part0017

Throughout this book, we’ve discussed the three primary growth stages of marijuana plants—seedling, vegetative, and flowering—and how a plant’s needs change throughout these phases. Much like hormonal teenagers require a special brand of diplomacy, your plants require a special mix of light, water, nutrients, and temperature depending on their growth stage. In this section, we’ll arm you with specific knowledge of each of these factors so you’re ready to manage each stage.

In Step 7: Germination, after the seeds were popped and/or transplanted, we ended up with a cotyledon. Once the cotyledon produces the first set of serrated leaves, it’s considered a seedling. It remains a seedling until it produces a growth with five or seven blades. This typically takes about 10 days from germination. The seedling is highly sensitive and only starting to form the root system that will act as an anchor for the plant above it.

The seedling stage can also be called the early or pre-vegetative stage. Like in the vegetative stage, plants in the seedling stage prefer light in the cooler, blue part of the spectrum. The seedling stage is ideal for the use of compact fluorescent lights or CFLs, discussed previously in Step 3: The Light . If using high-intensity lighting at the seedling stage, make sure there is enough distance between the light and your plants. Many growers use lighting schedules of 18 hours on (light) and 6 hours off (dark) or 20 hours on and 4 hours off. Start with 18 hours on and 6 hours off during the seedling stage. Once the plants have grown hardier, they’ll be able to take more intense light in greater amounts. Your seedlings should experience somewhere between 4,000 and 7,000 lux during this early stage of growth.

You’ll want to use water with as close to zero ppm TDS and a pH of 7 as possible during the seedling phase to eliminate mineralization of your water or improper nutrient uptake. Your plants should generally need watering every two to three days. Pot sizing can have a big impact on how often you water. Avoid having your plant in too large a container where the soil stays wet for long periods of time or too small a container where the soil dries up too quickly from an overabundance of roots. Be careful not to overwater at the seedling stage, as it’s easy to do. Allow the top inch of soil to dry out between waterings. This forces the roots to go seeking water, expanding their network and stabilizing the plant in the growing media.

Your growing media should have all the necessary macronutrients and micronutrients your plant needs to thrive for its first couple of weeks. Some growers opt to use a mild starter solution such as Clonex to give their seedlings an additional edge. Beyond this, wait until the vegetative stage to start any fertilizing program. Young seedlings can easily be given too much fertilizer and suffer from toxicities. Rarely will a plant that suffers during the seedling stage reach its full potential in size and bud yield. Remember that less is more at this stage, especially when it comes to nutrients.

Seedlings like a warm, humid environment. Air temperatures should be between 75°F and 78°F, with relative humidity around 70 percent. Depending on your setup, the heat from your lighting may be enough to bring about these temperatures, or you may need some additional help. Many growers leave their seedlings under domes, and others use small space heaters or heaters in their ductwork. The air temperature shouldn’t fall below 60°F during the dark periods, so factor this in if you are relying on heat from the lights.

Once your plant has been established for a couple of weeks, developed its root system, and produced true leaves with seven blades or more, it is officially in the vegetative phase. During this phase, the plant will put all its energy into increasing its biomass: the leaves, stems, and branches that make up the basic structures of the plant. This main growth stage will determine how big your plants get and how much bud weight they’ll be able to support. Your plants will remain in the vegetative stage for as little as 2 weeks or as long as 14 weeks, depending on the strain or inherent features such as autoflowering. Most plants can remain in the vegetative state in perpetuity if the photoperiod doesn’t change. With purchased seeds, you’ll know the breeder’s recommendation as to the length of the vegetative stage, so you can schedule when to make the switch to flowering. The key is that the plant be sexually developed and strong enough to support and carry the weight of the flower. Also consider the height available in your grow space. Cannabis plants will often grow 60 to 70 percent or more in size during the flowering stage. For example, if you have 6 feet of available height, you should switch to flowering when your plants are 3½ to 4 feet in height if possible.

