Spruce trees comprise approximately 40 different species of evergreen trees used for lumber and beauty. Native to the Northern Hemisphere, they are commonly used as Christmas trees. They do extremely well in the colder temperatures of winter. Keeping them properly watered during the growing season is challenging.
How Much Water
Watering spruce trees is tricky. Over watering causes branches to turn brown, starting at the bottom. If the soil is heavy, such as clay, ensure that trees do not stand in water. If the roots are choked of oxygen, fungal disease attacks the tree, or it creates a shallow root system, allowing the tree to easily topple. Standing water leaves behind mineral build-up affecting the soil quality. Watering is crucial the first two days after a tree is planted. Soak the soil once a week when it is not raining. Place a hose trickling water by the tree's base and allow it to run for several hours or overnight for large trees. Extremely large trees should only be watered once a month, unless drought conditions are occurring.
Spruces create an extremely deep root system when watered deeply. In order to support large trees, the roots need to go deep into the soil to provide support. Waterings cannot be frequent and shallow, or roots will remain on the surface. If the tree even survives, it would not have an adequate support system for any growth. Tree roots follow the water. Deep, infrequent waterings will make sure the roots go deep into the ground to follow the water through the soil.
Mulch helps keep water in the soil and limits evaporation. It smothers weeds that compete with the spruce tree for water resources. Place 3 to 4 inches of mulch in a 4-foot diameter around the tree. When trees are properly mulched, they will not need watered until after spring rains have ended. Summer waterings are less frequent than with unmulched spruce trees. Check the mulch in the fall ensuring it is an adequate cover for winter. If necessary, add more mulch around the spruce tree.
When To Water
Do not begin watering immediately when the ground thaws. As the soil dries from spring warmth, the roots follow any water in the soil, encouraging depth. Watch the amount of rain received during the spring rainy season. If rain is infrequent and short, water the tree deeply keeps the roots from staying near the surface of the ground. Frequent waterings should stop in mid-August to prepare the tree for winter, unless drought conditions persist and the tree is stressed. One last, deep watering in late fall before the first frost is recommended to help the spruce tree overwinter.