3

MAINTAINING

Your GARDEN

With beginner’s luck and a modicum of knowledge about growing plants, it is possible to grow a bumper crop of pot even on your first try. The trick is to produce a heavy harvest of pot on successive tries. One reason that might explain why beginners often grow a good first crop is a result of hybrid vigor. Most commercial cannabis seeds today are crossbreeds or hybrids that for the first crop grow stronger and heartier than the second generation plants will, and in subsequent crops clones will become successively weaker. But clones are so much cheaper and easier to deal with than starting from seeds that the advantages of cloning exceed the drawbacks. In order to compensate for the weakening of the plants over time it is imperative to take advantage of every trick in this book. It is tempting to take shortcuts, but avoid the temptation. Every little detail I have included is for a good reason. Now let’s get started.

pH Levels

Healthy plants are grown in soil or soilless mix with a pH level of around 7, which can be measured on a pH pen/meter (available from hydroponics stores for around $100). Such a pen is invaluable in growing plants indoors and allows you to monitor pH levels in both soil and water. Be sure to check the units of measure on the brand of pen you are using, as they may vary.

Check the pH of your water reservoir on a regular basis and keep it as close to pH 7 as you can. You can use pH up or pH down solutions (available at hydroponics stores) to balance your water to a reading of 7. Try not to put too much pH adjuster in the water at any one time. If you mess up and put in too much pH up, don’t put in pH down to rebalance the water. Better to drain your water and start over with clean water. Having a perfect pH of 7 isn’t useful if your solution has too many chemicals and not enough pure water. If after adding fertilizer to your water reservoir, you add pH up and then find that your final pH reading is 5.8 instead of 6.3 to 7 (the perfect range for pH) just leave things alone and go with that. If you try rebalancing with too much pH up or pH down, you may find your salts and pH meter readings are bouncing up and down and they may be unable to accurately read the final mix.

Ideally you must try to feed your plants a fertilizer and water mix that has been perfectly balanced to a pH of 6.3 to 7. Adding fertilizer to water will lower the pH of the water, so you’ll probably need to adjust it with a little pH up. Once you become familiar with the amounts of fertilizer and pH up required for your garden, start adding pH up before you add fertilizer. You will require less pH up if you add it before the fertilizer. It may require a little practice to become familiar with the levels of pH up and fertilizer required, but in time it will become second nature. A monthly check with a soil slurry will show a reading of the pH that has built up in your soil or soilless medium. Read further along this chapter for more information on how to conduct a soil slurry test.

Salts Levels

Salts levels indicate the strength of fertilizers and can be determined using an EC pen, also known as a salts meter, invaluable in growing healthy marijuana and at $100, a worthwhile purchase from the hydroponics store. EC or electrical conductivity indicates how much dissolved salt is in a given sample. That is why EC is also referred to as TDS (Total Dissolved Salts) or Salinity (the amount of salts in a solution). All nutrients are salts, so EC is the same as measuring total nutrients in a solution. The water in your reservoir should have no salts in it and thus show a 0 reading on your salts pen when tested. When fertilizer is correctly proportioned into the water reservoir your salts pen should show a reading no higher than 10 for budding plants (8 is ideal) or 14 for vegetative plants (12 is ideal). If you goof up your fertilizer mix and end up with too much fertilizer, add water to bring the salts/fertilizer level down or change the water and start over. If a slurry of one part water and one part soil tests above 5 on the salts pen, it means the plants are getting too much fertilizer. If it tests below 3, the plants are getting too little fertilizer. A slurry reading of 4 on the salts pen is perfect.

Feeding

Ever wonder why some weed is bitter and goes out all the time between puffs? The answer, in a nutshell, is fertilizer. Too much fertilizer will ruin your weed. How much and how often you feed your plants are perhaps the trickiest parts for novice growers. As I’ve mentioned, every two weeks is a good feeding schedule for indoor vegetating plants and every three weeks for indoor flowering plants.

