What to Do About Yellow Leaves on String of Turtles

String of turtles, also known by its scientific name Peperomia prostrata, is a popular trailing succulent loved for its rounded, textured leaves that resemble tiny turtle shells. However, despite their reputation as an easy-going houseplant, string of turtles can sometimes develop issues like yellowing leaves.

Don’t worry if you see that your string of turtles’ leaves are turning yellow. With some careful care, you can get the plant back to being healthy and happy. What makes string of turtles leaves turn yellow? This article will explain what causes them and how to fix them.

Overwatering

Excessive watering is one of the most frequent reasons for yellow leaves on string of turtles. As semi-succulents these plants prefer their soil to dry out a bit between waterings. If the soil is kept consistently moist the roots are prone to rotting which leads to the leaves turning yellow and dropping off.

Signs of Overwatering

• Leaves turn yellow or translucent
• Lower leaves drop off
• Mushy, brown stems
• Foul odor coming from the soil

Fixing Overwatering

• Stop watering and allow the soil to fully dry out before resuming
• Remove the plant from the pot and inspect the roots – trim any that are black or mushy
• Repot in fresh, well-draining soil
• Water less frequently going forward

Only water when the top few inches of soil become completely dry. Improve drainage by amending the soil with perlite or switching to a terra cotta pot.

Underwatering

While overwatering is more common leaving string of turtles too dry can also lead to yellowing leaves. If the soil dries out completely for an extended period it can stress the plant and cause the lower leaves to turn yellow and drop.

Signs of Underwatering

• Dry, cracked soil
• Wrinkled, drooping leaves
• Leaves yellowing from the bottom up
• Little to no new growth

Fixing Underwatering

• Water the plant deeply right away
• Check soil frequently and water when just the top few inches become dry
• Mist the leaves between waterings to increase humidity
• Move the plant to a shadier spot to reduce water needs

Try to keep the soil evenly wet, but not drenched. Increase watering frequency during hot, dry weather spells.

Inadequate Light

String of turtles requires bright, indirect light to thrive. Low light will cause the leaves to turn a pale greenish-yellow. Without sufficient light, the plant can’t photosynthesize properly and the leaves yellow due to lack of nutrients.

Signs of Too Little Light

• Yellowing leaves, especially on inner parts of vines
• Sparse, small leaves
• Leggy growth with more space between leaves
• Slow growth

Improving Light Conditions

• Place the plant in bright, indirect light like an east or west window
• Supplement with a grow light if indoor light is insufficient
• Rotate the plant periodically to expose all sides to light
• Prune leggy stems to encourage bushier new growth

Make sure your turtles get at least 4 hours of bright, filtered sunlight every day for the best growth.

Lack of Nutrients

An important cause of yellow leaves on string of turtles is insufficient nutrients in the soil. These plants need fertilizer to thrive since most potting mixes lack the essential nutrients on their own.

Signs of Nutrient Deficiency

• New growth is smaller and paler
• Older leaves turn yellow while new leaves remain green
• Plant looks healthy but has poor color

Fixing Nutrient Deficiency

• Fertilize every 2-4 weeks during spring and summer with a balanced houseplant fertilizer
• Switch to a potting mix amended with slow-release fertilizer
• Repot in fresh soil annually to replenish nutrients

When fertilizing, always use half strength and don’t overdo it. Stick to a consistent schedule for best results.

Environmental Stress

Stress from things like temperature extremes, droughts, or drafts can also make the leaves on string of turtles turn yellow. Stress drains resources from the plant which leads to nutrient deficiencies.

Signs of Environmental Stress

• Yellow lower leaves while upper leaves remain healthy
• Leaf loss or yellowing after changes in environment
• Failure to improve after fixing other issues

Alleviating Stress

• Provide stable temperatures between 65-80°F
• Shield plant from hot/cold drafts
• Keep plant out of direct sun in summer
• Maintain proper humidity levels of 40-60%
• Don’t let plant dry out completely

Minimize stress by keeping conditions stable and consistent. Give extra care while the plant recovers from stress.

When to Worry

A few yellow leaves here and there is normal and not too concerning. But significant yellowing of new growth or extensive leaf loss indicates a more serious underlying problem. Seek advice from your local greenhouse if yellowing persists after addressing all the common issues. Rapid leaf loss may be a sign of an incurable problem like a disease, virus or pest infestation.

Catching and correcting yellow leaves early gives your string of turtles the best chance of recovery. With attentive care and patience, your plant can regain its vibrant, healthy appearance!