When accepting clones or cuttings, there is always a danger of bringing in pest or problems along with the new acquisitions. Even if a clone appears perfectly healthy, it can be transporting mites or mildew and this can really put a damper on your already work-intensive hobby.
I will cover several ways to help prevent transfer in this article, but the first and most important one is a simple rule:
When accepting a clone, assume it has mites and treat it accordingly. What does this mean? In a word Quarantine!
I grow organically, but when it comes to prevention and dealing with pests I choose a nuclear warhead and dip new clones/cuttings into Avid. While the precautions on this systemic pesticide look pretty heavy, there are two main factors that rest any fears I have. First, I do not spray the product at anytime. Instead, I mix per label directions and use this as a dip. Second, my research uncovered the fact that Avid is used heavily in my local agriculture on many berry and fruit bearing plants, so I am already likely to be consuming large quantities. Some growers choose to use more Earth friendly products such as Neem Oil, but Neem is really hard on the plants and does not always ensure a full kill.
The proper way to apply Avid is to dip the clones as soon as they arrive and then again three days later, ensuring that all emerging eggs are also killed. Mites have a life cycle of three days.
I will actually treat clones and then place them inside a dome and use duct tape to seal it shut. This prevents any pests from escaping and infecting your garden. I am also a fan of pest strips. Make no mistake, these contain a controversial toxin called dichlorvos and it is a carcinogen. I guess it’s really according to how bad you hate mites or as we call them, The Borg. I would never use them around flowering plants, but I have been known to tape one up inside a dome with newly received clones.
The other big issue with clones is the dreaded powdery mildew. It is also invisible in spore form, meaning your clone can look perfectly healthy, but as soon as conditions are right, powdery mildew can spread so fast it can literally destroy a garden in days. Keeping your humidity low and temps between 70-74 degrees Fahrenheit during the dark cycle will severely hamper mildews ability to spread. So, with mildew, think environment before treatment. If your conditions are poor, no treatment will stop the spread of PM.
I have had some really good results using safer mildew treatments made up of natural oils such as garlic and cinnamon. During the winter months, we treat any new clone upon arrival and again while it is in the vegetative state. Some old timers like to use lemon water, but my research tells me that mildew actually likes a slightly acidic condition. Air movement is also crucial to prevent mildew.
Sometimes infestations require drastic measures and I have taken down entire grow rooms, killed all the early flowering plants, and fogged my rooms to prevent infestation. Sometimes, this can be the only solution since treating flowering plants is a big-time no-no. Young clones can always be dipped and you simply start fresh; this can be less stressful than combating mites cycle after cycle.
Many times, clones are improperly labeled and its quite common for me to see medicine grown from a cutting from a club that is not what the grower was told. While it takes additional time and effort, many times it can be safer and more productive to actually start some good seeds and find your own elite clone without bugs and fungus.