7 beginner mistakes I made when growing (and how to avoid them)

Published on 26.03.2026 from Redaktion hanfplatz

Last year I had the opportunity to test five feminized Amnesia Fast seeds from Cannapot in an outdoor grow. The strain is considered beginner-friendly, mold-resistant, and very robust. And yet, I still managed to make almost every classic beginner mistake.

For legal reasons, the plants were not allowed to flower. This article is therefore solely an informative account of my experiences during the cultivation phase and what I would do differently next time.

The good news: despite my mistakes, the plants showed impressive resilience. That speaks volumes for the genetics. But imagine how much better the result would have been if I had done these 7 things right from the start.

📋 The 7 mistakes at a glance

1. Incorrect germination method (water bath instead of a damp cloth)
2. Incorrect substrate (herb soil instead of cannabis growing soil)
3. Jiffy pot not opened during repotting
4. Incorrect pot size and incorrect repotting time
5. Completely forgot about fertilizer
6. Too shady a location
7. No training (LST or topping)

Amnesia Fast seeds Cannapot, 5 feminized seeds in the bag

Amnesia Fast – Cannapot Seeds

Cross: Amnesia x Amnesia Auto XXL · Semi-automatic, mostly Sativa · 8–9 weeks flowering time · Mold and pest resistant · THC: 18%, CBD: 0.2%

View Cannapot on hanfplatz.de

💧 Incorrect germination method: Seeds in a water bath

My first mistake was in the very first step. I placed the five seeds on a cotton pad in a bowl filled with water. It looked like a clean solution, but it was anything but.

Hemp seeds on a wet cotton pad in an orange bowl

First seedlings on the cotton pad with visible root tips

Left: Seeds in a water bath – Center and right: The seedlings survived, but the stress was avoidable.

⚠️ The problem: Too much water means a lack of oxygen at the seed coat. This delays germination, promotes mold growth, and produces weaker seedlings. The cotton pad was completely saturated.

✔️ Here's how to do it better

💡 The right method

✓ Two layers of damp kitchen paper or a slightly damp cloth
✓ Place seeds in the pan, fold, cover, and place between two plates.
✓ Temperature: 22–25 °C, dark and warm
✓ The cloth should be damp, not wet. No standing water!
✓ The first radicles appear after 24–72 hours

Tip: The Cannapot Seedcracker is a handy tool specifically designed for seeds that are difficult to germinate or older seeds. It lightly scratches the seed coat and significantly increases the germination rate.

🌎 Wrong substrate: Herb soil instead of cannabis growing soil

For the substrate, I used what was available in the warehouse: Compo Bio potting and herb soil, peat-free. Sounds reasonable, but it isn't for cannabis.

Compo Bio Herb Soil Bag next to Terracotta Pots

Compo Bio herb soil is good for basil, but low in nutrients for cannabis in the growth phase.

⚠️ The problem: Potting soil for herbs is intentionally very low in nutrients to prevent sensitive herbs from burning. Cannabis, however, needs a significantly richer and, above all, more aerated substrate during its growth phase for healthy root development.

❌ Herb soil (my mistake)

❌ Very low in nutrients
❌ Often too fine and compact
❌ Poor air permeability
❌ Nutrients depleted after 1–2 weeks

✔️ Cannabis growing soil

✓ Balanced nutrient profile
✓ Loose, airy structure
✓ pH value already optimized
✓ Provides care for 3–4 weeks on its own

💡 Suitable substrates for beginners

✓ Plagron Grow Mix or Biobizz Light Mix (beginner-friendly)
✓ Alternatively: Herb soil + 20–30% perlite for better aeration
✓ pH value of the substrate: between 6.0 and 7.0

🪴 Jiffy pot not opened during repotting

Jiffy peat pots are practical because you can plant the entire plant, pot and all. Biodegradable, no root stress. In theory. But I forgot one crucial step.

Jiffy peat pots from above, one with a small seedling

Jiffy pot with seedling placed in large terracotta pot

Left: Jiffy pots after germination. Right: The Jiffy was placed directly into the large pot without an opening.

⚠️ The problem: The Jiffy pot often remains intact in moist soil for weeks. The roots reach the bottom and stop growing. The result: stagnant growth, even though everything looks normal on the outside.

💡 This is how it's done right

✓ Before inserting, completely tear open or remove the bottom of the Jiffy pellet.
✓ Lightly score the sides of the Jiffy in 2-3 places
✓ Then place the Jiffy into the prepared planting hole.
✓ Alternatively: Germinate directly in small plastic pots

🪟 Wrong pot size and wrong time to repot

The Jiffy pots with the seedlings were placed directly into large terracotta pots. A short transition phase, quickly done, I thought. But this step slowed down growth rather than speeding it up.

Five Jiffy pots on the windowsill, seedlings at different stages of development

Small seedling in a Jiffy pot already in a large terracotta pot

Small seedlings in pots that were far too large. The root system could not penetrate the substrate.

