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

exposed. Extreme care must be exercised during transplanting.

This ‘Marley’s Collie’ (Sensi Seeds) is planted in a 5-gallon (19 L) bucket and was grown in a greenhouse.

MIDDLE: Strong healthy roots are vibrant white. Feeder roots are fuzzy white. This rooted clone is ready to transplant

LEFT: Male pre-flowers (a small nub above the fourth internode) develop on plants after about four weeks of vegetative growth.

This close-up shows female pre-flowers, white pistils growing from newly formed green calyx. Female pre-flowers usually sprout after male pre-flowers.

This large mother plant is growing in a 10-gallon (38 L) container. She can provide more than a hundred clones every month.
    Like the roots, the stem grows through elongation, also producing new buds along the stem. The central or terminal bud carries growth upward; side or lateral buds turn into branches or leaves. The stem functions by transmitting water and nutrients from the delicate root hairs to the growing buds, leaves, and flowers. Sugars and starches manufactured in the leaves are distributed through the plant via the stem. This fluid flow takes place near the surface of the stem. If the stem is bound too tightly by string or other tie-downs, it will cut the flow of life-giving fluids, thereby strangling and killing the plant. The stem also supports the plant with stiff cellulose, located within the inner walls. Outdoors, rain and wind push a plant around, causing much stiff cellulose production to keep the plant supported upright. Indoors, with no natural wind or rain present, stiff cellulose production is minimal, so plants develop weak stems and may need to be staked up, especially during flowering.
    Once the leaves expand, they start to manufacture food (carbohydrates). Chlorophyll (the substance that gives plants their green color) converts carbon dioxide (CO 2 ) from the air, water, and light energy into carbohydrates and oxygen. This process is called photosynthesis. It requires water drawn up from the roots, through the stem, into the leaves where it encounters carbon dioxide. Tiny breathing pores called stomata are located on the underside of the leaf and funnel CO 2 into contact with the water. In order for photosynthesis to occur, the leaf’s interior tissue must be kept moist. The stomata open and close to regulate the flow of moisture, preventing dehydration. Marijuana leaves are also protected from drying out by an outer skin. The stomata also permit the outflow of water vapor and waste oxygen. The stomata are very important to the plant’s well being and must be kept clean to promote vigorous growth.Dirty, clogged stomata would breathe about as well as you would with a sack over your head!
Pre-Flowering
    Cannabis grown from seed dawns pre-flowers after the fourth week of vegetative growth. They generally appear between the fourth and sixth node from the bottom of the plant. Cannabis plants are normally either all male or all female. Each sex has its own distinct flowers. Pre-flowers will be either male or female. Growers remove and destroy the males (or use them for breeding stock) because they have low levels of cannabinoids (THC, CBD, CBN, etc.). Female plants are cultivated for their high cannabinoid content.
Mother Plants
    Growers select strong, healthy, potent mother plants they know are female. Mothers are given 18-24 hours of light daily so they stay in the vegetative growth stage. Growers cut branch tips from the mother plants and root them. The rooted cuttings are called “clones.” Cultivating several strong, healthy mother plants is the key to having a consistent supply of all-female clones.
Cloning
    Branch tips are cut and rooted to form clones. Clones take 10-20 days to grow a strong healthy root system. Clones are given 18-24 hours of light so they stay in the vegetative growth stage. Once the root system is established, clones are transplanted into larger containers. Now they are ready to grow for 1-4 weeks in the vegetative growth stage before being induced to flower.

‘Haze Heaven’ female is starting to flower heavily. Branch internodes are shorter and white female pistils grow from calyxes.

Once the branch tip has been cut, bottom leaves are trimmed off before planting the clone, an exact replica of the mother plant

Clones grow a strong root system in 14-21 days under fluorescent light. Once rooted, they spend from 7-30 days in vegetative growth.

Male plants flower before females. Males show signs