Big Trees Nursery can provide post planting care for your trees but here are the basics.
Improper watering is responsible for 80%+ of post planting problems. After the first day’s initial heavy watering the goal is to apply water after the soil, at a depth of 6”-18”, has dried out to slightly moist but not powder dry. The only practical way to check the soil at that depth is to use a soil probe or soil moisture sensor. We recommend the use of Watermark soil sensors. Large boxed trees should have their own dedicated irrigation system or be hand watered for the first year. Your goal is apply water periodically in sufficient amounts to keep the root zone, (generally at 18” to 30” deep) in a range between saturation, (the day of watering) and only slightly moist. Applying water too frequently keeps the soil too near saturation which will rot the roots and applying too much water per application keep the bottom of the root ball saturated, even though the top dries sufficiently. Since roots will not populate the backfill soil in significant amounts for 3-6 months you need to check moisture in the root ball area. The back fill area will need water very infrequently at the start since there are no or few roots utilizing the water. For starters, apply water on to three times a week in sufficient amounts to saturate to a depth of 30”. Frequency can vary from once a month if it is a very rainy January, to 3 times a week if it is a hot windy Santa Ana September. Planting ground cover, lawn or flowers which require normal watering in the drip line area risks keeping the soil too wet for the tree. It is best to mulch under the tree or plant drought tolerant plants once the tree is established. The berms that were built to facilitate the initial soaking can be removed so long as you have a system the wets the root ball adequately. Drip, bubbler or spray systems can do this.
Fertilizing and Pruning
There is no need for any fertilizer for the first 3-6 months as the tree arrives with sufficient amounts. After that time you may apply a slow release, fertilizer per the rate on the container. We have good results using phosphonic acid or equivalent as a root protectant and enhancer. When pruning, do not remove over 10% of the green foliage the first year.