Germination Troubleshooting Guide

Our troubleshooting guide is a step-by-step method to assist in detecting probable errors and also to help prevent them. If you had a poor germination result it is important to find out the cause so that it doesn't happen again. Our seeds are the best indicator you can have to weed out problems. If our seeds don't germinate then something is not working properly in the set-up or procedure*!

* Damage due to postal delivery or poor storage may be another cause.

Quality Guarantee

Our reputation as a reliable seed company is based on constant and strictest quality control by our breeders. From production to packaging we scrutinize the quality of every seed and select by hand. Our selection is so strict that we also dismiss perfectly healthy seeds simply because of a smaller size or unusual shape.

All our seeds are pre-tested...and we mean ALL seeds from all strains. Every single seeded mother plant has been tested for perfect germination prior to sale. This ensures that there are no "bad batches".

We are specialized in quality and not quantity. All seeds are fresh seed stock (3-12 months) and sales turnover is quick among distributors and resellers. There is never any old seed stock on the market regardless of where or when a customer buys our strains.

Poor germination results can only be the result of negative outside influences after purchasing the seeds and are beyond our control. This does not necessarily mean that the grower is at "fault". Even the most experienced grower can run into unforeseen problems such as fungus infected soil, a technical malfunction on an EC meter, etc. Often growers buy the wrong soil because it is recommended by the manufacturer or retail store (consult our Soil Guide for more info).

In some rare cases frost during delivery can damage seeds. If your seeds are subjected to freezing temperatures (such as lying outside in a mail box) you should dethaw them slowly. Put them in the refrigerator a couple of hours for this purpose.

In addition to the germination rates we also control other important factors of quality such as a high level of healthy seedlings. Seedlings should not appear crippled, feeble, tiny, with dehydrated leaf tips, etc. However, this is a biological product and despite the best production methods a minor % of seedlings (calculations based on 100+ seeds) may not appear healthy and need to be removed. It is therefore always best to germinate an extra seed or two as a back-up, especially if you are only growing a few plants.

Ensuring Authenticity

We work with distributors who enjoy the best reputation in the industry for professional storage and service. Our resellers are supplied by us directly or through our distributors. Although we make an effort to identify any black sheep in the cannabis seeds market it is impossible for us to monitor resellers all the time.

Customers should make sure that they receive their seeds in the original Mandala Seeds packaging to prevent fraud. We cannot guarantee authentiticy for seeds that have been removed from the sealed Mandala packaging. When you purchase our seeds from a reseller you should receive 1st class seeds: mature, healthy colouring, with well-defined mottled skin. If you get seeds that are tiny, greenish/yellow, scuffed, or immature, these are not original Mandala Seeds!

We are not responsible for the sales and services offered by resellers. However, if you have any serious suspicion or complaint regarding your purchase please contact us with a copy of your order transaction and reseller details.


A very small percentage of plants turn out to be triploids (ie. have three sets of leaves) among thousands of specimens. This does not impair plant health and is a feature unique to cannabis as a plant species (ie. not restricted to our genetics). For more info on triploids please see our FAQ. Also very rare, but not a reason for concern, are twins. These appear when there are two embryos in one seed. If both seedlings are the same size you should separate them quickly before roots get entangled and then you have two plants for the price of one! If one seedling appears inferior just remove it. If a seedling has fused cotyledon leaves or a young plant has fused leaf tips on a leaf this is nothing to worry about and it has absolutely no impact on growth or flowering. Nature is always trying out new combinations and that cannot be prevented in selective breeding.

Germination Instructions

Please read our Germination Instructions before germinating your Mandala seeds. Due to the high quality and fresh stock of our seeds we advise against soaking the seeds in water or germinating in paper tissue. Germination results will vary when pre-soaking seeds. Fresh seed stock can germinate under these conditions, but not always. Most often, only pre-germinating in moist paper tissue works for fresh seeds. But this is also not full-proof and should only be done if you have enough seeds to spare.

This does not mean that pre-soaking should never be used with seeds from other sources, or that we criticize growers who prefer this method. We are aware that some breeders recommend it for their products. But to prevent complications and achieve the consistent level of high germination rates that you should be getting from your Mandala seeds please trust our advice and follow our guidelines.

Please take note that customers who soak their Mandala seeds in water or wet paper tissue do so at their own risk. We are not accountable for any failure in germination or complications caused by this method.


Germination Problems

Seeds did not germinate

The first step is to look at what happened to the seeds.

There are 3 possibilities:

a) the seeds all look the same like when you planted them (intact, healthy colour).

b) some or all seeds are intact, but have noticeably changed colour and are darker; some may also have a whitish substance coating the rounded end, or the embryo inside has turned soft or slushy.

c) some or all of the seeds cracked open and the taproot appeared - but there was no further growth.

Possible causes for:

a) Healthy & intact seeds don't germinate if the substrate is too dry. This could mean that it was too dry from the start, or that the substrate dried out before the seed could absorb enough moisture to trigger germination. Open some of the seeds to check the embryo. If it is healthy, white and firm then the seeds required more water to germinate.

Second probability is that the seeds are damaged from frost.

b) Dark seeds indicate fungal attack. A whitish substance is visible fungal mycelia. Fungus spreads under cold, wet, & anaerobic conditions. Several combinations of factors can lead to seeds rotting: poor soil quality (infected, bad pH, or high EC), pre-soaking seeds in water, substrate is too wet, substrate is in a cold environment, and/or excessive high humidity caused fungal growth in substrate (due to humidity dome/propagator, pots covered with plastic, poor ventilation).

