Creating the proper feeding schedule for cannabis plants, combined with cannabis light schedules for the different stages of growth, makes a massive difference in their performance. In this article, we explain how a cannabis feeding schedule impacts growth, yield, and quality and why cannabis plants need a nutrient plan.
Also, we discuss what to consider for an optimal nutrient schedule, cannabis light schedules during the different stages, common mistakes to avoid when making a custom nutrient plan, and our top tips to help you achieve the best possible results as an indoor cannabis grower.
Why a Feeding Schedule for Cannabis Is Important
Cannabis plants require primary, secondary, and trace elements to grow into healthy, productive, and large-sized plants. Knowing exactly what nutrients a cannabis plant needs at the different stages of its life cycle will allow you to perfect the feeding schedule. Imagine a fridge full of food, with everything you need ready to accommodate the plants to avoid over feeding or underfeeding cannabis.
Understanding Cannabis Nutrient Needs at Every Stage
| Class of nutrient | Nutrients |
| Primary Nutrients | Nitrogen, Phosphorus and Potassium |
| Secondary Nutrients | Calcium, Magnesium and Sulphur |
| Trace Elements | Zinc, Iron, Boron, Copper, Cobalt, Molybdenum, Nickel and Manganese |
Cannabis Feeding Schedule – The Seedling Stage - 18/6
During this stage, cannabis seedlings are delicate and will require primary, secondary, and trace elements, but only in small amounts. The reason is that the roots are only beginning to form and will not have the capacity to absorb high amounts of nutrients.
Too many nutrients or a high EC level can cause nutrient burn and stress in seedlings. It may result in strange growth patterns as far as leaf formation and stem elongation are concerned. This is also a good reason to check if you are growing seedlings in soil that contains too many nutrients and is classed as ‘hot soil ‘because it can burn plants. Aiming for an EC level between 0.8 – 1.2 during the seedling stage is optimal to achieve the correct levels of cannabis nutrition.
● The cannabis lighting schedule is typically set to 18 hours of light and 6 hours of dark.
● Growers should aim for an EC nutrition level between 0.8 and 1.2.
● pH levels should be between 6.0 and 7.0 during the seedling stage.
Cannabis Feeding Schedule - The Vegetative Stage - 18/6
Cannabis plants surpass the seedling stage after 14-21 days and then enter the vegetation stage. By now, roots are beginning to spread out, and the plants will be on their 3rd—4th internode. During the vegetative stage, cannabis plants produce leaves, stems, and branches and prepare themselves to grow as much foliage as possible before flowering is induced.
Nutrients should be rich in nitrogen and lower in phosphorus and potassium to promote new leaf growth and give plants a healthy and vibrant green shine. Secondary and trace elements are also essential; however, aiming for an EC level between 1.2 and 1.8.
● The cannabis lighting schedule is typically set to 18 hours of light and 6 hours of dark.
● Growers should aim for an EC nutrition level between 1.2 and 1.8.
● pH levels should be between 6.0 and 7.0 during the vegetative stage.
Cannabis Feeding Schedule - The Flowering Stage
Once a timer is set to 12 hours of dark and 12 hours of light, plants will produce growth hormones and auxins and stretch upwards. Cannabis plants can double or even triple in height, depending on the strain. After 14 days, flowering plants will focus all of their energy on flower production, producing pre-flowers that reveal the plant’s sex.
At this stage, growers should lower the amount of nitrogen and increase phosphorus and potassium, as well as secondary nutrients and trace elements. The EC level should now be between 1.8 – 2.0 for the best results and to ensure that plants do not experience nutrient burn or toxicity.
● The cannabis lighting schedule is typically set to 12 hours of light and 12 hours of dark.
● Growers should aim for an EC nutrition level between 1.8 and 2.0.
● pH levels should be between 6.0 and 7.0 during the flowering stage.
Cannabis Feed Schedule - Flushing Cannabis Plants
During the final two weeks of the flowering stage, it is very important to cut off all nutrients and allow the plants to use up their internal reserves stored in the leaves and roots. Plants need to be flushed to remove any undissolved salts that have accumulated over the duration of the vegetative and flowering stages. This will also dramatically improve the taste and how the dried buds burn when smoked.
Using pH-balanced water in the range of 6.0 – 6.8 is best for soil-grown cannabis, and the EC level can range from zero to 0.5. Checking the runoff solution from the base of the pots is the best way to determine how many nutrients and salts remain in the growing medium. Enzymes like ATAzyme are proteins that catalyse reactions. They also help to flush out the soil by breaking down starches, carbohydrates, and nutrients as recommended by R.Q.S.
● The cannabis lighting schedule is typically set to 12 hours of light and 12 hours of dark.
● Growers should aim for an EC nutrition level between 1.8 and 2.0.
● pH levels should be between 6.0 and 6.8 during the flowering stage.
Cannabis Nutrient Schedule - Tools and Equipment
To ensure total control when feeding your cannabis plants, the most accurate way to know the exact pH and EC levels is to use specific tools and equipment. Below is a list of everything you will need to keep in your grow room and use every time you prepare your nutrient solution and test the runoff.
● Plastic measuring jug/watering can
● Nutrient bottles
● A calibrated digital EC pen
● Digital pH pen or pH test strip kit
● A plastic saucer to collect the runoff solution
● A feeding chart guide, such as Atami grow guides
Creating a Cannabis Watering Schedule
How much water you feed your cannabis plants will depend on their stage, the cannabis light schedule, temperature and humidity, and how dry the growing medium has become. As covered below, there are several ways to create the ideal watering schedule and when and how much water to feed your cannabis plants.
1. Lifting the pot off the ground to see how light it is before watering.
2. Insert your finger down the pot’s side to feel how dry or moist it is.
3. A measuring jug is used to know the amount of water to give.
4. Watering the plants at the same time each day, 1-2 hours when the lights turn on.
5. Checking the pH levels of the water source before saturating the growing medium.
6. A digital EC pen checks if the nutrient EC levels are optimal.
How a Cannabis Feeding Schedule Impacts Growth, Yield, and Quality
● A well-made and followed schedule will ensure that your plants receive the exact amount of nutrients needed for the seedling, vegetation, and flowering stages.
● Under fertilized cannabis plants, leaves will feel paper-thin and weak, and plants will show deficiencies. Yellowing leaves, brown spots and crispy leaves will be a clear sign of underfed cannabis.
● Using low EC levels during pinnacle flower development will result in low-yielding cannabis plants.
● The overall quality of your crop will reflect whether the plants were hungry or overfed. Underfed plants will always underperform during the final four weeks of the flowering period, and overfed plants will result in a harsh-tasting crop that burns with black ash.
3 Common Mistakes to Avoid with a Feeding Schedule for Cannabis
Now you have an awareness of the different nutrients cannabis plants need and the recommended pH and EC levels, some mistakes can still occur, which can set you back as an indoor grower. Below is a list of 3 common mistakes to avoid.
Over Fertilizing or under-fertilizing cannabis plants
Over- or underfeeding plants is easy and has a massive effect on plant health, vigour, terpene, trichome, and flower production. The best way to avoid over- or underfeeding cannabis is to work within certain pH parameters and pay close attention to how your plants look and whether the leaves are wilting or showing signs of nutrient deficiency.
Nutrient lockout
pH acts like a gatekeeper for nutrient uptake and availability. No matter what the EC level of your nutrient solution is, if you do not meet the requirements for the correct pH levels (6.0 – 7.0 for soil), then the plants will experience a nutrient lockout.
Not checking EC levels
To avoid overfeeding, always use an EC or TDS meter (total dissolved salts) to accurately measure the strength of your nutrient solution before feeding, as advised by M.S.N.L.
Atami's Top Tips for the Best Cannabis Nutrient Schedule
Following Grow Guides
Our first tip is to follow the instructions provided on the nutrient bottles. When using Atami nutrients, we recommended checking out the Atami grow guides and keeping a printed-out version in the grow room as a reference when making a nutrient solution.
Planning a Grow Journal
Recording and writing down every step of your indoor growth is a great practice. This way, you can look back on future grows and determine where you possibly went wrong. Creating a cannabis grow journal will make you a better grower and allow you to learn from any mistakes you may make after every harvest.
