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Articles by Dr. Francis Gouin

Compost works for us at construction sites, landfills and wastewater treatment plants

Silt-laden water from construction sites and poorly managed farm fields are notorious for contaminating our streams, rivers, lakes and bays. Silt fences are mandatory at construction sites, but even when properly installed they do not hold back clay. Adding wood chips or straw bales won’t help.
    However, adding a berm of compost a foot tall on the lower side of the silt fence will stop the clay. Filling Filtrex-Sox with compost is an excellent solution. Compost works because of its high exchange capacity. Yet many state and county regulations still specify only silt fences.
    Seeding the berm with vigorous grasses such as tall fescue or rye makes it even more effective. The roots of the grasses not only stabilize the berm but also absorb nutrients both carried by the surface water and released by the mineralization of compost.
    Compost is also an effective filter for covering landfills. Research done in Australia and replicated in the U.S. has demonstrated that compost prevents methane — generated by decomposing organic waste under anaerobic conditions — from escaping into the atmosphere. The microorganisms in the compost convert the escaping methane gas into carbon dioxide.
    In composting biosolids using forced air, finished compost filters the air exhaust and controls odors.
    All of the progress we have made and knowledge gained is due to the Clean Water Act, enacted by President Lyndon Johnson. The Act established the USDA Biological Waste Management Laboratory in Beltsville, where I had the honor of working.
    At the Biological Waste Management Lab, we developed the science of composting, maximizing the rate of composting and assuring that composted biosolids are safe to use. I worked there from 1972 until it was disbanded in 1980 by President Ronald Reagan. My research contributions were developing uses for the compost in nursery, greenhouse crops and landscaping.
    I later became involved in developing composting systems for yard debris, crab waste, paper-mill sludge and garbage. I also established the first commercial composting school, The Better Composting School, which attracted students from across the country and world.


Help with Rot and Blight

Q    I need help with two problems:        
    1. All of my squash, yellow summer and butternut, are developing blossom end rot. I added calcium nitrate upon seeing the first blossoms, but that has not helped.
    2. I have a spot in the Goshen Farm sharing garden. My tomatoes look like they have blight. These tomatoes have been stalked and lower limbs removed about eight inches up. Forty yards away in what they call the slave garden, I planted three tomatoes but had no stakes. These tomatoes are lying on the ground and have no signs of blight. Am I correct in assuming there is blight in my own space? If so, how do I get rid of it for next season?

–Paul Bunting, Annapolis

A    When was the last time you had the soil tested?
    If the squash is having blossom end rot, I suspect the calcium level is low or there is a calcium/magnesium imbalance. Applying calcium nitrate after you see the symptoms may help in reducing the problem for the rest of the summer, but it will not eliminate the rot.
    Have your soil tested by either Waypoint in Richmond or Ag Lab in Delaware.
    With regards to blight, I strip the foliage at least 12 to 14 inches from the bottom stems and also limit the number of stems at the bottom to three to promote good air circulation. The tomato plants that are not staked most likely have better air movement. Are both tomatoes the same variety? Some varieties are more susceptible than others.


Ask The Bay Gardener your questions at DR.FRGouin@gmail.com. Include your name and address.

Turn on the blooms with Bloom

To keep plants in hanging baskets growing and flowering for two months or more, dump one-half cup of Bloom in a single lump on an eight-inch diameter hanging basket, or one cup for a 10-inch basket. At each irrigation, pour water onto the mound of Bloom. As the water flows through the Bloom, it absorbs nutrients and makes them available to the roots of the plants.


