Many trees and shrubs can still be planted in New Jersey this fall, generally from late September through mid-November, if the soil can be dug and about six weeks remain before the ground freezes. Early October is still inside that window for suitable plants. A short list of species should wait until spring.
Why fall planting still works here
Fall is an optimum time to plant many trees, shrubs, ground covers, perennials, and bulbs in New Jersey because rainfall is generally more uniform than in spring and summer, according to the Rutgers New Jersey Agricultural Experiment Station. Soil is still warm enough for roots to grow, while cooler air puts less stress on the plant and slows water loss through the leaves.
That is the advantage of planting now rather than waiting for a hot, dry stretch next summer. Dates are only a guide. If the ground is already too hard to dig, or a hard freeze is close, the six-week rooting period is gone and spring is the better date.
Perennials and bulbs are on a shorter clock than most woody plants. Rutgers recommends planting them in early to mid-fall so roots can grow before winter freeze-thaw cycles. If those are still in pots in October, plant them soon. Do not hold them for a late November weekend.
What can go in now, and what should wait
Deciduous and evergreen trees and shrubs can be moved in early fall or in spring, with important exceptions. Birches, beeches, most oaks, magnolias, and hemlocks should be moved only in early spring, as the Rutgers fact sheet on transplanting trees and shrubs explains.
Broadleaf evergreens such as boxwood, holly, and mountain laurel are best planted in early fall, with careful watering, or saved for spring. By mid-October, an exposed, windy site is a reason to wait. A sheltered spot that you can water until the ground freezes can still work.
Some plants settle better in spring even when fall is fine for their neighbors. Kousa dogwood and rhododendron are in that group. Confirm the timing for the specific plant rather than treating fall as the right season for everything in the nursery row.
If a pot is one of the spring-only species, do not force it into cold soil just to finish the bed this year. Protect it and schedule the planting for early spring.
After the plant is in the ground
Match the plant to the spot before the hole is dug: sunlight, drainage, mature size, and winter exposure. A perfect planting date will not fix a shrub set where water sits, or a tree that will outgrow the bed.
Keep mulch off trunks and stems. Mulch over the root zone is useful. Mulch piled against the bark is not.
Keep watering newly planted trees and shrubs after the leaves drop, as long as the ground is not frozen. Fall rain helps, but a dry October or November still stresses a plant that has not rooted beyond its original ball or pot.
That is the work we plan for on a fall landscape installation: the right species for the date, a site the plant can live in, and watering that continues after the crew leaves.