Watering New Plantings in the Fall
Here's a brief post for quick reference if you're starting a new planting with just weeks before the first winter freeze.
Below is a copy of the guidelines we left with a client after planting a row of mature arborvitae.
The big thing to remember when planting in the fall is that the potential of success is higher because the needs of the plant are lower than other times of the year. That said the window could be smaller to get the plant what it needs before the harsh winter conditions set in. Its important to act quickly and efficiently.
Deciduous trees/plants (trees that lose their leaves in the fall) go dormant for the winter and drawn the water they need earlier in the fall. If you're planting late, mulch heavily to protect roots from killing frost. Water in early spring when the tree is searching for water to start the leafing process.
Evergreen trees/plants circulate water all winter and may only go dormant for the harshest weeks of the season. With that you have a longer opportunity to help the tree establish. Don't mulch as heavily unless the tree begins to mulch on it's own. You'll notice foliage dropping around it's base which is natures way of mulching and protecting what could be weak dry roots. If mulch is required water immediately in the spring but do not fertilize until the tree is strong enough to handle the stimulation.
Whenever you're planting, you're taking a tree that was living happily and healthily in one place, uprooting it, then placing it somewhere else with hopes that it continues. Consider the changes the plant is experiencing. If conditions are better than those previous it will do better, if conditions are lesser than it may take more work on the part of the plant to catch up. As the planter or caretaker we interfere to help the plant transition. If after some time it does not look healthy, we, as the caretaker are to blame. Consider the care immediately after planting as a rehab program and you are sure to see great success for the life of the plant.