Darlingtonia californica (cobra lily) — Mike's cultivation thread + color-form genetics

Overview

Mike's long-running thread on Darlingtonia californica (47 posts, 2013-2025) covers cultivation methodology, killing-protocol heuristics, and a 2023 demonstration that color is genetically determined rather than purely environmental.

Cultivation summary

The hard cultivation rule (Mike, post #45, 2023): keep soil temperature at or below 75°F at all times. Air temperature is irrelevant; soil temperature determines survival.

Mike's protocol evolved through three phases:

Pre-2017: standard outdoor cultivation; ended in mass die-off
2017 (post #4): full sun until 75°F threshold + shade cloth + sulfur for powdery mildew + pure peat substrate + no-standing-water watering regimen
2020 (post #44): "taking a break from Darlingtonia" after another heat-wave loss

pokie22's contradicting protocol (post #18, 2017): standing water required, full sun year-round including 100°F+ days, multiple substrate types — successful in California climate. Direct contradiction with Mike's protocol; microclimate likely explanatory.

Color-form genetics demonstration

Mike's 2023 side-by-side experiment (post #46) directly demonstrates that color is genetic, not purely environmental:

Red 'red like alpine farms' Del Norte Co, CA: solid red bodies
Green Rattlesnake Creek Josephine Co, OR: stays green under identical conditions

Even in cultivation, outdoor-grown red variants typically don't fully color up until fall — under indoor LEDs with anthocyanin-maximized spectrum, color can be driven year-round.

Standout traits

Cool-soil obligate in cultivation — Mike's hard rule (post #45, 2023): keep soil temperatures ≤75°F at all times. Air temperatures are irrelevant ('can be 110°F out there and they'll still do fine if the soil stays cool')

Above-soil-temp-75°F mortality threshold — soil temps above 75°F for a few days can wipe out mature plants, particularly in small pots or shallow trays (Mike, post #44, 2020)

Smaller plants are more heat-tolerant than mature plants (Mike, post #44)

Color is genetic — direct side-by-side cultivation evidence (Mike, post #46, 2023): 'red like alpine farms' colors solid red while Rattlesnake Creek green form stays mostly green under identical conditions

Color expression strongest in fall in outdoor culture — even genetically-red variants don't fully color up until fall outdoors (Mike, post #46)

Indoor LED with anthocyanin-maximized spectrum can drive solid color year-round in genetically-red variants (Mike, post #46)

Flower scent varies clone-to-clone — Mike (post #41, 2018) describes one as 'a slightly sweet cucumber'

Photos (23)