Before testing your water pH and fertilizer levels, test your pH and salts meters for accuracy using a test solution (available at any hydroponics shop). Simply dunk your pH meter in a small glass of the pH 7 test solution and check the reading. If adjustment is needed, turn the adjustment screw on the meter until the readout number on the pen reads 7. Then you can test the pH of your water. The same goes for testing your salts meter. The correct salts test solution registers 10 on the meter. By adjusting the set screw, you can adjust your salts meter until it reads a perfect 10 in the test solution. The salts meter is much more reliable than the pH meter and keeps its settings longer between adjustments, but I still check it almost every time I use it. After testing or using your meters rinse them off in clean water before putting them away.

You are not supposed to reuse the salts and pH test solutions in case they have become contaminated. I make certain to change my testing solutions once a year.

It takes some practice to get the amount of fertilizer right, but it helps to do your experimenting outside of your water reservoir until you calculate the appropriate amounts.

I follow a simple procedure I recommend for anyone starting out. You’ll need:

Then follow these steps:

  1. Fill a two-gallon bucket with water from your reservoir.

  2. Add one to two teaspoons of pH up and stir the water.

  3. Following the directions on the label, add about three tablespoons of part one of the nutrient formula and stir.

  4. Following the directions on the label, pour another three tablespoons of part two of the nutrient formula and stir.

  5. Check the salts level with your salts pen. It should be between 10 and 12 parts per 1,000 (ppt), which will show as 10 or 12 on your salts meter.

  6. Measure the solution in the bucket with a pH meter. The pH should be between 6.3 and 7.0 on your pH meter. If either of these numbers is not reached, simply increase the amounts of pH up and/or fertilizer until the proper numbers are obtained, keeping track of the amounts. If pH readings in your test bucket are too high, do not add pH down to the water. Simply empty the bucket and start over with a fresh two gallons of water and put in less pH up to start.

  7. Once you reach the appropriate pH and salts levels, calculate how many two-gallon buckets are in your water reservoir. (In a 30-gallon reservoir, it would be 15.) Then multiply your two-gallon pH and fertilizer measurements by that number, and use a measuring cup to add the appropriate amounts of pH up and/or fertilizer to your water reservoir. Remember to always add the pH up ahead of your nutrients.

Do not expect to use the same water to fertilizer ratios when mixing bloom fertilizer as you do when mixing vegetative formula. Each fertilizer requires its own mixing ratios. After a few tries, it becomes relatively easy to get a perfect mixture of pH and nutrients.

If your fertilizer ratios are off, your plants will tell you. An unhealthy or overfertilized cannabis plant will look yellow and weak, often drooping its branches, and it might show signs of burning on the edges of its leaves, which can become reddish brown and dead looking. When a cannabis plant is seriously burned by overfertilizing, its leaves might become pock marked with dead patches. Underfeeding is sometimes indicated by red stems and branches, but when cannabis leaves turn red it is usually a genetic trait and not a sign of distress.

If your plants show any of these symptoms, or after several feedings you should test the pH and fertilizer/salts levels of the soil in your plant pots by making a soil slurry. Think of the soil slurry as a thermometer that measures the health of your plants. To make a slurry you mix one part of pH 7 room temperature water and one part soil until the soil has the consistency of molasses. Take the soil sample from the rootball of the plant rather than the surface of the plant pot, and don’t worry about tearing a few root hairs out in the process. Let the solution stand for several minutes; then strain the mix through a coffee filter and place your salts meter into the slurry to take a reading. If your salts reading is 4–6, your soil has the perfect amount of fertilizer.

If the salts reading is too high (above 8), rinse the plant soil with several gallons of water, and wait at least two weeks before testing with a soil slurry again. Keep testing every two weeks and do not begin fertilizing again until the salts readings drop to between 4 and 6 in your slurry test. You might want to use a clearing agent like General Hydroponics FloraKleen, which will dissolve away accumulated fertilizer as it releases the nutrient bond between plants and salts. The clearing agent can also be used in the final flush of your plants one week before harvest to wash away the bitter taste from heavily fertilized weed

If the salts reading is too low (below 3) in your ini-tial slurry test, increase the frequency of fertilizing without exceeding the strength of the fertilizer and water mix beyond 8 on the salts meter for flowering plants or 12 for vegetating plants. After several feedings under the increased frequency schedule, the salts readings in your soil should rise.

