Water

Watering is the most important thing you can do for your street tree or greenstreet. It may also be the most difficult task to accomplish. Transporting water from the source to the tree is a challenge. Furthermore, because of compaction and pollution, urban soil is hydrophobic and difficult to penetrate. This means that you need to cultivate or loosen the soil so that the water can reach the tree's roots. There are a number of different tools and techniques available to aid your watering efforts.

Guidelines

• Water each young tree 15-20 gallons once a week between May and October (that’s 3-4 large buckets).
• Using a hand cultivator, loosen the top 2-3 inches of soil to alleviate compaction and help the water and air reach the roots.
• Water slowly so the water penetrates the soil and does not run off of the surface.
• Water at the soil level, not the leaves of shrubs and groundcovers.
• If it rains 1inch or more in a week's time period, you do not need to water.

Tools

• 5-gallon bucket
• hand cultivator
• hose
• Treegator & Treegator Jr.
• hydrant adaptor
• trash-can

Suggestions

• Poke small holes at the bottom of a large trash-can. Fill it with 15-20 gallons of water and leave the trash can next to the tree overnight.
• Ask building maintenance staff to water trees while they are hosing off sidewalks. Ask street vendors and merchants to dump water from their containers (coolers with melted ice or flower buckets) into nearby tree pits at the end of the day. Make sure water with detergent or bleach is dumped into the gutter, not the tree pit.
• Apply a three-inch layer of mulch, preferably shredded bark, to the tree pit. Mulch keeps the water from evaporating quickly, reduces soil compaction, and improves the soil as it breaks down. Do not pile the mulch against the trunk of the tree or shrub; water will accumulate and rot the trunk.