How To Grow THCA Flower: A Step-By-Step Guide

We love THCa for a few reasons. Not only does it fall under a legal loophole per the 2018 Farm Bill, but its decarboxylated nature produces the familiar effects of Delta-9 THC.

Interested in growing it? I know I am. While THC gets most of the attention, many cultivators are now specifically focusing on maximizing THCA content in their harvests.

If you’re wondering how to grow THCa flower or what to expect while growing THCa flower at home—this guide is for you.

Familiar with growing regular THC cannabis flower? You should have no problem growing THCa flower.

The process is essentially the same, but the key difference is that the plant’s growth is slightly tailored to produce and preserve the THCA cannabinoid.

As a quick reminder, THCa is the precursor to Delta-9 THC. On its own, it’s non-psychoactive, and if you were to consume THCa in its non-psychoactive state, it wouldn’t produce effects other than potential anti-inflammatory and neuroprotective benefits.

Once it’s heated (decarboxylated), THca converts to Delta-9 THC and produces the classic buzz we know from cannabis.

There are several factors to keep in mind before you start the grow process:

Just like growing regular hemp or cannabis plants, the quality of your experience starts with the strain you choose. Different cannabis plants produce different amounts of cannabinoids and terpenes.

Ask yourself: what am I looking for in this THCa strain? That could be potency, cannabinoid production, maximum terpenes—the list goes on.

A good rule to keep in mind is that cannabis strains with high THC potential (usually 25%+) will produce high levels of THCa. Some of our top picks include:

• White Widow: Heavy trichome production
• ACDC: CBD-rich but still produces solid THCA levels
• Northern Lights: Resilient genetics (beginner-friendly)
• Gorilla Glue: High resin production and cannabinoid content

Between these strains, you’ll likely find seed varieties like auto-flowering and photoperiod. If you’re after cannabinoid production and maximum THCa, photoperiod plants give you much more control of the growing cycle.

Autoflowers will still produce solid cannabinoid levels, but often less than photoperiods since controlling their cycle is a bit more challenging. Still, they deliver fast harvests and compact sizes for those growing indoors and/or discreetly.

If you’re wondering how to grow THCa flower while maximizing cannabinoid content, indoor growing gives you much more control over all environmental factors. With outdoor grows, you’re leaving it up to nature.

It really comes down to preferences. For high cannabinoid levels and maximum control, grow THCa flower indoors. If you don’t mind a slightly weaker cannabinoid content and prefer a more natural process, grow THCa flower outdoors.

When growing high-THCa flower, lighting is one of the most crucial parts of controlling the growth cycle and maximizing THCA content.

You’ll need high-quality LED grow lights if growing indoors. They’ve become the industry and home-grow standard for two reasons: energy efficiency and customization.

Here are a few ways to ensure maximum trichome production and THCa development in your cannabis plants:

• Full spectrum coverage on blue light during the vegetative stage
• Red spectrum during the flowering stage to boost trichome production
• Light intensity of 600-1000 PPFD during flowering stage

Growing outdoors? You can take advantage of free, natural sunlight.

For high-quality THCa flower, keep environmental conditions in these ranges during different stages of growth:

• Vegetative Stage: 70-85°F (21-29°C) with 40-70% humidity
• Early Flowering Stage: 65-80°F (18-26°C) with 40-50% humidity
• Late Flowering Stage: 65-75°F (18-24°C) with 30-40% humidity

Never skimp on nutrients—they can make or break the overall quality of your THCa flower. A nutrient-rich soil foundation makes sure your plants get the essential elements they need for optimal growth.

Your plant’s feeding schedule should look something like this:

• Nitrogen-heavy during vegetative growth
• Phosphorus and potassium-heavy during flowering
• Micronutrients like calcium, magnesium, and sulfur
• Silica supplements strengthen cell walls and improve stress resistance

When choosing between organic vs. synthetic nutrients for growing THCa flower, this really comes down to preferences. Still, there are a couple of things to note:

Organic: This might be more complicated, but it creates complex soil food webs that definitely pay off in terpene profiles and cannabinoid development.

