Seed Germination & Early Growth

Regular cannabis seeds produce approximately equal numbers of male and female plants. Male plants produce pollen rather than buds and are typically removed unless breeding is your goal.

Pros:

• Natural genetics, unmodified through feminization techniques
• Ideal for breeding projects and creating new strains
• Often more resilient and adaptable to environmental stress
• Usually less expensive than feminized or autoflowering seeds

Cons:

• Approximately 50% will be male plants (not suitable for bud production)
• Requires monitoring during pre-flowering to identify and remove males
• Less efficient use of space and resources for harvest-focused growers

Germination notes: Regular seeds typically germinate with a success rate of 80-90% when fresh. No special considerations are needed beyond standard germination practices.

Feminized seeds have been bred to produce only female plants (99% probability), eliminating the need to identify and remove males.

Pros:

• Nearly guaranteed female plants (bud-producing)
• No wasted space, time, or resources on male plants
• Ideal for small growing spaces like Maltese apartments or balconies
• Perfect for beginners who don't want to deal with sexing plants

Cons:

• Generally more expensive than regular seeds
• Can't be used for breeding programs
• Slightly more sensitive to stress during germination

Germination notes: Feminized seeds sometimes have slightly harder seed coats. A 24-hour water soak before the paper towel method can be beneficial. Handle with extra care, as stress during germination can increase the rare chance of hermaphroditism.

Autoflowering seeds contain genetics (typically from Cannabis ruderalis) that allow them to flower based on age rather than light cycle changes. They're almost always feminized as well.

Pros:

• Fast lifecycle (typically 60-75 days from seed to harvest)
• Compact size, ideal for limited space and stealth
• Can grow in variable light conditions
• Perfect for Malta's climate with multiple harvests possible per year
• Simplified growing process for beginners

Cons:

• Generally lower yields than photoperiod (feminized) plants
• Less time to recover from mistakes or stress
• Higher cost per seed
• Less opportunity for training techniques

Germination notes: Autoflowering seeds require gentler handling during germination and transplanting. Direct planting in the final container is recommended to avoid transplant shock. Autoflowers benefit from slightly lower germination temperatures (21-24°C) compared to photoperiod seeds.

The paper towel method is popular for its simplicity and high success rate. It allows you to monitor germination progress easily.

Materials Needed:

• Cannabis seeds
• Paper towels (unscented, no prints)
• Two clean plates or a plastic container with lid
• Distilled or filtered water
• Tweezers

Step-by-Step Instructions:

1. Moisten 2-4 paper towels with water. They should be completely damp but not soaking wet.
2. Place half of the paper towels on a plate.
3. Place your seeds on the paper towel, spacing them about 2-3cm apart.
4. Cover seeds with the remaining paper towels.
5. Cover with the second plate or lid to create a dark, humid environment.
6. Store in a warm location (21-27°C/70-80°F). The top of a refrigerator or near a water heater works well.
7. Check daily to ensure paper towels remain moist, adding water if necessary.
8. Seeds typically crack open within 24-72 hours, developing a small white taproot.
9. Once the taproot reaches 1-2cm (about the length of the seed itself), it's ready for planting.

Pros:

• High success rate (85-95% with viable seeds)
• Visual monitoring of germination progress
• Ability to identify and plant only successfully germinated seeds
• Simple, requiring minimal materials

Cons:

• Risk of damaging delicate taproot during transplanting
• Potential for contamination if hygiene isn't maintained
• Requires attentive moisture maintenance
• Extra handling step compared to direct planting

Direct soil planting mimics nature's method, minimizing handling and transplanting stress, particularly beneficial for autoflowering varieties.

