ASA Grow Tips

Horticulture

Friday, December 18, 2009

By Americians for Safe Access

First time growers should start with a soil-based grow rather than hydroponics. You need to get a feel for the growth and life cycle of cannabis in order to have confidence that things are going well. Soil is more forgiving than rockwool or other hydroponics media. Micro nutrient balances, which are critical to proper growth and vigor, exist in soil naturally. Soil is inexpensive and not suspicious to neighbors who may wonder what all the equipment is for otherwise. Make sure that the soil is not too dense. Use perlite to lighten and loosen the soil. This provides necessary space in the medium for air. Air is an important factor in cultivating any type of plant.

Light

Get a high intensity discharge (HID) light. High-pressure sodium systems are the best for vegetative and flowering. Without a HID light, you will not produce dense buds. You may substitute fluorescent fixtures with warm bulbs (not cool white), but the yield from such a system would be low. Do not use a regular incandescent bulb - this will not provide the correct spectrum of light for the plants. Fancy specialty "grow bulbs" don’t have the intensity needed to grow dense buds, but they will definitely keep the plants alive.

Cannabis flowers form naturally outdoors in the fall, as the days grow shorter. Indoors, we can force cannabis to flower by creating a growing space where the light cycle can be controlled. 12 hours of uninterrupted darkness are necessary to force cannabis to flower. This period, known as the flowering period, continues for approximately 6-8 weeks depending on the strain of cannabis.

The vegetative period, which precedes the flowering period, is usually done (with clones) under 24 hours of continuous light. This period usually lasts from five days to two weeks depending on strain and vigor of clones. Plants will usually double in size during the change from the vegetative to the flowering period. You may want to make a note of that in order to accommodate the height and width of your garden.

Nutrients

There are three main nutrients that plants use: Nitrogen (N), Phosphorus (P) and Potassium (K). These will be noted on the plant food label with relative % numbers as N-P-K. A good balance for the vegetative cycle would be something with a high N ratio, such as 20-10-10. When changing the plants from vegetative to flowering (i.e. changing the light cycle from 24 hours of continuous light to 12 hours of light and 12 hours of uninterrupted darkness), the nutrient ratio must change as well. Plants use phosphorus to make flowers or “buds”. During the flowering stage, feed your plants a high phosphorus plant food. Something like 10-20-10 would be appropriate. Don’t get hung up on the actual numbers. It is the ratio that is actually important. Feed cannabis like a vegetable. Follow the instructions on the label and be careful not to overfeed!

Water

Water your plants whenever they are dry and not too often. Overwatering is a common cause of death to cannabis. Overwatered plants droop and look like they need water. The first reaction is to water a plant that looks droopy. What the plants are actually lacking is air. They are drowning and the last thing that they need is more water. One simple way to check for the proper time to water is to lift the pot that the plant is in after watering. Feel the weight of the watered pot and make a mental note. Next time you think the plant needs water lift the pot and see how heavy it is. If it feels light, then water it. If it feels heavy then don’t. Young plants will use less water. As the plant grows and the root ball fills the container, it will use more water.

pH

pH is a measure of the acidity or alkalinity of the root zone and water. In general cannabis likes the root zone to be acidic, around 5.6 - 6.3 is the range. You may want to get a pH test kit and check your tap water to see if it skewed in one direction or the other. If your plants are not thriving, are turning yellow or appear to be burning at the edges of the leaf, then you may need to consult a more exhaustive source of information about how to go about solving these problems.

Air and temperature

Cannabis needs fresh air. You will have to find a way to circulate the air in the growing chamber. Fresh air from the outside is the best. Fans will move air sufficiently in and out of the closet from the house. You just need to be aware. Without some kind of fresh air, plants don’t have the carbon dioxide needed to create new plant material. No fresh air, no CO₂, no big buds. Temperature is also a reason to circulate the air. HID lights create a lot of heat and high temperatures will inhibit growth. Keep the temperature between 75 and 85 degrees and you will not have growth problems related to heat. Too cold is bad as well, especially in the root zone. Under 60 degrees, the plant will be unable to take up nutrient properly and you will experience problems.

By keeping the basic needs of the plant in mind cannabis will reward you enormously. Light, food and water and air are all critical to the proper growth of the cannabis plant. Good luck!