Chapter 8: Case Study & Garden Calendar

Marijuana Horticulture: The Indoor / Outdoor Medical Grower’s Bible

by Jorge Cervantes

The First Crop

Nigel and Terry lived together in Central London and worked for the same large British company. When both were offered a transfer to a new firm in Holland, they jumped at the chance. The new company was in the west, near the coast, and in close proximity to some picturesque rural districts. They rented a house in the countryside where they could enjoy the solitude and reduce the stress associated with corporate life.

The house they rented was on a large piece of land, not in direct view of neighbors. Near the house was a big shed once used to service farm equipment. It had power, water, and a functioning toilet and shower. Interesting?

After settling in at work and making the house comfortable, Nigel and Terry got to thinking. “That shed’s just sitting there empty, and wouldn’t it be just perfect for a hydro setup?” As it turned out, the property they rented was owned by an elderly woman who lived in Belgium. The rent was paid to a real estate agent in town, and no neighbors had even spoken to them in the six weeks since they moved in, so they figured the place was pretty safe. After a few nights sitting up and discussing their prospects, the lads decided to capitalize on their good fortune, and “go for the grow!”

At the back of the shed was a storage area that had been partitioned off from the rest. It spanned the entire width of the building, about 33 feet and was approximately 10 feet wide. This seemed like an ideal place for the new project, but a few questions arose. Exactly how big were they going to make this thing? How much cash were they willing to invest? What were the consequences of success versus failure, or worse, discovery? Being corporate minded, the lads decided to make an executive decision. Seek advice from a professional.

Holland is world-renowned for its indoor weed production; consequently, grow shops are abundant. Nigel and Terry found the staff at their nearest “grow-op” to be open, professional, and well equipped to deal with their specific inquiries. After an enlightening chat, the boys decided to play it safe and use only half the area of the storage room 16 feet 6 inches x 10 feet. They figured that organic was the way to go, and the simplest growing method (pots and soil) would be best for starters.

They bought enough timber and other materials to construct two benches 16 feet 6 inches long x 4 feet wide. They bought 100 1.3 gallon plastic pots, ten 13-gallon bags of organic potting soil, and enough white, laminated wooden panelling to cover the walls. The idea was t construct the basic room, fill the pots with soil, place them on the benches, and check that the design was solid before progressing further. All went together well, total expense USD $780.

This system was relatively easy to setup. The inline fan was installed high up on the rear wall. Its job was to expel ht air from the grow room and create enough draw to pull cool air in through a vent (large gap) between the opposite wall and the grow room floor. When and if smell became a problem, the carbon filter could be connected to the Trin and its fan speed increased to maintain constant odor-free airflow. The two pedestal fans would be incorporated to increase air movement but not until all else was setup. The lamps were arranged to cover an area f approximately 3 feet 3 inches x 3 feet 11 inches each. The reflectors supplied with the lighting kits were cheap, half octagon, aluminum horizontal hoods. However, they were lightweight and seemed very bright when the lights were turned on.

Clones were potted and placed on the benches (ten under each lamp). For the first five or six days, the lights were kept about one meter above plants, then gradually lowered to about half that height as growth became healthy and vigorous. Watering was done by hand, and because the soil was a premixed organic blend, no extra fertilizer was added for the first week.

Nigel and Terry hovered over this first crop like proud fathers. They adhered to a daily schedule of watering, monitoring pH, and inspecting leaves for signs of insect attack and nutrient imbalance. As a result, the plants develop quickly and were ready to begin flowering, the lights were set back from 18 to 12 hours per day. About this time, they began to add organic nutrient supplements to the daily soak. As the plants developed further, they worked up quite a thirst; all pots were watered until their individual drip trays nearly overflowered.

The carbon filter was connected around week 6, in an effort to prevent odors escaping the shed. This tactic worked well, but it reduced airflow. As the plants increased in size and density, it became increasingly difficult to keep grow room temperatures below 86F. On a couple of occasions, the temperature rose above 91F, and bud development definitely suffered. The guys remember one time when every plant stopped growing for three or four days after the room overheated.

