Cannabis Grow Guide by Royal Queen Seeds

By Steven Voser


Just like baby humans, cannabis seedlings are super fragile and need plenty of tender loving care to flourish. Unfortunately, many growers run into the same issue during the early stages of their cannabis plants’ lives; their seedlings grow long, stretchy, and weak stems.

This, in turn, can lead to a host of issues that put your crop at risk of delivering subpar results. Below, you’ll learn how to prevent and fix stretching in cannabis seedlings.

Understanding the Seedling Phase

Cannabis seeds are equipped with all of the vital nutrients needed to sustain a seedling during the first few days of growth. However, they still need to drink.

In optimal conditions, the seed shell will crack open and a taproot will pop out, immediately digging downward in search of water. Soon, you will see a sprout rise from under the soil, spread out its first baby leaves (cotyledons), shortly followed by the first set of true leaves.

Leaves have an equally important job as the taproot, but they are in search of other energy sources—light and carbon dioxide. This duo helps seedlings create the sugars they need to spur rapid and healthy growth.

How to Prevent and Fix Stretching in Cannabis Seedlings

The Perfect Light Conditions for Cannabis Seedlings

To grow healthy seedlings, it’s important to give them the right amount and type of light as soon as they break out of their shells. Cannabis seedlings like to receive around 18 hours of light per day at an intensity of 375 lumens and 4000 lux.

Meeting these requirements depends on several variables, including the type of light you're using and the size of your growing space. For a small area of 70×70 cm, a 150 W LED grow light positioned 30 cm above your seedling will suffice.

What Causes Abnormal Stretching?

If you notice your cannabis seedling stretching too much, it’s likely a response to stress—typically due to inadequate light, which can eventually cause the seedling to topple over.

In the same way taproots dig for water and nutrients, the top part of the plant will stretch vigorously if it’s not receiving enough light. It’s a survival mechanism in which a plant uses up all its stored energy to rise above competing flora. Indoors, there’s no competition—but your seedling still behaves as if there is.

How to Prevent and Fix Stretching in Cannabis Seedlings

Other Potential Causes of Stretchy Cannabis Seedlings

Besides light deprivation, there are a handful of other factors that cause cannabis seedlings to stretch. One common cause of leggy seedlings is poor nutrient content in the soil.

More precisely, cannabis seedlings benefit from nitrate-derived nitrogen. Unlike ammoniacal nitrogen, nitrate-nitrogen is a lot easier for plants to absorb and fuels shorter, bushier vegetative growth. If your seedlings are stretching despite ideal light conditions, we highly recommend checking the ammoniacal nitrogen content in your soil and fertiliser.

Another cause of tall, thin seedlings is heat. While cannabis seedlings like warm, humid conditions, too much heat can cause a plant’s leaves to grow more slowly than its stem, resulting in tall and stretchy growth. 

To promote healthy seedling growth, we recommend keeping the temperatures in your grow room at 19–20°C during the day and roughly 13°C at night.

Finally, cannabis seedlings can also stretch if they’re receiving too much or not enough light per day. While some growers opt to keep their seedlings under 24 hours of light per day, we recommend sticking to 18 hours to keep running costs down.

Seedlings are fragile, and giving them too much light can cause stress and stretching. Remember, those dark hours are just as important for your young plants to develop healthy roots and respire.

How to Prevent Cannabis Seedlings From Stretching

To prevent your cannabis seedlings from stretching, it’s crucial to dial in lighting variables, including intensity and distance from the canopy. Using LED grow lights from Royal Queen Seeds in accordance with these principles will ensure healthy, stocky seedlings every time you grow.

For example, when using the Mars Hydro FC1500 150 W LED Grow Light, position it 30–45 cm from the tip of your plants throughout the seedling phase to provide enough intensity while reducing the risk of burning. Likewise, position the more powerful Mars Hydro FC3000 300 W LED Grow Light 45–60 cm from the tip of your seedlings to hit that growth sweet spot. 

With your lighting situation perfected, use these additional tips to further reduce the chances of your weed seedlings stretching:

  • Use a timer to maintain 18–24 hours of light per day during the seedling phase.
  • Keep temperatures between 20–25°C and humidity around 65–70%.
  • Only water your seedlings when the top 3 cm of soil feels completely dry to avoid damping off.

