Pine trees grow best when planted in the warmer temperatures of the late summer and early fall months. They can also be successfully planted during the late fall or early winter months, as long as the soil never gets deeply frozen. If the soil is too hard, the roots of the young tree will not be able to dig their way down to the nutrients in the soil and the tree will starve.
Pine seedlings get the best start when planted indoors by a window until the weather improves and they are well-established enough to be transferred outdoors. Before transplanting, the seed should have fallen off the top of the seedling and it should be forming needles and growing taller. They should be kept in a location where bright sunlight can hit the seedlings for several hours each day.
Planting pines in the spring is not generally a good idea, unless the soil at the planting site is well-drained, which will prevent root rot. Pine trees don't appreciate having their roots continuously soaking in standing water, and this condition often kills young trees before they can put down a strong taproot. Well-drained soil can be recognized by its ability to soak up rain water. If it rains for days on end, as it often does in the spring, and the water still doesn't sit on top of the soil, then the land has excellent drainage.
Late Summer Planting
Planting in the drier season of late summer is better for the tree as it forces the pine to extend its root system downward rather than outward. The tree does this automatically when water is scarce in order to receive the amount of nutrients it requires.