b Gardening Design: September 2006

Gardening Design

Wednesday, September 27, 2006

Natural and organic fertilizers in your garden.

Natural and organic materials which yield plant nutrients upon decomposition are often available for purchase either separately or in combination. These materials may be applied to the garden separately or combined, used in the compost pile, or mixed with manure.

Natural deposites (rocks, sands, shells, etc.) Such naturally occurring materials are usually not easily obtained in today's modern agriculture; however, where available they represent sources of mainly potash, phosphorus, and lime (calcium and magnesium) for organic gardeners.

Phosphorus -- Rock phosphates are natural deposits of phosphate in combination with calcium. The material as dug from the earth is very hard and yields its phosphorus very slowly. When finely ground and with impurities removed, the powdery material is only slightly soluble in water, but may be beneficial to plants in subsequent seasons following application. The reaction of phosphate rock with acids from decaying organic matter in the garden or compost tend to make the phosphorus available to garden plants. Collodial phosphate is also available and widely used.

Apply both phosphates at the rate of 2-5 pounds per 100 square feet of garden soil.

Or, when applying manure or compost, mix at the rate of 2½ pounds phosphate per 25 pounds manure or compost.

Broadcast the material over the soil surface and work into the topsoil at least three weeks before planting. Manure or other organic fertilizer should be added at this time.

Since the materials are so slowly decomposed, sidedressings are seldom beneficial.

Potash -- Potassium is widely distributed in nature, occurring in rocks, soils, tissues of plants and animals, and water of seas and lakes.

In gardening practice, materials such as wood ashes, tobacco stems, wool suint, seaweed, potash salts, greensand, and ground rock potash are used alone, in combinations with other materials yielding other nutrients, mixed with manure, or in compost piles.

Since the potash bearing materials vary so much in composition and rate of decomposition, specific application rates must be determined for each material and its combinations.

In general, ground rock potash at 5 pounds per 100 square feet may be broadcast over the soil surface three weeks prior to planting and spaded in. Langbeinite (Sul-Po-Mag) is used at 1 lb/100 sq ft.

Micro-nutrients -- An advantage for using organic materials as fertilizers is that they contain many of the elements also needed by the plants in addition to N, P, and K (for example, manganese in manure).

Besides the general amounts of micronutrients found in most organic materials, certain ones are concentrated into such naturally occurring materials as gypsum (calcium and sulfur), marl (calcium), dolomite (Calcium and magnesium), limestone (calcium), basic slag (iron, calcium, manganese and magnesium), and finely ground borosilicates.

Lime -- Reducing the acidity of the soil is the primary purpose for using lime in the garden. However, liming materials also provide nutrients for plant use. Calcium and magnesium are the two elements most commonly provided by lime. Gypsum is used where more calcium is needed without raising the pH.

Natural deposits of lime which are an organic gardener might use are limestone, dolomite, shell, and marl. All these forms must be finely ground to provide maximum benefit to the soil and plants. Dolomite is preferred due to its ocntent of both calcium and magnesium.

Lime to sweeten the soil should be applied only when the needs have been established by a reliable soil test. Under most Florida soil conditions, applications of 2 to 5 pounds of finely ground dolomitic limestone per 100 square feet usually will be sufficient except on very acid soils.

Apply lime well in advance of the planting date, preferably 2 to 3 months before the garden is planted. Mix well with the soil and keep moist for best reaction. Application closer to planting time is permissible, but its benefits are delayed.

Monday, September 18, 2006

Organic gardening means no pesticides

Rotenone is a safe and effective organic insecticide (biocide, pesticide) derived from derris roots, used by traditional societies in the east for centuries and approved for use by all organic associations. The effects are not persistent, it is biodegradeable and breaks down quickly into harmless by-products, and it is harmless to birds and mammals.

But most organic growers don't use it: less than 6% of the respondents to a US Department of Agriculture survey of certified organic vegetable growers reported using rotenone (American Journal of Alternative Agriculture, Vol. 13, No. 2, 1998).

"I don't think we are unique among experienced organic growers in using very little intervention in pest management." (Organic grower, US)

"I, too, use no biocides. People who think you have to use biocides to farm assume incorrectly that organic farmers use botanical biocides. This is not the case. Very few organic farmers merely switch from synthetic to organic biocides. For some this may be a first step in the transition to organic growing, but it is not the rule. Organic farmers have shown that food crops can be grown with the same or more production per acre, with the same or less lost to pests, without using biocides or NPK (chemical) fertilizers." (Organic grower, US)

"Pesticides are the badge of the amateur"

  organic grower

Soil for your square foot garden.

