The Flowering Stage: Things to Know About and Do During

The Flowering Stage

The flowering stage is a crucial phase in a plant's lifecycle, important for maximizing yield and quality. It comes after the vegetative phase and is when plants start producing flowers or buds. Managing the flowering stage is essential for achieving the best possible results. 

This stage is triggered by changes in environmental conditions, specifically light cycles such as shifting from an 18-hour light schedule to a 12-hour one. For most plants, the reduction in daylight hours signals the start of flowering. 

Signs Indicating the Start of the Flowering Stage

• Pre-Flowers: Small white hairs (pistils) appear at the leaf nodes.
• Stretching: Plants grow taller as they prepare for flowering in order to support the developing flowers.
• Leaf Structure Changes: Leaves may change in shape and size.

Physiological Changes 

• Bud Formation: Buds begin to form and becomes the main part of the plant's growth
• Increased Resin Production: For cannabis, resin production increases which enhances the potency and aroma of the buds.
• Nutrient Uptake Changes: With the development of the flowers, the plants' nutrient needs will shift as well with a greater need for phosphorus and potassium.

Differences Between Plant Types

• Cannabis: Requires strict light cycle and nutrient management to maximize bud production and potency.
• Tomatoes: They are not as light-sensitive as cannabis, but they still benefit from careful nutrient and watering management for a more generous harvest.
• Ornamental Flowers: Many decorative plants have their own unique needs and flowering triggers, which may include factors like temperature and humidity.

Key Factors to Monitor 

Light Cycle:  For many plants, especially those grown indoors like cannabis, the flowering stage is triggered by a specific light schedule. Ensure complete darkness during the dark period, as even small light leaks can disrupt flowering. Transition from an 18-hour light/6-hour dark cycle used during the vegetative stage to a 12-hour light/12-hour dark cycle. This mimics the shift from long days of summer to shorter days of autumn, giving the plant a signal that it is time to flower. Use lights that emit the appropriate spectrum for flower development.

Nutrient Needs and Adjustments: Plants will need the following nutrients to support bud development and overall flower health.

• Phosphorus (P): It is vital for flower formation. Use bloom-specific fertilizers that have higher phosphorus content.
• Potassium (K): It supports strong stems and enhances flower quality. Ensure your nutrient mix includes sufficient potassium.
• Reduced Nitrogen (N): While still necessary, nitrogen should be reduced compared to the vegetative stage to prevent excessive leaf growth.

Watering Practices: Plants will need less frequent but deeper watering compared to the vegetative stage. This is to encourage strong root growth. Also ensure good drainage to prevent waterlogging or the medium getting saturated with water. Adjust watering frequency based on the plant’s size, the growing medium, and environmental conditions.

Temperature and Humidity: For optimal conditions, maintain the daytime temperatures between 68-77°F (20-25°C) and nighttime slightly cooler. Avoid high temperatures that can cause stress on the plant. Then keep humidity levels around 40-50% to prevent mold and mildew build up. 

Common Challenges and Solutions

CHALLENGES	DESCRIPTION	SOLUTION
Pest  and Diseases
Pests	Aphids, spider mites, whiteflies	Regular inspection. Clean environment and introduce beneficial insects.
Diseases	Powdery mildew, bud rot	Regular inspection. Clean environment and apply fungicides (flowering-safe only).
Nutrient Deficiencies
Deficiencies	Phosphorus, potassium, magnesium	Soil testing. Targeted feeding (bone meal, sulfate of potash, Epsom salts) and balanced nutrient regimen.
Signs & Symptoms
Phosphorus	Dark green/purple leaves, stunted growth, poor bud development
Potassium	Yellowing leaf edges, brown spots, weak stems
Magnesium	Yellowing between leaf veins (starts from bottom)
Environmental Stress
Stress Factors	Temperature extremes, humidity fluctuations, light stress	Use temperature control (fans, AC/heaters), humidity control (dehumidifiers/humidifiers) and light management (adjust distance/intensity).
Indicators
Heat Stress	Wilting, leaf curling, scorched tips
Light Stress	Bleached/burnt leaf tips, reduced bud size
Humidity Stress	Mold/mildew on buds (high humidity)

Best Practices for Maximizing Yield

Pruning and Training

• Topping: Encourages multiple main colas. This technique involves removing the top part of the main stem of a cannabis plant. This is done to prevent the plant from growing too tall and to encourage more lateral growth. With the main stem removed, the plant redirects its energy to the side branches, resulting in a wider, bushier plant with more sites for bud development.

• Lollipopping: Focuses energy on upper buds. This technique involves removing lower growths on the cannabis plants that are unlikely to receive adequate light and thus, are less productive. Removing the lower leaves will redirects the plant's energy and resources to the upper, more light-receptive leaves. 

• Defoliation: Improves light penetration and airflow. Remove some of the large fan leaves to improve light penetration to the lower buds and increase airflow. This will also reduce the risk of mold and mildew. 

Supporting Heavy Buds: You can use the following to support branches and prevent breakage.

• Stakes: Insert stakes into the soil and tie branches to them for added support. Bamboo stakes are a popular choice due to their strength and flexibility.
• Trellises: Use trellises or netting to support the plant structure and keep heavy branches upright.
• Yo-Yos: Attach yo-yos or plant supports to the ceiling of your grow space, allowing you to gently lift and support heavy branches.

Harvest Preparation

Indicators of Readiness

• Trichome Development: Use a magnifying glass or microscope to closely inspect the trichomes (tiny resin glands) on the buds. Harvest when the trichomes are mostly milky white with some turning amber. Clear trichomes indicate the plant is not ready, while fully amber trichomes suggest the plant is past its peak.
• Pistil Color: Observe the pistils (hairs) on the buds. When about 70-90% of the pistils have changed from white to a reddish-brown or orange color, it is usually a good time to harvest.
• Bud Density and Aroma: Buds should be dense and emit a strong, characteristic aroma. If the buds feel airy or lack fragrance, they may need more time to mature.

Pre-Harvest Techniques

• Flushing: Use plain water to remove excess nutrients.
• Dark Period: Give plants 24-48 hours of darkness to enhance the resin production.

 Final Steps:

• Trimming Fan Leaves: Before the final harvest, consider trimming away some of the larger fan leaves. This makes the harvesting process easier and can reduce the risk of mold during the drying phase.
• Hydrate the Plants: Ensure your plants are well-hydrated in the days leading up to harvest. This helps maintain bud turgidity and overall plant health until the final cut.

 

Managing your plants during this stage may be a lot of work, but having careful attention to your plants' development could bear you a bountiful and high-quality harvest.

For more tips, tools, and resources, visit GrowAce.com. Explore related articles and guides to deepen your understanding of plant growth stages and enhance your growing journey.