     As I prepare my fall garden, I’m walking in the footsteps of an Ohio gardener with poor soil who planted in bales of straw rather than install raised beds. He found his solution in a British gardening magazine on growing vegetables. Now I’m trying it, starting with four bales of straw that I placed in full sun along the edge of my vegetable garden.
    To minimize weed problems, use straw rather than hay. Straw is the residue after the grain has been harvested. Select bales tied with plastic string and not sessile. Both sessile and jute string will decompose and the bales of straw will fall apart. Those tied with plastic string will remain whole because plastic does not decompose. Place the bales of straw on either black plastic or non-woven geotextile ground cloth.  
    Before planting, prime each bale to initiate the composting process. Spread two and a half cups of high-nitrogen lawn fertilizer — not mixed with herbicide — over each bale. For organic preparation, spread three pounds of organic fertilizer over each bale. Next wet the bales thoroughly and insert a long-shank thermometer to monitor temperature changes within the bales. The fertilizers will initiate composting in the center of each bale, raising the temperature. Sprinkle the bales with water daily to keep them moist so composting will take place. When temperatures again equal ambient air, the bales are ready to be planted.
    Within five days after I applied the fertilizer on each bale, temperatures within the bales fertilized with Holly Tone Organic reached 120 degrees. The bales treated with 10-6-4 fertilizer increased to only 100 degrees. It took nearly three weeks for these bales of straw to achieve the Holly Tone temperatures.
    By the end of the third week of priming, the bales treated with Holly Tone Organic started producing inky-cap mushrooms; the bales treated with chemical fertilizer followed one week later.
    At the end of the fourth week of priming, temperatures dropped to between 95 degrees and 100 degrees in all of the bales of straw.
    When the internal temperatures are the same as the ambient air, I will plant the bales with broccoli, cauliflower, Brussels sprouts, kale and collards. My Ohio model claims to obtain at least two years of growth, sometimes three, from each bale.
    Regardless of the results, I will write about this new method of growing vegetables and share my results and photos. I write now in hopes that you will also try so that we can compare results.
    As my dad always said, “You will never know until you try.”

Outmaneuvering Stem Borers in Zucchini
    Every year, readers complain that stem borers have killed their zucchini plants only after a few weeks of production. I have had the same problem. To enjoy zucchini for most of the summer, I make repeated plantings.
    I’ve tried with no success spreading wood ashes around each hill as recommended by organic gardening magazines. I’ve had moderate success spraying under the foliage with the insecticide Sevin starting as soon as the leaves appeared and repeating weekly.
    This year I sprayed only the stems — not the leaves or petioles — with a jet stream of Sevin, starting under the flower bud farthest away from the roots. I am still harvesting zucchini squash from the original planting with no sign of borer injury. Protecting the stem with Sevin keeps the borer from gaining entry.  
    This year’s succession of plantings resulted in a surplus harvest, which I take to the SCAN food bank at St. James Episcopal Church on Rt. 2.