Trying to Make a Better Rain Garden

www.bayweekly.com/RainGarden-072017

Q    I just read your July 20 column Make a Better Rain Garden and have a couple of questions.
    I built a pond, near my house in rural Prince Frederick about 20 years ago. It is 100-by-60 feet and has a heavy-duty, one-piece, rubber liner under a foot or two of sand (and now, an additional 20 years of organic muck). The depth varies from one foot (a ledge along the edges) to six feet in the middle. It has two pumps, and I planted it out with native plants — arrowhead, pickerelweed, spatterdock, native water lilies — and added fish.
    I have been renting the house for eight years. The renter (with my blessing) has ignored the pond. It still holds water but is a slimy mess, has shrubs and small trees crowding around the edges and is basically going back to nature.
    I will be moving back soon. I am older now and have no interest in the maintenance required to keep the pond healthy. I have been thinking about my options: from doing nothing to filling it in and planting grass on top. Then I read your article … maybe a rain garden?
    I also don’t have the energy or budget to do it right (as you describe in the article). Is there a quick and dirty option? One that will require minimal work and still provide some of the benefits?
    For example: what if I cleared the jungle from the edges, drained the pond, let the muck dry out, drilled some holes through the liner, filled the hole with decent soil and planted native plants?
    If I go the rain garden route, do you have a list (or website) of native plants that might work in a Maryland rain garden? And maybe where to buy them?
    I always enjoy your articles.

–Steve Farrell, Broomes Island

A    My suggestion is to drain the pond, use a power auger to drill holes through the membrane and below and fill the holes with pine bark mulch. Based on your submitted pictures, I would plant bald cypress, available from the state forest nursery, deciduous holly, alder and cattails.


Grass Isn’t Always the Answer

Q    I need your expert advice. I have a street strip of grass nine feet wide and 18 feet long, separate from other parts of my yard that have pretty grass.
    I have been very frustrated watering that strip. A little silver dollar-size sprayer attached to a hose sprays a circle in one spot and takes forever to water areas like this.
    I looked at hoses with holes in it that I could use in the center of the area.
    What would you suggest?

–Ruth Gross, Bowie

A    Why don’t you forget about growing a lawn between the sidewalk and the curb and plant ground cover — junipers or Saint John's Wort, vinca major or vinca minor — something that will not need to be irrigated or mowed. Ground cover juniper is extremely drought-resistant, likes full sun and is nearly maintenance free. If you plant through landscape fabric, you will not even have to weed.


Ask The Bay Gardener your questions at DR.FRGouin@gmail.com. Include your name and address.

My model is good enough for the National Botanical Garden

The purpose of rain gardens is to reduce surface runoff by capturing water in ponds where it can infiltrate the soil. Many rain gardens begin with dug ponds lined with sand and gravel. Water-tolerant plants added in and around the ponds absorb more water.
    This design can absorb only a limited amount of water based on the soil porosity, a measure of texture and compaction. After a heavy rain, water can stand for days and weeks, so the gardens become breeding grounds for mosquitoes. Even tolerant plant species have problems surviving standing water.
    There’s also a septic smell to some newly constructed rain gardens. The odor is caused by soils containing more than three percent organic matter, which is typical with a manufactured medium with compost blended in. When soils and materials rich in organic matter are water-logged, they undergo anaerobic digestion, resulting in odor.

Getting It Right
    A well-designed and constructed rain garden should not retain water for more than a couple of days and should promote the growth of plants tolerant to wet soil conditions. Soil for its bottom should contain only well decomposed organic matter, not freshly made compost.
    Here’s how to meet both those goals.
    Water absorbing capacity can be significantly increased by either auguring holes in the bottom of the rain garden during construction or by trenching.
    If the rain garden is big enough to accommodate a power trencher, trenches four feet wide and up to four feet deep should be dug at 18- to 24-inch intervals across the bottom of the pond.
    Fill trenches with pine fines in 12-inch lifts. Pack the pine fines using a eight-foot four-by-four timber between each lift until the trenches are filled. Finally, place a covering of sand or gravel over the bottom of the pond.
    In small ponds, augur four- to 10-inch diameter holes spaced about 18 inches apart to a depth of three to four feet. Fill the holes with pine fines in 12-inch lifts and packed similarly. Cover the bottom as above.
    Pine fines are the fine particles that collect in the manufacture of pine bark mulch. They contain 100 percent lignins, which resist decomposition. When buried deep in the soil and covered with sand or gravel, they will not generate odors. Pine fines are also a rich source of humic and fulvic acids. Both of these naturally occurring acids will help loosen the soil, allowing it to absorb more water. Further, the pine fines will serve as a wick, pulling water down where it can be better absorbed.
    Augering or trenching deep into the sub-soil greatly increases its absorbing capacity. This system also increases the surface area and water-absorbing capacity of the soil.
    To accommodate plants in the pond, place a four- to six-inch layer of a sandy loam soil with two to three percent natural organic matter over the layer of sand or gravel. Never amend the soil with perlite or vermiculite. Perlite will deteriorate into slime after several years of freezing and thawing. Vermiculite flattens into plate-like particles in only six to eight months after they have absorbed water.
    I have used this system many times and never had a failure. The largest project I was involved in was the National Botanic Garden at the base of Capital Hill in Washington, D.C. Following heavy rains, the existing water gardens overflowed into the gardens. To increase the water garden’s ability to absorb more water, we augered 10-inch holes in the bottom to a depth of five feet at 24-inch intervals. The holes were packed and the bottom covered with gravel as described.


