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FAQ:  How do I add compost to mature trees and shrubs?

Q:  My established plantings need some compost, but won’t all that digging hurt the root systems?

A:  Think “massage” and not “excavation” to add compost to mature trees and shrubs.  It’s hard to overdo it when using compost and as little as 1/8 of an inch can net visible results.

While there are many ways to apply this soil amendment, these are among the easiest:

For mulched trees 

Scrape away mulch and, using the spreading method of choice, apply up to 2 inches of compost out to the drip line (the widest point of the tree canopy).  

Rake lightly to even out the surface.  But no need to dig in.  This application method is called “top dressing” for a reason.  Happily, over the coming weeks and months, Mother Nature will take care of soil incorporation for you.  Simply reapply the mulch once the area has been covered with compost.

If some of the area under the tree is grassed 

Gently work up to 1/2 inch of compost into the turf with a rake or broom.  You are giving the earth a gentle back scratch, not plowing.  But it’s okay to scratch a little harder where you have bare spots or fairy rings, because compost has been known to help solve some of these types of yard maintenance issues.

A light sprinkle with the hose or irrigation system can also help move compost from the grassy surface to the soil.

But keep the water use to a minimum.  If the application area gets too wet, you’ll just lose all that compost to runoff, wasting both the water and the compost while becoming a contamination source for receiving waters or the stormwater system.

For shrubs and planting beds

Remove mulch, lay down up to 2 inches of compost, and remulch. As an alternative, if you want to apply 3 or 4 inches of compost, it can serve as mulch.

Just be careful to avoid piling compost up around woody stems and tree trunks.  This practice invites insects and could, eventually, kill the plant.

Are you watering with tap water?

City water contains chlorine and chlorine kills microbes – both good and bad.  Will watering plants with tap water kill the beneficial microbes delivered through compost use?

 

Chlorine, chloramine, fluoride, and salts are used to treat city and household water systems.  None of them are beneficial to plants, soils, or the microbial populations contained therein.

The good news is that if your city’s water system maintains chlorine at recommended levels, most plants won’t be harmed and soil/compost microbes will quickly recover.

Generally, chlorine also dissipates quickly.  Fill a 5-gallon bucket with tap water and let it sit for a day or two before using the water on plants.

Chloramine, a compound that includes both chlorine and ammonia, is a little harder on plants and soils.  It is used throughout the US, including a number of metropolitan areas served by McGill composting facilities.  Check out this list to see if your water system is among them.

Over time, chloramine use can acidify soil and damage plants.  If this chemical is running through your watering tap, keep an eye on soil pH.

Fluoride is added to drinking water supplies to strengthen teeth.  It is also found in some fertilizers and perlite.  Burned tips and edges of leaves can be a sign of fluoride toxicity.

Using compost to maintain a neutral pH will limit fluoride availability, as will switching to rainwater or filtered water.

Household systems designed to soften water using salts can damage soil and plants, too. 

Short of installing a new spigot in the H2O line before it reaches the water softener, adding calcium to the soil through applications of gypsum or lime can help.  So does simple leaching (over-saturating the soil to flush out excess salts). 

But know that leaching will also wash away nutrients.  If you opt for this method, be sure to add some compost post-watering to help rebuild the soil.

Collecting rainwater and mixing it with tap water can dilute the harmful impacts of chemicals and salts.

For home use, rainwater harvesting systems can be as simple as a $5 bucket sitting in the yard or as sophisticated as a $2500 tank set-up.

Just make sure water in open-top collection containers is not allowed to stagnate and become a breeding ground for mosquitoes.

Want more information about using tap water for watering plants?  We found this article that discusses the various chemicals used in water treatment and how they impact plants and compost.

Whatever happened to aiming for the best waste management option? 

If it’s easier to do, then it’s the thing to do.  If the job can be done faster by cutting corners, go for it.  If it’s the cheapest option, buy two.  Somewhere along the path of societal evolution, easiest-fastest-cheapest has become synonymous with best.  This linguistic transmogrification is so pervasive, society no longer takes notice of its shortsighted slide down a spiraling path toward all things inferior.

