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Entries in soil amendments (5)


This Soil Amendment Is the Ultimate Renewable Resource. 

The Coconut Tree

When I first began studying gardening in the 1960’s, most books about perennials were published in the UK, where peat and vermiculite were the additives most recommended to convert clay into gardening soil. Since I had never heard of peat, but I did know about peat moss. I assumed that I could substitute one for the other since sphagnum peat moss is so plentiful in Canada.

Bulk peat mossIn the early days of perennial gardening, many of us didn’t understand exactly how peat helped to convert clay into what the British gardening books called loam. Today we have soil scientists who can explain how clay binds with organic matter, such as peat moss, to be broken up into a workable and nourishing growing medium.

Peat moss harvesterRecently, there has been a lot of buzz that peat moss is not the renewable resource that we once thought it to be. Because its harvest requires the digging up of vast tracts of wetlands, environmentalists insist that mining this organic product will deplete the earth and upset its ecological balance. Sphagnum producers have been disputing this fact vigorously. They claim that sphagnum peat moss is a renewable resource because it can regenerate itself. Ecologists disagree because that process can take anywhere from one hundred to one thousand years, during which time much wildlife will have disappeared from the region. They argue that natural renewal, to be beneficial to mankind, ought not to take so long.

In its defense, I must report that peat moss has proven to be a wonderful, multipurpose garden product. Therefore, if I were to respect the ecologists, I would have expected them to suggest a very good substitute. They have not. Up until recently, nothing had proven to be as convenient or efficient as peat moss for urban gardening, especially in situations where where compost is not always available, or where high acidic amendments are needed.

Coconut fruitBy coincidence, the exhortations of the environmentalists happened to coincide with the introduction of an acceptable, viable substitute for peat moss-as-soil-amendment. Known as coir, it is the coarse fibre extracted from the outer shell of coconuts and therefore, the ultimate renewable resource. I have used it this season, for the first time, as a soil amendment. I can report that it handles identically to peat moss, except for the fact that it does not generate any dust [to tickle one's nostrils] because it is slightly hydrated prior to use.

Pile of coconut shell fibreCoconuts supply a wide variety of edible and useful products. However, in many South East Asian countries, where it is harvested and processed, by-product, waste material from its shells accumulatied over time. In some locations, it sat for years in giant piles, while in others, it was deliberately incinerated. Until recently, there had been no use for this apparently worthless waste.

Clever entrepreneurs have now created something out of nothing by identified the organic, horticultural potential of shredded coconut shells and have begun to market it as a legitimate organic soil additive. This product carries OMRI (Organic Materials Review Institute) approval meaning it has been approved for use in organic production and processing. As a renewable resource, it has no ecological drawbacks to its use.

Researchers at Auburn University and University of Arkansas compared peat and coir as soil amendments for horticulture. They found that coir performs on par with peat. In addition, both its high water retaining capacity [ten times its weight] and excellent drainage are equal or superior to sphagnum peat.

Coir contains no weeds and pathogens and has greater physical resiliency (withstands compression of baling better) than peat moss. It has an easier wetability than peat, i.e. it does not repel water, and can hold eight times more air; it decomposes more slowly than sedge or sphagnum peat moss and its pH level average of 6.1 is acceptable.  

Bale of coirAt its source, coir is pressure compacted into consumer-friendly sized components in order to lower freight costs and to reduce the carbon footprint of shipping it to markets overseas. It is available in bales and in cello wrapped bricks that fit so conveniently into the trunk of small cars and stack efficiently for storage.Coir brickEach brick, when soaked overnight in 3 litres [a bit more than 3 quarts] of water, will produce 9 litres [about 10 quarts] of soil additive.

Coir mulchSpontaneous gardeners might consider this process to be an inconvenience. However, I have solved that problem by buying a large number of bricks, which I store in my garage for future use. At the beginning of the gardening season, I hydrate as many bricks as possible and store the reconstituted coir in oversize buckets. That way, I build up a generous supply to be used as needed.


Gardening in Hard Clay Soil or the Importance of Being Stubborn

The last two homes I lived in were built on hard packed clay. Gardening was challenging. Unlike my colleagues who have made peace with nature and plant only what will grow in dry or wet clay, I was never prepared to compromise or surrender. I am flower deprived because my growing season is short. That’s why I was determined to plant everything on my wish list. Clay was not allowed to be an obstacle. I found a way to overcome the situation and now I grow whatever l like that will thrive in my zone.