Apologies to Flint, Michigan

    In my June 29 column, The Poop on Biosolids, I wrote “Unless the biosolids come from Flint, Michigan, the lead levels in Class A biosolids are far below EPA standards in Compro, Orgro and Earthlife. The same is true for cadmium.”
    A Bay Weekly online reader in Flint who is knowledgeable about the biosolids has corrected me. He has assured me that Flint is generating Class A biosolids. The assumption that I made was based on the research I did with biosolids from Baltimore in the late 1970s before Mayor Schaffer cleaned up the sewer system. I apologize for making that assumption.


Ask The Bay Gardener your questions at DR.FRGouin@gmail.com. Include your name and address.

Vertical Mulching and Tree Roots

Q    I enjoy your articles. Recently you’ve written about trees & Bloom.
    I have two chestnut oaks that now have slime flux. Do you think your method would help these trees? I have called forestry schools, and they tell me I can’t do anything. Commercial tree companies want to sell me a fertilizing service for $1,000 with no guarantee.
    Would drilling at three feet cut through and damage the roots? I have about 20 of these oaks and all have shown some stress the last few years. I wouldn’t want to hurt their roots.
    Do they sell Bloom in the Annapolis area? Or is there some substitute?

–Dave Bastian

A Making the tree healthy is the best treatment for curing slime flux. Vertical mulching with Bloom ASAP will stimulate those chestnut oaks to generate new growth, which will result in compartmentalizing the region in the trunks that is generating the slime flux.
    I vertical mulched using compost on my own cherry bark oak tree here in Deale 25 years ago when we moved here, and within two years the slime flux stopped. I drilled six-inch diameter holes. Don’t worry about damaging roots. If you hit the roots with the auger, the tree will generate new roots from the damaged area. When a tree is dug, balled and burlapped, the tree loses 80 percent of its roots, and it recovers.
    I have vertically mulched my 200-year-old cherry bark oak five times, and it is healthier than ever.
    Bloom is sold at Homestead Gardens in Davidsonville.


Girdling Ivy Kills Trees

Q    I enjoyed your vertical mulching article in Bay Weekly. I have two large silver maples and another mature tree. Vines have almost completely covered them, and I wanted to know if this is harmful and should I remove it. I imagine it would damage the bark to just rip the vines off after they’ve gotten so attached. And the deep vines up in the trees do provide habitat for birds and squirrels. But if it’s killing the tree, then I guess I need to take action.

–Rich Kavanagh, Deale

A The silver maple is a short-lived tree. Yes, I have seen over the years where English ivy has killed trees. This will occur if the vines completely circle the trunk and you can see the bark of the tree growing over the vine. It kills the tree by girdling.  If the vines are mostly growing straight up the tree, like many do, it is not a problem. From the looks of the top growth visible in the picture you sent, it appears that the new growth is sparse, which means that the vines appear to be girdling the trunk.


Replacing a Silver Maple

Q    We have sadly watched a large silver maple die over the past few years. It was probably about 50 years old and the source of a plague of box elder bugs. We are having it removed soon and need to know a good replacement. Also, will we have to wait to see if there is any disease or bugs in the soil that could infest a new tree?
    Do you have any suggestions for a quick-growing shade tree? We are thinking honey locust or dogwood. Our home is in Upper Marlboro.
    We really enjoy your column. Thank you for your advice.