Materials Needed:

• Cannabis seeds
• Small pots (7-10cm diameter) or seedling trays with drainage
• Light seedling soil mix or germination medium
• Spray bottle with water
• Clear plastic dome, bag, or plastic wrap (optional)

Step-by-Step Instructions:

1. Fill small pots with seedling soil mix, leaving 1cm space at the top.
2. Lightly water the soil until moist but not soaked.
3. Make a small hole about 0.5-1cm deep with your finger or a pencil.
4. Place one seed in each hole, with the pointed end or visible seam facing down.
5. Gently cover with a thin layer of soil (about 0.5cm).
6. Lightly spray the surface with water.
7. Cover with a clear plastic dome or plastic wrap to maintain humidity.
8. Place in a warm location (21-27°C/70-80°F).
9. Check daily for sprouts and to ensure soil remains moist.
10. Once seedlings emerge (typically 3-10 days), remove the plastic cover.

Pros:

• No transplant shock - roots develop undisturbed
• Simpler, more natural approach
• Reduced risk of damaging delicate taproots
• Ideal for autoflowering strains
• Can plant directly in final container (for autoflowers)

Cons:

• Can't visually confirm germination before planting
• May waste space with non-viable seeds
• Slightly lower success rate (75-85%)
• Harder to maintain optimal moisture levels

Specialized starter cubes and plugs offer convenience and consistency for seed germination, creating an ideal environment for developing roots.

Materials Needed:

• Cannabis seeds
• Starter cubes (Rockwool, peat pellets, or rapid rooters)
• Tray with humidity dome
• pH-adjusted water (5.8-6.3)
• Tweezers

Step-by-Step Instructions:

1. If using Rockwool, soak cubes in pH-adjusted water (5.8) for 30 minutes.
2. If using peat pellets, soak in warm water until fully expanded.
3. Place cubes in a tray with drainage.
4. Insert one seed per cube into the pre-made hole, about 0.5-1cm deep.
5. Gently cover the hole with a small piece of the medium or lightly pinch closed.
6. Place the humidity dome over the tray.
7. Keep in a warm area (21-27°C/70-80°F).
8. Maintain moisture but avoid oversaturation.
9. Seedlings typically emerge within 3-7 days.
10. Once sprouted, remove dome gradually over 2-3 days.

Pros:

• Excellent balance of moisture and aeration
• Easy transplanting with minimal root disturbance
• Reduces risk of overwatering
• High success rate (85-95%)
• Very clean method with lower risk of contamination

Cons:

• Higher cost than basic methods
• Rockwool is not biodegradable (environmental concerns)
• Requires pH adjustment, especially for Rockwool
• May dry out quickly in Malta's climate without humidity dome

Soaking cannabis seeds in water can be particularly effective for older or harder seeds, kickstarting the germination process before using another method.

Materials Needed:

• Cannabis seeds
• Clean glass or cup
• Distilled or filtered water at room temperature
• Paper towels or soil for the next stage

Step-by-Step Instructions:

1. Fill a clean glass with room temperature water (21-24°C/70-75°F).
2. Drop your seeds into the water.
3. Place in a dark, warm area for 24-48 hours.
4. Check periodically - viable seeds will sink after absorbing water (usually within 2-24 hours).
5. After 24 hours, look for seeds that have cracked open or show tiny taproots.
6. Remove seeds from water before roots grow too long (ideally within 48 hours).
7. Transfer to soil or paper towel method to continue germination.

Pros:

• Quickly identifies viable seeds (sinkers vs. floaters)
• Helps soften hard seed shells
• Excellent for older seeds or seeds with thicker shells
• Can kickstart slow-to-germinate strains

Cons:

• Potential for drowning seeds if left too long
• Risk of bacterial growth if water isn't changed
• Usually requires a secondary method to complete germination
• More challenging to handle seeds once they've sprouted

Heat mats can significantly improve germination rates and speed, especially in cooler environments or during Malta's winter months.

