Hardening off Your Cannabis Clones
Clone Care At Nurseries & Dispensaries
Most clones are stored under 24 hours of artificial light in nurseries and dispensaries. When a clone is moved from 24 hours of artificial light directly into intense sunlight, it can experience shock. To avoid this, we suggest hardening off your cannabis clones. Hardening off consists of two main parts: getting your plants used to an environment they have never been exposed to and getting your plants acclimated to direct sunlight and dark cycles. It is important when introducing your plants to anything new, to do it in a gradual manner so they are not overly stressed by the changes they experience. The first day you transplant your clones they will be stressed as their roots are suddenly exposed to a new medium. It is not recommended that you then subject them to other stressful events like direct sunlight, too much heat, or dark cycles.
A Process For Hardening Off Your Clones
When your plants have had a day to adjust to their new pots you can start bringing them into their future environment outdoors. Again, this process is supposed to be gradual. Do not put them outside on a day where temperatures are due to rise over 95 degrees! Finding a good place for them to experience the outdoors is crucial. You want to ensure that they are not completely exposed to the direct sun. In the shade or dappled sunlight, under a shade cloth or some other kind of sun protection is recommended. It is also important that animals do not have access to your clones, so make sure they are off the ground where curious cats can’t nibble on them or where dogs might lift their legs outside.
Leave your plants in this selected area for a full day, assuming the weather is appropriate – too much wind, heat, or other forces can stress your plants or cause them to break, die, or wilt due to stress. When it starts to get dark, and the sun and temperatures drop, bring your plants back inside or provide them with supplemental lighting in a safe environment. This can be done simply with a porch light, a flood lamp or an outdoor garage light.
Do the same procedure for the next few days; partial shade, indirect sunlight and a breeze will all be beneficial. A breeze moving the leaves around will strengthen the branches while lowering the risk of mildew. The partial sunlight will get the plants invigorated to grow and the shade will ensure the heat is not so strong that they become overwhelmed. We recommend a week to a week and a half in the partial sunlight before moving to full sun as your plants should have healthy established root systems by the time they move into direct sunlight. It’s also crucial they are watered before being placed in direct sunlight because in small pots the plants can dry out quickly under the strength of the full sun.
It is important to keep a close eye on your plants in this early stage of life and watch for signs of heat stress such as drooping or curling leaves. If they do show signs of stress give them a break and move them back to the shade. Continue to give supplemental lighting through the dark cycle of the day ensuring they do not receive more than 10 hours of darkness. Most growers will do a cycle of 18 hrs light and 6 hours darkness during the vegetative cycle. Your plants are photosensitive meaning they will flower when they receive too much darkness. If you have not kept your clones in the vegetative grow state long enough this is called pre-flowering and can also add stress to your plant.
For more information on growing cannabis plants please check out our Cultivation Resources.