When did easiest-fastest-cheapest become synonyms for best? When did we stop aiming for the best waste management choices and settle for inferior? 

There are good, affordable options out there that can strengthen/support recycling mandates and result in better waste management systems.  But progress toward zero waste is s-l-o-w and too many communities are still stuck in their comfortable ruts.

Progressive leadership looks to the future, ever-steering its constituency toward that proverbial “brighter tomorrow.”  For waste management, that horizon does not include landfills or incinerators. But it does include high-rate industrial composting … if public and private facility owners aim for the best and not the cheapest.

What are the best options for biodegradable wastes, the best organics collection strategies, the best composting technologies, the best facility designs, the best uses for compost products – who asks these questions before plunging head first into a development project?

Or, if someone asks the questions, do they really mean what’s the cheapest technology, design, and collection strategy? 

As for the resulting compost product, is the real objective to put it to highest and best use or to get rid of the stuff as easy and as fast as possible?

‘Best use’ is hard to achieve with an inferior product

Stormwater management, erosion control, carbon sequestration, turfgrass management, landscaping – these rank among the best uses for compost products.

They represent markets that place high dollar value on stable, quality soil amendments with no odor, high organic matter content, macro and micro nutrients, and other characteristics linked to a high-performance product that can be safely used by anyone, anywhere, at any time.

Poor quality compost cannot meet this minimum standard.  For the most part, its sale and distribution is restricted to low-dollar markets like farming and landfill cover.

The catch here is that, when managing mixed organic wastes, it usually requires a combination of the best facility designs, composting technologies, and management protocols to produce a really good compost product.

To achieve top quality, keep product moving out the gate, and ensure the highest possible revenue stream, a facility owner must match those aspirations with a high-quality manufacturing process and competent management that includes a professional sales effort.

Shortsighted strategies won’t meet long-term goals

Many communities are waking up to the fact that their long-range plan needs to include a viable strategy for organic waste management that keeps biodegradable materials – especially, food waste – out of landfills and incinerators.

Composting certainly fits the bill, and it’s often possible to modify an existing yard waste windrow permit to include other organics.

But what happens a few years down the road when that one load of food waste per week turns into a load per day, and then two loads per day, and then 10 loads per day?

When the entire city is source-separating organics curbside, and the vast majority of those garbage trucks are headed for that crowded, outdoor windrow composting facility, what happens then? 

Historically, facility owners (public and private) can struggle through years of banned feedstocks, failed lab reports, public complaints, unsellable product, fines, and/or legal fees before finally facing the facts. Their antiquated composting system simply isn’t up to the challenge of today’s urban waste streams … and their bargain basement facility wasn’t such a bargain after all. 

Successful high-volume processing of urban streams that include highly putrescible materials and biodegradable plastics requires tight environmental control and a high-rate composting process. 

If a facility owner wants to process in the least amount of space, taking the least amount of time, using the most reliable, predictable process, then that owner is going to convert that lesser system to the best system for mixed urban organics.  A covered and/or encapsulated aerated static pile (ASP) system, preferably with computerized control/monitoring and biofiltration, meets those expectations.

But how much might that region or business have saved/earned by investing in an expandable, high-rate facility in the beginning?  Remember, we’re not just talking composting, but all the dollars saved associated with compost use, too.

While Nero fiddled, Rome burned

Fiddling about while the city buries itself under a mountain of garbage is not an example of good governance.  In the private sector, failing to invest in upgrades and new technologies sets a company up for obsolescence.

Both depict outcomes resulting from failure to act when the time is right.

Unlike even 10 or 15 years ago, when most people were clueless about the many benefits of organics recycling on a municipal/industrial scale, today’s taxpayers are aware of composting as a waste management strategy.

Large volume waste generators in the private sector have been using commercial composting services for decades for one reason only – it’s more cost-effective than landfills.  As a bonus, it also gives corporations green points to use in their marketing messages.

Is it right for governing boards to continue to expect taxpayers to pay more simply because those who made the decision failed to be proactive in their decision-making?

No single option will be right for every community.  But giving serious consideration to organics recycling is always the right thing to do.