Benefits of Heat Mats:

• Provides consistent bottom heat, ideal for triggering germination
• Can reduce germination time from 2-4 weeks to just one week
• Helps maintain optimal soil temperature of approximately 24°C (75°F)
• Works with any germination method (paper towel, direct soil, starter cubes)
• Especially useful during winter months when ambient temperatures fluctuate

Usage Tips:

1. Place heat mat under germination tray or container
2. Use a thermostat controller for precise temperature management
3. Set temperature to 24-25°C (75-77°F) for cannabis seeds
4. Place a thermometer in the growing medium to verify actual temperature
5. Remove heat mat once seedlings have emerged and established roots

Advanced heat mats with thermostat controls allow for precise temperature adjustments based on your specific strain's needs. By maintaining soil at the optimal temperature, heat mats not only speed up the germination process but can also improve overall success rates.

A simple humidity dome creates a microclimate with higher humidity, perfect for germination.

Materials:

• Clear plastic container or tray with lid
• OR clear plastic cup/plastic wrap
• Seedling tray or small pots

Setup:

1. Place seedling containers in a tray
2. Cover with clear plastic dome or upside-down container
3. Alternative: cover individual pots with clear plastic cups
4. For paper towel method, use two plates to create a closed environment

Check daily and remove any excess condensation by briefly lifting the dome to allow air exchange. Once seedlings emerge, gradually acclimate them to normal air by partially removing the dome for increasing periods each day.

Maintaining ideal germination temperature improves success rates and speeds up the process.

Simple heat solutions:

• On top of refrigerator: The gentle heat from a refrigerator's coils provides warmth
• Near water heater: Ambient heat helps maintain temperature
• Elevated shelf: Heat rises, so higher shelves are often warmer
• Seedling heat mat: Affordable and effective (€15-30)
• Warm room: A bathroom after a hot shower provides temporary heat and humidity

For winter germination in Malta's cooler months, place germinating seeds in the warmest room of your home, typically the kitchen or a south-facing room. For a DIY solution, you can place seeds on top of a router, cable box, or other electronic device that generates gentle heat - just be careful of excessive temperatures.

Tracking temperature and humidity helps identify issues before they affect germination.

Basic monitoring:

• Small digital hygrometer/thermometer (€5-10)
• Place inside humidity dome or near germination area
• Check at different times of day to understand fluctuations
• Keep a simple log of temperature, humidity, and germination progress

Advanced monitoring:

• Wireless hygrometer with alerts when conditions fall outside optimal range
• Smart controllers that automatically adjust heating elements
• Data logging to identify patterns and optimize future germination

Even a basic monitoring setup can dramatically improve your success rate by helping you understand the actual conditions your seeds are experiencing. This is particularly valuable in Malta, where indoor temperatures and humidity can fluctuate significantly between day and night, especially in older stone buildings with less insulation.

Unlike many aspects of cannabis cultivation, light plays a different role during germination:

• Cannabis seeds do not require light to germinate; in fact, darkness is preferred during the initial germination phase
• Light becomes important only after the seedling has broken through the growing medium and begins photosynthesis
• Once sprouted, seedlings should receive moderate light levels—around 50% brightness from grow lights—to help direct growth upward without causing stress
• Gradually increase light intensity as seedlings develop stronger stems and more leaves

When seedlings first emerge, they're extremely sensitive to light intensity. Too much light can stress or even kill delicate seedlings, while insufficient light will cause stretching and weak growth. For the first 2-3 days after emergence, filtered or indirect natural light is ideal, or artificial lights kept at a greater distance than usual.

Light is crucial for seedling development, but too much intensity can damage tender young plants.

Indoor Lighting:

• Light cycle: 18-24 hours of light daily
• LED distance: 60-75cm initially, gradually decreasing to 50-60cm
• T5 fluorescent: 10-15cm distance (excellent for seedlings)
• Light intensity: 10,000-15,000 lux (gradually increasing)
• Signs of too much light: Curling leaves, yellowing, stunted growth
• Signs of too little light: Stretching, thin stems, large spacing between nodes

Outdoor/Balcony Lighting:

• Morning sun: Ideal for seedlings (gentler intensity)
• Midday sun: Too intense for seedlings (provide shade in Malta)
• Dappled light: Excellent for first week outdoors
• Hardening off: Gradually acclimate indoor-started seedlings over 7 days

Proper watering is perhaps the most critical and often challenging aspect of seedling care. Overwatering kills more seedlings than any other factor.

