UNINTENDED EARLY FLOWERING
Julie (Internet): I'm growing outdoors and some of the clones seem a bit retarded, as the buds have formed on the stalk. I had heard you said to go ahead and remove them to hopefully re-grow til the end of the season. My question is how to remove them - there is no stem to snip off at the base of the bud, they are coming straight out of the stalk. I've not seen this before. They are pretty small but very sticky. What should I do?
Ed: There are three reasons why plants may start to flower early. The first is that the plants were placed outdoors while there was still a dark period long enough to force flowering. The second cause might be that there was a dramatic change in the lighting environment. The third is that the plants are receiving a critical amount of darkness that is enough to force the variety to flower.
When plants are placed outdoors early in the season, March or April, there is still a long enough dark period to force flowering. On March 22, the first day of spring, the plants receive a little less than 12 hours of darkness. This forces them into flowering. As the days get longer most varieties, excluding some indicas, go back to vegetative cycle and then flower normally in the fall. Some indicas continue to flower and never re-vegetate.
When some varieties of seedlings or clones are grown under continuous light or a long light cycle such as 20 hours daily and then placed outdoors where they receive only 14-15 hours of light, the change of light cycle is enough to trigger a flowering response even if the variety usually doesn’t flower under a 9 or 10 hour dark period. Plants with this problem usually readjust to vegetative growth after a few weeks.
Varieties differ in the number of hours of darkness needed to initiate flowering. Early maturing varieties often require as few as 8 or 9 hours of uninterrupted darkness daily to force flowering. In lower latitude areas such as southern California and other areas in the lower tier of the U.S., and Mediterranean Europe including Spain and Italy, indica and indica-sativa hybrids flower very early, resulting in small plants, because the dark period is too long, even in mid-summer, to keep the plants in vegetative growth. Instead they are forced into flowering.
The solution for this problem is the same no matter what the cause; the dark period must be interrupted. When the dark period is interrupted by light for even a few moments, the darkness countdown is restarted from zero. Use a warm-white fluorescent or high-pressure sodium (HPS) light. Imagine that the light is like a water spray that must reach all parts of the plant. The light only has to contact it for a brief moment.
If the plants flowered because they were placed out too early in the season, you can stop using a light-break in mid-May. If the plants are coming from a continuous light environment they will need the light for about a month before they adjust to the new environment. Indicas growing in low latitudes require the light-break until they are ready to be forced to flower.
Oscar (U.S.A.): I had a 3 foot by six foot white flood tray with a 35 gallon reservoir, with 32 plants in it. It was a mix of sativas and indicas. We had a ventilation setup and CO2 hooked up with a timer. I used a 600-watt HPS lamp on a Light Rail. The temperature was kept at 72 degrees and humidity at 50 percent. My harvest was only 8 ounces. How can I increase my yield?
Ed: Part of the reason that the plants had a low yield is that their growth rate was slowed because of the low temperature. As far as temperature is concerned, plants function in much the same way as cold-blooded animals; their metabolism is affected by the temperature. When the temperature is cool, plants’ rate of metabolism and photosynthesis is slow even if all other conditions—light, water, nutrients and CO2—are abundant. With the high light and high CO2 conditions in your garden, the growth rate will increase considerably when you raise the temperature to about 80 to 85 degrees. That’s an approximation. Use a surface temperature thermometer to read the temperature. Then maintain the leaf temperature at about 85 degrees by adjusting the room temperature.
Another reason the yield might be low is the varieties of plants that you grew. Since you were growing a garden of mixed sativas and indicas, the sativas may have towered over the indicas, shading them and thwarting their growth. For best yields, row plants that have similar growth characteristics.
MESSED UP TIMER
Angela (Internet): The power went out during night-cycle. The light came on early and I turned it off, and then reset the timer to the correct hours.
Are my three weeks into flowering cycle plants in danger or will they be OK? What if the light timer has been doing this for weeks?
Ed: If the light interruption happened only once it will have little or no effect on the flowers. If the timer had messed up regularly the flowers would appear stressed. They would be loose and stretched and might have an odd appearance. Hermaphroditism also sometimes occurs. If the buds appear normal, I think that that the light mishap was an anomaly.
Kelly (Wisconsin, U.S.A.): I live in the Midwest. If I plant seedlings outdoors in the middle of July how big a yield can I expect to receive from a plant that normally yields 400 grams in ideal conditions? Would the plants stay in vegetative state for 30 days, until mid-August, and then go into flowering?