Starting at the top and working down is a lot easier than trying to claw one’s way up from the bottom.  So, aim for the best solution first, even if it’s not the easiest, fastest, or cheapest option.  

Then, use easy-er, fast-er, cheap-er tweaks to mold that system into the perfect waste management approach, customized to meet the unique needs and expectations of each community or business. 

Considering the pros and cons of waste management technologies?

Evaluations of waste management technologies can be riddled with inaccurate, incomplete, and outdated information – and the full dollar value of compost use is rarely included.

Elected officials making decisions on behalf of taxpayers may be experts in their respective fields.  But most lack knowledge in many areas specific to municipal governance, especially waste management technologies.  Consequently, staff and consultants are often asked to do some research and provide a report of findings, including recommendations.

A couple of articles released last month aimed a spotlight on inherent weaknesses in a process that relies on published research and interpretive reports for decision-making.

One piece focused on a study out of North Carolina State University.  It concluded the best use for compost was as landfill cover.  The other, from the University of Washington’s Dr. Sally Brown, said those research assumptions were off.  Many benefits of compost use weren’t considered.

No matter which viewpoint seems right to those who read the articles, the fact that there are two different takes on “best use” for compost – both from very reputable sources – focuses attention on one of the biggest struggles engineers and consultants face as they attempt to develop meaningful recommendations for policy-crafters and lawmakers.

A never-ending information stream floats about in cyberspace.  Available facts and bits of data are of sufficient quantity and quality to support almost any position one chooses to promulgate.  Adding or subtracting just one factoid in the mix of observations can result in a very different conclusion.

And the sad-but-true fact is that too many studies involving waste management systems fail to include the full range of economic and environmental benefits of composting.  Conspicuous by their absence are those elusive “dollars saved” numbers resulting from compost use.

Level playing fields for waste management technologies are hard to find  

Decisions related to organic waste management options present unique challenges.  Credible research comparing all four of the modern commercial technologies in the same study is rare.  Landfill gas-to-energy, thermal waste-to-energy, anaerobic digestion, and high-rate composting – finding a level playing field for technology comparisons feels like the impossible dream.

A researcher must wade through an ocean of irrelevant and often conflicting studies to find the few that fit the bill.  Volumes and types of materials may differ from one study to the next.  The specific parameters and amount of data collected won’t match up.  One report might focus on energy generation while skipping over input costs.  Others fail to include industrial composting and/or anaerobic digestion along with landfills and incineration or base conclusions on data that is now decades old.

Unfortunately, staff/consultants hired by municipal governments to gather information for these kinds of reports must rely on this mishmash of published data.  Rarely (if ever) does that consultant or in-house specialist have the budget to conduct new economic research comparing four different technologies at field scale using identical waste streams under real life conditions.

Hunting for needles in haystacks

A literature review may require the researcher to sort through a hodgepodge papers and websites to find information.  The hunt can include bench-scale studies, computer modeling outcomes, masters theses, field trials, magazine articles, and published budgets from public record projects. 

From this jumble comes the reviewer’s analysis, report of findings, and recommendations.  But proprietary information like construction and operating costs from privately-owned composting facilities is rarely available in the public arena.  As a result, a consultant’s report may not reflect an accurate picture of a technology’s true potential or the latest innovations.

In the real world, research scientists are limited by budgets, people power, time, personal knowledge, and the expectations of funders.  And while that may be the nature of the beast, the resulting scientific paper merely represents a snapshot of conditions and available data as they existed within the framework and specific timeline of the investigation – nothing more.

Scientists understand this.  But the elected officials using those study results to guide their decisions may not, taking those studies as gospel.  They don’t see inconsistencies or information gaps.  They don’t ask the right questions.

But if all of those studies ignored compost use, do any of their only-halfway-there conclusions really matter?

Getting waste management comparisons to the finish line

Just to see if it could be done, we took a stab at stitching together a balanced comparison of organics management options. Pulled the most recent data we could find from multiple studies.  Adjusted dollars for inflation.  Converted all energy input/output to a common unit of measure.  Cobbled together bits and pieces from a slew of research papers, municipal budgets, and other web resources.  

