The important object in transplanting is to transfer the plant to its new position in such a condition that growth will immediately continue as nearly normal as possible when growing conditions become favourable. Growth is first excited and maintained by very fine, fibrous roots, almost thread-like in character, which attach themselves to the soil. It is this fine root growth which is so sensitive to injury from drying-out processes, and which must be protected against the sun's rays, and also from the effect of wind. A dry wind will work greater injury to plants which are left uncovered during any unnecessary length of time than will a bright sun on a moist day.
It is often necessary to transplant material under exceedingly unfavourable conditions, due to wind, or sun, or when plants have advanced in leaf growth. Under such circumstances it is advisable to "puddle" the roots at the time when the plants are removed from the temporary nursery rows, and before they are planted permanently. "Puddling" consists in dipping the roots of the plants in a basin hollowed out of the soil and filled with a molasses-like mixture of loam and water. This "puddling" process leaves a coating of mud over the fine roots and prevents excessive drying out until the material is planted.