–Leda Kress, Upper Marlboro

A Most fast-growing trees such as silver maple have short lives. However, the Shade Master honey locust is a fast-growing cultivar that has a relatively long lifespan.
    The box elder bug only feeds on female box elder maple trees. We have lots of box elder maples growing in this region. I doubt very much if the bug caused the death of your tree. Silver maple trees are prone to fusarium wilt, which may have been the problem. Since it has had a slow death, I strongly suspect that your tree was infected and you need not worry that it will affect the Shade Master locust.


Ask The Bay Gardener your questions at DR.FRGouin@gmail.com. Please include your name and address.

Early-rising yellow-bellied sapsuckers

The rings of evenly spaced holes you see in the trunks of smooth-bark trees are the work of yellow-bellied sapsuckers. The birds drill into apple, beech, birch, cherry, linden, peach, plum, red maple and southern magnolia as well as pine and cedar trees. I have received several reports from readers wondering what is causing the holes because they have not seen any woodpeckers on their trees.
    To see yellow-bellied sapsuckers in action you will need to rise early. They do most of their feeding starting about an hour before sunrise, when the sap is at its highest concentration of sugars.
    Most woodpeckers make holes in trees in search of insects. Yellow bellied sapsuckers puncture the bark for the purpose of lapping the sweet sap that lies just inside.
    In most instances, the damage done by yellow-bellied sapsuckers is not sufficient to cause permanent damage to healthy trees. However, I have seen rather severe die-back of southern magnolias at the top of the tree where the stem was about six inches in diameter. In this instance, the holes made by the sapsuckers were about a half-inch apart in a band about four inches wide. I had never seen such a concentration of holes in such a narrow band.
    Sapsucker damage on cherry, peach and plum trees can result in increased borer infestation in the trunk.
    Both flat-head borers and peach-tree borers are always in search of easy entry into the bark of these species. If you see a gummy red resin exuding from a hole started by a sapsucker, you can assume that a borer found its way into the wood and is well established.
    It is not unusual to see some trees heavily damaged while a nearby tree of the same species does not exhibit any damage. One can only assume that the sap of one tree is more appealing than that of the other.
    Yellow-bellied sapsuckers can be repelled by tying foot-long, one-inch-wide strips of aluminum flashing to branches near the stem of the tree. Giving the strips a few twists so as to form them into a spiral will allow for more movement by the wind. To allow for maximum movement of the strips, attach them to the branch with cotton string two to three inches long. Use cotton string that will rot in a year so as not to girdle the branch.


   Harlequin Beetle Alert   

    Harlequin beetles are already feeding on the leaves of plants. As their population can multiply rapidly, start checking the foliage of your plants now; they are not fussy as to what they feed on. Look for them in the morning before temperatures rise. As the day warms, they will migrate into the more shaded areas. Early on, you can control them manually by either squishing them with your fingers or drowning them in water containing dish detergent or vinegar.


Ask The Bay Gardener your questions at DR.FRGouin@gmail.com. Please include your name and address.

