Grow cannabis in Dearborn Heights, MI

Growing cannabis in Dearborn Heights: the 17 days between a typical last frost and a safe one

In a typical spring, the last frost at the Dearborn station, 2.2 miles from the city, comes around May 1. Plant out that week and you are betting on an average year. Wait until May 18 and a later frost becomes a long shot, about a 1 in 10 chance.

Those 17 days matter more than they look, because the other end of the season is just as tight: frost can return by October 1. So what is your plan for a plant that is ready to go outside before the weather is?

Michigan home grow rules (as of October 2026)

Adults 21 and over: yes. Plant limit: 12 per residence in total.

Not visible from a public place; enclosed area with locks or other security devices. Source: MCL 333.27955; conditions: MCL 333.27954. Local rules (landlords, HOAs, city codes) can add more; this is a summary, not legal advice.

The spring tent decides the season

Seeds started April 6 to 20 are four to six weeks old by May 18, and young plants grow fast in that stretch. Give each one a pot big enough that roots do not circle it during the wait. Keep the light on a long day so the plants stay in veg, and if they outgrow the tent, top them instead of moving them out early.

April is why they stay in. The station averages about 10 freezing nights that month, with lows near 37°F, and May still averages more than one. A sunny 58°F April afternoon on Ford Road says nothing about the night that follows it.

Winter is the long haul around it. The station counts about 136 freezing nights a year, including about 29 in January alone, when lows average near 18°F. A basement tent holds steadier than a garage, but the floor stays cold: set pots on a stand, warm seedlings from below, and schedule the lamp for the overnight hours so its heat covers the coldest part of the day. January's 81 percent outdoor humidity matters little in a heated house, which runs dry; only a damp, unheated basement calls for a dehumidifier in winter.

By late summer the air turns heavy. July and August average 72 percent humidity and September 71, so a flower run in those months needs fans moving air under the canopy and a dehumidifier that keeps working after lights-out.

Month	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Avg high °F	32	35	45	58	70	79	84	82	75	62	48	37
Avg low °F	18	19	26	37	48	58	62	61	53	42	32	24
Humidity %	81					65	72	72	71	66

Highs and lows: NOAA 1991 to 2020 normals, Dearborn station (2.2 miles away). Humidity: Open-Meteo historical model data, average daily humidity in 2024, for the months shown. Planning averages, not a forecast.

Outdoors in Wayne County

Michigan caps a residence at 12 plants in total, and every plant has to be in an enclosed area with locks or other security devices, not visible from a public place. If an outdoor spot meets that, plant out May 18 or later. Nights average 50°F or warmer only from May 23 to September 24, and an early frost can land October 1, which leaves about 136 days. That is short for a photoperiod plant that flowers into mid October. Autoflowers or fast-finishing strains set out in late May leave room to harvest before the cold.

Last spring frost	May 1 in a typical year, May 18 to be safe (later only 1 year in 10)
First fall frost	Oct 15 typical, as early as Oct 1 (1 year in 10)
Frost-free season	about 166 days
Nights stay 50°F or warmer	May 23 to Sep 24
Start seeds or clones indoors	Apr 6 to Apr 20
Move plants outdoors	May 18 or later
Season note	Frost can arrive before mid October here: long flowering plants may not finish outdoors

A grow that stays your business

Dearborn Heights is a residential city of about 64,000 that wraps around Dearborn, so the Dearborn Summer Market and the Homecoming Festival are a short drive away. If you fall into conversation with another grower at one of them, what you tell them about your plants is your decision.

Canna GLAP encrypts each entry in your grow log on your phone before the upload. Pry open our servers and you would come away with coded grow records and nothing that decodes them. The spring you held your plants until May 18, and what that did for the harvest, stays in notes only you hold.

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 Dearborn Heights ask

When is it safe to plant cannabis outside in Dearborn Heights?

Wait for May 18. Frost usually ends around May 1, but one still arrives after May 18 only about one year in ten, and average nights stay under 45°F until May 8.

How many cannabis plants can I grow in Dearborn Heights?

Michigan sets the cap by residence, not by person: 12 plants for the whole residence, kept in an enclosed area with locks or other security devices and not visible from a public place.

When should I start cannabis seeds in Dearborn Heights?

Indoors, April 6 to 20. That gives the plants four to six weeks before they go out on May 18, with an early frost possible by October 1 at the other end.

Growing near Dearborn Heights

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