Mature pine trees are a stately addition to any landscape, and the green needles provide winter interest, as well as shelter for songbirds and other wildlife year round. Pine trees, along with spruce and other conifers, tend to be pretty low-maintenance plants, and they need little attention once they have become established. However, older pine trees will benefit from deep watering during very dry conditions, and watering in the late fall will help the trees get through the winter.
Water older pine trees when the weather is very dry. Pine trees may not show any obvious signs of drought stress other than possibly dropping more needles than usual, but if nearby deciduous trees are wilting, it may be time to water your trees.
Give your older pine trees a big drink of water just before winter hits. Pine trees that are well hydrated will be less likely to become damaged by cold temperature, strong winds or dry air during the winter. If you live in an area where the ground doesn't freeze, older pine trees may need water throughout the winter if the weather is dry.
Use a soaker hose to water mature trees. Circle the hose on the ground around the perimeter of the pine boughs and leave the water on until the ground is saturated but not waterlogged. Depending on the dryness of the soil and the strength of your hose, this may take 30 to 90 minutes. Watering is most effective when it is done early in the morning or in the evening.
Allow fallen pine needles to lay in place to act as a mulch for your mature pine tree. Mulch will help retain soil moisture and will also keep down weeds. You can also use other mulch, such as shredded bark. Even just an inch or two of mulch can make a big difference for mature pine trees.