As we discussed in Step 3: The Light , your marijuana plants are looking to receive 10,000 to 50,000 lux of blue spectrum light throughout the vegetative stage. It is at this point many growers will switch their lighting from the CFLs used on seedling to HIDs, such as metal halide or high pressure sodium, or LEDs. Vegetative plants require intensive lighting to grow their fullest and fastest. Some growers maintain the 18 hours on and 6 hours off lighting schedule of the seedling stage, but many switch to 24 hours on and remain with this schedule until flowering. Remember that plants will not flower until lighting has been adjusted to 12 hours on and 12 hours off. This means you can keep cannabis plants in vegetative states in perpetuity by giving them at least 13 hours of light time. Some growers keep “mothers” in a constant vegetative state this way and take cuttings as needed in order to create flowering plants.

You should find a rhythm to watering your plants in the vegetative stage. As mentioned, there are various factors that compete to dictate the watering needs of your plants. As they grow, their roots will take in water more quickly. Familiarize yourself with the weight of a recently watered plant by safely picking up the pot periodically. You’ll only need to elevate the pot a few inches to get a sense of the weight. When you have an idea of the weight the plant should be, use this as a benchmark to determine if your plants need watering. Set a regular watering schedule, such as watering every two to three days, and follow it throughout the vegetative stage. But still continue to monitor individual plants, and adjust your schedule if and when necessary.

The vegetative phase relies heavily on nitrogen for new growth and biomass. You’ll remember that nitrogen is the first of the macronutrients indicated in the standard nutrient profile (see The Big Three ). A good profile for a fertilizer for the vegetative state might be 6-4-4 (containing 6 percent nitrogen, 4 percent phosphorus, and 4 percent potassium) or 10-5-7 (containing 10 percent nitrogen, 5 percent phosphorus, and 7 percent potassium). In addition to nitrogen, your plants need a complement of micronutrients too. Most nutrient fertilizers with an NPK ratio also contain micronutrients, as do many soil mixtures. Elements such as boron, iron, magnesium, and molybdenum are critical to the metabolic processes of cannabis plants but are only needed in minute amounts.

Your air temperature should remain where you set it in the seedling stage, namely 75°F to 78°F, but you can lower humidity to the 50 percent RH level (humidity was discussed in Step 4: The Environment ). These are the perfect environmental conditions to grow happy, healthy “vegging” plants. You’ll want to maintain these balmy conditions until flowering, as they are ideal for biomass growth. Avoid any large temperature swings in your environment during the dark periods, if applicable. Your plants should never experience air temperatures lower than 60°F. Temperatures above 80°F will result in slower growth for most strains.

HOW TO UP-POT YOUR PLANT

Once your plants’ roots have fully expanded in the soil, you will want to transplant or “up-pot” them. Do this when your plants have four or five sets of leaves, and again about two weeks before the vegetative stage ends. If you’re unsure when to transplant, check the root development. The roots should penetrate the soil in a tight network but not be too dense. Also check drain holes to see if roots are outgrowing the container. Use clean hands or gloves and keep the process and work area as sanitary as possible.

FOLLOW THIS PROCESS:

1. Prep the larger pot. Select the appropriate size of pot, and fill it with growing media. Make a hole in the medium that will allow the plant to maintain the same surface level it had in its original pot.

2. Wet the media. It should be moist throughout but not overwatered and soggy.

3. Remove the plant from the original pot. Try to transplant when your plant is midway between watering cycles (when the soil is slightly moist but not dry and crumbly). Turn the plant on its side, grip it by the base of the stem, and gently extract the root ball.

4. Place the plant in the bigger pot. Place the plant in the center of the hole in the new pot. Do not force it or you could damage the delicate roots. Make the hole bigger if you need to.

5. Fill it up with your media. Fill in the gap around the circumference of the plant. Do not add soil on top of the existing soil in the root ball; plants will suffer if they experience a change in soil depth.

6. Add water. Water lightly but thoroughly with a mild rooting solution, and return the plant to its enclosure. Wait at least two weeks after transplanting before initiating flowering.