Soil for your square foot garden is a mixture of:

    8 cubic feet of compost
    4 cubic feet washed sand
    4 cubic feet coarse vermiculite
    2 litres of wood ash
    0.5 litres gardener's lime or 1 litre ground limestone

Try to include some good topsoil, mainly for the sake of the clay content. You can also use sphagnum peat moss, coconut coir, perlite, though they're inert and don't contain any nutrients. Sawdust is difficult stuff in garden soil, best avoid it -- especially sawdust from pressure-treated timber, which has poisons in it.

Sunday, September 17, 2006

Organic gardening.

Never mind all the high ideals: do it for selfish reasons. Some people say: "But it's so much more trouble." In fact it's so much less trouble to work with nature than to fight it. Why turn your garden into a battleground -- a battle you can't possibly win? And why poison your food?

"We abuse the land because we regard it as a commodity belonging to us. When we see land as a community to which we belong, we may begin to use it with love and respect."

Aldo Leopold, author of the environmental classic "Sand County Almanac"

And when you apply that lesson in your garden, lo and behold, nature suddenly becomes your friend and ally, doing most of the work for you.
What about pests? Don't you need pest-killers? "The pests are my professors," famously wrote Sir Albert Howard, founding father of the organics movement -- pest attack simply showed him where the soil fertility needed attention. He'd fix it, the pests would vanish. Not just a fairytale -- any good organic grower will confirm it.

It's not just "muck and magic", it's a lot more scientific than trying to kill everything with deadly poisons -- including beneficial predators that kill pests. Healthy plants have good resistance to pests (like healthy people), but they have to be well-fed for that (also like people), and they get their food from the soil (again like people). If it's not in the soil, the plants won't be healthy (and nor will the people). So feed the soil.

The essence of organic growing is soil management and fertility maintenance: feed the soil, not the plant -- the soil will feed the plant very much better than you can.
What's a weed? Same as a pest really: an expert can diagnose an ailing soil's deficiencies and imbalances merely by seeing what weeds are growing in it. They're there for a purpose, well summed-up in the title of a wise book called “Weeds -- Guardians of the Soil” by Joseph Cocannouer.

Fighting weeds is futile. Some grow to cover an exposed soil that's vulnerable to erosion and run-off -- nature hates exposed soil.

So cover it yourself, with a mulch.
Other weeds are deep-rooting plants that go down to the subsoil to collect fresh minerals when the topsoil runs out of them. Composting will fix that -- but leave some of the deep-rooting weeds (herbs actually) growing here and there to open up the soil, your vegetables will appreciate it (so will the earthworms). But they're stealing soil nutrients from your plants? Then your soil is in a bad way! -- certainly not fertile enough for vegetables. Believe the weeds! Tend to the soil and they'll stop pestering you, they'll be easy to manage.

You can find more information on http://journeytoforever.org/

Why and where you should build a square foot garden?

45sqft2If you're already an organic gardener, you probably already have everything you'll need: space for square foot beds, fertile soil, compost, knowledge and experience. If you're a row gardener, these are permanent no-dig beds, no walking on them -- like raised beds, whether you build them raised or flush with the surface. If you're a raised-bed grower, use raised beds.
If you have a garden, but you're no expert, or new to growing food, first choose a good site. What makes a good site? Lots of sunshine, and tons and tons of that "well-drained, rich, loamy soil" the seed packets tell you to plant your seeds in, as if the stuff grows on trees. So just choose a good place where there's enough light, we'll fix the soil.

Take up a bit of lawn if you like, the soil under a lawn is usually quite good. Use a sharp spade to cut through the turf: make vertical cuts (use your foot), slicing it up into one-foot squares, then peel the squares off like a carpet. 

You only need to take off an inch or two. Pile the squares in a block, grass-side down, wet thoroughly as you go, cover the top with a garbage bag to keep it moist, and it'll rot down into a useful supply of well-drained, rich, loamy soil.

If you have some suitable garden space with fairly soft soil you've been using for growing, use that. If all you have is some rough, hard ground, don't despair, it'll do, with a bit more trouble. Put some pegs in the ground and use string to mark where the beds will be (include a 15" path space round the beds), and then cover it with a thick layer of hay, grass clippings, dead leaves, anything that'll make a good mulch. Make it at least six inches thick; if it sinks, add more. Keep it well-watered, and don't let anyone walk on it. After a few weeks the ground will be much softer. Scoop off the mulch (you can use it later, in the garden or in the compost), and you can begin.

If you don't have mulch, use an old carpet, or lots of newspapers or cardboard cartons, or even garbage bags. Give the surface a good sprinkling first (not enough to puddle or muddy it). Keep checking to see the soil is moist, sprinkle again if not.

This is another way of preparing lawn for growing beds rather than removing the turf, though it'll take a while. Carpets work well.