How to Fertilize String of Turtles

Peperomia prostrata

Reviewed by Kiersten Rankel M.S.

Quick Answer

Use a balanced liquid fertilizer (10-10-10 or 3-1-2) diluted to quarter strength. Feed once a month during spring and summer. Stop fertilizing entirely in fall and winter when growth slows.

When Should I Start Feeding My String of Turtles?

Because String of Turtles is grown indoors in most climates (zones 10a–12b), feeding timing follows seasonal light levels more than outdoor temperatures.

Pacific Mar–Sep

Mountain May–Aug

Midwest Apr–Sep

Northeast Apr–Sep

Southeast Mar–Oct

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How Often Should I Fertilize My String of Turtles?

Feed once a month during the active growing season, roughly April through August. This slow-growing plant doesn't need frequent feeding, and more is not better here.

Taper off in September and stop completely by October. String of Turtles goes semi-dormant in winter, and fertilizing during low-light months leads to salt buildup in the soil.

If you notice the leaf patterns fading or growth stalling in summer, a light feeding can help. Yellowing lower leaves or crusty white deposits on the soil surface are signs you've been feeding too much.

Feeding Calendar

Spring & Summer

Quarter-strength liquid fertilizer once a month

Early Fall

Skip or one final quarter-strength feeding in September

Late Fall & Winter

No feeding

What Is the Best Fertilizer for String of Turtles?

A balanced liquid fertilizer with an NPK ratio around 10-10-10 works well for String of Turtles. This semi-succulent Peperomia doesn't need heavy feeding, so balanced nutrition supports both its compact foliage and trailing stems without pushing leggy growth.

Always dilute to one-quarter of the label's recommended strength. String of Turtles has delicate, shallow roots that burn easily from fertilizer salts. A weak solution applied consistently is safer than a strong dose applied rarely.

Liquid fertilizer is the best delivery method because it distributes evenly through the small pot these plants prefer. Avoid granular or slow-release formulas, which can create salt pockets in the compact soil mix.

Synthetic

Schultz All Purpose 10-15-10

Affordable liquid concentrate. Use 2 drops per quart (quarter of the label rate) for this sensitive Peperomia.

Jack's Classic All Purpose 20-20-20

Water-soluble powder that dissolves cleanly. Mix at one-quarter strength (1/8 tsp per gallon) for gentle, even feeding.

Organic

Liqui-Dirt Organic Concentrate

Gentle all-in-one organic option with mycorrhizae. One-quarter scoop per gallon keeps feeding light enough for this delicate plant.

Worm castings

The safest organic option for sensitive plants. Sprinkle a thin layer on the soil surface every 2-3 months for slow, steady nutrition.

How Do I Fertilize My String of Turtles?

Water your plant first

Give your String of Turtles a thorough watering and let it drain. Fertilizing dry soil risks burning the shallow, delicate roots.

Dilute to quarter strength

Mix your balanced liquid fertilizer at one-quarter the label rate. For most concentrates, that's about 1/8 teaspoon per gallon of water.

Apply to the soil, not the leaves

Pour the diluted solution slowly onto the soil surface. Avoid getting fertilizer water on the turtle-patterned leaves, which can cause spotting.

Let it drain completely

Allow all excess water to flow out the drainage hole. Never let the pot sit in fertilizer runoff, as this plant is sensitive to salt accumulation.

Flush the soil every few months

Run plain water through the pot until it flows freely from the bottom. This washes out any fertilizer salts that have built up between feedings.

Got More Questions?

Can I use coffee grounds on my String of Turtles?

It's not recommended. Coffee grounds are acidifying and can compact the loose, airy soil mix that Peperomias need. The risk of root rot outweighs any nutritional benefit.

What happens if I over-fertilize my String of Turtles?

You'll see brown, crispy leaf edges and white crusty deposits on the soil. In severe cases, the delicate roots burn and the plant drops leaves. Flush the soil with plain water several times and skip feeding for at least two months.

Should I fertilize my String of Turtles right after repotting?

Wait at least 4-6 weeks. Fresh potting mix already contains some nutrients, and the roots need time to recover from the disturbance before handling fertilizer salts.

Can I use succulent fertilizer on String of Turtles?

Yes, a dilute succulent fertilizer works fine. String of Turtles is semi-succulent with similar low-feeding needs. Just make sure to dilute it further than the label suggests.

Why are my String of Turtles leaves losing their pattern?

Fading leaf patterns usually mean too little light, not a fertilizer issue. Make sure the plant gets bright indirect light before increasing feeding. Over-fertilizing in low light makes things worse.

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About This Article

Kiersten Rankel M.S.

Botanical Data Lead at Greg · Plant Scientist

About the Author

Kiersten Rankel holds an M.S. in Ecology & Evolutionary Biology from Tulane University. A certified Louisiana Master Naturalist, she has over a decade of experience in science communication, with research spanning corals, cypress trees, marsh grasses, and more. At Greg, she curates species data and verifies care recommendations against botanical research.

See Kiersten Rankel's full background on LinkedIn.

Editorial Process

Fertilizer recommendations verified against Peperomia prostrata growth data from Greg's botanical database, cross-referenced with USDA hardiness zone data and published horticultural research.

8,781+ Greg users growing this plant

USDA hardiness zones 10a–12b

Citations:
NC State Extension
Royal Horticultural Society

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