Sometimes relatively pale or fragile seeds can grow into the best plants. You can’t tell the quality of a seed just from looking at it. If in doubt, order quality seeds from a reputable cannabis breeder.

Plant Problems

What do I do if my plant runs into problems?

Look at pictures of sick plants and get solutions.

How do I get rid of gnats?

Fungus gnats are tiny annoying bugs that fly around your soil. You can use insecticide to kill them, but Fungus Gnats are a sign of a separate problem: the top layer of your medium is too wet. Make sure you only water when the top inch of your medium is dry, and don’t drench it. With good watering practices, Fungus Gnats simply can't reproduce and disappear.

Learn about other bugs and pests.

Growing Mediums

What kind of soil should I get?

Any quality potting soil can work. Don’t get soil with time-released nutrients (like Miracle-Gro soil) and don’t use dirt you find outside.

If you’re looking for a specific brand for growing cannabis, a lot of people like Fox Farms soil. If that’s what you choose, I recommend starting with Fox Farms Happy Frog soil and mixing the soil with about 30-40% perlite for a great cannabis soil starting mix.

Some growers use a soilless growing medium or potting mix, for example coco coir...

What about growing in coco coir?

Growing in coco coir is a simple type hydroponics that gets faster growth and bigger yields than soil. But since coco coir grows can be hand-watered, it feels a lot more like growing in soil than hydroponics. Learn how to get started growing cannabis in coco coir.

Smart pot (fabric container for growing cannabis)

What type of container should I use?

Any plant container should work. For the easiest growing, I personally recommend getting a smart pot (a growing container made out of fabric). That’s what I use. They deliver more oxygen to the roots to help increase growth and prevent problems like overwatering.

Learn more about different cannabis growing containers.

How can I get started with hydroponics?

Learn about the different hydroponic methods and jump right in!

Cannabis Nutrients & Supplements

Do I need special nutrients to grow cannabis?

Fox Farms nutrient trio is a good nutrient system for growing cannabis Yes and no. Cannabis plants have two stages of life and it is important they get the right nutrients at the right time. When using liquid nutrients, use a “Grow” nutrient formula for the first stage of life, and a “Bloom” formula when buds are forming.

Nutrients from the store can be used, but many growers believe you’ll get the best results by using a cannabis-friendly nutrient system.

Here are NPK ratios to help you pick the right nutrients if you can't get one that’s specifically formulated for a plant like cannabis. “N-P-K” are the three numbers listed on every nutrient bottle.

Veg/Grow - High N, Medium P, Medium or High K.
Bloom/Flower - Low N, Medium or High P, Medium or High K

Note: Don’t use anything with time-released nutrients like fertilizer spikes, or Miracle-Gro soil - they deliver too much N in the flowering stage.

I don’t pay attention to pH, but I keep running into nutrient problems. Is pH really that important?

Yes. Managing pH is the #1 way to prevent nutrient deficiencies when using properly formulated liquid nutrients.

Can I use tap water to water my plants?

Cannabis plants are not that picky about water as long as your nutrients are right and there's not too much salt. Many growers can use their tap water. If your local tap water is toxic to plants and can’t be used, you can use filtered or RO (reverse osmosis) water. If using RO water, make sure to supplement with a Cal-Mag (calcium & magnesium) supplement to make up for the lost minerals that normally come in tap water.

Can I grow cannabis with Miracle-Gro?

Here’s a question: why don’t you brush your teeth with baking soda? Baking soda definitely works, but the problem with it is that we already have something much better that’s more specialized to do it’s job.

Miracle Gro can grow cannabis to the vegetative stage(it has too much Nitrogen for flowering), but why not use something that’s meant to do this job?

In short: Get some nutrients that works well for cannabis. It’s worth the few extra dollars!

Do “finisher” additives (sugar, molasses, ‘big bud’ type additives) work?

They probably won’t hurt your plant, and they may help, but there’s no real evidence either way (at least not yet!)

Which nutrients make the biggest buds?

This is a trick question. Nutrients keep plants healthy, but light makes buds. You need nutrients to prevent nutrient deficiencies, just like humans might need a multivitamin.

As long as your plant is healthy, you will generally increase yields by providing all parts of the plant with enough light. This is easier with plant training. Light is like “food” for your plants.

Cannabis & Light

How much light do I need?

Cannabis plants need bright light... but not too bright Outside your plant needs 8+ hours of direct sunlight a day for the best results. The less light your plants get, generally the lower your yields.

Indoors, you need bright grow lights to get cannabis to produce a lot of bud, but smaller lights can also be used to produce great cannabis - just in smaller amounts.

Growing practices like plant training can often dramatically increase yields indoors. Using your indoor grow space wisely can make the difference between harvesting 4 ounces or harvesting 16 ounces in the exact same setup.

Should I get LED grow lights? Which model is the best?

LEDs can grow great cannabis, but there are many sellers who make bold, untrue claims about what LED grow lights can do.

LEDs are efficient light sources and come with built-in fans, which can make it easier to disperse heat in a small space, but they’re not magical. If a claim sounds too good to be true, it probably is!

LED grow lights DO NOT consistently produce bigger yields than a HPS grow light of the same wattage (at least not as of the year 2014), but LEDs do have other possible benefits like increased terpene and resin production. Learn more about LED grow lights.

Increasing Yields

What’s an easy free way to increase yields indoors?

Master plant training so it's easier to get light to all parts of your plants. Keep grow lights the correct distance from the top of your plants. Generally you want to keep indoor grow lights as close as possible without causing heat problems or light burn.

Do CO2 Bags Work to Increase Growth and Yields?

No. They won’t hurt your plants, but they won’t help them grow faster either. Learn how to do CO2 right.

Does "defoliation" (plucking leaves) help or hurt growth/yields?

It's an understatement to say there is a lot of controversy about defoliation. Some growers swear it increases yields, others swear it actually hurts yields. Most people agree that first-time growers should not pluck leaves.

As for my experience, I have gotten good results with defoliation in the flowering stage to expose bud sites on leafy plants. If bud sites are already exposed, or if plant is not particularly healthy and leafy, I personally recommend against defoliation.

Is it worth it to Re-Veg?

Is it worth it to "re-grow" a plant after it's been harvested?

Re-vegetating means harvesting a plant, leaving some green growth left, then switching the plant back to the vegetative stage for a second much smaller harvest. Seems good on paper, but this technique gives you much less control of your plant in addition to more time taken and smaller yields. Every grower I know who's tried re-vegging has said it works, but they'll never do it again.

Short answer: It works, but it's not worth it!

Cannabis Gender & Life Stages

How long until plants start making buds?

Cannabis starts making bud in the flowering stage (the second stage of life). However, nearly all cannabis plants need to get 12 hours of darkness each day to be in the flowering stage. Learn more about cannabis life stages.

How long does it take to grow weed?

Why do most growers want female plants?

Only female plants make buds. Learn more about male and female cannabis plants.

Where do I look to tell the sex of a plant before it starts flowering?

You can’t. There’s no way to tell the gender of cannabis by looking at the plant in the vegetative stage. Unfortunately growers (and scientists!) have been trying to figure this out for decades and no one has been able to find a way that definitively tells you one way or the other. You either have to wait until the plant starts flowering to separate males from females, or you can start with clones or feminized seeds (so all the plants end up female).

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