Spring Bloom Surveys in the Santa Monica Mountains: A Field Note from the 2026 Restoration Year

The 2025–2026 winter delivered a solid 17.4 inches of cumulative rainfall to the western Santa Monica range, well above the ten-year median, and the spring bloom that followed has been the most consistent we have recorded since the closing of the post-2018 burn-recovery program. This note walks through what we saw on three early-season survey transects, what came up that we did not expect, and what it means for the propagation calendar in the second half of 2026.

Survey area and methods

The three transects discussed here run through Topanga State Park, La Jolla Valley in Point Mugu, and a small private parcel in the upper reaches of Carbon Canyon for which we hold a long-running monitoring agreement. Each transect is a 200-meter belt, two meters wide, walked twice in the spring and once in late summer. We log species presence-absence at five-meter intervals, percent cover for shrub and herbaceous strata, phenology stage where applicable, and any observation we cannot identify in the field.

The transects were chosen years ago to span the dominant pre-burn vegetation classes in the western range: northern coastal sage scrub at La Jolla Valley, mixed chaparral at Topanga, and a transitional band that includes a small patch of remnant southern oak woodland at Carbon Canyon. They give us a workable, if biased, sample of community-level recovery, and they let us watch how the same suite of restoration introductions performs across slightly different rainfall regimes.

What we saw, in summary

The headline result is that cover has held or improved at all three sites for the established native shrub layer (Artemisia californica, Salvia leucophylla, Eriogonum cinereum) and that the herbaceous layer has shifted noticeably toward native annuals at La Jolla Valley and Topanga — a shift we have been hoping to see since the second post-burn restoration cycle. Carbon Canyon remains under heavier annual-grass pressure, particularly Bromus diandrus, but even there we logged native annual cover at 18% on the lower transect, an increase from 11% in 2024.

The less expected finding is the resurgence of Phacelia tanacetifolia at Topanga. This species has been spotty on the transect since 2019, never exceeding three or four scattered plants per visit. In the April survey we counted 41 individuals along the belt, several of them well outside the small seeded plot we put in three years ago. The plants outside the plot were almost certainly recruited from the seed bank rather than the recent introduction, which we read as a positive signal for in-place soil health.

Carbon Canyon: a slower recovery

Carbon Canyon has consistently lagged the other two sites for as long as we have been measuring it, and the 2026 numbers do not change that picture. The slope is steeper, the soil holds less water, and the pre-burn seedbank had already been compromised by years of annual-grass dominance before the 2018 fire ever reached it. We have been seeding in three pulses each winter for the last four cycles, and the establishment rate is, charitably, modest.

What did encourage us in 2026 was the cluster of Mimulus aurantiacus seedlings on the lower bench, behind the large Quercus agrifolia we use as the third anchor point. We counted 23 first-year individuals in roughly a six-meter radius. None were planted there. The most plausible explanation is dispersal from the parent population a hundred meters downslope; we have observed similar local recruitment when the rainfall pattern is unusually consistent in March, which it was this year.

The hardest part of restoration on a degraded slope is being patient enough to let the seedbank, where any of it survives, do the work it can do on its own. Our role is to remove pressure, to refrain from over-introducing, and to mark and protect the volunteer recruits when they appear.

We will not be increasing the seeding rate at Carbon Canyon for the 2026–2027 cycle. The improvement we are seeing, modest as it is, is largely on the back of in-situ recruitment and reduced grazing pressure since the fenceline reinforcement last fall. We do plan to add a fourth small monitoring plot on the upper bench, where the soil profile is shallower and where we have not yet documented post-burn shrub cover above 20%.

La Jolla Valley: an exceptional year for annuals

La Jolla Valley, by contrast, produced one of the more striking annual-bloom displays we have ever logged on the transect. The standout was Eschscholzia californica, the California poppy, which carpeted the south-facing slopes between waypoints 4 and 12 in mid-March and was still flowering, more sparsely, at the April visit. We counted 312 flowering individuals in the 200-meter belt at the peak visit. The previous transect record, set in 2019, was 187.

This is partly a rainfall effect, and partly the slow accumulation of seed bank since the 2017 prescription burn that removed a substantial mat of non-native grass. The two effects are difficult to separate precisely; what we can say is that the years in which we have seen comparable poppy density on this transect have all also been wet years, and that the annual-grass cover has been declining on the same belt for six successive surveys.