Also check the pH of your soil slurry with a pH pen. If the pH of your soil is too high, you can flush the soil with pH 7 balanced pure water and you can reduce the pH in your garden over time through subsequent waterings and feedings with a lower level of pH about 5–6. If the pH in your soil is too low (under 5), you can flush it with a deep watering of pure water and you should increase the pH over the next several feedings and waterings to about 8 on your pH pen. When soil readings have returned to normal, begin feeding plants again on a regular schedule and balance water and fertilizer to a perfect 7 on the pH meter. Take a soil slurry reading every month and at the first sign of any growth problems or yellowing of the plants.

Watering

Watering techniques are simple for container systems — when the soil dries out to about a third of the way down the container, water them. Usually, you will water your garden on scheduled days once or twice a week, but don’t wait until the plants are too dry. Lift each plant container before watering to determine how much water to give. Since plants use water at different rates, some will need more than others. If the container is light, give it lots of water. Give as much as the plant will take without water running out of the container’s drainage holes and overflowing the tray. Water lightly on the first go round — just enough to wet the soil at the top of the container. Then wait 15 minutes for the soil to expand to the sides of the container. Then water again. This deep watering allows the water to be absorbed into the center of the root ball without uselessly running down the inside of the container and into the tray. In a five-gallon plant pot, I normally water with one half gallon of water on the first round and a second half gallon on the second round. This deep watering method can also be used when fertilizing your plants.

I prefer using a hose, a submersible sump pump, and a wand for watering rather than lifting heavy buckets. The sump pump attaches to one end of your hose and drops into the 30- to 50-gallon watering container in your grow room. The wand attaches to the other end of the hose and is used for reaching faraway plants. I remove any spray heads from the wand using a hacksaw because I want only a soft, smooth flow of water that does not take as long as a spray nozzle does to fill the plant pots. I plug the power cord for the sump pump into a switched extension cord so I can turn the water flow on and off by flipping a switch. I always recommend wearing rubber-soled shoes to avoid any shocks on bare feet when using the power cord. With so much water in the room, some inevitably hits the concrete floor, and water can conduct some electricity into your feet when you switch on the power for the sump pump. Remove the sump pump from the water tank when not in use. Leaving it in the water all the time can ruin the seals. Whenever you use the sump pump to deliver food to the plants, rinse it afterward with fresh water to prevent damage to the seals. Just drop the sump pump in the fresh water and run it for a few seconds until the nutrients are flushed away.

If you notice any of your plants wilting between waterings, just top them up with water and don’t change the watering schedule of your entire garden. Some plants need more water than others, and some are missed on occasion during the watering cycle due to the effects of good reefer and just plain forgetfulness. Usually, the largest and strongest plants need the most water.

I have also used an outdoor watering timer to water my plants. The electronic timer is run by two AA batteries, which means it is not subject to electrical power interruptions. And this means the timer can be trusted to turn on and off over a given cycle if you want to go away on business trips or vacations. It takes a little practice to get the exact water flow rate by adjusting the tap, but after a few tries it becomes easy. The timer is connected to a hose that runs from the water tap to the grow room. Connect the grow room side of the hose to another piece of plastic hose called a manifold. Drip emitters are plugged into the manifold and feed water through ¼ “-thick individual plastic lines that run to each plant pot in the grow room. A visit to any hydroponics shop can provide you with the parts and expertise needed for setting up this type of drip line.

