Ed’s New Book for Cannabis Cultivation

By. Dion Markgraaff

Our cannabis community has a great new opportunity to learn more of the latest scientific research with the release of the new book, Ed Rosenthal’s Marijuana Growers Handbook, an Ask Ed complete guide for medical & personal marijuana cultivation. NUG Magazine got an early look at the official course book for Oaksterdam University, which has just been released.

Ed’s decades of personal experience, his documentation of unmatched travel experiences, and his lifetime correspondence and interaction with countless growers around the world have come alive in these 500 pages. This book is an instant classic filled with great pictures throughout the manuscript that serve as instructional illustrations of well thought out points and revelations.

A quick skim through the book reveals a world changing thesis for all cannabis growers. Ed states the old 12/12 light system should be replaced. Under the title Critical Light Period he states on page 373 that your flowers need only 10 hours of darkness daily, they can be provided 14 rather than 12 hours of light each day so that they receive almost 17% more energy with which to produce sugars used for more and faster growth.

One of my favorite sections is the part where Ed reminds us of the future free-open market when he describes The Tomato Model, fighting against the fear some cannabis growers have today for legalization/liberation.

We decided here at NUG to bring you a glimpse into this epic novel, reprinting Ed’s introduction to his book, a section on how to increase the potency of your plants, and another fascinating tip about adding Ultraviolet B (UVB) light.

If you are going to take the time, effort, and risk to grow some cannabis plants then you had better try to make them as good as possible. Knowing how to recognize when you should harvest your plants is important to maximize their medicinal properties. Knowledge is power and Ed’s new textbook is an educational supernova for society growing cannabis.

Although using marijuana may not be addictive, growing it is.
Why grow marijuana? The reasons can be many, and varied. Perhaps you have never considered growing marijuana. Or, perhaps, you never tried because it felt like a difficult, risky undertaking. You may have even tried your hand at raising a young plant or two but abandoned the project when the plants failed to thrive or were overcome with mold or pests.

Despite any potential pitfalls, there are many compelling reasons to embark on this journey. Â First, there are practical benefits from being able to choose which strains to cultivate selecting for height, grow time, aroma, taste, and the wide spectrum of the mental and bodily effects varieties offer. Also, many medical cannabis patients understandably prefer to have the control over their medicine that a personal garden allows, with the knowledge that it is grown safely and organically. Another factor can be cost: it is generally much less expensive to grow one’s own than to pay for someone else’s packaged product, and less risky than buying a bag from some unknown source.

As a plant, cannabis is similar to any other plant it likes light, water, nutrients, and human attention. Yet it has some unique characteristics and a long history of interaction with the human species. Time, observation, and research have taught us the best ways to care for marijuana to achieve big, beautiful buds and amazing harvests. Any effort you make to learn how to cultivate this fascinating plant will be well rewarded, and this book will help demystify the process.

The most powerful reason to grow marijuana, in my experience, is the enjoyment and satisfaction that comes from forming a personal relationship with this fascinating plant.  As I can attest, this is the only truly addicting aspect of marijuana.

Marijuana Grower’s Handbook is designed to help you grow bountiful yields of high quality marijuana. Whether you are a beginner or an experienced grower, this book provides the information to help you grow a garden that will provide you good harvests, enjoyment, and an enriching pastime.

Most gardeners, myself included, have an anthropomorphic attachment to marijuana. They name their plants, develop a fondness for one or the other. There are some good reasons for this: unlike other annuals, marijuana has separate male and female plants. It has distinct life stages including growth and reproductive, and it takes between 50 and 80 days of flowering to ripen, each day of flowering comparable to a year in the life of a human. The best part of gardening is that at the end of the journey you will harvest some of the best buds you have ever smoked, all ripened to perfection.

PRECAUTION: The legality of marijuana depends on who you are and where you are located. If you are living in a state where it is legal for medical marijuana patients or suppliers to grow, then you will have a different attitude about growing than someone who lives in the majority of states and countries where marijuana is illegal to use or grow.