EQUIPMENT LIST:

• Clonex or similar rooting solution (optional)

• Growing media

• Large containers—typically one to five gallons, depending on what you are transplanting

• Water—reverse osmosis (RO) or deionized (DI) preferred; as close to zero ppm TDS as possible

That powerful moment when you decide to induce flowering is upon you. Make sure your plant is in a big enough pot for the roots to continue to develop for the next two to eight weeks (throughout the completion of the flowering stage). For autoflowering varieties (see here ), flowering will start automatically sometime after two weeks into the vegetative stage, so you don’t need to worry about inducing flowering. For regular seed varieties, when you change your lighting schedule to equal light and dark periods (12 hours on and 12 hours off), you’ll be changing the direction of the life cycle of your plant. Your formerly vegetative plant will transition to flowering and start producing buds. This is an exciting milestone. Your plant should be experiencing greater light intensity than in previous stages; up to 75,000 lux is appropriate for the flowering stage. Be certain you have no light leaking in during the dark period of your lighting schedule, as this can confuse the plant and induce hermaphroditism, in which the plant will have both male and female reproductive parts. A single “hermie” can pollinate and ruin an otherwise great crop (see Sexing Plants ).

Continue to water with your growth solution from the vegetative stage for the first week of flowering to allow your plants’ nitrogen need to fade before switching over to the blooming solution you will primarily use throughout the flowering stage. Your plants are getting bigger, with more developed root systems, and now they need to bring in enough water to support those huge buds they’re growing. Because of this, your plants will take in more water than they did in the vegetative stage and will tend to dry out faster. Stick to a regular watering schedule, but continue to monitor for signs of underwatering, such as droopy leaves or a slight yellowing of fan leaves. Keeping the humidity lower for pristine bud development will also increase the need for watering. Your plants are pretty hardy at this stage, so, depending on your container, you can usually let the top two to three inches of soil go dry between waterings. You want to be careful not to overwater because standing water can lead to bud rot.

Remember that flowering plants have less of a need for nitrogen and more for phosphorus and potassium. Phosphorus and potassium are major players in the development of buds and trichomes, so you want to give your plants copious amounts of these elements throughout the flowering stage. For impressive flowering, try a fertilizer with a 2-8-4 or similar nutrient profile. Be sure to flush your plants with water one week prior to harvesting. Flushing removes salts and other compounds that have built up throughout the cultivation process and has been shown to greatly improve the quality and flavor of bud. Keep a healthy dose of micronutrients available to the plant through the growing media or fertilizer.

In the flowering stage, your plants will prefer conditions a little cooler and drier than in previous stages. The ideal temperature range is 68°F to 75°F. You’ll want to bring humidity down to about 40 percent RH to encourage buds to develop with as much resin and as many sticky trichomes as possible. Some growers reduce RH all the way to 30 percent for the final week of flowering prior to harvesting to force even more resin. Be careful not to shock your plants with cold in dark hours. Hours of cold temperatures can slow or stop bud development. Continue to make sure the air temperature doesn’t fall below 60°F, but keep in mind your average temperature is lower in the flowering stage, so you have less room for error.

TAKEAWAYS & EQUIPMENT LIST

Great job! You’re in the homestretch. Just another couple of steps to go and you’ll be smokin’ with the big dogs!

In Step 9: The Care, we talked about:

• The lighting, water, nutrients, and temperature needed for the seedling, vegetative, and flowering stages

• The right time and method for up-potting your plants

SHOPPING LIST FOR PLANT CARE

Clonex or similar rooting solution (optional)

Growing media

Large containers—typically one to five gallons, depending on what you are transplanting

Water—reverse osmosis (RO) or deionized (DI) preferred; as close to zero ppm TDS as possible

In the next step, we will start to get into more advanced topics, including pruning, sexing, cloning, and pest management. You’re doing a great thing by learning to cultivate marijuana for yourself and at this point should have a decent understanding of a complete growing operation. This is a good time to go back and review anything you want to know more about. Stick with us, and we’ll soon have completed this first and most important book in your journey in the knowledge of cultivation.