As their crop approached maturity, Nigel and Terry noticed something strange going on. Most plants were finishing off nicely, but some (generally the biggest) didn’t seem to be maturing properly. The buds on the plants growing right under the lamps were big but didn’t seem as solid or resinous as those on other plants. This condition became more noticeable as time progressed. By the 8 week warm, the larger plants started to go a bit yellow and drop leaves. It was time to pull the pin on this caboose!

The crop was harvested a few days later and hung to dry. In general, the smaller plants produced better quality buds than the larger plants. The yield was 8.4 pounds of very nice weed, and with that in hand, who was going to complain?

Actually, the boys were very happy with their first result, as everything ran quite smoothly. They had a few problems with heat, but they learned a lot and gained the confidence to expand their room to its full potential, 33 feet x 10 feet.

The Second Crop

This was a time of change and serious improvement. Over the past three months, Nigel and Terry had visited the local hydro store on many occasions and had struck up a friendship with one of the owners who worked there. He had given them heaps of useful advice, and the boys realized that without his input, the first crop could have been easily ended in failure.

The Store owner (we’ll call him Bob) offered to help the boys design their new double sized room, provided they purchase all their new equipment from him, of course. He insisted that the system they were currently running used too much power, generated too much heat, and was to labor intensive to be successfully doubled in size and maintained by two guys already working full time jobs. As usual, Bob was talking sense, and Nigel and Terry decided it was a safe bet to play it Bob’s way and part with the necessary cash. The total cost of Bob’s proposed improvements weighed in at USD $7552 (Eur $6000). Calculating at a rate of Eur $2200/kilo, the first crop paid for itself and more than half expenses of the proposed expansion and improvements. Cool!

Bob’s plan was to: 1 – Double the length of the existing two benches and line the walls of the other half of the storage area with white laminated wood; 2 – Set up an automatic watering system with a large reservoirs to reduce manual labor; 3 – Plant double the amount of clones per area to reduce time in vegetation by a week; 4 – To achieve adequate air flow, install a new 500 cu/hr fan for air extraction, and use the existing 3200 cu/hr for air intake; 5 – Make use of current advancements in reflector technology to decrease the number of lights required from 20 to 14 and consequently reduce the power usage for heat generation by the same ration; 6 – Bob also suggested ditching the pot idea in favor of cocopeat slabs. “Just supply the plants with a top quality organic nutrient, and the garden will be state of the art and organic.”

The room was setup pretty much as Bob had planned. Five Danish made plastic 6 foot 6 inch x 3 foot 3 inch trays were loaded up with coco mats and placed on each 33 foot long bench top. Each tray was installed with a 3-degree tilt to promote drainage. An elaborate systems of drippers and drainage pipes was constructed and each bench was run as a separate entity with its own 400 liter reservoir and 6000 L/hr pump. Both pumps were timed to run x times a day for y minutes, and nutrient runoff was pumped out of the grow room and into the shower drain.

The fans were installed placing the 5000 cu/hr fan high at one end of the room and the 3200 cu/hr fan down low at the other. The 5000 removed air via the vent in the upper central part of the room. The vent was box shaped and permanently connected to a carbon filter. When the filter was not required, a cover on the underside of the box was removed, and air was drawn out through the exposed opening. The 3200 forced cool air through ductwork that ran along the floor under each bench. This air entered the room in four places under each bench, equally spaced along their length. Four pedestal fans were used to mix the air and push it in the general direction of the outlet vent.

The room was lit using fourteen 600-watt lamps, each covering an area of 4 feet 8 inches x 3 feet 11 inches. This was achieved by using high tech adjustable double parabolic reflectors (Adjust-a-Wings). These flexible “wings” were highly reflective and could spread light evenly and broadly at a range of heights above the plants. They were rated to cover areas of 4 feet 11 inches x 4 feet 1 inch and above with 600-watt lamps, so 4 feet 8 inches x 3 feet 11 inches was within prescribed limits. Another lighting product was used in conjunction with the wings and referred to as a Super Spreader. These fit below the lamp and spread excess light and heat from that hot area across the light’s entire footprint. They allow lamps to be close to plants to produce rapid growth but keep growth rate and plant size even.