Watering guidelines:

• Water volume: Start with small amounts (50-100ml) in a circle around the seedling, not directly on the stem
• Frequency: Only water when the top 1-2cm of soil is dry to the touch
• Method: Use a spray bottle, pipette, or small watering can with fine shower head
• Water temperature: Room temperature (21-24°C)
• Coverage: Initially water in a small radius around the seedling, expanding as roots grow

Signs of improper watering:

• Overwatering: Drooping leaves that feel firm, yellowing, slow growth, algae on soil surface
• Underwatering: Drooping leaves that feel paper-thin, dry soil, stunted growth

A good rule of thumb: It's better to underwater slightly than to overwater. Cannabis seedlings can recover quickly from mild drought stress, but root rot from overwatering can be fatal.

Seedlings need slightly different conditions than germinating seeds or mature plants.

Optimal seedling environment:

• Temperature: 20-25°C (68-77°F) during light period, 18-20°C (64-68°F) during dark period
• Humidity: Start at 65-70%, gradually reducing to 50-60% as true leaves develop
• Air circulation: Gentle airflow helps strengthen stems and prevents mold
• Light cycle: 18-24 hours of light for photoperiod and autoflowering varieties

Transitioning from dome:

If using a humidity dome, follow this schedule to acclimate seedlings:

1. Days 1-3 after sprouting: Full dome coverage
2. Days 4-5: Remove dome for 1-2 hours, twice daily
3. Days 6-7: Remove dome for 4-6 hours during day
4. Days 8-10: Remove dome during day, replace at night
5. After day 10: Remove dome completely

Young cannabis plants require minimal nutrients initially, especially if planted in pre-fertilized soil.

Feeding guidelines:

• First 1-2 weeks: No added nutrients necessary
• Weeks 2-3: Begin with 1/4 strength seedling/vegetative nutrients
• After week 3: Gradually increase to 1/2 strength as plants show more growth
• Nutrient types: Higher nitrogen (N) for vegetative growth
• pH: Maintain 6.0-6.5 for soil, 5.8-6.2 for soilless media

Signs of nutrient issues in seedlings:

• Yellowing from bottom leaves up: Potential nitrogen deficiency
• Yellowing with green veins: Potential iron or magnesium issue
• Leaf tip burn: Nutrient burn (too strong feeding)
• Purple stems: Potential phosphorus deficiency or genetic trait

Several techniques can help strengthen seedlings and prepare them for healthy vegetative growth.

Strengthening practices:

• Gentle airflow: A small fan on low setting helps strengthen stems
• Proper spacing: Allow 10-15cm between seedlings for good air circulation
• Avoid stretching: Keep light source close enough to prevent leggy growth
• Support if needed: Small stakes or toothpicks can help overly tall seedlings
• Proper light spectrum: Blue-dominant light encourages compact growth

When seedling stage ends:

Your plants have officially exited the seedling stage when they display these characteristics:

• 3-5 sets of true leaves (serrated cannabis leaves)
• Established root system (visible at drainage holes)
• Thickening of the main stem
• Accelerating growth rate
• Approximately 15-20cm in height
• Typically 2-3 weeks after germination for photoperiod plants
• Often just 10-14 days for fast-growing autoflowers

Proper preparation minimizes transplant time and reduces stress on the plant.