Synthetic: These nutrients let you be incredibly precise with your plant’s feeding, which might be more ideal for maximizing THCa production.

This is a great technique many growers use to ensure light gets to all areas of their buds:

• Start during the early vegetative stage
• Use soft garden ties to secure branches horizontally
• This lets you create a flat, even canopy for maximum light exposure

Along with low-stress training, another easy way to maximize light exposure and THCa production in cannabis plants is by removing excess leaves:

• Remove large fan leaves shading buds
• Thin out the inner canopy for better air circulation
• Removing growth on lower branches that receive low light to push energy upward

When’s just the right moment to harvest THCa flower? Take a look at the trichomes and harvest when they’re at peak development. Follow these tips:

• Use a magnifying glass or jeweler’s loupe
• Earlier harvest (more clear trichomes) might preserve more THCA
• Harvest when trichomes are mostly milky white with some amber trichomes

Once harvested, you must properly dry and cure your THCa flower to ensure THCa is preserved efficiently:

• Slow-dry plants in a dark room at 60-70°F with 45-55% humidity
• Dry until stems snap instead of bend (typically 7-10 days)
• Cure in glass jars at 62% humidity for at least 2 weeks, “burping” every day
• Lower temperatures throughout this process help preserve THCA

The quality of your grow starts with the quality of your seeds. Always research to ensure you’re buying from reputable seed banks packed with positive reviews across various options.

When growing THCa flower in cannabis strains, try to look for seeds with strong trichome development instead of THCa concentrations or percentages.

• Germinate seeds using the paper towel method or directly in the soil
• Aim for 70-85% humidity with temperatures around 75°F (24°C)
• Lay low on nutrients during this time (seedlings are sensitive)
• Give them 18-24 hours of low-intensity light

• Transplant once seedlings have 3-5 sets of true leaves
• Start LST techniques early to control the plant’s structure
• Start your regular feeding schedule with nitrogen-focused nutrients
• Continue this for about 4-8 weeks, depending on your desired plant size

• Switch light schedule to 12 hours on, 12 hours off
• Continue LST training until weeks 2-3 of flowering
• Transition to nutrients with higher phosphorus and potassium
• The flowering stage can bring on some pests—stay on the lookout

• Monitor trichome development closely
• Harvest when trichomes are mostly milky white for high THCA
• Consider harvesting in stages, taking upper buds first as they mature earlier
• Don’t over-handle your buds—too much moving and grooving can shake off trichomes

• Hang whole cannabis plants or branches in a dark room at 60°F (15°C) with 50% humidity
• Dry slowly over 10-14 days to preserve cannabinoids and terpenes
• Cure in glass jars at temperatures below 70°F for the least decarboxylation possible
• Burp jars daily for the first two weeks, then weekly for at least a month

• Store in airtight containers away from light, heat, and air
• Keep storage temperatures below 65°F (18°C)
• Try vacuum sealing for long-term storage
• Use humidity control packs

If cannabis is recreationally legal in your area, then it’s legal to grow THCa flower. However, THCa flower on the market that’s legally sold nationwide is much different than the raw cannabis flower you’re growing at home.

THCa products are rigorously lab-tested with an intense quality-control process to ensure they remain federally legal and compliant with the 2018 Farm Bill.

The cannabis you’re growing? It’s basically the wild west. Since raw cannabis plants, hemp plants, and high THCa plants are practically identical, it’s best to follow your local laws in this case.

As of March 2025, here are the current laws for cannabis cultivation across the United States:

• In recreational states like California, Colorado, Michigan, and Massachusetts, home cultivation of limited plants is legal
• Medical cannabis states often let patients grow a certain number of plants
• States where cannabis is completely illegal likely bans growing it too

THCA legal states include the 21 states plus Washington D.C. that have legalized recreational cannabis. That said, state and local laws vary. The number of plants you can grow always differs.

Before you start growing THCA flower, do your research. Even if cannabis is fully legal in your state, there might be limits on how many plants you grow.

With the guide above, you should have no problem growing high-THCA cannabis or hemp plants with milky trichomes and wicked potency.