Before you start to plan a garden you should have a clear understanding of the laws regarding cultivation of marijuana. With this information you can make a realistic assessment of the situation and decide whether gardening is for you. You should also begin to make contingency plans based on worst-case scenarios.
In states where medical patients are allowed to grow marijuana there are often strict limits on the number of plants or the amount of space that can be devoted to the garden. Marijuana cultivation is often considered a serious offense so it is imperative to take precautions to keep yourself free.

Some questions you might ask yourself before you commence this venture are:
-Am I willing to take on the responsibilities and risks?
-Can I afford a legal quagmire?
-How do my roommates feel about it?
-Do I really have a secure area?

Most marijuana arrests are the result of accidents, lovers spats, nosy neighbors or jealous friends. People who snitch to get out of trouble also appears in the statistics. It pays then, for marijuana growers to become nicer people than they might otherwise be. Don’t alienate others. Treat your friends better. Be nice and helpful to your neighbors. Let the harried driver cut in. Develop a broader perspective on life.

Here are some excerpts from Ed’s new book:

MGH2 EXCERPTS [page 365-366]

Flower ripening starts between the fifth and eighth week. The calyxes (ovaries) start to swell. These are false seed pods; the flowers have not been fertilized and no seed can develop. The swollen calyx is one indication of ripeness. It begins about two weeks before maturation, so the timing depends on the variety.

Capitate trichomes, the tiny stalk-like resin glands that fill with THC, terpenes, and other cannabinoids, start to grow on the leaves surrounding the flowers. The flower areas will become totally covered with resin glands. The length of this stage of growth can last from two to five weeks, depending on the variety. Varieties that ripen in seven weeks usually spend about three weeks in this period of heavy flower growth. Late-season and long-maturing varieties linger in this stage for five weeks or more.

The trichomes become more prominent and stand more erect. The cap that tops each one swells with resin. The viscous, sticky liquid contains terpenes and cannabinoids such as THC, which are produced on the inside membrane of the trichome cap. As the resin accumulates in the cap, the flowers odor becomes more intense.

The odor reaches a peak at the same time the trichomes begin to fluoresce in the light, twinkling like little crystals. In some varieties, they are so prominent that the whole bud sparkles. Using a magnifying glass, a photographer’s loop, or a microscope, you can monitor the buds progression to the peak of ripeness by watching the resin in the gland tops. Under magnification, you can see the individual glands turn from clear to amber or a cloudy white as they mature. These colors indicate that the THC is beginning to degrade into two other cannabinoids, CBL and CBN, which are not nearly as powerful as THC. When they begin to change from clear to amber or cloudy white, the buds should be harvested. This is the peak moment.

No bud should be picked before its time. Plants and varieties differ as to maturation pattern. Some plants mature all at once, so that the whole plant can be picked. Other varieties mature from the top down, or the buds on the outside of the branch mature faster than inner buds hidden from the light. Once the outer buds are harvested, the inner branches are exposed to light and quickly ripen. It can take two weeks of choosing mature buds before the plant is totally picked. Picking the plant a little at a time ensures that every bud is at maximum potency and quality.

[page 382-385]

Marijuana has evolved a very successful survival strategy. It domesticates easily and escapes domestication just as easily. Throughout almost its entire history of symbiotic relations with humans we accepted its natural life cycle without trying to alter it beyond developing varieties that matured a little sooner or later.

To make a change there has to be an advantage for at least one species. We have always respected marijuana as a fall flowering and ripening crop. However, it turns out that our interests and the plant’s natural proclivities have diverged.

John Lydon published his Ph.D thesis in which he reported on experiments he performed on marijuana. They showed that the amount of THC that a high quality marijuana plant produces goes up in a direct ratio to the amount of UVB light that the plant receives.

