Whether you want to grow 3 plants or 30,000 there are many factors to take into consideration: Would you rather grow a strain that produces 38g per season or one that yields 9 Kilos? Would you rather grow a strain that has a high incidence of unwanted side effects (Anxiety, paranoia, headaches, etc.) or one that has a very low incidence of said effects? Do you want to grow a strain that has a 29%THC level or one that has 5%THC? One that has 0%CBDs or one that has 47%CBDs. Would you like to know which strains are almost totally immune to powdery mildew, fungus and mold or one that is particularly vulnerable to these diseases? One that can grow clear into the snows of Fall or one that needs a Mediteranian climate to thrive? Do you want to grow a strain that produces particularly well under indoor lighting or one that requires an outdoor grow to thrive? Atrain that reach only 18" to 24" tall or one that grows to 12 feet? A strain that needs little water or one that requires a good deal of water? Then there are strains that absolutely must have a good deal of support and those that require none at all. Strains that take 20 weeks of flowering (After a long vegetative period) and strains that go from seed to harvest in 28 days. Interested in the medical conditions a given strain is good for? Here you can find over 120 medical conditions are listed among over 500 strains. There are even strains with near zero THC and over 42%CBDs for medical use with no high whatsoever. There are strains that have an intense odor when growing and will alert anyone within several hundreds of yards and there are strains with little odor or even an aroma that smells like something different than marijuana altogether. If you think you are going to get this information in one place - you are right. It is this book. Other than that, I hope you have thousands of hours to read many dozens of books AND search hundreds of web sites. That is what I did for the last two years. These are the results. This is NOT a book strictly about horticultural practices for marijuana in general (though you will find brief comments and an excellent all around organic bug and disease control spray menue herein). If you want in depth general marijuana horticultural information there are many sources easily available. George Servantes is one of the best and there are countless videos on You Tube for such information. This book is completely about STRAINS, what they need to grow, how they grow best, and every aspect about each strain.. You will find it invaluable.