How do I know if my outdoor Cannabis is flowering?

There's really no mistaking a fully flowering weed plant from a vegetating weed plant. Your pretty cannabis girls are beginning to smell. They're getting a lot of sticky resin on the buds growing all along their branches. Plant energy is focused now on bud production instead of leaf and branch expansion. Remember how small your plants were just two months ago? If you have any pictures of them when they were young go back and look at them because the rate that weed grows is really astonishing. You're about halfway to the finish line now, and while the flowering phase of cannabis is more challenging than the vegging phase, it's also more fun because you get to see your marijuana growing on the branch. It's like growing corn that you can smoke!
Flowering cannabis plants in an outdoor setting
These organically-grown cannabis plants are in the flowering stage. Treat them well and they'll provide you great marijuana in a couple months.

Ok so my Cannabis is flowering. What should I expect?

Your plant will continue growing buds all along the branch. When these individual buds grow into a large group they're called colas and they will lengthen and thicken, with the biggest colas being located at the ends of each branch. Ultimately, your cannabis will reach a peak ripeness at which point you will harvest your outdoor cannabis.

How do I take good care of my flowering Cannabis plant?

A flowering cannabis plant needs to be treated with more care than a vegging plant. All of your pruning should be done now because cuts to your plant now take on added significance: if your flowering plant thinks it's dying prematurely due to heavy pruning it can potentially become a hermaphrodite and pollinate itself, drastically lowering the potency of your buds. Budworms now become a very real threat and daily inspections plus weekly spraying is required to keep them away. Humid or rainy days can allow bud rot (botrytis) to grow on your buds, and windy days can break the heavy, bud-laden branches off your plant.

Can you make a Cannabis Flowering guide for me to follow?

My job is to get you to the end of your first grow with homegrown outdoor cannabis for smoking, and if it takes another guide to do it then dammit, I'm making you a guide for flowering cannabis!
Gardener inspecting his cannabis plant
Daily inspection for bugs and disease is vital if you want to grow the best outdoor cannabis

How to Care for your Flowering Cannabis

  • Stake your plants if you haven't already. Remember that the rounded end of the stake goes in the soil.
Your buds are going to get heavy on the branches so you'll need a way to support the plant in the wind. The earlier you stake your marijuana plants the better, since staking can damage the roots a bit. Make sure you stick the rounded end of the stake into the soil (not the flat end) and insert it slowly to minimize root damage.
  • Perform daily inspections for insect eggs and damage. Spray your plants regularly for pests.
Spider Mites and Budworms are the biggest threats to your cannabis in flower and you'll need to read and reread the Cannabis Pest Control section to make sure you know what bugs to look for and how to get rid of them when you find them.
  • Don't spray anything on your flowers on humid days. Humidity creates an ideal environment for botrytis to grow in flowering cannabis. Adding more water to your leaves and flowers makes it more likely for botrytis to gain a foothold.
Frankly, you never need to spray your leaves with water except for pest control. All the moisture your plants need is in the soil, but if you're just dying to spray your leaves with water make sure you absolutely do not do it when it is humid outside because that will create an environment for mold to grow on your buds. Also, don't spray water on your plant in direct sunlight since that can cause your leaves to burn.
  • Your large fan leaves will begin to yellow and fall off. This is normal.
Your flowering cannabis plant will draw energy from the fan leaves to use for increased bud production. The leaves will wither and fall off. Each plant you grow has its own personality so don't sweat it if they all aren't dropping leaves at the same rate or at the same time. I've had some plants drop hundreds of leaves and other plants drop single-digits; leaf-dropping behavior depends on the plant.
  • Prevent Bud Rot
Botrytis likes to colonize on decaying vegetation so keep the area around your plants clean. If you pruned any leaves but left their little leaf stem attached to the plant, remove those leaf stems to prevent botrytis from forming there. Gather up any leaves falling off your cannabis plant, plus any other leaves you have lying around, and take them away from your garden. If you have leaves on the plant that are brown, remove the brown part of the leaf. Wash your hands and clean your gardening tools regularly with alcohol to avoid transmitting disease between plants.
  • Inspect your Cannabis for signs of Bud Rot (botrytis) weekly
During your daily plant inspection, look for any smaller bud leaves (not fan leaves) that are brown, crispy, or otherwise look different than the other leaves you're used to seeing. Hopefully you never find a bud leaf like that but if you do, the bud that leaf is connected to likely has gray mold (botrytis). Gently pull on that leaf until the attached bud pulls away from the stem and bud cluster. If you see gray buds or black stems then you have bud rot in that location. Follow the steps below to remove the bud rot:
  1. Be gentle. You don't want any spores to become airborne and infect a different part of your plant.
  2. Gently cut the affected bud off and remove it from your grow location. Place it in a bag, close the bag and trash it.
  3. Clean your hands and trimmers with alcohol.
  4. Reinspect the cut location on the plant to make sure you've removed all the bud rot. Remove anything in that area that looks suspicious...better to be safe than sorry with bud rot.
  • Look for signs of Budworm / Caterpillar damage to your Cannabis each day
This is covered in-depth in the Cannabis Pests section but it's worth repeating. In my experience growing cannabis outdoors in Southern California, budworms are the single worst cannabis pest and will do the most damage if left unchecked. Would you like it if your most beautiful outdoor cannabis colas were lost to an arrogant, gluttonous budworm? If you don't stay on the lookout for budworms that just might happen. Make sure you read the pest control section for budworms and follow a regular regimen of plant inspection and spraying to keep these guys off your plants. Indicators of budworm damage include bud sites turning brown, though much like the symptoms of bud rot you may see a single dead bud leaf. When you inspect those bud sites, look for sand-grain sized balls that are black or brown. That's caterpillar poop, and you have a problem. The good news is that you can usually find the worm by following the poop around the buds. The bad news is you MUST find that worm, otherwise he'll just keep eating and eating into your buds. Budworms bore a hole down into your buds. Once you've found the worm, escort him off of the premises and feed that fucker to the birds. Cut away any buds that are dead and remove any worm poop you see, as these will eventually mold.
A budworm on a cannabis plant
This is what a budworm looks like on a cannabis plant. Terminate...with extreme prejudice.
  • Support your branches to prevent breaking off
As your primo cannabis colas begin to swell late into flower, they may be too much for the branches to handle. Everything might look fine until an unexpected windy day arrives and causes the heaviest cola-bearing branches to break or topple over. This is easy to prevent with some gardener's tape tying your branches to your stake. There are many methods you can use to secure your branches so just choose one that you're comfortable with. Make sure you do it though, you don't want to wake up one morning to see your favorite cannabis cola lying on the ground.

Ok Ron I have a handle on this and my pot plants are doing great. Please tell me when to harvest my cannabis plants!

Once September comes rolling around you should begin reading my section on when to harvest your outdoor cannabis. You'll still have a couple weeks minimum before your actual harvest occurs, but the actual time you harvest your outdoor cannabis will be based on many different indicators. You'll primarily look at the trichromes under a loupe to determine when to harvest your plants, but you also need to look at the swelling in your buds, the color and behavior of the bud hairs, and the overall plant appearance. If you have the time, grab some tea and head on over to the Harvesting Cannabis page now. See you there mang!