In response to a deluge of questions seeking advice on soil improvement, this week we will take a look at how to go about rescuing soil which has either been ‘used up’ or appears to be ‘un-plantable’.
Soil, whatever its type (sandy, clay, etc.), is a living, breathing entity which, just like human beings, requires careful nurturing — in the form of food, water and air — if it is to be actively healthy enough to operate as a successful growing medium for whatever type of plant you wish to cultivate. If not correctly cared for — this is a never ending process — it becomes sick and, again just like human beings, can actually die and ‘dead soil’ grows no plants.
There is an established trend, probably invented by malis and certainly perpetuated by them, that garden soil must be dug out, carted away and completely replaced very couple of years or so which, providing the soil is cared for, is not the case. One can only surmise that either malis have no basic understanding of soil or — and this is not a pleasant thought — that they make a profit for themselves in the process, possibly even selling used soil from one garden to an unsuspecting customer under the impression that it is ‘new’.
The richer the soil, the healthier the plants; but that doesn’t mean you have to change the soil
It could — and this is highly possible — be that a mali has all but killed the garden soil he is supposed to care for, by overuse of chemical interventions as, judging from experience and readers’ observations, Malis are addicted to using toxic chemical sprays as often as they can; plus, some of them insist on regular overdoses and chemical fertilisers too. Malis, it is important to understand, judge their success according to overall ‘show’: the size of flowers, greenness of grass, absence of weeds being their measure and they will try to persuade homeowners to spend absolute fortunes on nursery bought plants to help their own reputation along — few malis are content to sow seeds, tend them and await results. They want to impress you with ‘knowledge’ — sadly lacking in the majority — and dazzle you with ‘instant garden spectacles’ before demanding a pay rise!
Basically, all soil, whatever its consistency, needs regular helpings of organic matter. This can be in the form of organic, preferably homemade, compost; in the form of old, well rotted, organic manure; or in one, or a mix, of the numerous types of organic mulch; plus, if at all possible, generous servings of that wonderful stuff known as ‘Biochar’ — the latter is a form of organic, wood charcoal.
Clay soil may also benefit from the addition of a reasonable amount of river sand — not, it must be stressed, sea sand which contains more salt than the majority of plants will tolerate.
All of the aforementioned additions can be dug into existing garden soil, depending on the presence of established perennials and on the number of purely seasonal plants already in place. Any major digging is best carried out when the garden is ‘between’ planting stages such as before or after seasonal plants are put in.
If, however, the garden is already fairly densely planted, then laying any additions is best done in the form of mulch — this is laid directly on top of the existing soil surface, around but not in direct contact with, the trees / shrubs / plants growing there. Mulch can be laid from just one to six inches deep when spread around growing plants or as much as one to two feet deep on top of ‘used’ up soil (soil devoid of essential nutrients) if it is then going to left for at least three months before the area is brought under cultivation. Leaving it will allow it to be slowly broken up and taken down into the soil below by the combined efforts of beneficial insects, weather and regular watering.
Alternatively — and this method is especially suited to vegetable growing areas — construct slightly raised planting mounds by doing the following: lay mulching material / organic compost, in a line or circle, up to six inches in height (it will quickly rot down) on top of existing soil, dig a trench, up to one foot deep, along either side of the mulching material line / circle, carefully using the soil to cover the mulch. Also half fill the trenches with mulch. Water well to help settle it down and then plant on top of the raised mound / circle. The buried mulch provides ‘fast food’ to plants / seeds as they grow and slowly rots down to feed and improve the soil in the long-term.
Yet another way of feeding the soil is the very convenient ‘Chop and drop’ system. Instead of hauling organic plant waste off to the compost heap / bin, simply, while weeding for example, cut up and drop it on the soil surface from where it will weather down with beneficial insects, earth worms for example, helping it along the way. Do not, however, do this with weeds that have already formed seed heads or else you will end up with more weeds than you bargained for! The main thing though, is to keep on feeding and caring for soil on a year round basis: this way you are also building up nutrient rich ‘new’ soil to help keep your garden a living, happy, healthy and productive space.
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Published in Dawn, Sunday Magazine, October 18th, 2015