CannaGLAP

Grow cannabis in Barstow, CA

Growing cannabis in Barstow: deciding which months your plants spend in the Mojave heat

Barstow's summer is not a heat wave you wait out. It lasts about four months, with roughly 25 to 31 afternoons at 90°F in each month from June through September, and a July night still averages about 72°F.

Before you size an air conditioner for that stretch, ask a different question: does your best plant need to be flowering in it at all?

California home grow rules (as of October 2026)

Adults 21 and over: yes. Plant limit: 6 living plants per private residence, however many adults live there.

Locked space, not visible from a public place; cities and counties can set reasonable rules for indoor grows (but cannot ban them) and may ban outdoor grows; a landlord may prohibit growing on a rental. Source: Department of Cannabis Control; conditions: Prop 64 text as passed in 2016 (H&S Code 11362.2 and 11362.45). Local rules (landlords, HOAs, city codes) can add more; this is a summary, not legal advice.

A central Mojave grow room, planned around the calendar

The Barstow station sits 0.3 miles from town at 2,220 feet, so these are close to the town's own numbers. From June through September it averages about 111 afternoons at 90°F, nearly every day of those months, and July highs average 102°F. A lamp adds its heat on top, and a garage or shed on an outside wall can run far hotter than flowers tolerate. Buds that form in that heat tend to come out loose and short on smell.

If you do run through summer, flip the lamp to run from evening to morning so the afternoon peak falls in the dark period. With July and August nights near 70 to 72°F, outside air cools a tent only a little. An air conditioner in a well-insulated room ends up doing most of the work, and it pulls water out of air that was already dry: 18 percent in July 2024.

The other choice is to let summer carry the small plants. Mother plants, cuttings and young plants in veg (the leafy growth stage) take heat with less lasting harm than flowers do, though fresh cuttings in air that dry need a clear dome. Then switch to flowering in October, when highs drop to about 81°F, and let the buds ripen through November and December, which average no 90-degree days.

That cool-season run costs you cold instead. Barstow averages about 32 freezing nights a year, most in December and January, when lows sit near 35°F, so an uninsulated shed or garage makes a poor winter flower room. Use a heated room, run the lamp through the coldest hours, and set seedlings on a heat mat. The reward is dry air that leaves bud rot little to work with.

MonthJanFebMarAprMayJunJulAugSepOctNovDec
Avg high °F59637077869610210193816857
Avg low °F353944495765727063534235
Humidity %592318222826

Highs and lows: NOAA 1991 to 2020 normals, Barstow station (0.3 miles away). Humidity: Open-Meteo historical model data, average daily humidity in 2024, for the months shown. Planning averages, not a forecast.

Outdoors in the Mojave

California law allows 6 living plants per private residence, no matter how many adults live there. They must be locked up and kept out of sight of any public place. Cities and counties can make rules for indoor grows and are allowed to ban outdoor ones. A landlord may prohibit growing on a rental, so check what applies at your address before you plant.

Where an outdoor space is allowed, sow seeds indoors March 4 to 18 and move plants out from April 15. The last frost lands after March 24 only one spring in ten, and about 208 days run from planting to the early fall frost date of November 9. Plants grow through the 90-degree months, so afternoon shade and deep watering matter more here than feeding, and photoperiod buds that finish in October meet far milder days than September's. Autoflowers do not wait for long nights: one sown shortly before it goes outside ripens as June's heat builds, so shade it.

Last spring frostFeb 22 in a typical year, Mar 24 to be safe (later only 1 year in 10)
First fall frostNov 23 typical, as early as Nov 9 (1 year in 10)
Frost-free seasonabout 271 days
Nights stay 50°F or warmerApr 18 to Oct 23
Start seeds or clones indoorsMar 4 to Mar 18
Move plants outdoorsApr 15 or later

What the desert can see, and what it cannot

A grow can be guessed at from outside: an air conditioner humming all night, shade cloth over a yard. Encryption cannot hide any of that. What it can do is keep the records themselves from being one more thing to guess at.

Each grow record is encrypted on your phone first, and the encrypted copy is what reaches our servers. Break into those servers and you would find grow records you cannot read, with no key stored beside them. What you learned about getting buds through a Barstow summer stays yours.

What is encrypted: your plants, notes, photos, feed logs and harvests. What is not: account details (such as your email, name and plan), a grow name or town if you type one, your team, and your sensors' names. The full list: what a hacker would get.

Questions growers in Barstow ask

Can I grow cannabis through a Barstow summer?

Yes, in a cooled, insulated room with the lamp on at night, but it is the hardest season here. Keeping summer for young plants and flowering from fall into winter avoids most of the heat.

Does Barstow get cold enough to hurt a grow?

Yes. Frost typically arrives around November 23 and keeps coming until about February 22, so a garage or shed tent needs warmth all winter.

Do I need a dehumidifier in Barstow?

Rarely for flower. Outdoor humidity averaged 18 to 28 percent from June through October 2024, and a heated winter room usually runs dry too. Young plants are the ones that need added moisture.

Growing near Barstow

All California cities · Every state where adults may grow at home