How to stop the Japanese beetles that cause the problem

     If you have brown patches in your lawn, I expect the cause is Japanese beetle grubs eating the roots of the grasses. Japanese beetles are out in full force, feasting on roses, linden trees and other favorite ornamentals, as well as puncturing and eating peaches, raspberries, blackberries and plums. Soon those same beetles will be landing on your lawn and depositing eggs in the earth. When those eggs hatch, hungry young larvae will begin feeding until fall when the soil cools and they burrow deeper in to survive the winter. Next spring those same larvae will crawl up closer to the roots of your lawn and resume feeding until they pupate and emerge as adults. The larvae are light gray with brown heads and curl into the letter C when disturbed.
    The brown patches you are now seeing are from last year’s larvae that survived the winter.
    Back when we lived in College Park, we did not have Japanese beetles. That’s because College Park was ground zero for the research that resulted in the development of the milky spore system of Japanese grub control. The developer was Dr. George Langford, chairman of the Department of Entomology. To test the effectiveness of the system, in the mid-1950s he treated all of the lawns within the city limits. A single treatment was highly effective.
    When Clara and I moved to Deale in 1990, the lawn was full of mole tunnels. Moles love to feast on. Realizing the mole problem was due to a large infestation of Japanese beetle grubs, I treated the entire lawn with milky spore powder the summer of 1991. It took three years before I had 100 percent control. I have never had to repeat the treatment. Japanese beetles are flying around and feasting on our little leaf linden, and they are laying eggs in my lawn, but the milky spore is digesting the larvae as they hatch. The milky spore system of control is self-supporting once it becomes well established. It has now been almost a quarter century since I first used milky spore, and I no longer have moles tunneling nor dead brown spots in my lawn.
    True, there are insecticides you can spread on your lawn that will kill the grub, but these insecticides have to be redone yearly. The use of them on lawns can also contribute to the pollution of the Bay. If you live near the Bay or its tributaries, do not use these insecticides; to be effective, they must be applied over the entire lawn.
    Milky spore is available in two forms, powder or granular. The powdered form is measured using one-quarter teaspoon at three-foot intervals. The granular form is applied using a spreader. One bag of granular milky spore will cover approximately 7,000 square feet. Milky spore must be thoroughly and promptly soaked into the soil soon after being applied. Applying it just before a predicted heavy rain is best unless you have an in-ground sprinkler system that covers the entire lawn.
    Milky spore can be used in the spring, summer or fall, but now is the best time because this is when the Japanese beetles are laying their eggs.
    Milky spore is a good, safe and effective grub control system, but it cannot be used in conjunction with any of the other harsh insecticides recommended for grub control. Having Japanese beetles laying eggs in your lawn every year keeps the milky spore population alive and well.

Organic matter adds ­hidden benefits to soil

Addition of organic matter does great things for soil. It works as a slow-release fertilizer and source of essential nutrients. It reduces the density of heavy silt and clay loam soils. It improves soil’s nutrient retention and increases water retention. All of these benefits redound to plant growth.

Retention of nutrients
    Adding organic matter to soils increases the retention of nutrients and makes them available to the roots of plants. This process is known as increasing the cation-exchange capacity of soils. You learned in the July 24 column how organic matter releases nutrients slowly through mineralization. In addition to supplying the major elements, compost supplies trace elements such as boron (B), iron (Fe), zinc (Zn), manganese (Mn), sulfur (S) and copper (Cu). These essential trace elements are important to the growth of healthy plants and to the quality of the crops they produce. But they’re not part of commercial fertilizer mixes.
    Increasing the cation exchange is especially important in sandy loams or loamy sands. Nutrients leach through these sandy soils quickly. Because sandy soils are well aerated, they do not retain organic matter. So to maintain productivity on sandy soils requires frequent applications compost or animal manure and the use of cover crops.
    On sandy loams or loamy sands, use no more compost or manure than six cubic yards per 1,000 square feet for the initial application. On silt or clay loam soils, make that four cubic yards as these soils are better able to retain nutrients than sandy loams or loamy sands. Repeated applications should be one-half or one-quarter.
Water-holding Capacity
    The addition of organic matter to sandy soils increases water-holding capacity.
    The addition of organic matter to heavy silt or clay loam soils increases water infiltration, thus increasing their ability to retain water while at the same time allowing excess water to drain.

Soil Density Reduction
    It won’t work to use sand to improve the drainage of heavy silt or clay loam soils. Short of 55 to 60 percent, the addition of sand will only result in making the soil like concrete.
    Adding 10 percent compost will increase both the organic matter concentration and the productivity of heavy silt or clay loam. Pine fines are one of the better organic materials to use to lighten heavy soils. Pine fines are a waste product from the manufacturing of pine bark mulches. Because pine fines contain high levels of lignins — a source of organic matter that resists decomposition — pine fines will persist in the soil for a long time.

Disease Control
    Another hidden benefit of amending soils with compost is its ability to control soil-borne diseases. Quality compost contains three naturally occurring fungicides and numerous beneficial microorganisms known to control common soil-borne diseases as fusarium, pythium and rhizoctinia. To get this bonus, use recently made compost. As the compost ages, these benefits are gradually lost as the biological activity of the compost decreases.