The relevance of this information to this discussion is that when the angle of the sun to the earth is most perpendicular, on June 22, the first day of summer, is when that hemisphere receives the most UVB light, which is past the far end of the visible spectrum, on the blue-violet side. As the angle of the Earth and sun becomes more oblique, Earth receives a higher proportion of light from the red spectrum and less blue and UV. By September or October, when sinsemilla normally ripens, not only is the light far less intense, but the amount of UVB being delivered is a small fraction of the amount that is received on June 22nd.

Marijuana buds that are ripening under the intense sun of early summer grow bigger, denser and are more potent than when they ripen under the waning sun and variable weather of the fall.

To induce flowering in plants they should be placed under 12 hours of darkness each day. Darkening curtains are placed over the garden, There are many ways to accomplish this. They range from moving the plants to and from a dark place daily, to covering the garden using an opaque plastic sheet over tunnels, to automated blackout gardens.

To force plants to flower you must be punctual and watch the daily changes in dawn-dusk times to make sure that the plants are getting enough darkness. You can also use an automatic system to regulate the curtains.

There are two ways to approach restricting light: darken in the morning or at night. Morning darkening is the preferred method. The shade material is placed over the garden each morning before dawn. The plants need to be shaded counting forward 12 hours from dusk. If dusk is at 9:00 pm and dawn is 6:00 am, curtains should cover the garden before dawn, around 5:30 am They should be removed at 9 a.m. after receiving 12 hours of no light.

The other method is to install the curtains in the evening. Count back 12 hours from dawn, which occurred at 6 am in the above example. The curtains are placed over the garden at 6 am Then at 9 pm, after dusk ends and night begins, the curtains are removed so that any condensed moisture can evaporate into the night air.

To force the plants to flower during the summer they need to receive the critical dark period each day. Covering the plants with a blackout cloth each day so they receive 12 hours of darkness pushes the plants into flowering mode.

In late stages, mold prevention measures should be taken because moisture levels often build up when the plants are covered. Spray the plants with Serenade® biological fungicide, Zero Tolerance® herbal fungicide, potassium bicarbonate, diluted milk or other organic fungicides to prevent fungal attacks.

The advantage of placing the curtain over the garden early in the morning rather than before or after dusk is that the plants transpire and dew settles after dusk. The plants stay wet under the tarp. When the tarp is spread in the morning there is less moisture to deal with. The further from the plants that the coverings are placed the less of an effect condensation has on the garden.

The very best outdoor marijuana is grown using this technique. The reasons are more intense light, more UVB light and better weather conditions with less chance of cool weather that slows growth and development.


Ultraviolet B (UVB) light is a spectrum of light that is invisible to us but is visible to insects and some other organisms. On humans it causes suntan and sunburn and is implicated in the formation of eye cataracts. Tanning bulbs emit
UVB light.

UVB light also affects marijuana potency. The potency of high quality marijuana increases in direct ratio to the amount of UVB light it receives. This is very significant. In California, where medical dispensaries operate in an unrestricted market, many dispensaries reject fall-harvested outdoor material as inferior. They have found it lacks the potency of indoor crops and is a harsh smoke. However, marijuana grown outdoors that was forced to ripen August 10th was accepted—because it had the high potency and lacked the harshness of indoor crops. Harshness is probably a result of cool nights.

Indoors, under fluorescent and High Pressure Sodium (HPS) lamps, gardens receive little UVB light. Metal Halides (MH) without glass reflectors emit a bit more. However, there are ways of supplying your garden with UVB light. Tanning lamps work, that is, lamps that tan people, because of the UVB light they emit. Using tanning lamps increases the THC content of the crop. Reptiles and lizards require the UVB spectrum to stay healthy, so 10% of the output of œreptile fluorescent lights is UVB. Tanning lamps are available on the Internet. Use between 5-10% of your total wattage to these lamps. For a 1,000 watt garden use 100 watts of special lighting. Adding UVB light to your garden enhances your marijuana naturally, without special formulas and chemicals.

bringing you that fire! stay tune for more posts.

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