Text Excerpts
From Part One, Chapter Four:
High Intensity Discharge Lamps
Here is where we get down to the serious lighting: the high lumen output lamp you will use to grow out your plants. There are two types of HID systems suitable for your application: Metal Halide and High Pressure Sodium.
Metal Halide Lighting
Metal Halide lamps are highly efficient and the bulbs produce a bluish-white light with a spectrum similar to sunlight. They are available in 175, 250, 400, 1000 and 1500 watt ratings. For your purposes the 400 and 1000-watt (depending on area size) lamps are the ones to use. Metal Halide light is considered highly effective for vegetating plants and less effective during the flowering cycle.
All Metal Halide lamps are ballasted for a specific wattage, and you cannot use a 400-watt lamp with 1000-watt ballast, or vice versa. The ballast is typically a separate unit connected to the lamp assembly via a long, heavy cord. Ballasts produce heat and the long cord enables their placement outside the garden area.
Let's have a look at the lumen output and lumens per watt for Metal Halide bulbs:
BULB WATTAGE |
LUMEN OUTPUT |
LUMENS PER WATT |
400 |
40,000 |
100 |
1000 |
115,000 |
115 |
1100 |
133,000 |
121 |
You can see that, compared to fluorescent lighting at 70 lumens per watt, this is a substantial increase in efficiency. Metal Halide bulbs are also available in horticultural versions, providing more light in the red spectrum (useful for flowering) than standard MH bulbs. The average life of a 1000 watt Metal Halide bulb is about 12,000 hours when used for eighteen hours a day. The bulb life shortens as the bulb is used for fewer hours; the total light output gradually diminishes over time. It is advisable to replace MH bulbs every three crops . . .
From Part Two, Chapter Four:
How Long to Flower?
The time it takes a plant to complete its flowering cycle is built into its genetic profile and cannot be reduced. If plants receive less than twelve hours light flower production will suffer as a result, and the flowers will not mature any sooner. Given that the objective is to have the largest harvest possible, plants should be provided with no more and no less than twelve hours of continuous light over a twenty-four hour period. Remember, growth processes cease when the light is off.
If you don't already know the flowering time of the variety you're growing, Buck, you are about to embark upon a journey of discovery. Pure C. Indica varieties will have harvestable flowers in 6-8 weeks, C. Indica/C. Sativa crosses usually mature after 8-12 weeks of flowering, and pure C. Sativa strains will take 12-16 weeks or longer.
A Second Crop
Some gardeners like to grow two crops from the same plants. This is useful in terms of production as well as giving the grower time to evaluate the plants grown and select mother plants for cloning or breeding.
To grow a second crop, be sure to leave a few leaves and buds at the bottom of the plants when you harvest. Set your timers for a 16-18 hour photoperiod and give your plants a treatment of balanced or high-N fertilizers. Do not water heavily. Within about thirty days they should be bushy with new vegetation.
Flower the plants as before. If you are going to take cuttings, do it during the second to third week of flowering. Follow the instructions in Part Two Chapter Six. A second crop will not produce flower clusters as large as the first one, but the overall yield should be similar.
Flowering the Example Crop
As you know, this crop was put on a 12-hour photoperiod after the plants had been in their containers for 21 days and averaged 26.5 inches/67 cm tall. The 2-4-4 fertilizers were continued at every fourth watering, supplemented with Earth Juice Meta-K for extra potassium. For the first fertilization during photoperiod they were given Indonesian bat guano for supplemental phosphorus. The next watering they were given fertilizers with Maxicrop (and no Meta-K, since Maxicrop also contains K) to bolster trace elements. After the first week of photoperiod they had not begun to flower yet but this is normal. The bat guano applications were given every two weeks up until two weeks before harvest.
When the lamp was timed to a 12-hour photoperiod the dehumidifier was adjusted to its maximum setting and humidity maintained at 35-40%. Low humidity is critical during flowering; it's the first and most effective line of defense against botrytis, and thought to be an important contributing factor to potency.
By the third week the plants had not only grown considerably wider but taller too, thanks to natural elongation. Planet X elongates about six inches. Three of these plants, however, elongated over a foot. This demanded the lamp be raised to its maximum height and caused concern about light reaching the bottom foliage. As an alternative these three plants could have been bent over but the crown buds forming on them looked too nice to mess with. The other plants were raised to even the garden profile and bring their lower foliage closer to the light. Leaching was done at this time with each container having fifteen gallons of water poured through it.
The flowering process can be mighty tedious at times, simply because it takes so long compared to the other plant stages. Highlights include leaching, another monotonous process. Plants must be monitored for insects as well as signs of nutrient deficiencies and they also must be maintained and the garden kept clean. Watch very closely for male flowers.
The color of the foliage on the three largest plants in the example garden began to lighten up a couple weeks into flowering. The leaf veins were lightening along with the leaves, indicating an N deficiency. Feeding them with the balanced (3-3-3) fertilizers at one tablespoon/10 ml per gallon corrected the situation, returning the plants to their natural green tone four or five days after application. By week five all the plants had gotten the same treatment and the largest ones twice, so the fertilization schedule was increased to every third watering. It's better to be conservative with fertilization than to burn plants, and you want your plants to have minimum nitrogen and maximum phosphorus when flowering. Still, the leaves should be the same green they were during vegetation until the last few weeks of flowering when nitrogen will be deliberately cleared from the plants' tissue. Fertilization was stepped-up to every other watering. Remember, these plants were grown with CO2-enriched air . . .