Ed: If you were growing a sativa-indica hybrid the plant would resist flowering until mid-August. By that time it should grow large enough to produce three to four ounces of bud if it can survive the weather to maturity in mid-October. Indica and indica-sativa hybrids begin to flower in early August and will be ready in late September. They may remain fairly small, only producing a few ounces per plant.
WHEN TO FLOWER INDOORS
Keith (Norwich, England): I have 17 feet of grow space between the plant medium and the light. How tall should the plants be when I change the light cycle to flower? My plants are about 6 feet tall now and really bushy.
Ed: Height doesn’t matter. What is really important is that the whole garden area is covered with canopy. When light hits a solid surface such as a leaf it is absorbed and cannot be used again. So plants in a garden need not be tall but should be wide. The underbrush of tall plants, which receive little light, is not productive so why grow them?
Force the plants to flower when looking down at the canopy, you find that it covers about 2/3 of the garden surface. The plants will fill in the rest of the area during flowering.
TOO TALL FOR GREENHOUSE
Ann Spot (Rotterdam, Holland): I have 5 plants in pots in my greenhouse that have reached it’s ceiling. They have started to flower, so I'm afraid it’s too late to top or bend the stems. What should I do?
Ed: Letting the buds crash into the roof of the greenhouse will create a moisture crisis that will result in mold plaguing your plants.
Even at this late point bend the stems and then support the bends or creases with dowels or bamboo stakes so they stay upright. You may be also able to support the growth by tying the branches to the greenhouse structure.
Try to open up the space to light as you manipulate the plants so that as much bud as possible receives direct light.
Camille (Valencia, Spain): I was just given a 1000-watt HPS light, a 4 square foot tray and a tray with about 60 clones. Can I grow all the clones in the tray? What should I do?
Ed: Your tray can hold between 36 and 48 6-inch planting containers. Choose the healthiest, most vigorous plants to transplant, one per container. Choose a planting mix recommended at an indoor grow shop along with a complete vegetative fertilizer. Follow directions for use. Grow the plants for about two weeks under continuous light from the HPS. When the plants have grown up so they are almost touching each other, turn the light down to 12 hours and keep the plants in total uninterrupted darkness during this period. Apply “flowering formula” fertilizer as directed. Seven to nine weeks after initiating flowering the buds will ripen.
TWO PLANTS PER BUCKET
David R. (Internet): I am thinking of setting up a small four-plant wick system in a small crawl space under the stairs and I was thinking about putting two plants per 5-gallon container. What will happen? Will they thrive healthfully as long as there is a good medium and nutrient solution or should I use only one plant per pot?
Ed: Two plants growing in a 5-gallon container usually have a higher yield than a single plant. There are other advantages as well. With two plants the 5-gallon is covered faster because each plant has less space to fill. Eventually, the two plants fill the area more completely than a single plant. As a result the plants are ready to force flowering sooner and more buds are produced, increasing both the yield over a single plant and decreasing total growth time.
Connor (San Francisco, California): I found aphids colonizing my grow room. They are leaving behind exoskeletons visible in the picture of the leaf. How should I respond to this problem?
Ed: Your identification is correct. Your plants are under attack by aphids. Aphids are often herded by ants for their high sugar exudates, termed “honeydew.” If this is the situation you must eliminate the ants to get rid of the aphids. Ants are repelled and killed by the cinnamon and cloves. Herbal based pesticides such as ER’s Zero Tolerance and other brands eliminate aphids. You can make a water solution using one rounded tablespoon of a combination of cinnamon and clove powder soaked in a quart of lukewarm water for six hours. To get the extra killing power of the spice oils soak the powder in about 2 ounces of vodka for a few hours before adding the water. The oils dissolve in the alcohol. You can strain the mixture, but you can also use it with the powders.
Pyrethrum is a natural pesticide derived from plant flowers found in some commercial insecticides and anticides. Ant stakes and ant baits contain minute amounts of poisons, usually imoclad, that the ants carry back to the colony, resulting in community poisoning. The minute amount of poison is so targeted it is considered safe.
A tiny solitary wasp, aphidius coleman, lays a single egg inside an aphid nymph. The larva spends its life feasting inside the nymph, turning it into a mummified skeleton. When it matures it pops out “alien” style and is soon mature enough to mate and start laying. A single wasp can lay more than 300 eggs over its lifespan. Adults feed on aphid honeydew.