Quick answer: Monterey Cypress and Salt Wind — Trees are watered at the root zone, deeply and infrequently — a long soak that reaches down, then a dry spell that lets roots look for water, rather than a daily sprinkle that keeps everything in the top inch of soil. On the fog belt the question is rarely whether there is moisture in the air but how much got down to the roots.

Typical timing: Deep watering through the dry season, spaced further apart as the tree establishes; young trees need it far more often than mature ones.
What it involves: Watering at the drip line rather than the trunk, checking the soil six to eight inches down, and mulching so the water stays where it landed.
The standard: University extension guidance on landscape tree irrigation and drought response.
Where we work: The coastal terrace from Cambria to Morro Bay, sandy soil and clay both.
Our own record: 503 pages and 291 stories published on this site; Uncategorized (109) is the rail this page files under. Counted from our own archive, not a stock table.

Field note. What we see here is that salt air and wind dry a canopy faster than the thermometer suggests, so a tree can be water-stressed on a grey week when nothing looks hot to the person holding the hose.

On the other hand, more water is not a cure-all: on clay, a daily soak drowns roots more often than drought does, and the symptoms look almost identical from above.

Standards and sources: Irrigation and disease (UC IPM — University of California pest management) · Tree physiology (USDA Forest Service)
Prepared by Cambria Pines Tree Service Inc. — ISA-certified arborists working on the Central Coast.

Monterey cypress has the smallest natural range of almost any conifer, and it evolved in a place with salt in the air, wind every afternoon, and no rain in summer. Everything about how it grows and how it fails follows from those three conditions.

Salt

The species tolerates salt spray on its foliage better than almost anything else in the landscape. The needles are small and thick, the branchlets are dense, and the tree can lose a proportion of its outer foliage to salt burn and replace it without harm.

What it does not tolerate is salt in the root zone. The same adaptations do not extend to the roots, and a cypress in soil that accumulates salt will decline from the roots up. Which is why a cypress at the top of a beach lot thrives and one at the bottom, where the salt concentrates, does not.

Wind

A cypress grown in wind is a different shape from one grown in shelter: shorter, denser, spreading sideways, with a thin crown on the windward side and a longer one to lee. That shape is structural — the tree has built the wood to resist the load it actually experienced.

Which means a cypress is strong in the direction it grew and weak in the other. Remove the shelter it grew behind and you have changed the load without giving it a chance to adapt. That is the wind-shaped tree problem.

No summer water

The species expects a dry summer. It is not a drought-tolerant plant in the sense of surviving drought; it is a plant that is harmed by summer water. The pathogen that has killed more cypress in California than any other moves in water and infects through the roots, and it is present in the soil.

So the single most important thing anyone does for a cypress is keeping irrigation off it. A cypress in a lawn that is watered all summer is a cypress on a clock.

The shear problem

Cypress does not produce adventitious buds on old wood. Cut a branch back past the green and it does not resprout — it dies, and the tree keeps a permanent hole.

This is the reason the cypress hedges on this coast are sheared lightly and often rather than hard and rarely. A hedge that has been let go for a decade and then cut back to the line will not recover; it will thin from the cut surface inward and the wind will get through at exactly the place that mattered.

The canker

Two canker diseases affect the species here, and both enter through wounds. Which makes every pruning cut a decision, and makes the shears themselves a vector — a tool used on an infected hedge and then on a healthy one carries the pathogen.

Which is why the practical rule is: cut in dry weather, cut cleanly, and clean the blades between trees. For a hedge, that means cleaning between properties, not between branches.

What this means for a garden

Plant cypress where the drainage is good, the salt arrives as spray rather than in the soil, and the irrigation does not reach. Give it room to take its wind shape rather than staking it into a vertical. Prune lightly, in dry weather, and never into old wood.

Where a cypress is declining from the top, the cause is more often the roots than the crown, and the diagnosis is the same as for anything else. The species-specific version is cypress care.