Tipping fee revenue was assumed for all technologies.  Commercial composting was compared instead of municipal operations because [1] we had a pretty good idea of the costs for building and operating a big, industrial composting plant and [2] many of the published costs we’ve seen over the years for municipal construction and/or operations for similarly-sized or smaller facilities were far higher than our own experience.

Based on a 100,000 TPY operation, annual revenue calculations included tipping fees and sale of products like energy and compost, minus debt amortization for facility construction (without interest) and operating costs per ton processed.

Admittedly, the resulting numbers were very, very crude.  But the grand total of those figures?  All options netted about the same dollars per ton.

Yeah.  We were surprised, too.  However, what none of the studies calculated – including our own investigation – were all the additional economic benefits to be had through compost use. 

Compost use tips the scale in favor of organics recycling

Sadly, the oversights of these reports were not unusual.  The full dollar value of compost use was missing from almost every published economic evaluation of waste management technologies for organics.  The absence of this highly relevant data represents a glaring hole in the big picture, one that can negatively impact an entire region for decades.

Mostly, these benefits represent dollars saved, which are much more difficult to identify and calculate than dollars spent.  But that doesn’t mean those dollar values should be ignored:

  • There is a dollar value for carbon sequestration through compost use.  
  • There are dollar savings in water treatment costs when runoff is cleaner because of compost’s filtration abilities.  
  • Construction projects save when they use compost-based controls for erosion.  
  • Turfgrass managers save when there is compost beneath players’ feet.  There is also a reduction in the severity of sports injuries … more avoided dollars.
  • When compost use is specified as part of a communitywide stormwater program, stormwater systems and their construction costs can shrink.  
  • During times when synthetic fertilizer costs are high, the NPK content of compost can represent a real bargain.  There are also avoided costs related to transatlantic shipping and synthetics’ reliance on natural gas.
  • Compost helps soil combat weeds and control some plant diseases, reducing chemical use on lawns and sports fields.

When a government body responsible for the general well-being of hundreds (or millions) of people is not provided with all the facts, their decision-making suffers.

Granted, it’s devilishly hard to assign dollar values to some of these benefits.  This article by Dr. Brown demonstrates how involved the calculation of even one aspect of compost’s advantages can be.

Yet, the greatest value of organics recycling comes not from composting, but from compost use.  Ignoring this fact serves no one and significantly undervalues composting as an option for mainstream waste management.

If a municipality wants to be assured of choosing the very best technology option for its organic waste stream, issuing agencies and departments will include those important “dollars saved” calculations on the list of deliverables required of their consultant or engineer.

FAQ: Do I have to rake fall leaves?

Nature drops fall leaves for a reason, and it’s not to give sightseers an excuse to tour the countryside.  Those red, yellow, and gold gems will eventually decay to help fertilize the soil for the coming season.   So, no, leaf raking is not a necessity. 

Know, however, that the fall leaf drop can wreak havoc on stormwater systems.  One should, at the very least, make the effort to keep those leaves well away from stormwater inlets and  flow pathways.

Use a mulching mower to break up the leaf mat and accelerate biodegradation once that colorful blanket starts to fade.

If you can’t get through October or November without grabbing a rake, rough chop some of those leaves and use them to mulch planting beds and gardens.

The remainder can go to composting, of course.  Add them to your backyard compost pile, or prep them for curbside collection following your municipality’s guidelines.  And, please, do remove plastics, metal, glass, and other contaminants before moving those leaves to the curb. 

FAQ: Is fall a good time to use compost?

Most definitely, yes.  In fact, some believe the fall season is the best time to add compost to lawns and gardens.  For grassy areas, sprinkle a little over the surface and rake in.  For planting beds, add compost and work into the top layer of soil.  Alternatively, just leave the compost to sit on the surface of the planting bed and allow Mother Nature to work her magic over the winter months.  Cover the surface with leaves or other mulch to help retain moisture.  When spring planting season rolls around, the soil will be ready for you.  Compost products will vary, so always follow the manufacturer’s recommendations about exact amounts to use for specific applications.  You can find McGill’s recommendations here.