The drip line and timer setup should be used only for pure water, not for delivering hydroponics food to the plants. I recommend hydroponics fertilizers because they are the purest available and will not burn the plants like regular fertilizers, but even hydroponics nutrients will plug up the narrow lines and drip emitters over time. By hand watering and feeding, you can deliver the hydroponics food to just the plants that need it and avoid the ones that don’t. With a hydroponics drip system, all of the plants in the garden receive the same nutrients, even those that should not, such as plants almost ready for harvest or very young transplants. Hand feeding is still best.

A day or two after watering or fertilizing your container plants, use your fingers or a small rake to till the top few inches of soil in the pots. This breaks apart the crust that forms when the soil begins to dry out after watering, allowing the free exchange of air and gases that otherwise become trapped within the soil. The crust also causes a slower evaporation of the water from the soil, which results in a longer drying period between waterings which all translates into slower growth in your plants. While you break up the crust that forms on top of the plant pots, also run your finger around the inside top of the pot where the soil becomes compact. Breaking up this soil closes the gap between soil and container, ensuring that water won’t simply run down the sides.

Overwatering and Underwatering

If you overwater your plants, they will tell you. They will show sluggish growth, and the leaves will begin to turn yellow and then brown and then die. The soil will be constantly soggy. You might also find gnat flies in the soil and on the plants. If you happen to overwater, simply pour off the excess from the plant pot and then hold back on watering until the soil is dry to the touch at least a few inches below the surface. Then water and fertilize as usual on a regular two- or three-week cycle.

Usually, only one plant in the garden will show the first signs of underwatering. Look for a plant that is wilted and hanging listlessly compared to the other robust plants. A well-watered plant is firm and strong, with its leaves and branches held high and plump with water. An underwatered plant will look as though it is sick and dying, its branches drooping and the soil will be dry to the touch several inches down. Learn to anticipate the need for water before the plants wilt. If a plant wilts and is given water right away, say within a 24-hour period, it will recover with no ill effects. If a plant is allowed to stay wilted any longer than 24 hours, it might become sickly and never return to full health.

Insects

If you discover insect damage in your garden, buy a magnifying glass to identify which insects are damaging your plants. Once you have determined which pests are infesting your garden you may decide to order predator insects that will eat the offending pests. Although they can keep infestations down to some degree, I have never found predator insects to be effective in totally eradicating pests. As a general principle, check your garden once a week to see if there is any insect damage, searching under the leaves for the rotten little pests. Look for tiny spots or white specks on the leaves where the insects have been sucking the juices out of your plants. Look for any movement on the leaves as tiny insects fly or run away from you. Spider mites will spin webs in your plants if they breed heavily. If that ever happens you must remove the webs by hand before attempting any insect controls or treatments.

There are many insecticides on themarket, but every time you take a chance with a new insecticide you risk killing or setting back your plants. Some insecticides kill pests. Other insecticides kill both pests and plants. When cannabis plants are in flower, there is almost nothing you can do to eradicate insects that won’t hurt your plants. Best to pick the insects off by hand and then let nature take its course. Flowering plants are never far from harvest, and the best treatment for flowering plants with insect infestations is to pull them out of your garden when they are ripe or even a bit earlier and treat only the vegetating plants. Under-ripe marijuana can still be smoked and can provide a worthwhile buzz, although it is neither as sweet nor as potent as a fully developed plant.

I have a foolproof organic insecticide formula that kills all insects without harming my plants. It works on spider mites, thrips, gnats, and white flies, to mention a few of the most common indoor garden pests. Its active ingredient is Einstein oil, which is basically neem oil, from the neem tree, mixed with pyrethrums, which are made from chrysanthemums. Add a few drops of Safer’s Insecticidal Soap to the Einstein oil to help the solution stick to the plants. Einstein oil and Safer’s Insecticidal Soap are available at most hydroponics stores and garden supply stores and can be ordered online. Do not spray plants at the same time you fertilize, and remember, only spray cannabis in the vegetative cycle.