I amended the clay soil according to prevailing conventional wisdom of the times [it was many years ago]. Not only did I create a fertile, clay-based growing medium, but also I inadvertently created elevated flower beds. The additional quantities of garden sand, organic matter, and quality earth, used to amend the clay, increased the height of the beds by two feet. Now, they were sufficiently elevated and amended for perennials and roses to thrive. If ever their roots would reach a layer of unamended compacted clay below, they would have no difficulty penetrating that level. The soil would have softened and lightened over time, with the help of the nutrient-rich humidity and natural occurring elements in the organic matter above.

Today, soil scientists advise us not to use sand because it impedes proper drainage. Nevertheless, I continue to use it to help loosen hard soil. I break up the surface of the dry, hard packed clay with a shovel, making certain that the blade deeply penetrates the clay, spread a thin layer of garden sand over it, and power spray with a garden hose nozzle set to jet. The pressurized combination of water and sand penetrate the man-made crevices, making it easier to till and blend the soil with the other additives.

For those readers whose homes are built on large tracts of clay, I would not recommend amending expansive areas of land. The high cost of purchasing and spreading good quality organic matter, [sea compost is the best] that might help alleviate the problem, puts a damper on projects of such magnitude. I would suggest paying attention only to growing beds.

Beside sea compost, here are additional organic additives that one can include in the mixture of amendments to help convert clay soil to loam:- Chipped straw, composted manure, autumn leaves that have been shredded by the blades of a lawn mower, kitchen scraps [must be buried], old decomposing mulch, confetti from an office paper shredder, ripped up newspaper that has been soaked in water, shredded, waterlogged cardboard from boxes and cartons, coffee grinds, shredded pure cotton wadding, crushed egg shells, vegetable and fruit peel, coir, lint from a clothes dryer, bread crumbs from the catch tray of a toaster, composted garden waste, gypsum, peat, peat moss, rich black earth, and garden lime.

Some with generous budgets have successfully used perlite or vermiculite as humidity trappers for dry clay. Gardeners situated on wet clay, who experience spring flooding, might consider gardening on berms, higher wall-reinforced beds [decorative materials are available], or in large containers. These elevation solutions are necessary because pooling water may overwhelm beds that are only two feet off the ground and damage plant roots. Environmentally correct gardeners will avoid using peat or peat moss because these are not renewable resources. In the UK, a tax on peat is under consideration. However, in some areas, peat moss may be the only affordable organic additive available. Coir is one of the most renewable resources because it is nothing more than ground up coconut shells. It also provides work for poor laborers in third world countries.

For those who have been dreaming about planting beautiful perennials and roses but were stymied by natural occurring clay, I hope this post will be an inspiration to think outside of the box. The trick is not to plant at grade level but at least two feet off the ground, or higher.


Garden Math: How many Bags Do We Need? happens all the time. We purchase bags of soil, additives, or soil amendments for our flower or vegetable beds, bring them home, unload the car, lug the bags into the garden, pour and spread them on the beds. And then, lo and behold, we discover that the quantity we bought is not enough. Now the process must begin again.

Life is too short and our discretionary time too valuable to repeat any action unnecessarily. It would be more efficient if we had a guide to help us calculate, in advance, how many bags of garden product we need. One prominent nursery in Montreal, Jardins Jasmin, has posted such a guide online, but since their site is in French, I have translated their data as follows: - To cover a 10 feet by 10 feet area with 3 inches of garden product, based on standardized, retail-sized packaging, one will need 9 bags of top soil, or 9 bags of mulch or 23 bags of black earth. To lay grass over that same area, 10 rolls of sod are required.

This information has also been visualized by Greg Draiss who blogs at The Real Dirt on Gardening. In one of his blogs, he posted a YouTube video tutorial explaining how to calculate the amount of bags of soil, stone, bark, compost or mulch the gardener needs in order to spread a layer of garden product 3 inches deep This is a most useful guide for DIY gardeners. Hopefully, it will help to reduce the time allocated to buying and unloading. Click here to watch the video.

A measure of 3 inches is used because that is the minimum amount of mulch required to keep garden beds reasonably weed free. Spreading generous layers of any product is a far more efficient use of time and labor than spreading thin frugal layers. Not applying enough results in re applying again, sometimes immediately and often later in the season. Life is too short and too busy. Do it properly the first time round.


Gardening Grandfather

When I became a grandfather, the amount of time I was able to devote to my garden was reduced by more than half. I may be passionate about my garden, but it cannot compete with my grandchildren. Furthermore, the age of grandparenthood arrived with another restriction. Just about that same time my body started talking back to me. Grandparents need to be careful when lifting children and when loading or unloading heavy items from the trunk of a car because we may inflict painful injury to our bodies.

