Put tree watering on your 'bucket' list

A 5-gallon bucket with a hole can deliver water efficiently to a young tree's roots. (Photo courtesy Sacramento Tree Foundation)

Are you worried about your trees during our current drought? Young trees in particular need extra irrigation to make sure they stay healthy and grow strong.

During very dry conditions, young trees of all kinds are most at risk, particularly under 5 years old. These saplings benefit from a slow, deep drink.

According to the Sacramento Tree Foundation, young trees need an extra 10 to 15 gallons of water a week in summer to get established and put down deep roots. The best way to apply this extra irrigation is not with a hose, but a bucket – with a hole in it.

The bucket method – applying water via a 5-gallon bucket – allows water to soak in slowly even in Sacramento’s heavy clay soils. If you just pour 5 gallons of water on the ground next to the tree, it will run off instead of soaking in. With a hose, it’s just a guess how much water you’re applying.

With the bucket, you know exactly how much and where that water will go – down into the tree’s root zone.

SacTree staff experimented and found that a single 1/8-inch hole – located on the bucket’s side about 1 inch above the bottom – was most effective in delivering water at just the right rate. On the bottom, the hole got clogged with dirt. With multiple or bigger holes, the water drained too fast.

How do you use a bucket with a hole in it? Cover the hole with duct tape, fill the bucket, put in place, then remove the tape.

Place the bucket close, within a foot of the trunk, to newly planted trees; their root ball still hasn’t spread out. Alternate sides with each bucket application. As the tree grows, move the bucket farther away from the trunk. The feeder roots that need the extra water most are located along the dripline at the edges of a tree’s canopy.

In the first year, give a young tree an extra 5 gallons two or three times a week, SacTree recommends. In the second year, make it 10 gallons once a week. At three years, increase the extra water allowance to 15 gallons but apply it every other week.

Mulch will help your trees retain that moisture longer. Apply 2 to 4 inches of organic mulch (wood chips, bark, leaves, etc.) out to the tree’s dripline, leaving 6 inches of space around the trunk. Mounding mulch around the trunk allows fungal diseases to attack the tree’s crown.

Mature trees benefit from extra irrigation, too. Instead of a bucket, use a soaker hose encircling the tree at its dripline and set a timer for one hour. Do that once a month.