Global warming — Earth’s ‘carb’ overload 

Whether the basis for climate change is over-reliance on fossil fuels, loss of jungle canopy, too many chemical fertilizers, natural phenomenon, all of the above, or none of the above – the fact remains that global temperatures are showing an upward trend.  

Some claim the climb is caused by industrialization.   Others disagree and point to a Medieval Warm Period and other episodes of global warming through the ages.  But the crux of the matter is that, unlike our Middle Ages counterparts, the humans living in this era possess the skills, knowledge, and wherewithal to temper the impacts of rising global temperatures. 

We can pull less carbon out of those long-long-long-term storage deposits of coal and oil, plant a few more trees, and let cows eat grass instead of stuffing them with grain.  But we can also try to keep temperatures within our own Goldilocks Zone by sequestering more carbon in soils that won’t be disturbed for extended periods of time.   

Even if all new sources of carbon were reduced to zero, there’s still too much in the atmosphere now – and it has to go.  Scientists are working on numerous projects designed to remove excess carbon from the atmosphere, but soil sequestration remains among the simplest and least expensive solutions.   

First, it must be said that the much maligned “greenhouse effect” is actually a good thing.  It’s what makes this planet habitable for humans.   

In the atmosphere, radiation from the sun generates heat.  As it bounces around in the “greenhouse,” some of this heat is absorbed by the earth and some is released back to space.  But greenhouse gases like carbon dioxide and methane absorb and trap heat.  When there is an excess of this type of gas in the atmosphere, too much heat is trapped and radiated back to the earth, resulting in global warming.   

Other greenhouse gases include water vapor and nitrous oxide.  Industrial chlorofluorocarbons are highly-regulated, synthetic greenhouse gases. 

But carbon dioxide (CO2) has become a primary focus becausits increase is associated with human activity.  Atmospheric carbon dioxide levels have jumped from 280 parts per million to 400 parts per million since the mid-1800s, which coincide with the early days of the Industrial Revolution. 

To reduce carbon compounds in the atmosphere, science looks for ways to naturally or artificially sequester excess carbon for long-term storage. 

Putting the atmosphere on a low-carb(on) diet 

Limiting and reducing the amount of carbon in the atmosphere is the goal of carbon sequestration.     

Vegetation, oceans, and soils are examples of natural sequestration.  These carbon sinks naturally absorb atmospheric CO2.   

Carbon capture, ocean injection, and geological storage are examples of artificial sequestration.   Captured CO2 has a number of industrial uses, including the manufacture of fizzy beverages and plastic bottles.  Athe costs for these new technologies drop, their uses are expected to rise. 

As sinks go, compost use is among the best.  Amending soils with raw manures and biochar also sequester carbon, but neither offers such a wide range of other soil-enhancing benefits as does compost use.    

Almost everyone can contribute to carbon sequestration 

Regenerative agriculture can restore soil health and make a major impact on carbon sequestration.  In fact, the Rodale Institute says more than 100 percent of current global CO2 emissions could be sequestered if all pasture and cropland management was based on regenerative agriculture. 

But one needn’t be a farmer to create carbon sinks.  From backyard to utility easements to parkland, there is opportunity for every community to contribute to the reduction of the planet’s carbon overload.   

Know that things like soil type and local climate can influence carbon retention.  Tactics must reflect the region, because a good strategy for the arid west may not be the best choice for humid, subtropical Florida.   

Yet all sequestration approaches will have one thing in common – decades or centuries-long confinement of that carbon without disturbance: 

  • Establishing a lawn by incorporating compost?  Yes. 
  • Topdressing a garden plot that is tilled every year? Not so much. 
  • Using compost to amend a field that is plowed every season?  Not that great. 
  • Planting that same field with perennials or converting it to grassland?  Much better. 

Any patch of soil that can be amended, planted, and then left undisturbed for many years is a potential carbon sink.  This includes every community’s roadsides, athletic fields, and recreation areas. 

Bottom line:  Earth’s history is peppered with episodes of warming followed by ice ages.  Unless humans learn to manage carbon to moderate temperature extremes – no matter the cause — those who survive this era of global warming may learn the hard way that nature always seeks to return to a state of balance.    

How much compost for my garden?

