Cannabis Feeding Schedule Chart: The Short Answer
A feeding schedule chart is a stage-by-stage table. It maps each phase of growth to a nutrient strength, a root-zone pH, and a feeding frequency. Seedlings want weak food. Vegetating plants want steady nitrogen and a rising dose. Flowering plants want less nitrogen and more phosphorus and potassium as the weeks pass. That is the whole idea. Everything else on the chart is detail.
Treat the numbers below as a starting line, not a finish line. Strain, container size, light intensity, water hardness, and growing medium all pull the chart in different directions.
cannabis nutrients schedule for hydroponics
Baseline numbers by stage
- Seedling and clone (weeks 1 to 2): plain water, or a quarter-strength mix. EC 0.4 to 0.8. PPM 200 to 400 on the 500 scale. pH 5.8 to 6.2 in coco or hydro, 6.0 to 6.5 in soil.
- Early veg (weeks 2 to 4): EC 0.8 to 1.2. PPM 400 to 600. Feed every other watering in soil, every watering in coco.
- Late veg (weeks 4 to 6): EC 1.2 to 1.6. PPM 600 to 800. Nitrogen stays high. Calcium and magnesium start to matter here.
- Transition (first 10 to 14 days of 12/12): hold veg strength, then ease nitrogen down while phosphorus climbs.
- Peak flower (weeks 3 to 6): EC 1.8 to 2.4. PPM 900 to 1200. This is the heaviest feeding window in the whole grow.
- Ripening (final 2 weeks): EC 0.4 to 0.8, or plain pH-adjusted water if you flush.
What the columns actually mean
Most charts show four things: a product dose per gallon or liter, a target EC, a target pH, and how often to feed. The dose column is a suggestion from a nutrient company that wants to sell nutrients. The EC column is the one that matters, because it describes the actual concentration of salts hitting your roots. If the chart says 5 ml per gallon and your water is already hard, that 5 ml can land you well above the target EC.
When to Start a Cannabis Nutrients Schedule
PPM scales trip people up
There are two common PPM scales, 500 and 700, and they are just different ways of converting the same EC reading. A solution at EC 2.0 reads 1000 PPM on a 500 meter and 1400 PPM on a 700 meter. So a chart that says "feed at 1000 PPM" may be assuming either one. This is why experienced growers work in EC and ignore PPM altogether. It removes the ambiguity.
Cannabis Nutrients Schedule for Beginners
pH does more work than any bottle
Nutrients you pour in are not nutrients the plant can take up until pH puts them in range. Too high and iron, manganese, and zinc lock out. Too low and calcium and magnesium drop off. Keep hydro and coco between 5.5 and 6.2, and soil between 6.0 and 6.8. Check pH after you mix, not before, since nutrients themselves drag the number around.
How often to feed
- Soil: feed, then plain water, then plain water, then feed again. Rich amended soil may only need feeding in mid to late flower.
- Coco: feed every watering, with a plain cal-mag watering every week or two to rinse salt buildup.
- Hydro and DWC: nutrients are always present. Top up with fresh solution, and swap the reservoir every 7 to 10 days.
Mistakes I see most
- Running the maximum dose printed on the bottle. Start at half and work up.
- Mixing by volume and never checking EC.
- Chasing runoff numbers. Runoff tells you about salt buildup, not what the plant wants today.
- Jumping from 600 to 1200 PPM overnight. Ramp over several feedings.
- Forgetting that tap water already carries calcium and magnesium.
- Flushing too early and starving the buds during the last swell.
Autoflowers and other exceptions
Autoflowers run on their own clock and usually do fine at 60 to 70 percent of the numbers above. Keep them on a light veg feed longer, since they flip to flower on their own schedule rather than yours. Sativa-leaning plants tend to want less, heavy indicas and large containers tend to want more.
Read the plant, not just the chart
Dark, waxy leaves with tips curling down mean too much nitrogen. Crisp brown edges mean salt buildup. Pale new growth with green lower leaves points to a pH lockout rather than hunger. When the plant and the chart disagree, the plant wins. Ease back, give plain water for a cycle, and start again lower.
One last note: cultivation rules vary by state and by county. Check what your area allows before you set up a garden.