Gadenin日本語Get the app

Sunflower Not Growing Well: Causes & How to Fix It

Your sunflower is leggy, its leaves are small and curled, it stalled at a small size, or it is all leaf and no fruit. Stunted or odd growth almost always comes down to light, nutrients, roots, or a virus.

Check these first

  • Are the stems stretched with long gaps between leaves? That is a lack of light.
  • Are new leaves curled, twisted, or unusually small? Think virus or sap-sucking pests.
  • Are the leaves dark and lush but there are no flowers or fruit? That is too much nitrogen.

Most likely causes

From the pests and diseases recorded for this plant, the ones whose symptoms match, most serious first. Symptoms alone rarely confirm a cause, so use the linked page to check the signs and treatment.

Downy Mildew

Pale yellow to yellow-brown angular lesions form on the upper leaf surface with a gray-purple mold in the matching spot underneath. Lesions merge, the leaves die back and the plant declines early.

How to identify and treat: Downy Mildew

Crown Gall

Irregular galls form at the crown and on the roots, gradually enlarging and turning woody. They block the flow of water and nutrients, so the plant loses vigor and may die.

General description; not specific to this plant.

How to identify and treat: Crown Gall

Root Rot

Fine roots rot brown to blackish brown, growth stops and the lower leaves yellow. The plant wilts easily in the daytime and eventually dies outright.

General description; not specific to this plant.

How to identify and treat: Root Rot

Other possible causes

The three above are the causes on record for this symptom.

Other symptoms on this plant

What other growers did about it

A page like this one can tell you what sunflower not growing well is and what to try. What it cannot tell you is what actually happened to someone who had it on the same plant, at the same point in the season, and what they did next.

Gadenin is a free garden journal built around that. You photograph the plant, tag what you are seeing, and the entries line up by date for each plant you grow.

  • Tag the problem and the app tells you how many other growers have logged the same thing on the same plant.
  • Growers who make their records public can be followed, so you can read what they did and how it turned out.
  • Next season your own entries come back at the same point in the year, so you check the plant before it starts.

Free on iPhone. Recording, tagging and reading public records cost nothing.

Read next

Note the planting date and each feed. Growth that stalls after a heavy feed, or fruit that never sets, is easy to diagnose from a dated log.

See what other growers did about it

Log it in the free Gadenin app and tag what you are seeing. Your photos line up by date so you can tell whether it is spreading, and you can see how many other growers have logged the same problem on the same plant, follow them and read what they did next.

Free on iPhone. Android coming later.

Gadenin free garden journalGet the app