One of the reasons why many people, who come forward to set up a Miyawaki forest, eventually withdraw is the expense it involves. There is a common feeling that Miyawaki forests are very costly.  That is true only when you compare it with other afforestation methods.  We usually compare only the cost, never the results.   It is only on comparing both factors that we understand the difference.  The peculiarity of the Miyawaki forest is that it gets formed in three years.  In 15 years, it develops to a state that a natural forest takes 100 years to reach. But in order to achieve this, a few basic factors have to be taken care of.

Before erecting an 8- or 10-storeyed building, we have to lay a foundation strong enough to support it.  Similarly, when we set up a Miyawaki forest, we have to make use of good manure, and take care of the saplings as well.  Otherwise, the Miyawaki forest will not yield the desired results.  Merely planting several saplings in a clump does not mean it will grow into a forest.  It may take 100 to 150 years to become one, and we may not see it in our lifetime.  Secondly, the cost of setting up a forest in a one-square-foot piece of land is roughly Rs 300 or Rs 350.  Laying tiles or marble or mosaic over the same area is more costly.  So, it’s our mindset which decides what is costly and what isn’t.  Back to the Miyawaki forest.
Before planting a sapling in a Miyawaki forest, we have to look after it for three months.  This means, we have to prepare the potting mixture in the way we have shown several times already, and fill it in a grow bag.  This comes to Rs 20 or Rs 25.  The sapling may cost anywhere between Rs 10 and Rs 40.  We have to remove the original soil and transfer the sapling into the special mixture we have prepared.   By now we have already invested Rs 50.  Next, taking care of it for three months involves pruning, watering twice a day, checking whether it is getting enough sunlight, and growing well.  This may come to Rs 50.  The transportation costs should also be factored in.  Besides, there is a threat of 15-20 % wastage because all the saplings may not grow well or even survive.  Only those that develop strong tap roots are good enough for the Miyawaki forest.   All this will come to Rs 120 per sapling of a good tree.  This cost is unavoidable.
If we simply nurse a sapling bought from a nursery, it may not grow at all.  What we add here is manure in a particular proportion.  A one-square-metre plot may need up to 40 kgs of manure, depending on the nature of the soil.  This translates to 30-40 kgs each of cow dung powder, coir pith and rice husk.  This is costly but if we avoid it, the saplings will not grow.  Take cow dung powder, for instance.  If it is not prepared well, it will not have the required quality.  Fresh cow dung does not yield the expected results.  Using coir pith alone does not work either.
Thus the secret of success of the Miyawaki method lies in the right proportion of the potting mixture.  The other factors are: planting at least four saplings in one sq. m. of land, and choosing only indigenous varieties.  Only if all these conditions are met, will we benefit from a Miyawaki forest.  Only then will the growth rate, targeted by the Miyawaki model, be attained.