The supporting cast was strong as well: Lupinus succulentus and L. bicolor both above 30 individuals on the belt, modest pockets of Lasthenia californica, and a handful of Calochortus catalinae that we have been quietly hoping to see for years. The Calochortus is a particularly slow species to establish, and a single bloom is, in restoration terms, a meaningful event.

Topanga: returning to a steadier baseline

The Topanga transect was hit hardest by the 2018 fire, and recovery has, predictably, been the most variable there. The 2026 survey is the first since 2020 in which we did not record meaningful percent cover loss in the established shrub layer between the spring and late-summer visits. That is a small but important shift. It implies that the shrubs that came back after the burn are now reaching the size and rooting depth at which the summer dry season is no longer a near-term threat to their persistence.

The Phacelia data discussed earlier is the more visible story, but the steadier news is on the shrub side. We are not, at this point, planning further Artemisia or Salvia introductions at Topanga. The cover data and the size-class distribution both suggest that the existing population is approaching a self-sustaining configuration on its own.

Phenology shifts and propagation calendar

Across all three sites, the spring bloom this year ran roughly three weeks longer than the 2014–2024 median. The driver is almost certainly the early start of the wet season; the temperature pattern has been near average, and the late-season rainfall pulse in late March did not occur. Practically, the longer bloom means that seed collection windows for several of our key restoration species have been wider than usual.

For the propagation house, the most consequential implication is timing. We typically begin Artemisia californica stem-cutting work in May, with rooting expected by August in time for fall outplanting. Given the prolonged growth period this year, we are advancing that calendar by about ten days; the cuttings we took on April 26 are already showing callus formation, somewhat earlier than the recent-year norm.

Notes on non-native pressure

The non-native grass picture remains the most stubborn part of the story at all three sites. Bromus diandrus and Hirschfeldia incana together accounted for between 25% and 95% of the annual herbaceous cover on at least one transect waypoint, even at La Jolla Valley where the native annuals had a banner year. Our interventions on these species have been limited; we have a long-running policy of not pursuing chemical treatment on these transects, and the volunteer mowing and hand-pulling cycles can only address a small fraction of the affected area.

The good news, such as it is, is that the timing of the non-native bloom shifted earlier in 2026 than in any recent year, and the early die-back made it easier to identify and selectively pull Hirschfeldia in patches where we did want to reduce competition for seedling natives. We logged 412 person-hours of hand-pulling across the three sites between February and April, slightly above the four-year mean. We are not under the illusion that this scales; it is best understood as a triage tool focused on small areas of high restoration value.

Equipment and method notes

A small change in our field methodology this season: we have moved from paper datasheets to a tablet-based form for the per-waypoint species presence-absence record. The form is hosted on a small private instance, and it produces a CSV of the same shape as our 2014–2025 data. The lead surveyor still carries a paper backup and a film camera for reference photographs at fixed waypoints; the tablet is supplementary, not substitutive.

We had two tablet failures across the three transects (one battery, one screen freeze in direct sunlight). Both were recoverable with the paper backup. We will continue with the hybrid workflow for at least one more season.

What we will be watching

1. Whether the Calochortus catalinae population at La Jolla Valley re-blooms in 2027. A single year is not a trend.
2. Whether the Phacelia recovery at Topanga continues to expand outward from the seeded plot. We will mark a sub-plot for closer monitoring.
3. Whether the upper Carbon Canyon plot, once established, shows any post-fenceline-reinforcement improvement equivalent to what we are seeing on the lower bench.
4. Whether the early bloom shift we logged this year holds, given that El Niño conditions are forecast to weaken into the 2026–2027 winter.

Closing

The temptation, when reporting on a wet year, is to compress the news into the headline that things are going well. They are, on balance, but the picture is uneven and the long arc of recovery on these slopes is still measured in decades, not seasons. The fieldwork program will continue at the current cadence; the propagation house is moving slightly earlier than usual; and the volunteer schedule, as always, is the place to look for the small, immediate ways to be of help.

Our next field note will cover the late-summer visits in August. In the meantime, please feel encouraged to send corrections, observations from your own field work, and identification queries to the editor at the address listed on the about page.