Leggy growth on Plants

Symptoms

Leggy growth shows in the overall shape of the plant. One sign is leaves held on excessively long petioles. Another is stems with excessively long internodes.

A third sign is elongated stems with fewer leaves. You may also see the plant stretching toward a light source. Leggy growth is the term these sources use for this pattern of elongated stems.

Penn State Extension notes that some species tend to get leggy, with elongated stems and fewer leaves, when light is inadequate. The UC Statewide Integrated Pest Management Program lists leaves with excessively long petioles, or stems with excessively long internodes, as a symptom.

Check the stems for length, check the leaf stalks for length, and note which way the plant is stretching. The full list has three parts: long petioles or internodes, elongated stems with fewer leaves, and stretching toward light. If your plant matches one or more of these descriptions, the next sections cover causes and what to do.

Causes

The sources name inadequate or insufficient light as a cause of leggy growth. The UC Statewide Integrated Pest Management Program says these symptoms are usually caused by inadequate light. Penn State Extension also links leggy growth, with elongated stems and fewer leaves, to inadequate light.

Over-fertilizing is the second cause on the list. A plant that is over-fertilized can become leggy. Light and fertilizer are the two causes named, so those are the two places to look first.

A plant whose light needs do not fit the place where it grows is exposed to inadequate-light conditions, which cause legginess. A supplemental light source positioned far from the plant can make it stretch toward the light and become leggy.

Diagnosis

No cited source here names a look-alike for leggy growth, so this check uses only the symptoms and causes listed above. Start with the stems and see whether they are elongated and carry fewer leaves. Next, look at the petioles and internodes and ask whether either is excessively long. Then notice whether the plant is stretching toward a light source.

If those signs are present, the cause to rule in or out is inadequate light. Ask how far any supplemental light source sits from the plant, since a distant light makes a plant stretch toward it. Ask whether the light and temperature needs of the plant fit the place where it grows. Then consider fertilizer, because over-fertilizing can also cause a plant to become leggy.

What marks this problem is the combination of elongated growth and the two causes named, inadequate light and over-fertilizing. The description combines elongated stems, fewer leaves and stretching toward light. A plant that stretches toward a light source and has fewer leaves on elongated stems matches the description given by Penn State Extension.

Treatments

Every treatment listed for leggy growth is cultural. The UC Statewide Integrated Pest Management Program advises choosing plants whose growing requirements fit the environment. Light and temperature needs are the requirements it singles out. The aim is to avoid the inadequate-light conditions that cause legginess.

Penn State Extension says to keep your light source close to your plant. Positioning a supplemental light far away makes the plant stretch toward it and become leggy. Keeping it close avoids that stretching. As the plant grows larger, reposition the light source to keep it at an adequate distance. Moving the light as the plant grows larger keeps the distance adequate, which is the point of repositioning it.

Avoid over-fertilizing the plant, because over-fertilizing can cause it to become leggy. Fertilizer is the only factor besides light that the sources name, and the step for it is to avoid over-fertilizing.

Light-related steps cover three things. Choose a plant that fits its site, keep a supplemental light close, and move the light as the plant grows. The fixes work on the conditions that cause the problem: light and fertilizer. Choosing a plant whose light needs fit the site avoids inadequate-light conditions in the first place. No organic or chemical treatments are listed for leggy growth, so this page gives none.

Prevention

Prevention comes down to conditions: the light a plant gets and the fertilizer it receives. Match the plant to the place by comparing its light and temperature needs with what the site offers. A plant placed where light is inadequate is the setup that leads to legginess.

Where you add a supplemental light, set it near the plant rather than far away. Plan to adjust that distance when the plant grows larger. Avoid over-fertilizing, because it can make a plant leggy.

These sources give no fertilizer amount or schedule, so this page states none. Light and fertilizer are the two conditions the sources name as causes, and each has a matching step above. Stems stretching toward a light source are the cue to recheck how close the light is.

Plants most often affected

No plant page in this build records this problem yet.