Dear Danko: Expert Grow Advice from the High Times OG

Crowded pots, female pre-flowers, hybrid vigor, light leaks, and more.
Dear Danko: Expert Grow Advice from the High Times OG
Liudi Hara/ Shutterstock

High Times’ cultivation specialist Danny Danko answers all your burning questions about being the best grower you can be. But first, some quick tips from the expert himself:

  1. Use a light meter to measure whether you’re getting the minimum 6,000 lumens per square foot at the canopy level.
  2. Always check pH levels after you’ve added all the nutrients to your liquid plant-food solution.
  3. Dead leaves and plant debris on floors are a breeding ground for pests. Keep all growroom surfaces clean at all times.

Subject: Two Plants, One Pot
From: CG

I’m a beginner grower and I stupidly put two plants too close together in a midsize pot. I knew it was time to transfer them to a larger pot, and when I did so the roots were tangled. I tried to untangle them without harming them, but it just couldn’t be done. I knew that if I kept on messing with them I would make them really sick. They are now slightly in shock, but they don’t seem to be goners yet. Anyways, is it okay that the roots are tangled? Also, what can I do to bring them back up to health? I appreciate your time, man.

Dear CG,

Planting more than one cannabis plant in the same container is ill-advised and less than ideal. As you mentioned, the roots become tangled, and they will also compete for nutrients in your medium while the plants up top will also compete for light. This will result in significantly smaller yields than if the plants were in their own pots and not crowded together. At this point, I wouldn’t recommend separating them due to the stress that it can inevitably cause. Chalk it up to a lesson learned and remember in the future to “keep ’em separated.”

Subject: Praying Mantis
From: Bugging Out in Butte

A friend of mine told me that having a praying mantis in the growroom can help kill harmful bugs. Is this true?

Dear BOB,

Indeed, carnivorous praying mantises (or mantids) love to eat many of the insects that plague our ganja gardens, and they are one of nature’s most voracious garden protectors and a great organic alternative to chemical pesticides. Pests like aphids, white flies, and spider mites and their eggs make hearty meals for these predators. You can purchase mantis eggs online and have them delivered as pods containing up to 150 or more babies that will eventually hatch in warm weather or in your warm growroom. Once they’ve eaten their fill, they’ll want more food, so you’ll need to either feed them more bugs or send them on their way. It’s quite fun to watch them attack the vegetarian pests!

Subject: Drain to Waste
From: David H.

I’ve been growing hydroponically using a flood-and-drain system for some time and would love to see some info on drain-to-waste systems. Are they more or less efficient? What are the reasons that some growers choose to run nutrients through only once?

Dear David,

Hydroponic systems can either utilize the recirculation of nutrient solution, such as in your flood-and-drain unit, or drain to waste for watering purposes. The difference is that the first method waters your roots over and over with the same liquid, and the second method only uses the liquid once before it’s discarded. Both techniques each have their own benefits as well as some drawbacks.

Recirculating systems such as the flood-and-drain method you’ve been using simplify the watering process by reusing nutrient solution over and over for 1 to 2 weeks before being replaced. The pH level and the amount of nutrients (parts-per-million, or PPM) will vary and change as the plants use up water and food. Reservoirs must be replenished with fresh water and nutrients and be monitored at all times for variations in conditions.

The advantage of using a drain-to-waste system is that it prevents the spread of diseases, pathogens and root rot, and it negates the typical pH fluctuations of recirculating hydroponic systems. Drain-to-waste systems work best in gardens with a few plants in large containers rather than in gardens with many smaller plants bunched together. Even though it sounds like it’s inefficient (partly because of the word “waste” in its name), this type of system can actually end up costing less due to the level of control the grower has over the feeding process. If you use only a little more than the plants need, the actual “waste” is minimal in a well-dialed-in system.

Subject: Female Pre-Flowers
From: Vasco De Ganja

How can I tell what the sex of my plant will be before the flowering stage has begun?

Dear Vasco,

You need to examine the node where the leaves meet the stems and look for the pre-flowers. Male pre-flowers look like tiny spikes with balls on the end, and female pre-flowers look like tiny teardrop-shaped pods with white hairs sticking out.