What to Do if Your Seedlings Have Already Stretched

Check out the simple tips below to correct leggy marijuana seedlings:

  • Transplant deeper: Bury part of the stem during transplanting to stabilise your seedling. Mix in a generous amount of perlite or vermiculite into the top 5 cm of soil to boost aeration and prevent the stem from rotting in overly wet soil.
  • Add support: Use small stakes and ties to keep your seedling upright and prevent it from collapsing.
  • Improve lighting: Move your light into the recommended distance of the top of the seedling and keep it running for 24 hours per day for a week until your plant strengthens.
  • Increase airflow: After stabilising and supporting your plant, aim a gentle fan at the stem of your plant to help it adapt to light stress and grow stronger.

Risks of Placing LED Grow Lights Too Close to Plants

LED grow lights are certainly effective at helping cannabis plants grow strong and healthy. However, placing your light too close can expose plants to excess light and heat, which has a detrimental impact on seedling growth. Look out for these signs of light stress during the seedling phase:

  • Light burn: Also known as phototoxicity, seedlings exposed to excess light intensity will exhibit symptoms such as bleaching, curling, and necrosis (tissue death).
  • Stunted growth: Excess heat emitted from lights positioned too close to seedlings can cause plants to become stressed, inhibiting their growth. 
  • Patchy growth: Lights positioned too close to plants can cause leaves in the centre to become overly lit, while those around the edges become under-lit and appear more pale, possibly even yellow.

Influence of Light Spectrum and Light Distance on Stretching

LED grow lights emit different wavelengths that have varying effects on plant cells in terms of growth and potential stress. Cannabis plants are much more tolerant of narrow-spectrum LEDs that emit mostly red and blue wavelengths. Because these lights emit less heat, growers can place them within several centimetres from the tips of seedlings.

In contrast, broad-spectrum LED cannabis grow lights also emit white wavelengths and more heat. Position these lights according to their wattage. For example, aim to place 150 W LEDs around 30 cm from the tips of seedlings, and 300 W lights at least 45 cm away.

As well as adhering to these general guidelines, you should get into the habit of observing your seedlings and reacting accordingly. Look out for signs of stretching or stress and move your light closer or further away, respectively.

Likewise, you’ll need to continually readjust the height of your light as your plant grows taller. Simply use a tape measure and your ratchet straps to reposition your LED light source.

How to Prevent and Fix Stretching in Cannabis Seedlings

Thinning Your Cannabis Seedling Crop to Prevent Stretching

Thinning is a common agricultural technique that’s often forgotten among cannabis growers. As the name suggests, thinning is all about reducing competition among your plants by “thinning” out the population.

Cannabis plants grow very quickly and will naturally compete with one another for space, light, and nutrients. So, while you may have been taught to think that more plants will naturally translate into bigger, better harvests—that's not always the case.

In fact, many experienced growers opt to cull their weakest seedlings and only grow those that show the healthiest growth. This way, they focus their efforts on the plants most likely to produce the best flowers.

Thinning also helps growers maintain an even canopy across their grow room, which makes better use of limited light and space. Finally, thinning can help you avoid pests and other pathogens, as your grow space is less likely to be crowded.

To thin your plants, simply keep a close eye on your seedlings throughout the first 1–2 weeks of their life, and only keep those specimens that exhibit the healthiest, fastest growth.

Preventing Leggy Cannabis Seedlings: A Botanical Balancing Act

Stretchy cannabis seedlings are a common challenge, especially for new growers. But don’t fret—legginess isn’t a death sentence!

With proper lighting, thoughtful positioning, smart transplanting techniques, and climate management, you can easily rescue stretchy seedlings before they grow too lanky. Applying these principles going forward, you’ll prevent legginess altogether, resulting in much smoother growing operations and healthier and more productive plants.

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Privacy Policy - Royal Queen Seeds

To ensure a safe online environment and guarantee adequate data protection, we strictly comply with all legal requirements. In this privacy statement, we provide information about how and for what purpose data is collected, safety measures, storage periods and contact details.


