Watering Factors

Underwatering and improper watering are by far the most frequent causes of plant failure in a newly planted garden. However overwatering can be just as bad for plants as underwatering, and often the first symptoms look the same. Most evergreens are particularly sensitive to overwatering, even some like Arborvitae and Hollies that have a reputation for handling it better than other evergreens. One of the best ways to combat this while making sure your shrubs are getting the water they need is to water them deeply – meaning water less often, but for a longer time (and often slower). 

Deeper watering gives the soil time to partially dry out in between, lets the water penetrate down to the lower soil and roots, and doesn't leave the upper soil perpetually damp. Deep watering also encourages your plants to develop deep rather than shallow root systems, which will make them more resilient over time. 

(Note: This is especially true in heavy clay soil and shadier areas where the soil will have more trouble drying out)

Rainfall wasn't part of the list of timing factors, and that's for good reason. When it comes to new plants, the natural rainfall is rarely enough to replace even one watering session. Your plants haven't had time to spread out their roots yet, and the dense foliage on your evergreens can prevent the rain from ever reaching the base of the plant. 

If there's heavy rainfall (think over 1 in. of rain) in a day, you may be able to skip a watering session, but always check the soil before making that decision. Keep in mind that dry soil also can't absorb water as well as soil that has been kept consistently watered. Rain and your own supplemental water can run off away from the plants if the soil isn't ready to absorb it.