A good size for seedlings is between 15 and 30 cm. Large seedlings are harder to use with hand planting tubes, but are well suited to machine planting. The stem of tree seedlings should be strong, and have a diameter greater than 2.5 mm at the base. Hardiness Before planting, ensure the seedlings have been 'hardened', that is, 'weaned off' shade and nutrients, at the nursery. Deep green, lush and soft foliage indicate unhardened seedlings that may suffer from transplant shock, dry conditions and frost.
Reputable nurseries sell only 'hardened' seedlings.
If possible, collect your seedlings from the nursery close to the date of planting out. Protect them from sun and wind during transport. Store the seedlings in an open position protected from strong winds. If they must be stored for a long period, place them on raised mesh benches or on coarse blue metal to stop their roots growing into the soil, and to prevent fungal diseases. Seedlings need a light watering every day during fine weather.