Nitrogen deficiency

Lower leaves fade evenly pale, then yellow and drop, while new growth stays green. A little lower-leaf fade late in flower is normal.

Symptoms

• Older, lower leaves turn evenly pale green, then yellow, from the bottom of the plant upwards.
• Yellow leaves drop off.
• Slow growth overall, with smaller leaves.
• Late in flower, a gradual fade of the oldest leaves is normal as the plant draws on its reserves.

Quick checks

• Check feed and run-off pH.
• Check the EC against the chart for this week.
• Which week are you in? Late-flower fade is normal.
• Lift test for over-watering; check root-zone temperature.

How to fix it

1. 1
   Check

   Rule out pH, watering and cold first

   Check the basics first: feed and run-off pH (5.5–6.5), EC for this week, watering, climate and light. Most 'deficiencies' are uptake problems, not a lack of food.

2. 2
   Feed

   Feed to the chart

   In growth, make sure Grow A+B is at chart strength for the week, starting low and moving up as the plant responds. In flower, follow the Bloom chart.

3. 3
   Monitor

   Judge by new growth

   Change one thing at a time and give it 3–5 days. Damaged leaves won't recover.

Likely causes

• Feed too weak for the stage.
• pH out of range, so nitrogen isn't taken up.
• Over-watering or a cold root zone slowing uptake.
• Switching to Bloom too early, or not feeding enough volume.

What to avoid

• Don't panic-feed: overfeeding looks similar and makes things worse.
• Don't chase late-flower fade with extra feed.
• Don't change several things at once.

Prevention

• Follow the chart's EC for each week.
• Keep pH in range and calibrate your pen monthly.
• Water by weight.

Monkey products that can help

Grow A+B

The growth-stage base feed, with extra nitrogen for leaves, stems and shoots. Used at chart strength with pH right, true deficiencies are rare.

Follow the growth chart: equal amounts of Part A and Part B, added to the water separately and never mixed together neat.

View product →

Products support a healthy plant. They don't replace fixing the cause.

When to get help

If lower leaves keep yellowing after pH, EC and watering are all correct for a week, email info@monkeynutrients.co.uk with your pH, EC, medium and week.

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