Harvesting Cannabis

PUBLISHED: July 29, 2024

Towards the end of the flowering stage of cannabis grow cycle comes time to harvest, but how do you know when the time is right?

Getting Harvesting Right is Important

Harvesting cannabis is more than just a final step in the cultivation process; it’s a critical phase that directly impacts the quality, potency, and yield of your crop. Proper harvesting ensures that all the hard work, time, and resources invested in growing cannabis plants translate into a top-quality product. If done correctly, it maximizes the cannabinoids and terpenes in the buds, delivering a superior experience in terms of flavor, aroma, and effects. Conversely, improper harvesting can lead to a reduction in these essential compounds, resulting in a less satisfying product.

Understanding the nuances of when and how to harvest can significantly influence the final outcome. Timing is everything in cannabis cultivation, and recognizing the signs that indicate your plants are ready for harvest is crucial. This comprehensive guide will walk you through the entire harvesting process, providing detailed insights and practical tips to help you achieve the best results.

When to Harvest Marijuana

Determining the right time to harvest marijuana involves observing several key indicators that signal the maturity of your plants. Here are the primary signs to look for:

Fan Leaves Begin to Yellow

One of the first signs that your cannabis plants are nearing harvest is the yellowing of the fan leaves. As the plant shifts its energy towards bud production and ripening, it begins to deplete the nutrients stored in the fan leaves, causing them to yellow and die off. While some yellowing is normal, excessive yellowing could indicate a nutrient deficiency or other issues.

This natural process is a sign that the plant is maturing and nearing the end of its life cycle. However, it is not a definitive indicator on its own. It should be observed in conjunction with other signs of readiness.

Trichomes Start to Look Different

Trichomes are tiny, resinous glands on the buds and leaves of the cannabis plant. They produce cannabinoids and terpenes, which contribute to the plant’s potency and aroma. Observing trichomes under a magnifying tool like a jeweler’s loupe or a digital microscope is one of the most reliable methods to determine the optimal harvest time.

Trichomes go through several stages of development:

• Clear Trichomes: These are immature and indicate that the plant is not ready for harvest.
• Milky/Cloudy Trichomes: These trichomes indicate peak THC levels and are a sign that the plant is at its most potent.
• Amber Trichomes: These indicate that THC is beginning to degrade into CBN, which produces a more sedative effect.

For most growers, a mix of mostly cloudy trichomes with some amber trichomes is ideal for harvesting, providing a balance of potency and desired effects.

Swollen Calyxes

The calyxes are the small, teardrop-shaped structures that make up the buds. As harvest time approaches, these calyxes will swell and become more pronounced. This swelling is a sign that the buds are fully developed and have reached their maximum size and density. A good magnifying tool can help you examine the calyxes closely to ensure they are plump and fully formed.

Pistils Darken

Pistils are the hair-like structures on the buds that initially appear white and gradually darken to orange, red, or brown as the plant matures. When approximately 70-90% of the pistils have darkened and curled inwards, it is generally an indication that the plant is ready for harvest. However, relying solely on pistil color can be misleading, so it should be considered along with other indicators like trichome development.

When to Harvest Outdoor Marijuana

Harvesting outdoor marijuana involves a different set of considerations compared to indoor growing due to the variable nature of the outdoor environment. Proper timing is crucial to avoid weather-related issues that can affect the quality and yield of your crop. 

This section will delve deeper into the key factors to consider when deciding the optimal time to harvest outdoor cannabis, including how to navigate the challenges posed by the rainy season and cold weather.

Factors Influencing Harvest Timing

1. Strain Characteristics: Different cannabis strains have varying growth cycles and maturation times. Indica strains generally mature faster, often ready for harvest by early fall, while Sativa strains might take longer, sometimes not maturing until late fall. Understanding the specific characteristics of your chosen strain can help you anticipate the best harvest window.
2. Local Climate: Your region’s climate plays a significant role in determining the ideal harvest time. Growers in temperate climates might have more flexibility, while those in regions with early frost or heavy rainfall need to plan more carefully.
3. Latitude and Sunlight: The amount of daylight changes with latitude and season, affecting plant growth and maturation. Plants at higher latitudes may mature earlier due to shorter growing seasons, whereas those closer to the equator can have longer growing periods.

Monitoring Plant Maturity

To pinpoint the right time to harvest, closely monitor the maturation signs discussed earlier: trichome color, pistil darkening, and the overall health of the plant. Regularly inspecting these indicators will give you a clearer picture of when your plants are at their peak.

Rainy Season

The rainy season poses a significant threat to outdoor cannabis crops. Excess moisture can lead to mold and mildew, which can ruin your buds. Here’s how to manage this risk:

1. Weather Monitoring: Keep a close eye on weather forecasts. Knowing when rain is expected can help you make informed decisions about when to harvest.
2. Preventative Measures: If rain is imminent and your plants are close to maturity, consider harvesting a bit earlier. While the buds might not be at their absolute peak, it’s better than losing them to mold. Additionally, you can use temporary covers or shelters to protect your plants from excessive moisture.
3. Ventilation: Ensure your plants are well-ventilated. Adequate spacing and pruning can enhance airflow, reducing the risk of mold.

Cold Weather

Cold weather, especially frost, can damage cannabis plants and impact the quality of the buds. Here’s how to mitigate cold weather risks:

1. Harvest Before the First Frost: Frost can damage the buds and leaves, reducing potency and overall quality. It’s crucial to harvest before temperatures drop below freezing.
2. Protective Measures: If an unexpected frost is forecasted and your plants aren’t ready for harvest, consider using frost blankets or bringing potted plants indoors during the night.
3. Strain Selection: Choose strains known for their resilience to colder climates if you’re growing in an area with early frosts. Some strains are bred to withstand lower temperatures better than others.

Additional Tips for Outdoor Harvesting

1. Harvest in Stages: If your plants have multiple bud sites maturing at different times, consider a staggered harvest. This approach allows you to pick the most mature buds first, giving the lower buds more time to develop.
2. Timing of the Day: Harvesting early in the morning is often recommended as the plants are less stressed, and trichomes are intact. Avoid harvesting during the heat of the day when the plants are more likely to be dehydrated.
3. Pest Management: Outdoor plants are more exposed to pests. Regularly inspect your plants and address any infestations promptly. Pests can escalate quickly, especially as the plants near harvest.

By considering these factors and monitoring your plants closely, you can make informed decisions about the best time to harvest your outdoor cannabis, ensuring you maximize the quality and yield of your crop.

What Do You Need to Harvest Weed

To ensure a smooth and efficient harvest, you’ll need to gather the following tools and materials:

Essential Tools for Harvesting Cannabis

1. Trimming Scissors: Sharp, fine-pointed scissors are essential for precise trimming of buds.
2. Pruning Shears: For cutting down larger branches and stems.
3. Gloves: To protect your hands from resin and reduce the risk of contamination.
4. Magnifying Glass or Jeweler’s Loupe: For examining trichomes to determine the optimal harvest time.
5. Drying Rack or Lines: For hanging and drying the harvested buds.
6. Buckets or Trays: To collect trimmed buds and leaves.
7. Cleaning Alcohol and Cloths: To clean tools and surfaces, ensuring hygiene and efficiency.
8. Labels and Markers: To keep track of different strains and harvest dates.

Having these tools on hand will streamline the harvesting process and help maintain the quality of your cannabis.

Flush Cannabis Before Harvest

Flushing is an essential step to ensure the best possible flavor and smoothness of your final product. It involves watering your plants with plain, pH-balanced water to remove excess nutrients from the soil or growing medium. Here’s why and how to do it:

Why Flush Cannabis

Flushing helps to clear out any residual fertilizers and salts from the plant’s system, which can improve the taste and burn quality of the buds. Without flushing, these residues can lead to a harsh, chemical taste when the cannabis is smoked or vaporized.

Do You Need to Flush Cannabis?

Flushing cannabis before harvest is a widely debated topic among growers, but many agree that it can significantly impact the quality of the final product. Flushing involves watering the plants with plain, pH-balanced water to remove any residual nutrients from the soil or growing medium. This process can improve the taste, aroma, and overall smoking experience of the buds.

Why Flushing is Important

1. Improves Flavor and Aroma: One of the primary reasons for flushing is to enhance the flavor and aroma of the cannabis. Excess nutrients and salts can impart a harsh, chemical taste to the buds. Flushing helps to remove these residuals, leading to a smoother, cleaner smoke.
2. Prevents Nutrient Burn: Nutrient burn, characterized by yellow or brown leaf tips, can occur if plants have an excess of nutrients. Flushing helps to prevent this by clearing out the buildup of fertilizers, ensuring the plants use up their stored nutrients in the final weeks.
3. Better Burning Quality: Cannabis that hasn’t been flushed properly can produce a harsh smoke that irritates the throat and lungs. Properly flushed cannabis burns more evenly and produces a cleaner ash, enhancing the overall smoking experience.