COMPANY NAME: SNORKEL SPAIN, SL (hereinafter ROYAL QUEEN SEEDS)

C/ Vilar d'Abdelà, 5 (nave 1) CP: 08170 de Montornès del Vallès

+34 937 379 846

support@royalqueenseeds.com


The present Privacy Policy sets out the terms on which we will treat personal data at ROYAL QUEEN SEEDS; this includes any personal data collected through our website https://www.royalqueenseeds.com/ as well as any other data we process in the course of our business activities.

ROYAL QUEEN SEEDS collects the following personal data for the purposes listed below:

SECTION 1 – PERSONAL INFORMATION WE COLLECT

1.1 Account purchases

Account purchases can only be made if you are in possession of a personal account. When you create an account or purchase something from our shop, as part of the buying and selling process we collect the following personal information that you provide to us:

This information is required for delivery. In addition, when you browse our shop, we automatically receive the Internet Protocol (IP) address of your computer. Based on this information, we can optimise your online experience and at the same time protect our online environment.

Purpose of data collection

We collect and store account-related data for the following purposes:

(a) to carry out obligations arising from any contracts between you and us, and to provide you with information, products and services that you may request from us;

(b) to set up, manage and communicate with you about your account and your orders;

(c) to conduct market research and analysis;

(d) to confirm your age and identity, and to detect and prevent fraud.

1.2 Newsletters

With your explicit permission, we may send you newsletters about our shop, new products and other updates. We send newsletters based on your explicit consent. In the event that you purchase a product, and in accordance with current regulations, we may send you commercial communications in accordance with the legitimate interest of our company, always about products or services similar to those you have purchased or contracted. In any case, you may exercise your right of opposition through the channels announced in this Privacy Policy. The following information is collected in relation to the newsletter:

We do not need to know the sex of the person in order to send the newsletter (data minimisation: by law we must ask for data that is strictly necessary to provide the service, and in this case knowing the sex is not necessary to send the newsletter).

Purpose of data collection

The data collected is used to:

(a) personalise our emails, including your name and gender;

(b) provide gender-specific content.

You can withdraw your consent at any time by using the link provided in the newsletter or the contact information provided in section 2.

1.3 Customer service and contact form

In order to provide appropriate support, our customer service employees have access to information related to the account. Consequently, their support will be highly effective and friendly. The data provided in our contact form is used by our CRM provider, SuperOffice. We will only use your details to respond to your message.

SECTION 2 – LEGITIMATE INTEREST

If you have purchased any of our products, please note that we may process your personal data for promotional purposes, based on Royal Queen Seeds' legitimate interest only to offer you products or services from our company and about products or services similar to those you have purchased. You may exercise your right to opt out of future messages by the means set out in this Privacy Policy or through any notification you receive.

2.1 How do you withdraw consent?

If you change your mind, you can withdraw your consent for us to contact you for the purpose of collecting, using, or disclosing your data at any time by reaching out to us at: support@royalqueenseeds.com.

SECTION 3 – DISCLOSURE

We may disclose your personal information if we are required to do so by law or if you breach our Terms of Service.

SECTION 4 – HOW LONG DO WE KEEP YOUR DATA?

At Royal Queen Seeds, we will not retain your data for longer than is necessary for the purposes described in this Policy. Different retention periods apply for different types of data; however, the longest period we will normally hold any personal data is 10 years.

4.1 Account information

Data relating to the account remains relevant for as long as the consumer is in possession of an account. Therefore, the data remains documented for as long as the account exists. When our customers delete an account, the associated data will be deleted within a reasonable period of time. Requests regarding the inspection or correction of stored personal data or the deletion of an account can be sent to support@royalqueenseeds.com.

4.2 Newsletters

In the event that you give us your consent to inform you about our products or services, we will keep your data until you express your wish not to receive any further communications from us. However, we regularly (every month) carry out a relevance check. Registered customers (and their personal information) will be deleted whenever customers do not reply to our request. In addition, our newsletter mailing has an opt-out feature. Consumers can withdraw their consent by using this opt-out feature.

SECTION 5 – COOKIES

Cookies are small information files that notify your computer of previous interactions with our website. These cookies are stored on your hard drive, not on our website. Essentially, when you use our website, your computer displays its cookies to us, informing our site that you have visited before. This allows our website to function more quickly and remember aspects related to your previous visits (such as your username), making your experience more convenient. At Royal Queen Seeds, we use two types of cookies: functional and analytical.

