10. Reasons Why You Should Dig a Wide Hole

diagram w

- The width of the hole should be two to three times the size of the root plate of the tree you are planting. (Diagram 3)

- The hole should be wok shaped, so the roots can spread horizontally near the surface where optimum growth takes place

- A small planting hole (Diagram 1 and 2) can hinder plant establishment. The regenerated root system will have very little space to grow before encountering compacted and low oxygen soils, which inhibit root growth.

- The roots must ultimately spread beyond the planting hole. If the site soil is compacted and difficult to penetrate, the roots may circle inside the hole (Diagram 1), just as they can do inside a hard walled pot. If roots are unable to grow into the compacted sub-soil, a hole with sloping sides will allow roots to grow back towards the surface and continue to spread.

- Optimum root growth requires soil oxygen levels in excess of 15%,root initiation requires oxygen in excess of 12%, and growth of existing root tips requires in excess of 5-10% (Biddle, 1998). So therefore by digging a wider hole with sloping sides opens the soil up to the atmosphere to allow diffusion of oxygen (Perry, 1993) This gives the root system a greater volume of loose cultivated soil that is not compacted but aerated which allows good water penetration for rapid healthy root growth. (Diagram 3).
- Better to plant a $100 tree into a $200 hole rather than $200 tree into a $100 hole.

Make your first expense the best expense. Take the time and money to get it right.

Figure 11 Wide Planting Hole.