In response to these new realities in my life, I have cut back significantly on the amount of soil amendments that I purchase. Recently, I learnt an important bit of information from seasoned horticulturists.They insist that if a garden bed was well composed at the outset, then its soil only needs an annual application of marine or home-made compost to sustain it. This can be done slowly over the entire growing season at one’s convenience. What a relief to know that I can nurture my grandchildren and ignore my garden soil. And, to be doubly sure, I have invested in an ergonomic-friendly shaker of granular, slow-release fertilizer that I sprinkle over my beds in early spring. One never knows when a plants needs a snack.

I find it hard to accept the fact that a plant that was created by nature eons ago should need a lot of help from humans in order to grow. Perennials grow wild in their country of origin and I hope that they will adapt to my already-amended soil conditions. I am happy to let them grow as best they can with minimal interference from me. However, the same cannot be said for roses and rhododendrons. For maximum impact, which translates into maximum joy, these two emotion-evoking plants need nutritional help from us. I’ll concede that.

We are constantly reminded by soil amendment advertisers that their products are beneficial for our garden. Perhaps they are. But, what they help create is only sustainable if one continues to use these products forever. That’s a long time and a lot of money spent just to tweak nature.

Imagine what it would like to artificially amend one’s garden soil in order to grow plants that otherwise would not survive, and then to be hit with a bout of infirmity that makes it impossible or difficult to continue sustaining that garden. A lifetime of planning and work and financial investment would be wiped out in less than two seasons. One might be left with a garden of ghosts. That would be a depressing sight. I’d rather have a garden that is sustained by nature so that when I become too old to garden, I will be able to continue to enjoy looking at it. A self-perpetuating garden is a desirable objective when one becomes a grandparent.


When I Made Compost, the Worms Ate My Lasagna!

click on the image to learn more about worms in the garden.Preparing a flower or vegetable bed in hard packed clay used to be back-breaking work. Today, professional gardeners frown upon digging into clay in order to improve it. Some recommend a no-work method that allows the gardener to conserve strength. That process is called Comforter Composting or Batch Composting. It has also been labeled “The Lasagna Method” because of the layering technique used to create arable land. Here's how it’s done:-

1] Start in early spring.

2] Using an aerosol paint spray or garden hose, delineate the desired shape of the growing bed directly on top of the clay, grass, or weed patch.

3] Sprinkle that designated area with garden lime [calcium carbonate] and/or Dolomite [calcium magnesium carbonate] and/or Gypsum [calcium sulphate] and/or blood meal. Use whatever is easily available; try to add at least two. However, be concerned about commercial blood meal. It is no longer as nutritious as it was twenty years ago.

4] Cover with ½ inch layer peat moss or reconstituted compacted coir

5] Cover peat moss/coir with any of the following: two sheets of newspaper, supermarket brown paper bags, paper towels or contents of a paper shredder.

6] Moisten paper layer.

7] Over the wet paper, spread a 3 inch layer of green garden waste including grass clipping followed by decomposed leaves [if available].

8] Sprinkle with nitrogen-based Compost Accelerator and moisten. The accelerator is optional; the moistening is necessary.

9] Add a 1 inch layer of any good compost [homemade is better but store bought will do; Marine Compost or Forest Compost is preferred] and moisten.

10] Cover with 1 inch of any type of garden soil but not clay.

Repeat the layering procedure beginning at step 4, until the new garden bed reaches a height of 15 or 25 inches, depending on which of the following two options is preferred.

Option A: When the 15 inch “lasagna” decomposes, the clay beneath it will be sufficiently malleable to blend clay and compost together with a 4-pronged digging fork. By autumn the mixture will make an excellent growing medium, ready for planting.

Option B: To avoid the hard work of blending clay and compost, make sure from the outset that the “lasagna” will be 25 inches high. By starting  with a higher “lasagna” in the spring, one may ignore the clay underneath and plant directly into the new raised flower bed in autumn.

Both the 15 and 25 inch “lasagna” will benefit from continuous build-up of layers throughout the following growing season as more organic matter becomes available. In late autumn both will also benefit from additional layers that will over-winter.

Three more tips:-

- Keep the “lasagna” moist all season.

- Used coffee grinds, crushed egg shells, stale snacks and munchies and any other non-aromatic organic matter make a tasty addition to the “lasagna” recipe as long as they are buried under soil.

- Stubborn and perennial weeds that reappear and cannot be removed should be sprayed with any brand of controversial glysophate-based systemic weed killer, if such a product is still available.

Now what does this have to do with worms?

First, true blood meal sprinkled directly onto the clay surface makes that soil even more attractive to worms. When they burrow into clay, worms aerate the soil, making it easier for plant roots to take hold there. Second, all living organisms in the earth, including bugs and worms, eat decomposing organic matter and eliminate their body waste into their surroundings. Worm waste is the best fertilizer!