By Miguel Ángel Garcia


Video id: 976723279

As growers, how many times have we asked ourselves if we can fit one more plant in our indoor garden, only to second guess ourselves moments later, wondering if we might be overdoing it? What if plants grow to infinity and beyond, as our friend Buzz Lightyear said? Well, in this article, we are going to clear up your doubts as we help you understand how the density of your plants per square metre affects their morphology—specifically their height. We'll use data from our two-year trials on the RQS F1 hybrid Orion F1 to illustrate the optimal plant density for healthy growth and top yields. Moreover, we will explain how the photoperiod and light intensity affect the height of your plants in relation to yield. Let's go!

What Is Plant Density in Cultivation?

Plant density represents the number of individual plants per unit of area. As the international unit of area is the square metre, this is what we will use in our discussion.

It is a very important parameter because, as we will see, plant density conditions the competitiveness of plants to obtain light, nutrients, carbon dioxide, water, and even airflow, which is necessary to facilitate transpiration (when plants release water through their pores).

With this in mind, the great gurus of indoor weed growing generally recommend a plant density that maximises the available growing space while also allowing sufficient distance for plants to receive inputs and transpire. This is done with a clear goal to not only ensure optimal plant health, but to maximise the yield potential of the plants per square metre.

What is plant density

Effects of High Density in Marijuana Cultivation

The most notable effect of high plant density indoors is elongation of the stems. In other words, the plants will be taller than if they were grown in a low-density setup.

Another interesting and well-known effect of high plant density concerns the number of roots per plant and the impact on the leaf area index (LAI)—although this is a topic for another article.

It is important to state that in all the studies carried out on the F1 hybrid varieties from Royal Queen Seeds, an increase in plant height is clearly observed at higher plant densities compared to lower plant densities.

In order to understand this phenomenon, however, it’s necessary to become acquainted with the relationship between photosynthetic photon flux density (PPFD), daily light integral (DLI), and yield.

  • Impact on the Height of Cannabis Plants

The simplified explanation of why cannabis plants grown in a high density per square metre are taller than those grown in a lower density is that the plants, not receiving all the available light, have to compete, surging upwards in hopes of capturing more illumination.

In more scientific terms, if we keep the PPFD and DLI constant while increasing the plant density, each plant receives fewer photons per unit of surface and per unit of time. As a result, the plant devotes its energy to biomass production, elongating its stems, stimulating the concentration of auxin in the areas close to the apical (cauline) meristems. In doing so, more parenchymatous and vascular cells can ultimately capture more photons, allowing plants to increase photosynthesis and create more biomass as a result.

In plants with apical dominance, such as Cannabis sativa, when the concentration of auxin in the apical meristems is high, an inhibitory effect is exerted on the tissues of the intercalary meristems to grow laterally. If we trim apically (topping/FIM), we favour the concentration of auxin to be lower in this area, thus causing growth of the intercalary meristems and ultimately an increase in the width of the plant.

So now you understand that the less light available, the fewer the photons, the greater the concentration of auxin in the apical meristems, and therefore the greater the height of the plant.

High density in cannabis cultivation

Comparative Analysis: F1 Orion Hybrid

If we compare the growth patterns of seven cultivation operations during a two-year study period on the Royal Queen Seeds hybrid variety Orion F1, we observe the following results in plants grown at an optimal density versus plants grown in a high plant density regime, depending on the DLI applied:

  • Increase in height growth of up to 71% when the planting density is raised from 5.4 plants/m² to 7.9 plants/m²
  • It is possible to mitigate or dampen the height growth caused by the increase in plant density if we increase the DLI from 39 moles/m²/day to 65 moles/m²/day.
  • When we increase the DLI, we increase the photosynthetic photon flux density multiplied by the number of hours of the photoperiod in one day. As a result, the amount of auxin available in apical meristems is decreased and the plant not only grows less, but also has a higher yield in the form of more flowers per plant.
  • Increase in plant density does not produce an increase in yield.
  • Increase in DLI produces shorter plants.
  • Increase in DLI produces plants with higher yields.
  • Higher yields occur when plant density is optimal and DLI is high.

All of this data is worthwhile, and helps us to continue to understand how to optimise cannabis plant growth and health.

Want pro-grade canopy and yield control? Download our Pro Growing Guide for expert training techniques—LST, topping/FIM, and defoliation—to optimize light distribution and maximize flowers per square metre.

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Practical Implications for Growers

Note that in order to obtain higher yields in cannabis cultivation and more grams of flowers per plant, we need optimal plant density and a high PPFD per number of hours of the photoperiod per day.

Therefore, if we opt for high plant densities, the height of the plants will also be high, unless we increase the light power (the PPFD and the hours of the photoperiod per day), in which case we can keep the height of the plants lower.

Furthermore, we can reduce the height growth of marijuana plants if we perform apical trimming (topping/FIM) to reduce apical dominance.

  • Optimal Cultivation Conditions

In accordance with our research on RQS F1 hybrids, the optimal conditions for indoor cannabis growth occurred when plant density per square metre was optimal and light exposure was powerful, with a photoperiod of 18 hours.

Specifically, significant yield increases were reported when we applied optimal crop densities of 5.4 plants/m² at a DLI of 65 moles/m²/day (1000 micromoles/m²/s at 18 hours of light per day.)

That being said, by using near-perfect parameters (hard to replicate in indoor home cultivation), including giving the plant supplementary CO₂, a huge amount of light per day, adjusting the correct light distance from the canopy, optimising plants per square metre, and delivering a high quantity of nutrients, our Orion F1 hybrid autoflower variety delivered a massive 1.4 kg per square metre!

Optimal plant density in cannabis cultivation

Plant Density: It Makes a Huge Difference

As you can most likely see by now, it is important to strike a good balance between the density of cannabis plants per square metre and the daily light integral. For our case study, by applying optimal plant density conditions, we obtained more compact plants and higher yields.

Therefore, it is not by placing many plants very close together that we achieve higher yields—on the contrary. This simply results in taller, more spindly specimens with reduced flower weight per plant.

Now you know that there is an important relationship between plant density, light output, height, and yield. Using our own research, we hope to have conveyed this fascinating information to you, so that you can use it to your advantage!

Never Stop Experimenting

We encourage all growers to experiment with marijuana plant spacing and various light intensities. After all, what works for one grower doesn’t necessarily work for the other. Ultimately, there are few things more satisfying for a cannabis grower, whether expert or first-time, than improving and progressing in your practice.

And as we’ve alluded to several times in this article, perhaps the most influential factor dictating plant height and yield is the spectrum, composition, and availability of light. The spectrum of light is like its DNA, telling us how the photons are distributed in the various wavelengths that compose it. Two lights with the same power can have very different spectra, which can in turn greatly influence the growth and development of our weed 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: