Canna PK 13/14 is a cannabis nutrient used for only one week in the flowering cycle to boost phosphorous and potassium levels available to your plants. This encourages a rapid size increase in flowering buds.
The recommended feeding schedule for Canna PK 13-14 in the 4th week before harvest, which is the 5th week of flowering for an 8 week strain growing in coco coir. For a longer flowering strain, you need to adjust this to ensure you use it the 4th week before harvest. For example, on a 12 week strain you’d want to use Canna PK 13 14 at the start of week 9.
PK 13/14 is used as part of the full nutrient line by Canna. So you’d need to use it alongside Canna’s A and B fertilizers. It can be used for all mediums, including soil, coco, and hydroponic systems.
If you’re looking to grow weed in coco coir using Canna Coco nutrients, check out our Canna Coco feed schedule to learn more about how PK 13/14 should be used along with Canna Coco A & B, Rhizotonic, Cannazym, and Canna Boost.
Recommened dosage: How much Canna PK 13/14 should be used?
The recommended dosage of Canna PK 13/14 is 28 mL per 5 gallons of water according to the growth chart from their nutrient calculator website.
You use it for one week of watering only, the 4th week before harvest. It’s used during week 5 of flowering on 8 week weed strains. Avoid running longer than 1 week, and especially starting too early.
Use of PK 13/14 coincides with an increase in Canna’s A and B nutrients during that 5th week. This results in fast growth of the cannabis flowers.
After week 5 in an 8-week strain, PK 13 14 use stops and you will scale back the amount of Canna A and B as well for 2 more weeks, before the final week where you flush and use plain pH’d water.
Using small amounts of Canna PK 13/14 throughout entire flowering cycle
Some growers notice that using just Canna A and B base nutrients results in Phosphorus (P) and Potassium (K) deficiencies in certain strains. So they also use a light dose of Canna PK 13 14 outside of the one week recommended by the manufacturer.
For example, using 5-10 mL of PK 13/14 starting a few weeks earlier than the recommended 5th week has shown to reduce Phosphorus deficiencies.
Knowing when to use PK 13/14 during flowering will ensure that the pot plants receive a higher ratio of PK in their NPK percentages, which is something that the weed flowering process requires.
But less experienced growers should caution if using outside of Canna’s one-week-only recommended feed schedule. Using PK 13/14 too early may negatively impact bud growth. It’s best to watch for deficiencies in Phosphorous and Potassium and use a light dosage of early PK to address them, but never blast off the full dosage far in advance of that 4 weeks before harvest rule.
Going above the recommended dosage of PK 13-14 may also result in excess nutrients leading to nute burn, so monitor plants closely and keep a grow journal to best track what’s best time to use Canna PK 13/14 for the strain of marijuana you’re growing.
Additional considerations for Canna PK 13-14
The best time to use Canna PK 13/14 may vary a bit based on the strain and flowering rate which may vary based on the conditions of your grow room, so knowing when to use Canna PK 13/14 may vary accordingly.
If you do successive grows using the same strain of weed, make note of the final harvest date so you know the true finish time. Often this could be a few days or even a week later than you expected. Adjust the timing you start PK 13-14 accordingly and monitor the resulting buds to see if it helped.
When purchasing nutrients, if you’re running the full Canna line you’ll use much less PK 13 14 than you will all of your other nutrients. So you can get a smaller bottle of PK 13-14.
For example, if you plan to buy one-liter Canna A & B, Rhizotinic, Cannazym,and Boost, you’ll only need a 250 ml bottle of Canna PK 13 14. Or new growers can buy the complete set to get everything you’ll need to get started.
When to use Canna Boost and PK 13 14
Canna Boost is a flowering supplement that is meant to be used throughout the entire flowering stage for cannabis plants. PK 13 14 is only used for one week during flowering, typically week 5 on an 8-week strain.
Start using Boost when you flip the lights to 12-12. Or save some cash and start using boost when you first see indication of flowers appearing, usually about a week and a half after you flip the lights to initiate flowering.
I’ve had great luck growing plants with the Canna line and specifically using Boost. It has resulted in frosty, glistening buds and leaves and a sweet, earthy flavor that is a bit different than cloned plants grown by others using different nutrients. Combined in with a nicely dialed-in grow environment, getting your nutrients dialed in will really pay off.
Just remember that you need to know when to use Canna Boost and PK 13 14 at the right times for best results.
Using Canna PK 13/14 with autoflower weed strains
Determining the feeding schedule for Canna PK 13/14 can difficult for auto-flower strains.
If you’re using the Canna nutrient line for growing autoflowering weed strains, you’ll need to pay attention to when your flowers begin forming in order to calculate how far along you are in the growth cycle.
The vendor where you get your autoflower seeds should provide information on the likely flowering timeframe for these autoflower seeds.
Subtract 4 weeks from the total auto flower grow time to calculate the correct week to start adding PK 13/14 to your nutrient solution.