When compared to the first, this crop almost seemed to grow itself! The irrigation system alone (reservoir size, how many days reserve, nutrient dosing, the coco/Danish tray/run to waste system) saved Nigel and Terry about two hours a day.

The ventilation design combined well with the simple, effective lighting strategy. Air was pumped in and pushed up from below, cooling plants and lights on its way up. The heated air would rise naturally, be trapped by the ceiling, sucked towards the vent/filter, and exhausted from the room. With a small amount of adjustment, the air temperature could be maintained at 80-82F even when the plants formed a dense mass across the whole room.

The wing reflectors could be adjusted to provide even lighting when they were close to the plants (growth and flowering phases) and when they were farther away (early vegetative and final maturation phases). When reflectors were hung low over the plants, the spreaders dealt with any hot spots and insured even lighting.

Nigel and Terry’s second crop grew vigorously and evenly all the way through to maturity. They had a small problem early on with spider mites. Seems the clones they bought had a few mites on board. The mites were dealt with organically and effectively. Bob had suggested the boys use Ecolizer organic nutrients and follow their program exactly. The program suggested misting clones regularly with their “Bugs Away” foliar feed. This solution contains nutrition plus essential oils that coat mite eggs and suffocate them. No chemicals and it worked!

After a total of nine weeks growing, the room was filled with plants that formed a dense layer of evenly developed, dense, sticky, fat bud. The room resembled a “sea of green” rather than a collection of plants of assorted size and shape. As they harvested, Nigel and Terry joked about mowing down a mass of sticky green corn cobs. Cutting, hanging, drying, and particularly manicuring this much weed was one hell of a job and took them a month to finish. The final yield was 12.5 kilos (27.5 pounds) and the quality was A++.

At this point, the boys had covered all their expenses, they were almost half way int their third crop (which was growing strong), and were already 10 kilos in the black. This had been an ambitious project. Nigel and Terry had not achieved success without significant risk and a lot of hard work! Guess who was planning a well deserved “holiday in da sun”?

Comparing Statistics

First crop, 8.4 pounds / 6000 watts = 0.02 ounces / watt. 8.4 pounds / 14.4 square yards = 11.1 ounces / m sq.

Second crop, 27.6 pounds / 8400 watts = 0.5 ounces / watt. 27.6 pounds / 28.7 square yards = 18.4 ounces / m sq.

Bob’s advice helped the boys increase their power efficiency (g / watt) by 137 percent.

Bob’s advice helped the boys increase their space efficiency (g / sq m) by 65 percent.

Calendar and Checklist

A calendar helps growers know what to do and when to prepare t do it. A checklist add necessary routine to the process. The calendar outlines the average three-month life cycle of clones. It notes major points of interest during each stage in life. The weekly checklist consists of a few things that must be done every week to ensure a successful crop.

Savvy growers read and consider each and every point on the calendar weekly. They mark each point with a check when finished with it.

Growers should spend at least 10 minutes per day, per lamp, to have a productive garden. This is enough time to complete all the stuff on the weekly calendar. Much of gardening is simply watching and paying attention, but it takes time to have a decent productive garden. If using CO2 enrichment, or hydroponics, allow 20 minutes per day for maintenance.

Large chunks of time will be spent setting up the grow room and harvesting. These are not included in the 10-20 minute daily schedule.


The calendar starts on January 1st and is only three months long. To weeks for clones to stick (root), two weeks of vegetative growth, and eight weeks of flowering. This indoor calendar can be started any day of the year, no matter which direction the wind is blowing or what the weatherman says.

If the garden is full of clones grown with CO2 enrichment or hydroponically, the calendar could move up one week, depending on how fast the garden grows. Remember, light intensity substantially diminishes over four feet away from the bulb.