Lesson 3: Jumpstart your garden with compost tea

     Your organic garden will need a jumpstart. Organic gardening relies entirely on the release of nutrients from the decomposition of organic matter and the bodies of the microorganisms that digest the organic matter in the soil. In cold soils, nutrients are not readily available.
    Room temperature — a consistent 72 degrees — is the starting point for analyzing the situation. With 72-degree soil temperature, the rate of the mineralization of organic matter is approximately eight to 10 percent. If the soil contains three percent organic matter, it releases 24 to 30 pounds of nitrogen per acre per year. Producing a respectable crop takes between 80 and 100 pounds of nitrogen per acre.
    In summer, when soils are at room temperature and above, it takes a soil with five to 10 percent organic matter to produce a respectable crop. Even if soil temperatures increase above 72 degrees, the mineralization rate increases only a few percentage points. To grow a crop in soils containing less than five percent organic matter, you’ve got to add organic fertilizers, including compost. As the microorganisms that digest the carbon of the organic matter die, the minerals in their bodies and in the cells of the organic matter are released.
    The cooler the soil, the slower the process. Mineralization of nutrients from organic matter stops when the ground freezes. In spring, the mineralization rate of organic matter is not nearly up to summer’s eight percent. Even if the soil contained five to 10 percent organic matter, it would not supply sufficient nutrients to grow early spring crops such as cabbage, broccoli, cauliflower, celery and lettuce.
    Traditional agriculture uses starter fertilizers with early spring transplants. Starter fertilizers are made of water-soluble minerals that are instantly available to the roots of plants, regardless of soil temperature. Applying these fertilizers near the roots of new transplants helps establish them quickly in the soil and resume normal growth. 
    Compost tea can be used as starter fertilizer. Brew the compost tea at room temperature three or four days prior to transplanting. Partially fill a five-gallon pail up to half capacity with mature compost. To assure maturity, I strongly recommend using commercial compost. Top with water and stir vigorously. Stir the compost three or four times daily to provide adequate aeration for nutrient release from the compost. Or you can aerate the compost using an aquarium air filer as a substitute.
    When you transplant three or four days later, irrigate each plant with one to two cups of compost tea.
    A second batch of tea can be made using the same compost by filling the pail again with water and repeating the process. The second batch will not be as concentrated as the first unless you allow a week or more for it to release its nutrients into the water.

Part 2: How to supply nutrients organically

     In organic gardening, all nutrients are supplied through the process of mineralization. As organic matter is decomposed by the microorganisms that digest the cellulose and hemi-cellulose, minerals contained within the cells of the animal or plant tissues are released into the soil. After the microorganisms have digested all digestible cells, they die. Since their bodies consist mostly of proteins, the proteins are broken down by enzymes, releasing more nutrients, mostly nitrogen (N), into the soil. 
    The rate of mineralization is dependent on temperatures in the soil.
    Under laboratory conditions, mineralization rates are measured at room temperature, 72 degrees. Moist soil samples are held in temperature-controlled containers for several days, then the amount of available nitrogen in the soil is measured. This process is repeated until the figures are stable. Mineralization rates are faster at temperatures above room temperature and significantly slower at temperatures below room temperature. At 72 degrees, the mineralization of compost is between eight and 10 percent. Mineralization of organic matter stops when soil temperatures approach the freezing point.
    The rate of mineralization has a major effect on plant growth.
    Because soils are cooler in the early spring, the rate of growth is often reduced for early spring crops such as peas, cabbage, broccoli, cauliflower, lettuce and spinach. Cooler soils mean fewer nutrients becoming available. This problem can be minimized by selecting south-facing slopes for early spring and late fall crops. Planting the crops on ridges is another method of encouraging early warming of soils. A soil raised above a natural grade warms faster than a soil that is level on grade. Covering the area to be planted with a sheet of clear polyethylene several weeks before planting, followed by ridging and covering the ridges with black plastic mulch, is labor intensive but will stimulate early mineralization. Soils warm very rapidly under clear plastic due to the greenhouse effect. However, anticipate early growth of spring weeds, requiring light cultivation or spraying with horticultural vinegar. Ridging and mulching with black plastic will also provide weed control.
    Apply no more than four cubic yards of compost or animal manure per 1,000 square feet in any one year. Five percent is one year’s limit for organic matter added to the soil. Excessive applications of either can stimulate excessive vegetative growth and weak spindly plants. With the mineralization rate eight to 10 percent, 90 to 92 percent of the minerals remain in the soil’s organic matter. So repeated applications of compost and organic matter should be based on soil test results.
    If existing soils contain less than three percent organic matter, an initial application of four cubic yards of compost or animal manure the first year followed by repeated applications at two cubic yards in successive years (or on alternate years for sandy soils) can be adequate. In silt or clay loam soils, these levels may be excessive, requiring greater dependency on soil test results.
    Initially, compost or animal manure should be incorporated to a depth of six to eight inches, deeper if possible. Because organic matter reduces the bulk density of soils, deep incorporation promotes deep rooting, making crops more tolerant to drought. As deep incorporation of organic matter promotes deep rooting, the roots that penetrate this region will continue to maintain the organic matter concentration in that region.
    Repeated applications of compost or animal manure should be incorporated only in the upper three inches of soil. This results in concentrating the nutrients in the region where seed germination occurs and where roots of new transplants initiate growth. Leaching will move nutrients deeper into the soil as the growing season progresses.