Open some of the seeds to check the embryo. In rotted seeds the embryo is soft, yellowish, or almost like liquid (slushy).

A #1 seed killer is a closed humidity dome/mini-greenhouse.

Humidity domes are only required for rooting cuttings.

Many growers make the mistake of thinking that they need a high ambient humidity for germination or seedlings. The high humidity and lack of fresh ventilation quickly causes fungus in the soil or growing medium and the seeds rot!

Cannabis is not a swamp plant! The seeds need a well aerated growing medium to germinate well. Seedlings also cannot tolerate high humidity and can easily be attacked by fungus such as fusarium and pythium. Only the soil or growing medium should be moist for optimal germination and seedling growth. Ambient humidity is best below 50%.

You can use a humidity dome/mini-greenhouse as a tray for germination but you must keep the lid half-way open or completely seperate to ensure fresh air exchange and humidity levels below 50%.


c) This can happen for the same reasons as in b). But there can also be other factors involved. If a heating mat was used the substrate may have been heated up too much. In rockwool a high EC can kill the emerging seedling. Check the EC of your substrate and make sure your EC meter is functioning correctly. A sudden dry spell in the substrate is also lethal at this stage.

Also check your water quality. In some areas municipal water is extremely low quality. It can have an excessively high salt level and can be contaminated with minerals/heavy metals which stunt plant growth. High levels of chlorine and fluor are dangerous. You can smell chlorine - let it evaporate before use by filling a bucket with hot water. If you are in doubt about your tap water buy bottled mineral water (without gas). The pH should be adjusted to 6.5 for soil and pH 5.6-5.8 for rockwool..

Watering with organic teas or various other products is definitively counterproductive. During germination and seedling stage you should use pure pH adjusted water.

Other factors:

Jiffy's, peat pellets, and other types of starter plugs with an alkaline pH inhibit germination in cannabis seeds. Some substrates such as coco coir may also be pre-fertilized and have a high EC (salt) level Untreated coco coir contains toxic levels of sodium and chloride. Or they could have been treated with fungicides and pesticides. If you have used a particular product with poor results you should stop using it and switch to rockwool or soil.





Things to avoid

Seedling Problems

Some or all seedlings grow weak and tall

The major cause is lack of light. The seedlings are stretching in search of light. This leads to elongated and weak growth. Give your seedlings as much light as possible. Move them closer to the lamp. Put them under an HPS lamp if available. If you are growing near a window move the plants to the sunniest spot or supplement grow time with a lamp. Outdoors you should also provide as much light as possible. Support the seedlings with a stick or looped wire while they regain strength. As soon as they have sufficient light they will grow vigorously.






Some or all seedlings fell over and died

cannabis seedlingThis is usually caused by a fungal disease called "damping off". The cause is infected soil, waterlogged substrate, high humidity...any conditions that promote fungus. The fungus attacks the soft tissue in the stem which withers at the base or midway. The seedling collapses and dies. Another possible cause is that the seedlings died from lack of water or a high salt level in the substrate (which basically has the same effect of drying out the plant). Seedlings have only a small amount of roots and few leaves. They cannot retain much water and quickly dry out. High humidity in the grow space does not compensate for a desiccated substrate. Your soil/rockwool has to be moist enough to sustain healthy roots and provide water to the plant. Photo shows “damping off”.
Outdoor frost can kill seedlings overnight. Keep your seedlings indoor until there is no danger of sudden frost. See our GERMINATION GUIDE for great product tips on how to keep your seedlings warm outdoor or in the greenhouse.


Seedlings cannot open their first set of leaves

cannabis seedlingSometimes the seed hull and the inside skin is still attached to or enclosing the leaves. This happens if the seed was not planted deeply enough. Usually the seed hull is detached as the seedling emerges through the substrate. Spray the seed hull with mineral water and wait 1/2 hour for the moisture to soften the dry skin and soil residues. Then gently and slowly pull it off from the leaves. If it does not move easily spray more water. It is very important to remove it carefully because if you tear off the leaves the seedling dies.







We hope that this guide has been helpful in detecting the probable cause for any problems that you have encountered. The next step would be to run a test under improved conditions. For this purpose it is best to germinate just a few seeds as a trial. If everything goes well you see the results within 7+ days and can germinate the remaining seeds with confidence. A novice grower will also find this helpful advice before losing all of the purchased seeds on a set-up that requires modification!


If you are new to cannabis growing it is not advisable to start with hydroponics. Don't make your first cultivation experience unnecessarily complicated! In hydroponics you have to constantly monitor EC and pH, choose the correct nutrient formulas and feeding schedule, clean and flush your system, invest in expensive equipment, etc. If you are insecure about germinating and growing in rockwool or other hydroponic substrates, switch to soil or start with a small test group to gain experience.

Especially with our genetics you will find growing on soil very easy and rewarding. It is highly probable that any benefits you may be expecting from hydroponics, such as a higher yield, will be much simpler and securer to achieve with a straightforward soil cultivation!


Choosing the correct soil for germination and seedlings should not be difficult. However, some growers feel overwhelmed and insecure by the seemingly endless jungle of products, whilst others may live in countries with a very small and unsatisfying range of products. Please refer to our SOIL GUIDE for tips and recommendations.


What you need to know about growing in soil, how to buy the best soil product, organic additives, etc.

Quick Start GuideQuick, easy, effective...the most important gardening tips & tools explained in simple language.

Cannabis GerminationEssential reading before you germinate your Mandala seeds! Please read our advice carefully.