string of turtles · Asked on Instagram · 3 November 2026
Why is my string of turtles not growing under a grow light?
String of turtles usually grow more slowly than string of hearts and also like a bit more consistent moisture. In the photo the plant looks healthy but very newly rooted in a very gritty mix, so let it establish, keep it just slightly more moist, and give it bright but gentler light than the string of hearts.
The question
“Advice please. What am I doing wrong that my string of turtles is not growing? It’s sitting right next to my string of hearts, which is growing like crazy under the same grow light gets the same care including fertilizer not overwatering differences one is in a plastic pot with draining holes. The other one is in a ceramic pot. This is my first string of turtles and I see people whose plant grows like crazy. What am I doing wrong?”
What's likely going on
From the photo, the string of turtles (Peperomia prostrata) looks healthy but very young and close to the soil, with lots of tiny leaves and a very coarse, fast‑draining mix. That suggests:
- It’s still establishing roots. Freshly rooted or recently divided turtles often sit and “do nothing” for weeks or months while they build roots. Most of the growth is happening underground.
- The mix may be a bit too dry for this plant. Compared with string of hearts, turtles like slightly more consistent moisture. A very gritty, rocky mix under a strong grow light can dry so fast that they just “hold” instead of growing.
- Light may be a bit intense. Under very bright light, turtles stay small and compact and focus on survival, not long trailing growth. They naturally grow on the forest floor, so they don’t need as much intensity as string of hearts.
Nothing in the photo screams disease or rot, so this is more about dialing in care and giving it time.
What to do
- Check the roots (once). Gently slide the plant out of the pot. If roots are short and sparse, it’s just young—re‑pot back and be patient. If they’re circling, it may want a slightly bigger pot.
- Adjust watering. For turtles, water when the top 1–2 cm of mix is dry but the lower part is still faintly moist. Don’t let it stay bone‑dry for long stretches.
- Consider the soil mix. If the pot dries out within a day under the grow light, mix in some fine potting soil or coco peat so it holds moisture a bit longer while still draining well.
- Soften the light. Move it a little farther from the grow light, or give it bright indirect light instead of intense direct rays.
- Go easy on fertilizer. Use a weak, balanced fertilizer no more than once a month during active growth. Turtles are sensitive to salts and don’t speed up much with heavy feeding.
How to prevent it
- Use a small pot with drainage and a mix that’s airy but not pure grit.
- Keep a light, regular watering rhythm instead of long dry periods.
- Place turtles where light is bright but filtered; they don’t need as much as succulents.
- Repot only when the root ball is clearly full; being a bit root‑snug is fine.
When to worry
- Leaves shrivel, curl, or turn crispy even though you’re watering regularly (too much light or under‑watering).
- Stems or leaves become mushy, black, or smell bad (over‑watering/rot – reduce watering and check roots).
- Growth suddenly stops and older leaves yellow quickly (check for root rot, pests, or fertilizer burn).
If the leaves stay firm and patterned, it’s mostly patience—string of turtles is just a slower, fussier grower than string of hearts.
Answered by the GrowPls assistant. Every plant and room is different; if things don't improve, a clear close-up photo of the affected part is the fastest way to a better answer.
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