To make my all-natural insecticide, you’ll need:

Then:

  1. Add a few drops of Safer’s Insecticidal Soap to the water.

  2. Shake the room temperature Einstein oil vigorously and then mix with the soap and water solution.

  3. Pour solution into spray bottle.

  4. Shake the solution repeatedly and do so regularly while using.

  5. Spray the soil and wet the undersides of the leaves more than the tops.

  6. Wait 10 days and spray again.

  7. Keep repeating this cycle until all insects are gone.

This solution won’t hurt your plants. It is not so much the quantity or strength of the solution that you deliver to the plants that works — it is the repetition every 10 days. The first spray keeps the insects from breeding and kills most of the adults but does not damage the eggs. The eggs usually hatch within 10 days, so that is why you have to repeat the spraying cycle every 10 days. It might take several weeks or even months before every insect is eradicated, but eventually you’ll win the battle even if your plants were overrun with insects.

Yellow sticky cards are an excellent means of trapping insects and alerting you to pests. They can be purchased at any garden store, and as a general rule, I place a number of the sticky cards in with my vegetating plants but not so many in with my flowering plants.

If you use an air conditioner, insects are less likely to cause problems in your garden. They prefer warm, humid climates to breed in. Air-conditioned grow rooms are cool and dry like laboratories — a hostile environment for bugs and an excellent climate for keeping indoor plants healthy. Insects are attracted to weakened plants under stress, and air conditioners prevent plant stress.

When you discover insects, determine how they entered your garden in the first place, and plug that leak into your grow room. Then treat the insects as described above. To learn more about recognizing insects and insect damage, go to the library or research online for more photos and details.

Diseases

Diseases are occasional visitors to the indoor garden, and there are many known and unknown pathogens that can kill your plants or stunt their growth. Root rot. Fungal infections. Leaf spot. Disease is often brought into a sterile room on the soles of outdoor shoes and on dirty garden tools and other equipment. It stands to reason, then, that you shouldn’t share your cannabis garden tools with any other plants outside your grow room. If used equipment is brought into the grow room, it should be sterilized in bleach solution first. Also be sure to always use sterilized soil, so diseases aren’t carried from the outdoors to the plants.

Even if all the proper protocols are followed, insects can still carry diseases into your indoor garden, thereby infecting the plants. To treat any disease you find, clean and sterilize your room and then remove any infected plants and replace them with fresh, healthy plants. Don’t bother with fungicides for root rot or leaf spot or plant virus. Even when fungicides work the plants are often left permanently weakened by disease or virus. In extreme cases you might have to kill all your plants (including clones) and start a new garden from fresh seeds, although it is rare to have to go to such lengths. Usually, disease is aggravated by humid growing conditions, which cause your glasses to fog up when you enter the grow room. If that happens, install more vent fans or an air conditioner and everything will improve. For information on specific plant ailments, go to the library or on the Internet.

A good general principle when treating plants for any problem — whether it is overwatering, underwatering, insects, diseases, over- or underfertilization, high or low pH — is to be patient. Plants take a long time to react, so do not expect changes overnight and don’t keep pumping in the antidote to the problem. Go slow. Take time. Whenever there is a choice between doing too much or doing too little — choose doing too little.

Garden Maintenance Checklist

I suggest visiting your budding room and your vegetative room for a few minutes every day, just to keep an eye on problems before they become unmanageable. Use your five senses to discover problems. You will smell any electrical burning, plant ripeness, or plant rot in your room. You will hear any squeaks, squeals, and other strange noises from your grow equipment. Your eyes will alert you to plant health, insects, and lamp strength or burnouts. You will feel any heat buildup in the room. And your sense of taste will alert you to how well you have grown your product in the final test.

Aside from the feeding and watering we’ve already discussed, there are several tasks that should be done on a daily, weekly, or monthly basis. Use a calendar to keep track of feeding schedules and other information, such as breeding characteristics or individual plant health. Use plant tags that you stick into the soil to assign plant names or numbers to the plants in order to keep track of different species. The following checklist will help you keep track of tasks until you check them automatically.

Checklist

DAILY

WEEKLY

MONTHLY

BIANNUALLY

ANNUALLY