5.1 Functional Cookies

Functional cookies are used to enhance your online experience. Among other things, these cookies track what is added to your shopping cart. The use of these cookies does not require prior authorization.

5.2 Analytical Cookies

Analytical cookies are used for research and market analysis. The data collected with these analytical cookies is anonymous, making it unusable for third parties. The use of these cookies does not require prior authorization.

SECTION 5 – THIRD-PARTY SERVICES

Third-party services are required to conduct transactions and provide our services. In general, the third-party providers we use will only collect, use and disclose your information to the extent necessary to enable them to perform the services they provide to us.

However, certain third-party service providers, such as payment gateways and other payment transaction processors, have their own privacy policies regarding the information we must provide to them for your transactions.

We encourage you to read the privacy policies of these providers so that you can understand how these providers will handle your personal information.

In particular, certain suppliers may be located or have facilities located in a different jurisdiction than yours or ours. Therefore, if you choose to proceed with a transaction involving the services of a third party, your information may be subject to the laws of the jurisdiction in which that service provider or its facilities are located.

Once you leave our website or are redirected to a third-party website or application, you are no longer governed by this Privacy Policy or the Terms of Service of our website.

Web analytics service (anonymous data)

On this website we have integrated an element of a web analytics service (with anonymisation functionality). Web analytics can be defined as the gathering, processing and analysis of data about the behaviour of visitors to websites. An analytics service collects, among other things, data about which website a person came from (the so-called referrer), which sub-pages they visited or how often and for how long they visited a sub-page. Web analytics is mainly used for website optimisation and for a cost–benefit analysis of internet advertising.

Courier service

To complete deliveries we use a courier service. This courier service carries out the delivery between our company and the consumer's home. To complete these logistics, the company requires access to the consumer's name and address information.

Mailing service

Royal Queen Seeds uses a third-party mail service provider to send its newsletter. This provider has access to limited account information related to opt-in consent (e.g. email address).

Marketing services

Royal Queen Seeds has the support of a company that specialises in marketing and communication activities. Their access to personal information is very limited and mostly anonymous.

Payment services

At Royal Queen Seeds we use external payment services to handle our transactions (e.g. credit card payments).

SECTION 6 – SECURITY

To protect your personal information, we take reasonable precautions and follow industry standard best practices to ensure that it is not inappropriately lost, misused, accessed, disclosed, altered or destroyed.

If you provide us with your credit card information, the information is encrypted using secure socket layer technology (SSL) and stored using AES-256 encryption. Although no method of transmission over the internet or electronic storage is 100% secure, we follow all PCI-DSS requirements and implement additional industry standards that are commonly accepted. Information related to the account is protected with a hashing method. This method transforms the information into a generated hash. As a result, confidential information is protected and invisible, even to us. In addition, our databases are exceptionally protected against unauthorised access. For example, access to the database is only possible and permitted via approved IP addresses (e.g. from Royal Queen Seeds headquarters). Other attempts and addresses are rejected at all times.

Furthermore, data is anonymised as much as possible, so it cannot be directly linked to a specific consumer. With this data, however, we may be able to carry out market research and analysis. In addition, the third parties concerned (e.g. mailing service) are examined prior to our collaboration, comply with the GDPR from the EU and receive a processing agreement. Within Royal Queen Seeds, employees are assigned different access permissions. Specific permission provides access only to information that is strictly required to perform a task. Digital security measures are subject to change and must meet high requirements to ensure the safety of online customers. That is why, at Royal Queen Seeds, we appoint a security officer. Regular verification and improvement of security measures (where necessary) are part of the role.

SECTION 7 – CHANGES TO THIS PRIVACY POLICY

We reserve the right to modify this Privacy Policy at any time, so please check back regularly. Changes and clarifications will be effective immediately upon being published on the Website. If we make substantial changes to this policy, we will notify you here that it has been updated so you will know what information we collect, how we use it and under what circumstances, if any, we use and/or disclose it.

SECTION 8 – YOU HAVE THE RIGHT TO: