When to Expose Seedlings to Light or Sun?

Uncertain about the optimal conditions to cultivate your cannabis seeds – utilizing natural sunlight or artificial illumination? This article elucidates the precise amount of light required, strategies to avert seedling collapse, and the appropriate timing to transplant them outdoors.

The question, “At which critical moment should cannabis seedlings be transitioned to artificial lighting or subjected to the natural glow of the sun?” often resonates amongst aspiring cannabis cultivators, particularly following the indoor germination stage, which is orchestrated under meticulously regulated lighting environments.

For individuals embarking on an indoor cultivation journey, it is permissible to place the cannabis seedlings under artificial lights immediately following their breakthrough from the soil or the selected cultivation medium.

What Amount of Light Do Cannabis Seedlings Need?

When one opts to utilize High-Intensity Discharge (HID) lighting solutions, predominantly manifested in the guise of a metal halide lamp, it is emphatically recommended to maintain a safe and nurturing distance, no less than 50 centimeters, between the nascent seedlings and the radiant light bulb. This precautionary measure is instituted to foster a conducive growth environment, mitigating the risk of potential harm engendered by proximity to high-intensity light sources.

In scenarios where the lighting setup involves the deployment of compact fluorescent lamps, distinguished by a power output typically surpassing the threshold of 100 watts, it is sagacious to sustain an interim space of approximately 15 centimeters. This space should segregate the burgeoning apex of the fledgling seedlings from the lighting apparatus, thereby orchestrating a balance between ample light exposure and plant safety.

Alternatively, when adopting the usage of standard fluorescent tubes — having a power specification oscillating between 18 and 36 watts — it is permissible to situate the seedlings within a close-knit proximity of a few centimeters to the lighting source. This proximity is seen as an acceptable parameter given the relatively diminished power output of these lighting fixtures.

Furthermore, it stands as a cardinal rule to guarantee that cannabis seedlings, nurtured under the aegis of artificial lighting setups, are privy to a gentle breeze, typically dispensed by an oscillating fan. The adoption of a small-scale domestic fan, functioning at its minimal operational setting, is deemed sufficient in this regard. This provision ensures that a steady, gentle undulation is maintained, serving to significantly fortify the stems of the seedlings, enhancing their resilience and fostering a sturdy growth trajectory as they navigate their early growth stages.

Are Your Cannabis Seedlings Toppling Over?

In circumstances where cannabis seedlings experience considerable growth in height, subsequently leading to an unfortunate event of them toppling over, this occurrence is chiefly ascribed to their upbringing within an environment markedly defined by a lack of dynamic air movement, which potentially stifles their early growth phases.

Seedlings that are designated for growth in outdoor settings ought to be methodically located near a window receiving a significant amount of sunlight, particularly during the preliminary phase of one to two weeks following their emergence from the substrate. This strategic positioning serves to foster optimal growth conditions from the inception of their developmental journey.

As these fledgling plants evolve, manifesting their second or third set of serrated leaves — a phase that succeeds the emergence of the initially rounded cotyledons from the seeds — it is observed that they generally acquire a heightened level of hardiness. This newfound resilience typically permits them to flourish and prosper, basking unreservedly in the natural luminescence offered by the sun’s direct rays, thus embarking on a path of vibrant and healthy growth.

When Should You Move Your Cannabis Seedlings Outside?

If the external environmental conditions and temperatures are found to be conducive, it becomes feasible to initiate the process of acclimatizing the seedlings to the unfiltered illumination provided by direct sunlight. This can be achieved by gradually extending their daily exposure to the outdoor elements, thereby fostering a robust growth pattern.

Commencing with an initial period of approximately three hours of outdoor exposure, ideally coinciding with the peak sunlight hours of the day, the seedlings can then be introduced to a progressive regimen wherein an additional hour of exposure is incorporated into their daily routine. This incremental approach facilitates a smooth transition for the seedlings, gradually habituating them to the external environment. Consequently, over roughly two weeks, the seedlings would have adapted sufficiently to withstand a permanent relocation to the outdoors, where they can thrive and flourish in natural light and ambient conditions.