How to Flush Cannabis

To effectively flush your cannabis plants, follow these steps:

1. Timing: Start flushing about 1-2 weeks before your planned harvest date. For hydroponic systems, flushing can begin as little as 5-7 days before harvest.
2. Watering: Use plain, pH-balanced water. For soil grows, the ideal pH range is 6.0-6.8. For hydroponic systems, aim for a pH of 5.5-6.5. Avoid using tap water with high levels of chlorine or other contaminants; filtered or distilled water is best.
3. Water Volume: Water your plants with a volume of water that ensures thorough saturation. For soil, this typically means using 2-3 times the volume of your pot size. For example, if you’re using a 5-gallon pot, flush with 10-15 gallons of water.
4. Frequency: Continue watering with plain water every time you would normally water your plants. This ensures that any remaining nutrients in the medium are used up or flushed out.
5. Monitoring: Check the runoff water’s pH and electrical conductivity (EC). The goal is to see the EC levels drop over time, indicating that excess nutrients are being flushed from the medium. The runoff should eventually be clear or nearly clear.

Signs of Proper Flushing

You’ll know that your plants have been properly flushed when:

• Leaves Start to Yellow: As the plant uses up its remaining nutrients, fan leaves may begin to yellow and fall off. This is a natural part of the process and indicates that the plant is using its internal nutrient reserves.

• Clear Runoff Water: The water draining from your pots should be clear, indicating that most of the residual nutrients have been flushed out.
• Improved Aroma: You may notice an improvement in the aroma of your buds as the excess nutrients are cleared out, allowing the natural terpenes to shine through.

Alternatives to Flushing

Some growers argue that flushing is unnecessary, especially if they’ve used organic nutrients that don’t leave behind harsh residues. Instead, they may opt for a gradual reduction in nutrient strength leading up to the harvest, allowing the plants to naturally use up their nutrient stores.

How to Harvest Cannabis

Harvesting cannabis involves several steps to ensure the best possible outcome. Here’s a step-by-step guide to help you through the process:

Step-by-Step Guide to Harvesting Cannabis

1. Preparation:
   • Clean your workspace: Ensure that your harvesting area is clean and sanitized to prevent contamination.
   • Gather your tools: Make sure you have all the necessary tools and materials ready.
2. Cutting the Plants:
   • Choose a dry day: Harvesting on a dry day can help prevent mold and mildew.
   • Cut down the main stems: Use pruning shears to cut the main stems of the plant at the base.
   • Handle with care: Be gentle to avoid damaging the buds and trichomes.
3. Trimming:
   • Wet trimming: This involves trimming the leaves immediately after cutting the plant. It can help reduce drying time and prevent mold.
   • Dry trimming: This involves hanging the whole plant or branches to dry before trimming. This method can help preserve terpenes and cannabinoids.
4. Drying:
   • Hang the plants or branches: Use a drying rack or hang the plants upside down in a dark, well-ventilated room with a humidity level of around 45-55%.
   • Monitor the drying process: The drying process usually takes 7-14 days. The buds are ready for the next step when the stems snap rather than bend.
     
5. Curing:
   • Jar the buds: Once the buds are dry, place them in airtight glass jars.
   • Burp the jars: Open the jars daily for the first week to release moisture and allow fresh air to circulate. This process is called “burping.”
   • Monitor humidity: Aim for a stable humidity level of around 62%. Use humidity packs or meters to maintain the ideal conditions.
6. Storage:
   • Store in a cool, dark place: After curing for at least 2-4 weeks (longer is better), store your cannabis in a cool, dark place to preserve its quality.

By following these steps, you’ll ensure that your cannabis is harvested, dried, and cured to perfection, resulting in a high-quality product that’s ready for consumption.

Harvesting cannabis is an art and science that, when done correctly, can significantly enhance the quality of your final product. By paying close attention to the signs of readiness, preparing adequately, and following best practices, you can enjoy the fruits of your labor in the best possible way. Happy harvesting!