Negative Points

Marijuana Horticulture

by Jorge Cervantes

Clones grow slower than F1 hybrid plants grown from seed. An F1 hybrid is the heterozygous first filial generation – pollen and ovule. F1 hybrids have “hybrid vigor” which means that this cross will grow about 25 percent bigger and stronger than cuttings. hybrid vigor also makes plants less susceptible to pest and disease problems

Always start with the best mothers you can find. A mother plant yields clones in her image. If the mother plant lacks potency, harvest weight, or is not pest and disease resistant, the clone shares her drawbacks. These weaknesses are compounded when growing only one strain. An unchecked pest or disease infestation could wipe out the entire crop.

Some growers have a difficult time learning to make clones. If this is the case, continue to work through the little problems one step at a time, and you will learn. Some people have a little longer learning curve when cloning is involved. Take five t ten practice clones before making a serious cloning. You can also work with strains that are easy to clone.

Plants that are easy to clone

Most Skunk and Indica strains are easy to clone. Growers and sick plants cause most clone rooting problems. Weak plants that lack vigor provide slow-rooting weak clones. Poor growing conditions also affect clone strength.

Plants that are harder to clone

Ruderalis Indica and Ruderalis Skunk do not make suitable mother plants due to their auto-flowering capability. Outdoor strains with a slight tendency to pre-sex in an 18hr photoperiod include: Early Girl, Early Skunk and many others.

Getting Ready

Cloning is the most traumatic incident cannabis plants can experience. Clones go thru an incredible transformation when they change from severed growing tip to a rooted plant. Their entire chemistry changes. the stem that once grew leaves must now grow roots in order to survive. Clones are at their most tender point in life now.

Clones quickly develop a dense system of roots when stems have a high carbohydrate and low nitrogen concentration. Build carbohydrate levels by leaching the growing medium with copious quantities of water t flush out nutrients. The growing medium must drain very well to withstand heavy leaching without becoming waterlogged. Reverse foliar feeding will leach nutrients from leaves, especially nitrogen. To reverse foliar feed, fill a sprayer with clean water and mist mother heavily every morning for three or four days. Older leaves may turn light green; growth slows as nitrogen is used and carbohydrates build. Carbohydrate and hormonal content is highest in lower, older, more mature branches. A rigid branch that folds over quickly when bent is a good sign f high carbohydrate content

Hormone content is different in different parts of the plant. Root growth hormones are concentrated near the base of the plant close to the main stem. This is the oldest portion of the plant and is where most root hormones are located. The top of the plant contains older hormones; cuttings taken from this part root slowly.

Small clones with few leaves root faster than big cuttings with many leaves. At first leaves contain moisture but after a few days, the stem is no longer able to supply enough moisture to the leaves, and the clone suffers stress. A small amount of leaf space is all that is necessary for photosynthesis to supply enough energy for root growth.

Precautions

An embolism is a bubble of air that gets trapped in the hole in the stem. Embolisms occur when you take big clones and lay them n the counter before placing in water or a growing medium. When an embolism happens, fluid flow stops, and clones die. After taking cuttings, immediately dip them in water or a growing medium to prevent air from getting trapped in the hollow stems. Eliminate the threat of an embolism by taking cutting under water.

Clones root well within a pH range of five to six. Aeroponic clone gardens normally do best with a pH of five to five and a half. Most diseases grow poorly below these pH levels. Always make sure there is plenty of air in the rooting medium; this will stimulate root growth.

Do not kill clones with kindness and fertilizer. At best, giving clones an excess dose of fertilizer causes rooting to be delayed. In fact, a good dose of ammonium nitrate, a common fertilizer, will stop root hair from growing.

If an infestation occurs, apply aerosol pyrenthrum. Remember, all pesticides, natural or not, are phytotoxic. Spraying cuttings is a bad idea in general. If you must use sprays, use natural organic sprays, apply them when it is cool, and keep their use to a minimum.

Use anti-desiccant sprays sparingly, if at all, and only if a humidity dome is unavailable. Anti desiccant sprays clog stomata and can impair root growth in clones.

Do not over-water clones. Keep the medium evenly moist, and do not let it get soggy.

Any kind of stress disrupts hormones and slows rapid growth.

Keep the cloning area clean. Do not take clones where fungus spores and diseases are hiding! Pythium is the worst! Pythium flourishes in high temperatures and excessive moisture. Mites, whiteflies, thrips, etc., love weak tender clones. Remove infested clones from the room. Cooler conditions, 65-78F, slow mite and fungal spore reproduction and allow you to avert an infestation.