Composting and PFRP make them safe for your garden

Readers continue to write with concerns about composted biosolids and Bloom. To calm your concerns, I’ll lead you through the processes that make fully treated biosolids safe to use in your food garden.
    Since the early 1980s, thousands of tons of composted biosolids have been sold and used in the Baltimore-Washington, D.C., area and surrounding states. All made according to EPA and USDA specifications, Compro (biosolids treated at D.C.’s Blue Plains Wastewater Treatment Plant); Orgro (made at Baltimore Back River Wastewater Treatment Plant); and Earthlife, (made at City of Philadelphia Wastewater Treatment) have been used effectively by home gardeners, landscapers and growers of nursery and greenhouse crops.
    I have been involved in conducting research growing numerous crops using composted biosolids from all three major producers in this region. In addition to ornamentals, I have grown and eaten fruits and vegetables from compost-amended soils. I have reviewed numerous research manuscripts that support the use of biosolids compost in horticulture. Even agronomists who have studied the effects of biosolids and composted biosolids in the production of cattle feed and grain crops have reported no adverse effects when biosolids are used properly.
    To be cleared for composting, biosolids must reach Class A standards. At Class A, all nutrients and heavy metals are below EPA allowable levels. Wastewater facilities submit samples for testing monthly to keep this certification.
    During composting, PFRP (Processed Further to Reduce Pathogens) standards must be achieved, meaning the composting materials are maintained at 150 degrees for 10 consecutive days. Achieving these temperatures is not difficult because at the middle stage of composting temperatures often reach 180 degrees. EPA also requires that equipment used for loading the composting system be independent of the equipment used for moving the finished compost.
    The microorganisms at work in composting are bacteria, fungi and actinomycetes, which destroy organic and even inorganic compounds. Scientists at the Biological Waste Management Laboratory have used composting to destroy PCBs in contaminated soil. I have used composting to destroy dioxins in bleach-contaminated paper-mill sludge.
    The metals of greatest concern are lead and cadmium. Unless the biosolids come from Flint, Michigan, the lead levels in Class A biosolids are far below EPA standards in Compro, Orgro and Earthlife. The same is true for cadmium.
    The system used for making Bloom is even more aggressive. First the biosolids are steam sterilized under pressure; then they are digested by anaerobic organisms, which are more aggressive in destroying compounds than aerobic organisms.
    The roots of plants are selective in what they absorb. Plant roots can only absorb minerals; they do not absorb compounds and chemicals. In soils containing more than three percent organic matter, heavy metals such as lead and cadmium become fixed, thus making them unavailable for absorption. Much of this research was published by Dr. Rufus Chaney, a research scientist of worldwide reputation, at USDA Beltsville. He did most of his lead studies in lead-contaminated soils in Baltimore. I had the honor of working with Dr. Chaney while associated with the Biological Waste Management Laboratory.
    Skeptics who have forwarded warnings against biosolids, please note the distinction between raw biosolids, whose use I do not advocate, and composted and processed further biosolids.

Ask The Bay Gardener your questions at DR.FRGouin@gmail.com. Please include your name and address.

Vertical mulch with Bloom

A mature tree not only increases the value of your home but also offers shade during these hot days of summer, thus reducing the cost of air-conditioning. Trees also provide branches for hanging swings and places for birds to nest and perch.
    However, your surrounding lawn does not provide the best conditions for keeping mature shade trees healthy. Soil compaction is often a problem, as foot traffic, riding mowers and often other vehicles compact the soil surrounding the roots.
    Fertilizing the lawn does not feed trees. Turf grasses are heavy feeders on nutrients, leaving little to nothing for the deeper roots of trees. Apply an excess of fertilizer under shade trees, and you are likely making the turf susceptible to diseases.  
    Fertilizer tree spikes don’t help much, either, as research shows they fertilize primarily the surrounding grasses. Deep-root feeder probes often go too deep as they’re designed to prevent the fertilizer solution from bubbling to the surface.
    There is a better way.
    In the early 1980s, the University of Maryland installed a water feature in the center of the campus mall. During its construction, heavy equipment compacted the soil beneath the canopy of willow oaks lining the mall. Within one year, the trees went into severe decline, with large branches dying.
    To save the trees, I augered hundreds of four-inch diameter holes 10 inches to a foot deep at two-inch intervals. We packed the holes tightly with LeafGro. Next spring, the trees were producing lush new growth on many of the dying branches. By mid summer, we could see that the treatment had made a difference.
    The University repeated my treatment every seven to eight years. Thirty years later, the trees are still thriving.
    The treatment was so successful that I was invited to the University of Virginia in Charlottesville, where the construction of a new library had damaged mature southern red oaks. Since the red oaks were widely scattered, I varied the system by using a trencher and dug four-inch-wide and 12-inch-deep trenches in a wagon wheel fashion around each tree. The trenches started 10 feet from each trunk and extended beyond the drip line of the branches. Mixed in equal proportions with composted yard debris, soil from each trench was used to fill them to grade. All of the treated trees resumed normal growth within two years.
    Just prior to presenting my research finding at the National Arborist Association, I named the process “vertical mulching.” Many arborists from across the country have since used it successfully.  
    Within a year after moving to Deale, I vertically mulched two large cherry bark oak trees that were declining in vigor. Using a six-inch power auger, I drilled holes 10 to 12 inches deep at three-foot intervals, then filled them with LeafGro. I have repeated the treatment every seven to eight years.
    This year I vertically mulched using Bloom with fantastic results.  My 150- to 200-year-old cherry bark oak trees are not only covered with dark green leaves but also with longer new growth than ever before. The lawn beneath the canopy of branches is better than ever, though I have not applied a drop of fertilizer in more than 10 years. Because it is cut tall and let fall, the grass clippings surrounding each hole filled with Bloom have fertilized the soil between the holes. The lawn in the shade of the trees is a uniform green and growing just as fast as the grasses near the augered holes.
    I continue to be awed by the plant-growth responses I am observing from different uses of Bloom — the superior soil conditioner produced at Blue Plains Wastewater Treatment Facility from Class A biosolids.


