Cannabis Nutrients: A Feeding Guide for Clones

Cannabis needs three primary nutrients (nitrogen, phosphorus, potassium) plus calcium, magnesium, and micronutrients. Feed heavier nitrogen in veg, then shift toward phosphorus and potassium in flower. Keep runoff pH at 6.0 to 6.5 in soil, 5.5 to 6.0 in coco or hydro, and start young clones at roughly quarter strength.

What cannabis actually eats

Plants pull macronutrients in the largest amounts. Nitrogen (N) drives green leafy growth. Phosphorus (P) fuels roots and flower sites. Potassium (K) handles water movement and overall vigor. Then come the secondary nutrients: calcium and magnesium, which growers chronically underdose. Cal-mag deficiency is the single most common problem we see in the mail, especially for anyone running coco or reverse-osmosis water.

Micronutrients (iron, zinc, manganese, boron, and a few others) matter in trace amounts. A quality bottled line already includes them. You rarely need to dose them separately unless your pH has been drifting and locking things out. When we ship a freshly rooted clone, it arrives with almost no stored feed, so the first two weeks of nutrition set the tone for the whole run.

Feeding by growth stage

A clone that just went into its first pot wants very little. Start around 200 to 300 PPM (roughly 0.4 to 0.6 EC) and watch the newest growth. As the plant fills the pot through veg, climb toward 700 to 900 PPM with a nitrogen-forward ratio like 3-1-2 or 3-1-3. Once you flip to 12/12 and stretch begins, taper nitrogen down and push P and K up, something closer to 1-3-2. During peak flower we run 800 to 1000 PPM, then flush or ease back in the final week or two.

Those numbers are a starting map, not gospel. Genetics, light intensity, and root zone all change appetite. A heavy indica under 1000 watts eats more than a light-feeding sativa in a tent. Read the plant, not only the chart. If you want the timing side of this, our flowering stages guide lines up feed changes with what the buds are doing.

pH is the gatekeeper

You can mix a perfect nutrient solution and still starve a plant if pH is off. When the root zone drifts outside range, specific nutrients lock out even though they are present in the water. Iron and calcium go first at high pH; magnesium and phosphorus suffer at low pH. Check every feed with a calibrated meter, not strips. We keep a full breakdown in the cannabis pH guide, and it is worth reading before you blame a bottle.

Medium	Target feed pH	Typical veg PPM	Typical flower PPM
Soil	6.2 to 6.8	500 to 800	700 to 1000
Coco	5.8 to 6.2	600 to 900	800 to 1100
Hydro / DWC	5.5 to 6.0	500 to 800	700 to 1000

How often to feed

In soil, we often alternate feed and plain pH water, letting the pot dry back a little between waterings. That rhythm keeps roots breathing and prevents salt buildup. In coco, plants like frequent light feeds because coco holds almost no reserve, so daily or multiple daily feeds are normal. Hydro runs a constant reservoir you check and correct every day or two.

Watch runoff EC. If it climbs well above what you feed in, salts are stacking up and you need a flush. If runoff reads lower than input, the plant is eating hard and you can nudge concentration up. This feedback loop beats any fixed schedule.

Reading trouble early

Yellowing that starts on lower, older leaves usually points to nitrogen moving up to new growth, common late in flower and fine then. Yellowing on new top growth points to an immobile nutrient like iron or calcium, often a lockout, not a shortage. Rusty spots, clawing tips, and burnt leaf edges each tell a story. We keep a full symptom chart in our nutrient deficiencies guide so you can match the leaf to the cause before you overcorrect.

Every technique here works better with strong genetics. Browse our rooted, HLVd-tested clones or start with forgiving beginner strains.

Frequently asked questions

Can I use one nutrient for the whole grow?

You can, but you will leave yield on the table. A single balanced bottle works in a pinch, yet cannabis clearly performs better when nitrogen leads in veg and phosphorus and potassium lead in flower. At minimum, run a grow formula and a bloom formula, plus a separate cal-mag if you use soft or RO water.

What PPM should a freshly rooted clone start at?

Keep it light, around 200 to 300 PPM for the first week or two. New roots burn easily. We would rather see a clone slightly hungry than tip-burned. As it establishes and pushes fresh growth, raise the strength gradually and let the plant tell you when it wants more.

Do I need to flush before harvest?

Many growers run plain pH water for the last one to two weeks to clear excess salts and improve the smoke. Others taper instead of hard-flushing. Either works. What matters is that you are not slamming full-strength bloom nutrients into the pot the day before you cut.

Why do my leaf tips keep burning?

Burnt, clawed tips almost always mean nutrient concentration is too high for that plant right now. Back off PPM by 20 to 30 percent, flush lightly if runoff EC is high, and confirm your pH is in range so nothing is stacking up unused.

Ready to start a run with genetics that are HLVd-tested and female-guaranteed? Browse our cannabis clones for sale and give your feeding program a healthy plant to work with.