Blackout tarps used to force early flowering were not originally invented for cannabis. The original account traces their origins to floriculture, where growers manipulated flowering cycles in ornamental plants. Two examples are given: poinsettias and chrysanthemums. Growers used blackout cloth to trigger blooms by controlling light exposure. Cannabis growers eventually adapted the same basic approach, using tarps to shorten the day and force plants into flower earlier than the natural season would allow.
The Floriculture Origins: Blackout Tarps Were Not Invented for Cannabis
Late 1980s–1990s: Humboldt Adapts Blackout Techniques
In the late 1980s and 1990s, Humboldt County growers began adapting blackout techniques for cannabis. The practice was used to flip plants into early flowering, and it offered timing advantages.
Those advantages included moving harvests ahead of potential raids and ahead of fall floods. The technique remained relatively rare in those years, and indoor cultivation attracted much of the attention during the eradication years.
1996–Early 2000s: Proposition 215 Changes the Landscape
California Proposition 215, passed in 1996, opened new opportunities for medical cannabis cultivation. However, most growers continued using either full-sun outdoor or indoor methods. Hoop houses remained basic, and many farms still produced just one harvest per year.
At this stage, pulling tarps had not become a mainstream cultivation method. Light-dep was known, but it had not yet taken over the outdoor market.
Late 2000s–Early 2010s: The Breakthrough
The breakthrough came in the late 2000s and early 2010s, when growers began pulling tarps twice daily to create a 12/12 light cycle. That practice allowed mid-summer harvests, which beat fall rains, price drops and, later, wildfire smoke.
Stacking two or more harvests changed the economics of outdoor growing. Instead of one fall harvest, growers could produce two to three harvests in a season, and that change reshaped the market.
2010–2014: Light-Dep Takes Over the Emerald Triangle
By the early 2010s, light-dep was spreading across the Emerald Triangle. The original account identifies @light_dep_greenhouse as a major evangelist for the method, and its platform helped teach farmers how to scale light-dep production.
In 2014, the Golden Tarp Awards established light-dep flower as a recognized category. That was a cultural arrival for dep cultivation, marking its acceptance as a distinct form of flower, not just a workaround.
Market Effects: Humboldt Farm-Gate Prices Fall
The expansion of multiple harvest cycles increased the amount of flower entering the market, and farm-gate prices fell. The original account gives specific farm-gate price comparisons:
Period / Product — Price per pound
Humboldt 2009 — ~$3,000
Humboldt 2014 — ~$1,200
Later indoor — $1,800–$2,200
Later light-dep — $1,150–$1,300
These figures illustrate the economic changes that accompanied the growth of light-dep production.
2015–2018: Commercial Greenhouse Expansion
From 2015 to 2018, light-dep moved from hand-pulled tarps to commercial greenhouses. The original account describes that expansion as a shift from small, labor-intensive operations to larger, more systematic greenhouse production.
The Technology Leap: Motorized Curtains
The technology leap was motorized curtains. Manual tarps were replaced by automated blackout systems that could be pulled on a schedule, reducing labor and improving consistency.
That automation helped light-dep scale, and it made the method viable for larger operations that could not rely on twice-daily hand-pulling.
The Lasting Shift: A New Outdoor Calendar
Light-dep did not just add harvests. It created a new outdoor calendar, in which growers could plan multiple harvests, avoid fall weather risks and supply the market through much of the year.
Legacy: How Light-Dep Changed Outdoor Growing
The original account presents light-dep as a revolution in outdoor growing, not a footnote. It began in floriculture, was adapted in Humboldt to beat raids and rain, and ended as a standard method that changed how, when and how often cannabis could be harvested outdoors.
Sources
nuggnotes. "Tarps, Tents & Takeover: The Light-Dep Revolution." Instagram, Sep 19, 2025. https://www.instagram.com/p/DOzBCeRkgU3/
The original Instagram post behind this article. California Center for Rural Policy, Humboldt State University. "Humboldt County Cannabis Equity Assessment." Aug 2019. https://ccrp.humboldt.edu/sites/default/files/humboldt_county_cannabis_equity_assessment_final.pdf Documents the farm-gate price arc the article cites: about $3,000/lb in 2009, under $2,000 by 2011, $1,200 by 2014. Cannabis Now. "Golden Tarp 2015: The Year of Change." Cannabis Now. https://cannabisnow.com/golden-tarp-2015-the-year-of-change/ Confirms the Golden Tarp Award was created in 2014 to promote light-deprived cannabis, by Luke Bruner and Kevin Jodrey, at the Mateel Center in Redway. East Bay Express. "Cheaper, Stronger, Earlier Weed: The 1st Annual Golden Tarp Awards." East Bay Express, Aug 20, 2014. https://eastbayexpress.com/cheaper-stronger-earlier-weed-the-1st-annual-golden-tarp-awards-celebrates-this-years-light-dep-crop-1/ Contemporary report of the first Golden Tarp Awards (Sep 13, 2014) as a best-light-dep-crop contest. South Dakota State University Extension. "Are You Photoperiodic? Poinsettias Are." SDSU Extension. https://extension.sdstate.edu/are-you-photoperiodic-poinsettias-are-explanation-unique-plant-process Documents commercial floriculture's blackout-cloth practice for poinsettias and chrysanthemums — the short-day technique cannabis light-dep adapted. Defenbaugh, James. "Doubling and Tripling Down." Grow Magazine. https://growmag.com/feature/doubling-and-tripling-down/ Documents light-dep growers harvesting 2 to 3 times a year versus a single fall harvest.
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