Utricularia longifolia

Tropical Utricularia (bladderworts) are an overlooked gem of the carnivorous plant world. These tiny, often moss-like plants grow in mats or clumps and produce vibrant, orchid-like flowers when happy. Species like Utricularia sandersonii, U. bisquamata, and U. longifolia are easy to grow indoors with the right moisture, media, and light, they can quickly become a favorite in any collection.

Key Care Requirements

Light: The Key to Flowers

Tropical Utricularia don’t rely on traps for energy, they photosynthesize like other plants, so bright light is essential for fast growth and frequent flowering.

• Natural Light: A bright windowsill with several hours of indirect sun is ideal. Morning or filtered afternoon sun works well.
• Artificial Light: Use a full-spectrum LED or T5 grow light placed 6–12 inches above the pot for 12–14 hours per day.

Want flowers? Light is the trigger. Without strong light, most tropical Utrics will stay in leaf mode only.

Check out our cultivation guide on Light

Water: Keep It Wet (But Clean)

Utricularia thrive in wet, low-nutrient conditions. Their rootless or minimal-root structures rely on pure water to avoid mineral burn and maintain trap function.

• Golden Rule: Use only distilled, rain, or reverse osmosis (RO) water.
• Watering Method: Keep the pot in a tray of ½–1 inch of water at all times. The media should stay consistently moist to soggy. Never let it dry out.
• Top-water occasionally to flush the media and prevent stagnation.

Check out our cultivation guide on Water

Soil: Wet, Airy, and Inert

Tropical Utricularia grow in spongy, low-nutrient substrates. They don’t tolerate traditional potting mixes.

Recommended Mix:

• 1 part peat moss
• 1 part perlite or silica sand
• Optional: top layer of live sphagnum moss or milled sphagnum
  

Alternative Mix for Mat-Forming Species:

• 100% finely chopped long-fiber sphagnum kept very moist
• Never Use: Fertilized soil, compost, or vermiculite, they will kill the plant.

Check out our cultivation guide on Soil

Temperature & Humidity: Tropical but Flexible

Most tropical Utricularia are warm-growing and don’t require dormancy. They prefer stable conditions and constant access to moisture.

Temperature:

• Ideal range: 65–85°F (18–29°C)
• Can tolerate drops into the low 60s but not frost
  

Humidity:

• Prefer 50–80% RH
• Will flower better in higher humidity environments
• Great candidates for terrariums or domed pots

Utrics won’t wilt like sundews or VFTs when unhappy, they just stop growing or flowering. Keep them warm and wet.

Check out our cultivation guide on Temperature

Check out our cultivation guide on Humidity

Feeding: Optional but Encouraged

Tropical Utricularia catch microscopic organisms in bladder traps underground or in moss. Indoors, they may benefit from supplemental feeding.

Method:

• Place in pots with live moss or springtails, which they’ll consume
• Add a few crushed betta pellets, yeast, or fish food dust lightly to the surface once a month
• Avoid overfeeding, it can sour the media

Fertilizer (Optional):

• Use 1/4 strength MaxSea 16-16-16 as a foliar spray or light soil drench once a month
• Be cautious, too much can overwhelm the roots or trap function

Check out our cultivation guide on Nutrients

Pro Tips from The Trappery

• Flowering stalled? Increase light and humidity
• Want a dense carpet? Trim lightly and keep under strong light
• Great companions for small terrariums or as underplantings in Nepenthes pots
• U. sandersonii and U. bisquamata are beginner-friendly and flower profusely under lights