Compost makes a great addition to any garden plan.  But how much compost do you need?

A new plot in sand may require wheelbarrows of the stuff.  But if you are digging up a patch of lawn that has seen repeated compost applications over the years, the soil beneath the sod should be in pretty good shape.  A sprinkle might be all that’s needed.

How can you tell if the soil is good?  

The best method is soil testing.  (Contact your county Cooperative Extension Service for more information).  But you can use visual clues, too.  

Weeds like purslane, crabgrass, and dandelion are signs of a troubled soil.  

Stick a spade in the ground and turn over a shovelful of soil.  If it’s sticky and looks like modeling clay or dry and resembles beach sand, you’ve got big problems.  Fortunately, your soil is probably somewhere between these two extremes. 

Is it dark brown and loose?  Are there earthworms?  That’s what you want to see.  

How much compost do you need for a garden?

If building raised beds or container gardening, the soil blend should be about 30 percent compost.  When breaking new ground, incorporate 2 to 3 inches into the top 6 to 8 inches of soil.  

If your soil is very hard,  and you are planning deep rooted vegetables like tomatoes,  consider digging a little deeper.  Maintain the compost-to-soil ratio at about one part compost to two parts soil.

For an established garden with decent soil, just rake an inch or two into the surface before planting.   A 1/8 to 1/4 inch layer of compost sprinkled on the surface as needed throughout the growing season can revitalize flagging rows or containers.  The compost will feed your plants when you water. 

Three to 4 inches of compost can also be used as mulch during the growing season or as blankets when putting beds to sleep for the winter.  However, don’t pile compost up against tree trunks and stems of woody ornamentals.   

Our compost calculator can help you determine how much to buy.       

How much does compost weigh?

Depending on moisture level, figure 2 to 2.5 cubic yards of compost per ton.  A one cubic foot bag of compost will weigh about 40 pounds (1 cubic yard = 27 cubic feet).

A product shipped at 30 percent moisture will weigh less than one at 60 percent when it crosses the weigh scale, resulting in more cubic yards per ton than the wetter material when delivered.  

This may be good for keeping transportation costs low. But it also means the microbes responsible for aerobic degradation of the composting mass might die of thirst.  Weights that are too high could be indicative of low oxygen levels resulting from compaction and/or too much moisture — again, not good for the beneficial microbial populations.

An ideal compost will be 40-50 percent moisture.

Are compost and fertilizer the same?

Compost and fertilizer are not the same. But compost does have fertilizer value.

Wikipedia describes fertilizer as any material of natural or synthetic origin that is applied to soil or to plant tissues to supply one or more plant nutrients essential to the growth of plants.”

Compost’s nitrogen, phosphorus, and/or potassium (a.k.a. NPK) values are low compared to a synthetic fertilizer.  Some may add ingredients like urea to hike these macronutrient numbers.

That said, compost’s NPK value does have dollar value. The nutrients delivered by a compost product should be a factor in any input decisions involving synthetic fertilizer purchases.  Compost also adds a slew of micronutrients not typically found in common synthetics and improves nutrient uptake.

Compost feeds the soil. In turn, the soil takes care of the plants, offering a smorgasbord of nutrients, pest and disease resistance, and more.   But those nutrients are slow-release, feeding plants over time.  The benefits of a single compost application can stretch over multiple seasons.

Fertilizer’s sole purpose is feeding plants.  The primary function of most synthetic fertilizers is adding N, P, and/or K.  Application gives an immediate burst of nutrition.

Do you need fertilizer if you use compost?

For the home gardener, probably not, especially if that gardener is a long time compost user.

But for a commercial grower?  Maybe.  If the crop likes a punch of nitrogen (for example) at a certain point in the growth cycle, the addition of a synthetic fertilizer may be warranted.

However, the smart grower will carefully weigh the cost of any input against the expected return on investment. Sometimes, a lower yield will still net higher profits if input costs for synthetic fertilizers and pest control products are reduced or eliminated as a crop management expense.

Also, keep in mind that compost-amended soil reduces rainwater and irrigation runoff, which means more nutrients are retained in the soil.   This will impact synthetic fertilizer input requirement, as well.