Planting for success:
I often see new plants suffocated by the heavy soils around them and being over-watered by the existing overhead spray or drip system. To make sure drainage and soil pore space is sufficient for the new tree to establish, proper planting is key.
Be sure to plant with the roots ball at or slightly above surrounding grade and make sure the hole is 3X as wide as the root ball. If you have heavy clay soils, they should be amended with a lighter material to promote good drainage. I like to amend the soil from the hole by mixing in up to 50% “Gromulch” or 20% “Perlite.” The roots will have to grow into the surrounding soil eventually, but this gives them a good head start and reduces root competition when establishing.
I don’t recommend putting any fertilizer in your planting hole. Up to 20% of well-rotted organic compost or a handful of worm castings is OK for hungry plants like roses. 😊
When planting trees, they must also be properly staked. Unless you have a camphor or persimmon (brittle wooded), remove the bamboo/wooden nursery stake first. Print and out use these excellent tree planting specs from the City of Fremont: https://www.fremont.gov/2722/Planting
Creating the watering basin
The watering basin is the area around the tree where you are going to 1) Mulch 2) Water and 3) Weed around your new plant. It is established with a soil berm around the perimeter of your planting hole, which will act as a natural funnel for deep watering.
Mulch: Apply four inches (4”) of wood chips to insulate the soil and prevent weeds. Layer should be even like a pancake. Do not pile it against the trunk. Proper mulching is very important!
How much to water:
For perennials and shrubs: Water your plant to soak the root ball every day for the first week. Then, 1-gallon of water per # of container size 3X per week for the first 4 – 6 weeks until established AND until the hottest part of the summer has passed. (Example: 1 gallon for a 1-gallon size, 5 gallons for 5-gallon size.) Then reduce frequency to once per week to provide a deep soaking in lieu of heavy rain in the cool season. For the plant’s second Spring, California natives may not need any water, or just once per month to keep them looking good. Plants that like regular water should be watered once or twice per week and allowed to dry-down a bit in-between. Make sure to adjust out the location of emitters to the edge of the plant as it grows.
For 15-gallon tree: 5 gallons H20 3 X per week for the first 6 - 12 months. Then water 10 – 15 gallons once per week until the tree the tree is established, usually 1 - 3 years after planting.
For 24-inch-box trees: 20 gallons H20 2 X per week for the first 12 months. Then water 30 – 40 gallons once per week until the tree the tree is established, usually 3- 5 years after planting.
You know the tree is established when the root ball no longer wobbles in the ground when shaking the trunk. Support stakes can be removed at this time. After the tree is established, you can stop watering during the rainy season. For natives, you can taper off water all together. Always water you tree during drought years during the season appropriate for them.
How to water Trees:
My favorite way to water trees is with buckets 😊.
Since few people choose to go this route, I recommend you irrigate with two designated, pressure-regulated “tree bubblers.” These can be run off a conventional or drip system. They should be installed over the root ball and inside the soil berm.