7.3.4 Root ball diameter Table 7.3.4 states minimum root ball diameters for field dug plants, including those in in-ground fabric bag containers. Root balls larger than those stated in Table 7.3.4 shall be required when the plants have not been transplanted or root pruned for four or more years or when plants are dug out of season. If the trees have been in ground longer than four years, it is recommended to use the ball size for the next size larger. Root balls one size smaller than those in Table 7.3.4 shall be acceptable for plants frequently transplanted or root pruned. The minimum root ball size for multi-stemmed trees shall be one size larger than the sizes specified for single-stemmed trees of equivalent caliper as shown in Table 7.3.4. Collected or native material dug from woodlots or fencerows shall have a root ball 30% greater than stated in Table 7.3.4. Table 7.3.4 Root ball size in relation to caliper for field grown Standard type trees
20 25 30 35
Minimum root ball diameter (cm) 40 45 50 55
Approximate root ball depth (cm) 20 23 25 27
Minimum in-ground fabric bag diameter* (cm) 20 25 30 36
40 45 50 60
60 65 70 75
30 33 40 38
40 40 46 46
70 80 90 100
80 85 95 105
40 43 48 53
50 50 56 60
110 120 130 140
115 125 135 145
58 63 68 73
80
150 175 200
155 175 200
78 88 100
Caliper (mm)
* Adapted from the American Standard for Nursery Stock (ANSI Z60.1-2014) with approximate imperial to metric conversions.
- Canadian Nursery Stock Standard -
30