First Month
January 1st, First Week

Take clones and root clones. They root in 1-4 weeks.Sow seeds. Make sure they are warm fr speedy germination.
Mix dolomite lime into soil before plating.
Prepare grow room.
Set timer for 18 hour days and 6 hour nights.

January 15th, Third Week

Make sure the vegetative room is perfect before bringing in the clones.
Move in rooted clones or sprouted seedlings, place 24-36 inches under HID. Keep soil surface moist.
Fertilize seedlings and clones. Use an ALL PURPOSE fertilizer. Start regular fertilization schedule.
Special care should be given to soil. Moisture damping off and dry soil pockets could stunt plants now!

Second Month
February 1st, Fifth Week

Vegetative plants should be 6-12 inches tall with broad, firm, green leaves.
Continue regular supplemental fertilization program.
Move HID 12-36 inches above month old seedlings and clones.
Thin and transplant seedlings into larger pots.
Irrigate as needed.

February 15th, Seventh Week

Move vegetative clones into 12 hour flowering room.
Change to super-bloom fertilizer.
Plants should be 12-24 inches tall.
No leaves should be yellowing.If they are, fine tune the weekly checklist.
Over watering is sometimes a problem now. Check the soil with a moisture meter.
Increased air circulation and ventilation are essential.
Mist the garden with water to wash leaves.
Iron, magnesium, and nitrogen deficiencies could show up now.
Supplemental trace element mix should be applied.

Third Month
March 1st, Ninth Week

The plants are two months old and 18-36 inches tall.
Females should dawn white, hair-like pistils.
Male pollen sacks develop. Remove or save males for breeding.
Take clones for the next crop.
If there are any leaves yellowing and drying, fine tune the weekly check list.
Air circulation, ventilation, and relative humidity are very important now!
Leach sil to wash away any excess fertilizer salt residues.
Seedlings only two months ld should be given another month of growth before flowering in induced.
Cloning for sex may now be practiced.
Soil will dry out rapidly now; watch fr dry soil pockets.
Bend and tie plants ver to give garden an even profile.
Prune plants that are shadowing other plants (optional).
Heavily planted rooms should be ready for a second lamp. Add another lamp to increase harvest.
This is the time of peak THC production. During the next one to four weeks, the tops will double in size and potency!
Lower leaves may yellow. If many leaves are yellowing, fine tune the check list.
After fine tuning the checklist, remove yellowing leaves only if they are clearly going to die.
Garden might still be using quite a bot of water; make sure to check it daily of needed.
his is the last chance for spraying and fertilizing, if you pan to harvest within two weeks. If there are any nutrient, fungi, or insect disorders, this is the last chance you will have to use sprays to combat them.

March 15th, Eleventh Week

Tops elongate, making the garden’s prfile about 6-12 inches taller than two weeks ago.
Continue fertilizing with a high bloom fertilizer.
Older leaves may start to drop a little faster, due to decreased nitrogen in the super-bloom fertilizer or if only an HP sodium lamp is used.
Inspect for bud (gray) mold.
Check all factors listed n the checklist.
Buds should be oozing with resin by now.
Some shade-leaf yellowing is normal.
Indica and early maturing buds are nearly ripe now. Harvest if ready.
Water is needed.
No insecticides!
No fungicides!
No fertilizer!
Check for bud blight or bud mold.

Fourth Month
April 1st, Twelfth Week

The only change will be in growth of more and heavier calyxes on the flower buds.
Continue to water as needed.
Bud (gray) mold could become a problem. Constant scrutiny is a must! It shows up overnight, so watch out!
Everything should be ready for harvest by now. If it is not, consider growing an earlier-maturing strain of cannabis.
Harvest now or within a couple of weeks.
THC content is on its way downhill when resin glands turn amber.
Let “seed crops” g until the seeds are big and healthy before harvesting.
Harvest and clean up.
Move in rooted clones for next crop.

Marijuana Horticulture

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