Ask The Bay Gardener your questions at DR.FRGouin@gmail.com. Please include your name and address.

Don’t over-handle your onions

Onions are bulbing. Disturbing the plants now will reduce the storage life of the bulbs. Keeping your onion patch free of weeds is important, but from now until harvest you’ll want to weed by hand. An onion hoe may damage bulbs.
    The keeping quality of onions depends on strong and healthy plants. So you should irrigate your onions in drought. Since onions are generally shallow rooted, they should receive a minimum of one inch of water each week. I irrigate my onions twice weekly if we don’t get adequate rain. Use a rain gauge near your garden rather than depending on weather reports to measure precipitation.
    As soon as the majority of the onion tails turn yellow-brown-green, use the back of a steel rake to knock the tops down horizontal to the ground. Allow the tops to soften and start turning yellow-brown before harvesting.
    For maximum storage life, never remove onion skins from the bulbs. The outer layer reduces the transpiration rate of the bulbs, extending their storage life.
    I braid most of my onions, allowing the bulbs to remain attached to the tops. For storage, I hang them in an open garage, in the shade. The onions with the smallest necks are the best keepers and should be saved for later use. The first onions you should eat are those with fat necks, for they have a shorter shelf life.
    The bulbs of braided onions should be separated by gently pulling without disturbing the outer skin of the other onions.
    I store unbraided onions in small baskets hung from the ceiling of the garage. This allows air to circulate through the onions, minimizing rot problems. Check the baskets of onions every two to three weeks and remove any onions that are softening.


More about Bloom

Q    I really like the results I am seeing using Bloom after reading your article. Should I be concerned about heavy metals coming thru to be absorbed in my vegetable garden produce?

–Jan Fergus, via email

A  Bloom is a class A biosolid. Class A biosolids do not contain heavy metals. Today 85 percent of all biosolids generated in the U.S. are class A. The only heavy metals we are concerned with are lead and cadmium. Metals such as iron, copper, zinc, ­nickel, chromium and manganese are essential plant nutrients or needed by soil organisms.

Ask The Bay Gardener your questions at DR.FRGouin@gmail.com. Please include your name and address.

