Troubleshooting

Why are my leaves turning yellow?

Yellow leaves are your plant's way of talking — and the pattern of the yellowing tells you what it's saying.

Whole plant yellowing, starting with the oldest, lowest leaves

Usually nitrogen hunger or overwatering. Nitrogen is mobile, so a hungry plant robs its old leaves to feed new growth. Soggy roots cause the same look because drowned roots can't take up nutrients at all. Check moisture first: if the soil is wet, back off the water before you reach for fertilizer.

Yellow new leaves with green veins

That netted pattern — yellow leaf, green veins, worst on the newest growth — is classic iron deficiency, called interveinal chlorosis. And here's the catch: it's rarely a lack of iron in the soil. It's almost always pH. Above a pH of about 7, iron locks up where roots can't grab it. A chelated iron product gives quick cosmetic relief, but the lasting fix is bringing pH down (see our soil pH guide).

Yellowing with spots, streaks, or crispy edges

Now you're likely looking at disease, insect feeding, or scorch rather than nutrition. Snap a photo — or better, bring a leaf in a zip-top bag to the greenhouse — and we'll help you sort it out.