Materials needed:

• New container (with drainage holes)
• Fresh growing medium
• Water for pre-moistening soil
• Organic transplant solution (optional, e.g., diluted seaweed extract)

Preparation steps:

1. Fill new container 2/3 with growing medium
2. Pre-moisten the medium (moist but not soaked)
3. Create a hole in the center slightly larger than the current root ball
4. Let seedling dry slightly (12-24 hours since last watering) for easier removal
5. Prepare work area with good lighting and space
6. The best time to transplant is in the evening or during a plant's "dark period" to minimize stress from light and heat

Removing the seedling:

1. Gently squeeze the sides of the container to loosen the soil
2. Place your hand over the top of the container with the stem between fingers
3. Turn the pot upside down and carefully slide out the plant and root ball
4. For plastic cups, you can cut the sides to minimize root disturbance
5. Handle the plant by the root ball, not the stem or leaves

Placing in new container:

1. Place the root ball in the pre-made hole
2. The plant should sit at the same depth as before (stem base at soil level)
3. Fill around the root ball with additional medium
4. Gently firm (don't compact) the soil around the plant
5. Leave 2-3cm of space between soil surface and container rim for watering

Post-transplant care:

1. Water thoroughly around the root zone with plain pH-adjusted water
2. If using, apply diluted transplant solution/root stimulator
3. Place in shaded area or under reduced lighting for 24 hours
4. Maintain higher humidity if possible (60-70%)
5. Avoid feeding nutrients for 3-5 days after transplanting
6. Resume normal lighting after 24 hours
7. Return to regular feeding schedule after 3-5 days

Seed Scarification Technique:

For older or hard-shelled seeds that fail to germinate:

1. Gently rub the seed between two pieces of fine sandpaper (600 grit)
2. Just a few light rubs - don't damage the inner seed
3. Soak in water for 24 hours before attempting germination again
4. Add a drop of hydrogen peroxide to soaking water to prevent mold

Damping off is a fungal disease that causes seedlings to suddenly wilt and die, often with a pinched or discolored stem at soil level.

Unfortunately, once a seedling shows symptoms of damping off, it usually cannot be saved. Focus on preventing spread to other seedlings by:

1. Immediately removing affected plants
2. Improving air circulation
3. Reducing watering frequency
4. Applying natural fungicide to remaining plants
5. Ensuring proper spacing between seedlings

Leggy, stretched seedlings with weak stems are usually caused by insufficient light intensity or distance.

Stem-Burying Technique:

1. Prepare a deeper hole in new container
2. Carefully transplant seedling, burying stem up to just below cotyledons
3. Roots will form along the buried stem, creating a stronger foundation
4. Keep soil slightly drier for 2-3 days to prevent rot on newly buried stem
5. Resume normal care once new growth shows plant is established

Drooping leaves in seedlings usually indicate watering issues, but can have multiple causes.

Solutions:

• For overwatering: Allow soil to dry until top 2-3cm is completely dry to touch, increase temperatures slightly to help soil dry, improve drainage, and provide better air circulation
• For underwatering: Create a consistent watering schedule based on container size and environmental conditions, water thoroughly until slight runoff when soil is dry to touch, consider bottom watering to encourage deeper root growth

Other causes of drooping can include:

• Heat stress: Temperatures above 30°C/86°F
• Cold shock: Temperatures below 15°C/59°F
• Transplant shock: Typically resolves in 1-3 days
• Light burn: Light too intense or close to seedlings

Yellowing leaves (chlorosis) in seedlings can indicate several different issues.

Identifying specific deficiencies:

• Uniform yellowing of older/lower leaves: Likely nitrogen deficiency
• Yellowing between veins (veins stay green): Likely magnesium deficiency
• Yellow/brown edges of leaves: Potential potassium issue or light burn
• Mottled yellow spots: Possible calcium deficiency or pH fluctuations

The best way to deal with seedling problems is to prevent them with proper setup and maintenance:

• Use quality seeds: Start with genetics from reputable sources
• Maintain cleanliness: Use sterile medium and clean equipment
• Control environment: Keep temperature and humidity in optimal ranges
• Water properly: Develop a watering schedule appropriate to your growing medium and container size
• Provide adequate light: Ensure proper intensity and spectrum
• Be patient: Resist the urge to constantly check or handle seedlings
• Keep detailed records: Track germination rates, growth patterns, and any issues