Subject: Hybrid Vigor
From: Coinspinner

I have a question about breeding cannabis. Does the term “hybrid vigor” imply that we’ve bred out this strength from repeated back-crossing and the resulting loss of the second gene copy? I believe this is like the concept of “purebred” dogs, in that to get a true breeding strain you must cleave off the second copy by breeding back to a parent.

Dear Coinspinner,

Hybrid vigor is the result of crossing two unlike strains, such as a sativa from Africa and an indica from India. Also referred to as the “F1 cross,” the seeds from this pairing will perform with more gusto than either of their parents. The F2 and further crosses will not result in hybrid vigor—only the first filial generation will benefit from the vitality and strength of growth produced. The best seed breeders sell F1 crosses with hybrid vigor as these make the best mother plants for future clone gardens.

Growers wishing to take advantage of hybrid vigor on their own would benefit from reading up on breeding theory, terms and techniques. Two great books to begin with are Robert Connell Clarke’s Marijuana Botany: An Advanced Study: The Propagation and Breeding of Distinctive Cannabis and Greg Green’s The Cannabis Breeder’s Bible: The Definitive Guide to Marijuana Genetics, Cannabis Botany and Creating Strains for the Seed Market.

The second breeding technique you’re referring to is called back-crossing, wherein a particular strain is “crossed back” to its parent or even its grandparents. This is done in order to stabilize genetics when you’re growing out large populations and choosing wisely for desirable traits. Each subsequent generation should be more and more consistent in producing plants with the qualities you desire whether they are potency, flavor, odor, yield or bud structure.

Subject: Harvest Time
From: Zach’s Dad

I have a plant that’s about 2 feet tall. It started flowering early for some reason, but it’s budding beautifully at this point. It’s been raised strictly outside and it’s my first time trying to grow anything. My question is: How will I know when it’s the right time to harvest? Right now, there are about 25-30% red hairs. Is it too soon?

Dear ZD,

The amount or percentage of red hairs is not an accurate way to judge the proper time to harvest your plants. The best thing you can do is to get a magnification device such as a loupe or microscope that will give you a closer look at the actual trichomes on your buds.

Typically referred to as “crystals,” trichomes are actually glands filled with essential oils made up of cannabinoids such as THC, CBD and CBN, as well as flavinoids and terpenes. They look a little bit like clear little mushrooms with a stalk and a bulbous head. These gland heads can be separated and pressed together to make hashish.

As harvest time approaches, the gland heads will turn from clear to cloudy white, and then eventually amber as they begin to mature beyond ripeness. If you harvest when some of the gland heads are still clear, you’ll get a more uplifting high. If you wait until most are amber, the effects will be more lethargic. It really comes down to personal preference, but most people prefer them when they’re cloudy—that’s when the THC levels are at their highest with no degradation.

Subject: Light Leaks
From: Jordan C.

I have a closet grow box and two of my plants turned hermaphrodite on me. I asked some people and they all told me that light somehow must have gotten into my box. I believe them because the two plants affected were closest to the door. My question is: If such a small amount of light can do this to a closet grow, how do people keep their outdoor plants from turning hermaphrodite when there’s a full moon or bright stars? I’m going to grow a couple plants outside and would like to know if I need to cover them at night!

Dear Jordan,

It is true that light leaks can cause female plants to become hermaphrodites and exhibit male flowers, potentially seeding your whole crop with practically useless beans instead of sinsemilla (“without seeds” in Spanish) buds. If the plants receive strong light during their “night” cycle, when the lights are supposed to be off, they react with shock and the resulting stress can manifest itself in hermaphroditic tendencies. A small amount of dim light is usually insufficient to cause this reaction and it tends to happen more often when bright light interrupts the dark cycle.

Outdoors, the natural night cycle includes light from the moon and bright stars that does not affect the plants because they’re not bright or shocking enough by themselves. Only a street light or motion-detector light could really disrupt the outdoor dark cycle, as plants are accustomed to withstand small and dull amounts of natural outdoor light throughout the night. Avoid planting near artificial sources of light, but don’t worry about the naturally occurring glow of the moon and stars.

Need advice on growing and harvesting cannabis? Send your Q’s to

This feature was published in the July 2018 issue of High Times magazine. Subscribe right here.

1 comment
  1. The tops of branches (Where buds will be) are turning purplish to almost black. What is causing this?

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