Knowledge

Stone wool is a powerful and precise substrate that enables growers to fine-tune plant development with unparalleled control. However, with this precision comes the need for accuracy at every step of the growing process. At Cultiwool, we have seen how easily small mistakes can lead to big inefficiencies or lost yields, especially in high-density, high-value crops like cannabis. Whether you are an experienced cultivator scaling operations or just starting with stone wool, here are the five most common mistakes we see, and how to avoid them.

GreenLeaf Medical started in 2017 and has grown tremendously since then, growing and selling a full range of products to the medicinal market within the USA. Samer Abilmona has been in the cannabis industry for a little over 10 years, but he has cultivated cannabis for the majority of his adult life. He has been the Executive Director of Cultivation and Operation of GreenLeaf Medical since 2019, then the company consisted of one cultivation facility, started to work on the second, had one dispensary in Maryland, and recently received a license in Virginia. Nowadays, the company is a multi-state operator, with facilities in Virginia, Pennsylvania, and Maryland. The cultivation is tailored to their market leader, smokable flowers. Other products within their range are live resin, live rosin, and distillates for vape cartridges as well as for edibles. About 6 months ago GreenLeaf Medical merged with Columbia Care, now the Cannabist Company, Samer has been managing a few additional cultivation and extraction facilities in West Virginia, two facilities in Washington DC, and a second Virginia location.

Stone wool substrate has gained popularity in horticulture due to its excellent water retention and air porosity characteristics, which are essential for healthy plant growth. However, one common issue that growers often encounter when using stone wool is channeling. Channeling refers to the inefficient distribution of water and nutrients within the substrate. In this article, we will explore what channeling is, what typically happens when it occurs, how to identify its signs, and discuss methods to prevent it. We will also delve into why some stone wool products are more prone to channeling than others and explore the role of binders and wetting agents. Finally, we will touch upon the importance of choosing the right irrigation system to avoid channeling.

“I think dry backing is probably one of the techniques that a lot of growers use to increase cannabinoids and flavonoids content” Ryan mentioned. But how does it work and what does it really mean? This article is a continuation of the previous one, following an interview with Ryan Wankel, and will focus on the cultivation manipulation known as Dry Backs.

Cannabis is known to be a highly demanding crop, but what does it mean for growers' irrigation and lighting strategies? We wanted to know how does high light strategy influence the irrigation strategy for cannabis cultivation on stone wool? Therefore, for this article, we interviewed Ryan Wankel, our technical sales manager for North America.

Previous articles discussed aspects such as the importance of a correct irrigation scheme, daily dynamics in the stone wool, EC levels monitoring and adjustments, and more. Yet, there is one more important point to discuss, and it is the pH level.

EC is the abbreviation for the term electrical conductivity, which is a very important aspect to take into consideration when growing plants.

Previous articles have presented, among others, information regarding the importance of irrigation strategies, crop steering, measuring WC and EC in the stone wool, and more. In this article we discuss the ideal 24-hours irrigation dynamics for cannabis cultivation on stone wool.

One of the most interesting characteristics of stone wool is its ability to extract water at very low moisture content levels. Stone wool is able to take up water instantaneously when partially dried out, unlike other substrates where plant wilting would be inevitable. Furthermore, there is a moisture gradient from top to bottom. Where the top is drier to allow for aeration (which also makes the substrate ideal for hydroponic cultivation). Nevertheless, growers who are unaware of this characteristic of stone wool might be in the illusion of stone wool drying out too fast, risking over-irrigation, therefore, good understanding and knowledge about stone wool is required.

When handling the stone wool right, important aspects such as water content (WC), electrical conductivity (EC), and pH, can easily be monitored and adjusted when needed. The reason these aspects have to be closely looked at is their heavy influence on crop health, growth, and development. There are several things that can be adjusted to influence the WC, EC, and/or pH in the stone wool, such as irrigation amount, schedule, and the given nutrient recipe. This is what we called steering the crop with irrigation and stone wool offers this wide range of control.

Similarly to other growing media, when stone wool is delivered it is dry, meaning, it contains 0% water. In comparison to other substrates, stone wool has many advantages, such as lighter weight, a great moisture holding capacity, more convenient transportation, and longer shelf-life for unused products. Therefore, when a grower plans to start the cultivation of cannabis, the first step (and a very critical one) is to initially saturate the stone wool.