Lesson 1: From the ground up

     Organic gardening is a science based on being able to supply nutrient needs and ideal growing conditions that will produce healthy plants that can resist diseases and pests. Fruit and vegetables free of pesticides are considered healthier because they are untouched by man-made chemicals with the potential to cause health problems.
    Success in growing plants organically begins with selecting land that can generate ideal growing conditions. Site and soil are of utmost importance. Establishing an organic garden on a slight slope facing south gives you soil that warms more rapidly in the spring and stays warmer in the fall than soil on a northern slope. A warmer soil will release nutrients from organic soil matter faster. Sandy soil will warm faster than silt or clay soil because there is less water present and the soil is denser. However, during drought, sandy soils will need supplemental irrigation and/or mulch to satisfy the water needs of the plants.
    Full sun also helps warm the soil, enabling the release of nutrients from organic matter and maximizing ­photosynthesis.
    Well-drained soils are essential to promote deep rooting of plants and early warming of soils. Avoid poorly drained soils. Good air drainage is essential for the rapid drying of foliage to minimize disease problems.
    Since the organic content of the soil is the primary source of nutrients for plants, the pH measurement of soil acidity should be monitored by regular soil testing at three-to-five-year intervals. Soil testing is also a guide to maintaining optimum levels of nutrients such as calcium (Ca) and magnesium (Mg) and to prevent phosphorus (P) and manganese (Mn) from accumulating in excessive amounts.
    The organic garden thrives on organic matter. To be successful, you need to increase the organic matter of the soil to five percent and above. For every percent of organic matter present in soils, 10 pounds of nitrogen (N) is generated per acre per year through a biological process known as mineralization. To obtain optimum yield, you must maintain the organic matter content of the soil at between five and 10 percent. Maintaining levels of organic matter concentration above five percent requires yearly applications of organic matter. Good sources include compost, animal manure and organic fertilizers such as fish emulsion, cotton seed meal, bone meal and compost tea.
    In choosing seeds, the organic gardener seeks varieties with vigorous growth characteristics and disease resistance. In planting, avoid over-crowding, which increases competition among plants for sunlight and moisture. Crowded plants are more susceptible to diseases because they tend to be weak and their foliage is likely to remain wet for prolonged periods of time.
    Healthy plants are more resistant to diseases than weak plants. However, healthy plants are equally susceptible to insect damage, though they are better able to tolerate limited plant damage before significantly reducing yields.

Can the Bay Gardener solve it?

About 30 years ago, I began to build up my garden with compost and leaves. Every few years, I would gather and put down about three feet of leaves to rot and be tilled into the 50-by-50-foot garden space. The garden now has a beautiful loamy soil. I have been planting with wonderful results for about 20 years.
    About six years ago, I collected the leaves and put them down but did not plant for two years. I gather the bags of leaves, mostly oak, from neighboring houses. Several mulched bags of grass were in the mix this time.
    When I next planted my garden in a six-by-30-foot area, all the plants, tomatoes and cucumbers withered and died over a 12-hour period. The plants had been in the ground for about three weeks and had begun to produce small vegetables.
    I immediately removed them. The University of Maryland Extension Service recommended I plant buckwheat and oats. This I did for two years in a row. It grew beautifully, and so did the weeds.
    This year I have once again planted the garden. In the very same area, all the vegetables withered and died over 12 hours.
    The garden has been tilled many, many times. This is the only area that has the problem. It has not spread to another section of the garden.
    Could I have gotten some chemical like Roundup in the collected bags? If that is the case, why has it not moved with all the tilling?
    I might add that the dead plants have perfectly healthy root systems, and there are no tunnels or holes from moles or voles.
    I am totally at a loss as to what is happening and as to what I can do to fix the problem. Any advice you can give would be greatly appreciated.
–Pat Fessler, Crownsville

The Bay Gardener’s Solution


    The problem is not Roundup. Glyphosate, as the Monsanto weed-killer is called, deteriorates into phosphorus once it enters the soil. It does not have weed control properties when it becomes a soil component.
    I suspect that the soil is infested with fusarium, which is a fungus, or possibly sodium or soluble salts. I suggest that you have the soil tested by A&L Eastern Agricultural Laboratories. Request the S3 test to include soluble salts and sodium. Submit one sample of soil from the affected area and a second soil sample from the surrounding area. Do not indicate crop or request recommendations. Each soil sample should include at least five core samples from each area. Air-dry the samples overnight before mailing them for fast results. Print submission form and instructions from the web page: www.al-labs-eastern.com.
    Have the lab send me the results at DR.FRGouin@gmail.com. We’ll get to the bottom of this.

Rest and replenish your bed

If you were wise enough some years back to plant asparagus, you’ve been rewarded with a spring feast. Now it’s time to give your asparagus bed a rest to ensure future harvests.
    An asparagus bed planted in full sun in well-prepared and well-drained soil can remain productive for 20 years or more — if you treat it well.
    If you want your bed to serve you with an abundance of spears each spring, you must avoid over harvesting. Stop gathering spears by mid-June — now — to allow mature foliage to develop. An abundance of foliage is necessary to replenish the energy in the roots and crowns for next year’s crop.
    Extending the harvesting season until July will result in a limited crop next season because insufficient time was allowed for recovery. On the other hand, if you limiting the harvest to just a few weeks in the spring, the bed will expand too quickly, crowding the stems. This problem is corrected by extending the harvest season the following year.
    Weeds can be a severe problem in asparagus beds. Keeping up with weeds begins in the spring before the spears appear. Cultivate the beds lightly by using a Nebraska flat blade or a sharp hoe or by shallow tilling. I like to cultivate my asparagus bed the first week in April. We don’t start cutting asparagus spears until mid-April.
    Once the stalks have developed and the plants are in full foliage, an onion hoe is ideal for removing weeds. Soon after I make my final harvest in early June, I appliy Preen at the recommended rate. Preen is cleared for use on vegetable crops.
    Fertilize or mulch with compost soon after the harvest season. I apply calcium nitrate at the rate of one pound per 100 square feet and then apply a one-inch layer of compost. I also place a trickle irrigation line down the middle of each bed before applying the mulch. The trickle irrigation lines are on a feeder line of their own.
    In the fall, do not cut off the stems until the foliage has turned completely yellow. Patience allows all of the nitrogen in the stems to drain down to the crown, where it is readily available for next year’s crop.
    As asparagus beds age, they become more attractive to asparagus beetles. Thus far I have never had a severe infestation.
    However, in August you are likely to see caterpillars of different colors feasting on the foliage. These are mostly butterfly caterpillars that can most easily be picked by hand each day unless you are interested in promoting butterflies.


The Mystery of Bulb Storage, Solved

Q    I read your May 22 column (www.bayweekly.com/node/22306) on moving daffodil bulbs. It’s time to move mine, and your column is helpful. However, I have always wondered why you can’t just replant them right away. After all, they spend the summer in the ground if you don’t move them. But I’ve planted daffs right after I dug them, in June, and they didn’t do well at all. And these were my most vigorous growers. So why do they need to be stored until fall?
     –Lucy Goszkowski, Annapolis

A    Many bulbs are damaged in digging. Storing them before planting in the fall allows the wounds to callus. When bulbs are planted immediately after digging in the summer, damaged bulbs will rot. If you don’t mind gaps in your new planting, go ahead and replant the same day you dig.

Ask Dr. Gouin your questions at DR.FRGouin@gmail.com. Please include your name and address.

Last winter was hard on this easy-to-grow fruit tree — but not fatal
The winter of 2013-2014 was so severe that it killed fig trees back to the ground. Many plants also suffered severe rabbit damage at the base of the young stems with smooth bark. Rabbits eat the smooth brown bark at times when other food sources are scarce.
 
As we are located at the northern climatic range for growing figs, we need to anticipate winter damage at least once every 10 to 15 years. According to my records, the last time fig plants were killed back to the ground was during the winter of 1997-1998.
 
If the stems and branches are not exhibiting new growth by early June, the tops of the plants have been killed. However, if you look closely at the ground beneath you should see new shoots emerging from the roots.
 
Cut the dead stems as close to the ground as possible and use them next winter for starting the fire in your fireplace or wood stove. Fig wood ignites very quickly and makes good kindling. 
 
Allow the new shoots to grow two to three feet tall before thinning. To avoid crowding, allow at least 3 feet of space between new stems. Select only the more vigorous stems to develop and prune out the unwanted ones. Do not simply break them away but use clean, sharp pruners to remove stems close to the roots. If you break the unwanted stems, you are likely to see additional sprouting that you will have to remove later.
 
This year’s new growth will not produce figs. If you do see figs developing in the axils of the leaves, rub them away with your hands. Allowing the fruit to develop on the new growth will weaken and dwarf the stem.
 
Allow the new stems to grow five to six feet tall before pruning away the tip of each. Tip pruning will stimulate multiple branching, which will provide more fruit for the coming years and prevent the stems from getting too tall. Preventing the stems of figs from growing above six feet facilitates harvesting. 
 
I have never fertilized my figs in the 20 years that I have been growing them here in Deale. Fertilizing figs makes them difficult to manage. If the summer foliage has a good dark green color, it is best not to fertilize them. The plants will tolerate a wide range of soils and are not sensitive to different soil pH.  
 
Figs are a fruit crop that I recommend to home gardeners because they require little attention and never need to be sprayed. Pruning to facilitate harvesting is all the attention they need. 
 
If rabbits are a problem there are several preventions. Surrounding the area with two-foot-tall chicken wire is the simplest if you have an extensive planting. If you only have a few plants, there are white plastic wraps that expand as the trunk grows. You can also solve the problem by loosely wrapping the trunks with two layers of chicken wire.
 
There are several varieties of figs offered by mail order nurseries.  I grow Brown Turkey (pictured) and Golden Egyptian. I have not seen any differences in hardiness between these two varieties.  Both were killed to the ground this winter.

Time your pruning for both desirable growth and flowers

While azaleas were blooming mid-month, I passed a home in the Deale area where the bushes were so large that it must have been impossible to look out through the lower part of the front windows. They must have been sheared at some point because the middle of the plants appeared very bushy.
    This is a common problem and one that is simple to correct — once you get out the pruners and get past fear. 
    Well-established azaleas are almost impossible to kill. Their only sure death is by over-mulching or repeated mulching with hardwood bark. The plants are very shallow-rooted; over-mulching them suffocates the roots. Repeated applications of hardwood bark lowers the acidity of the soil and releases high levels of manganese, which prevents iron from being absorbed by the roots.
    If azaleas are well established and growing too well, simply prune them back 12 to 18 inches below the windowsill now, as the flowers are wilting. The sooner you prune the better. Stems up to three-quarters-inch in diameter will sprout new branches by the hundreds. Do not prune all of the stems at the same height. Cut some stems back 12 inches, others 18 and others 24 to give the plant a more natural appearance.
    Within three weeks after pruning, you will see small green dots emerging from the bark. Each of those is a potential branch. If you allow all the green dots to develop, you will get too many branches, giving the plant a bottle brush appearance. To avoid this, in mid-June or early July, use your fingers to rub away half of the developing nubs. These newly emerging branches are soft, succulent and easily removed. In mid-August repeat the process, this time keeping the best-developed and strongest branches and removing the others.  
    Do not fertilize or mulch the plants with compost until after vigorous growth appears on the pruned stems. Keep them thoroughly irrigated during dry periods.
    Since azaleas initiate flower buds beginning in mid- to late September, avoid shearing the plants after the middle of August. Flower buds are initiated at the ends of newly developed branches. If you delay shearing until mid- to late September, you will be eliminating most of the new growth, and the plants will have no flowers next spring.