Consulting Arborist in Granite Bay, California

Granite Bay sits between the valley floor and the west shore of Folsom Lake, on rolling granite ground that was oak woodland before it was large lots. Many of the homes here were set in among mature oaks, and people want to keep them. I am Christopher Hodge, an ISA Board Certified Master Arborist. I diagnose what is going wrong with mature oaks and write the tree reports the county asks for. I run no removal crews, so I have no stake in whether a tree comes down.

The trees of Granite Bay

California State Parks describes the open woodland around Folsom Lake as blue oak, interior live oak and foothill pine over annual grass. That is the native cover of most of Granite Bay. Valley oak joins them on the deeper soil in the swales and along the creeks, and it is the one that reaches great size.

Foothill pine, also called gray pine, is the tall gray green pine with the thin crown that leans out over the oaks. It carries very heavy cones. Placer County's tree rules exempt it by name.

The lake matters too. Folsom Lake was created in 1955, and its level normally moves from about 460 feet in early spring to under 400 by summer. Blue oak is a tree of dry ground. On lots near the shore, and in the ravines that drain to it, I pay close attention to how long the root zone stays wet.

Summer water is what kills these oaks

California's native oaks evolved without summer rain, and University of California integrated pest management guidance is blunt about it. Do not irrigate mature, established trees that have never been irrigated, and keep the root collar dry. Most native oaks that die of Armillaria root rot in California landscapes were predisposed by too much irrigation or some other stress. They were not struck by an unusually aggressive fungus. A lawn that runs to the trunk, or a new pool deck trapping water against the buttress roots, will do more damage over five summers than any pest here. Valley oak complicates it further, since it is a groundwater species with deep vertical roots.

What to watch for on a lot here

Projects in Granite Bay tend to be large: pools, sport courts, guest houses, long driveways. Each one moves soil, and the roots that feed a mature oak sit in the upper few feet of that soil and reach well past the branch tips. The best time to look at the trees is before the plan is final, when a trench can still be moved ten feet.

On the trees themselves, watch for a canopy that thins from the top, mushrooms at the base in fall, and bark that stays dark and wet at the soil line. Under a lawn, those usually point to the roots.

Placer County's tree rules, briefly

Granite Bay is unincorporated, so the county's Woodland Conservation rules apply, and this community is one of four the county holds to a stricter standard. Any native oak five inches or more in diameter is a regulated tree here, and other native trees from six inches. Near a creek, a pond or the lake shore, a tree of any size can be covered. If your project needs a tree permit, I prepare the report and the tree data for the site plan. The county's own pages are linked at the bottom of this page.

What I do here

• Diagnosis of oak decline, root disease and decay fungi
• Tree risk assessment for oaks over houses, pools and drives
• Review of irrigation, pool and grading plans before work starts
• Tree permit reports and site plan tree data for the county
• Three year survivability inspections of replacement plantings

When to call

A site assessment with a written report starts at $500. The site visit on its own is $250 and covers up to one hour on site. The most useful moment to spend it is before an irrigation redesign, a pool excavation or a grading plan is finalized, because most of what I get called about later started as a decision made on paper. Call or text (530) 391-6100.

Frequently Asked Questions

What trees are native to Granite Bay?

Blue oak, interior live oak and foothill pine make up the open woodland, with valley oak on the deeper soil along the drainages. Most of the big trees on older lots are one of the three oaks.

Should I water mature native oaks in summer?

If they are established natives that have never been irrigated, no. These oaks grew up on winter rain and a dry summer, and steady summer water at the root collar is the most common way a healthy old oak is lost, usually through root and crown rot. If a lawn already surrounds the trunk, the answer is not to shut the water off abruptly. It is to move water away from the root collar and reduce it in stages.

Can I build a pool near a mature oak?

Often, yes, if the tree is part of the plan from the start. What matters is how much of the root zone the excavation, the decking and the trenches for plumbing and gas take, and on which side of the tree. I mark the area the tree needs and the design works around it. It is far easier to move a line on paper than to save an oak after its roots are cut.

What size oak is protected in Granite Bay?

Five inches in diameter for any oak species, measured four and a half feet above the ground on the high side of the tree. Other California native trees are protected from six inches on a single stem. A tree an owner thinks of as a sapling can need a permit.

What does an arborist visit cost in Granite Bay?

With a written report, a site assessment starts at $500. For the visit alone, up to an hour on site and my findings in person, it is $250. Plan review for a pool or a grading project is quoted before I start.

Sources and official pages

• California State Parks: Folsom Lake State Recreation AreaThe park brochure describes the woodland around the lake, its 1955 origin, and its seasonal change in level.
• UC Oaks: Blue Oak WoodlandUniversity of California description of blue oak woodland, its shallow soils, slow growth, and lack of young trees.
• Placer County Code Article 19.50, Woodland ConservationThe article adopted by Ordinance 6040-B, including the 5 inch oak threshold, the named community plan areas, riparian zones, landmark trees and mitigation.
• Placer County tree permit handoutThe county's current handout covering the minor tree permit, the thirty day filing timeline and the site plan requirements for trees within 50 feet of work.
• UC IPM pest notes, Armillaria root rotUniversity of California guidance on oak root fungus, including why established native oaks should not be irrigated and how to keep the root collar dry.