Even with compost you can overdo it

Recently a Bay Weekly reader complained she could not grow cauliflower or broccoli. The plants grew big and lush but never produced edible heads — all this despite the large amount of compost she added to her garden soil each year.
    My response was too much of a good thing. Compost is a good source of not only long-lasting fiber but also slow-release nutrients. For every percent of organic matter in soil, an acre of soil generates 10 pounds of nitrogen each year. If your soil contains five percent organic matter, that translates to 50 pounds of nitrogen per acre per year.
    Growing a good crop generally requires between 100 to 120 pounds of nitrogen per acre per year. If your soil contains 12 percent organic matter, you should not have to apply any nitrogen fertilizer to achieve optimum plant growth — providing all other nutrients are present at optimum levels. If your garden soil contains 15 percent organic matter or more, plants are likely to produce super-lush growth. Leafy plants such as lettuce, cabbage, spinach, Swiss chard, celery and fennel should produce bumper crops. Cauliflower, broccoli, tomatoes, peppers and okra will likely produce large vigorous plants but limited fruit.
    This same problem occurs when you apply too much nitrogen fertilizer. Several years ago a Bay Weekly reader complained that his tomato plants grew like trees but hardly produced any tomatoes. As I was not able to diagnose the problem, based on our discussion over the telephone, I invited him to Upakrik Farm and requested he bring the bags of fertilizer he used. He brought a bag of 10-10-10 and a bag of urea. He said he used urea and not calcium nitrate as I had recommended in one of my Bay Gardener articles because the store manager said calcium nitrate was not available but urea would substitute. Urea contains 45.5 percent nitrogen while calcium nitrate only contains 15.5 percent nitrogen. In other words, the excessive amount of nitrogen from the urea caused the tomato plants to remain vegetative rather than producing fruit.
    Monitoring organic matter content in your soil is another good reason for having periodic soil tests, which also measure pH and nutrient levels.


Are Strawberries Perennial?

Q If you want to get several years of picking strawberries from the same plants, would you leave them alone after picking or would you mow the top leaves off? I know that the commercial guys plow them under each year and replant for the next year, but I had a decent crop this year and hate to till them in.

–Frederic Ames, Shady Side

A    The traditional method of growing strawberries is to rototill under the mother plants, leaving the daughter plants to produce next year’s crop. By doing so, the same bed can produce berries for three to four consecutive years. However, crown mites, often called cyclamin mites, cause crop failure on the fourth year.


Ask The Bay Gardener your questions at DR.FRGouin@gmail.com. Please include your name and address.

Biosolids are safe for food ­production; here’s why

Since I became involved in composting biosolids in the early 1970s, technology for processing wastewater has undergone major changes. Back then, most wastewater treatment facilities had only primary or secondary treatment technology. At the same time, industries were dumping all kinds of waste into sewer systems.
    The Clean Water Act promoted by president Lyndon Johnson led to major changes that now enable us to convert solid waste into usable products while returning more carbon to the earth. The act stopped wastewater dumping into our streams, lakes, Bay and oceans. It established a Biological Waste Management Laboratory managed by the U.S. Department of Agriculture and the Environmental Protection Agency. Studying the science of composting, this laboratory has developed efficient composting systems.
    The Clean Water Act also mandated that wastewater be returned clean to our waterways. Wastewater processing facilities were upgraded to secondary and tertiary systems. Tertiary systems not only return crystal clear water but also generate biosolids that are classified Class A, meaning they can be used to produce agricultural crops.
    The Blue Plains Advanced Wastewater Treatment Facility in Washington, D.C., is the largest plant using the world’s most advanced water treatment technology. Blue Plains processes 300 million gallons of wastewater each day and generates 450 wet tons of biosolids.
    The biosolids are heat-treated to 350 degrees under 87 pounds pressure per square inch. Then they’re infused with active anaerobic microorganisms, and the material moves into the digester. Anaerobic microorganisms are more aggressive in digesting organic carbon compounds than the aerobic microorganisms active in composting. The biosolids remain in the digester for 18 days before filter presses remove excess water.
    The end product is Bloom, a superior soil conditioner.
    Already self-feeding, its production is moving to energy neutral. The digester generates methane gas, used to cook the biosolids. Blue Plains is also installing solar panels over the sludge activators to reduce operating costs.
    Within three years, similar systems will be operating across the country.
    Advanced wastewater treatment and biosolid digestion are only part of the reason you can now safely use processed biosolids in producing food crops. Hard pesticides such as DDT and Chlordane have long been eliminated from use. Pesticides in home use have limited shelf life and are biodegradable. Along with pharmaceuticals, they are destroyed by microbial systems and by the heat.
    Because iron sulfate is added to precipitate the phosphorus from the water, Bloom is not 100 percent organic under current guidelines.
    Bloom is now sold at Homestead Gardens.


Ask The Bay Gardener your questions at DR.FRGouin@gmail.com. Please include your name and address.