⚠️ The problem: A small root ball in too much substrate means permanently damp soil. Waterlogging and root rot are common consequences. The plant invests energy in root development instead of leaf growth.

💡 The correct step principle

✓ Jiffy / Germination → 0.5 liter pot (first week)
✓ 0.5 L → 2 liter pot (as soon as roots emerge from the bottom)
✓ 2 L → 5–10 liter exhaust silencer for outdoor use
✓ Always repot when roots emerge from the drainage holes

Rule of thumb: The new pot should always be about twice the size of the previous one. Never jump straight into the final pot, even if it seems more convenient.

🧪 Completely forgot about fertilizer

That was perhaps my biggest mistake. After planting, I simply let the plants grow. No fertilizer, no additional fertilizing, nothing. The substrate can manage on its own for a short time, but not for the entire growth phase.

Five cannabis plants in terracotta pots outdoors, showing significantly different growth.

The different growth patterns of the five plants are clearly visible. Nutrient deficiency was one of the reasons.

⚠️ The problem: After about 2–3 weeks, the nutrient reserves of most substrates are depleted. Without fertilization, nitrogen deficiency becomes apparent: leaves turn light green to yellow from the bottom up, and growth slows noticeably.

❌ No fertilizer (my mistake)

❌ Nutrients depleted after 2–3 weeks
❌ Light, yellowish leaves
❌ Slowed growth
❌ Thinner stems

✔️ With adapted fertilizer

✓ Uniformly rich green leaves
✓ Vigorous, rapid growth
✓ Strong stem development
✓ Better foundation for all phases

💡 Fertilizer Introduction for Beginners

✓ From week 3 after germination: light, nitrogen-rich growth fertilizer
✓ Recommendation: Biobizz Bio-Grow or Plagron Alga Grow
✓ Dosage: Half the recommended dose to start, increase slowly
✓ Always mix with watering can, never apply undiluted to dry soil

☀️ Too shady a location

Some pots were placed in spots I had considered "bright enough." In retrospect, that was a clear miscalculation. The smallest plant, in particular, was visibly suffering from insufficient direct sunlight.

⚠️ The problem: Cannabis needs at least 6 hours of direct sunlight daily. With less light, the plant stretches, develops thin stems, and produces less leaf mass. Amnesia Fast, as a semi-autoflowering sativa, is particularly light-intensive.

💡 Choose the right location

✓ Prefer a south-facing location, at least 6 hours of direct sunlight daily
✓ No trees or house walls that cast shadows in the afternoon
✓ Pots have the advantage that you can move them if needed.
✓ Observe the sun's path over several days before choosing the location.

✂️ No training required: Just let the plants grow

I left the plants completely to their own devices. No topping, no LST, no intervention. The result was what always happens without training: a dominant main shoot growing upwards and weak side shoots that barely received any light.

Cannabis plant from above in a terracotta pot, open structure without training

The plant, viewed from above, shows the typical untrained structure: little branching, one dominant shoot.

⚠️ The problem: Without training, cannabis grows like a Christmas tree. The energy goes into a main shoot, and side shoots remain underdeveloped. A lot of untapped potential.

❌ Without training

❌ A dominant main shoot
❌ Weak side shoots
❌ Poor light distribution
❌ Much untapped potential

✔️ With LST training

✓ Uniform light distribution
✓ Many strong side shoots
✓ Broad, bushy plant shape
✓ Significantly more earnings potential

💡 LST (Low Stress Training) for beginners

✓ Starting from the 4th internode
✓ Bend the main shoot to the side using soft wire
✓ Fix horizontally so that side shoots receive even light
✓ No pruning required, minimal stress for the plant
✓ After a few days, the side shoots will point upwards.

For advanced growers: Topping involves cutting off the tip of the main shoot, resulting in two equally strong main shoots. This requires 5-7 days of recovery time. For beginners, LST (Low Stress Training) is the easier option.

🌿 Conclusion: Making mistakes is part of the process

Despite all my mistakes, the Amnesia Fast seeds from Cannapot produced robust, vibrant plants. This shows that good genetics forgive many beginner errors. Imagine what would have been possible if I had done these 7 things right from the start.

Discover Cannapot at hanfplatz.de

Information about the tested strain: Amnesia Fast from Cannapot

Amnesia Fast is a cross between the original Amnesia and an Amnesia Auto XXL. The result is a semi-automatic, predominantly sativa-dominant strain that matures faster than the original Amnesia and is significantly more resistant to mold and pests.

📊 Quick Facts: Amnesia Fast

✓ Genetics: Amnesia x Amnesia Auto XXL
✓ Type: Semi-automatic, mostly Sativa
✓ Flowering time: 8–9 weeks
✓ Scent: Frankincense, spices, lemons
✓ Cultivation: Suitable for outdoor and indoor use
✓ Special feature: Highly resistant to mold and pests

Cannapot has been in the seed business for over 20 years and is one of the best-known addresses for growers and collectors in German-speaking countries.

Matching Hemp shops:

Cannapot Hanfsamen - Online Cannabis Samen Fachhandel

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