Plant Gloxinia – Hollow-Side Up

Plant Gloxinia – Hollow-Side Up guide illustration

Plant gloxinia tubers hollow-side up, barely covered, in spring, in a pot that drains.

Planting Gloxinia care summary diagram

Plant the tuber hollow-side up, barely covered

FactorRecommendedAvoid
WhenLate winter or spring, once you can keep the pot around 70°FDo not plant into a cold, wet mix
OrientationHollow, concave side up, with any sprouts facing upDo not bury the hollow face down
DepthSet the tuber so the top sits at the mix surface, or is barely coveredDo not bury it several inches deep
PotOne tuber in a four- to five-inch pot that drains, filled with African violet mixDo not cram several tubers into a deep, undrained pot

Start gloxinia from a tuber in late winter or spring. The top is the hollow, dish-shaped face. Set that face up, almost at the mix surface, in a pot that drains. [1] Once sprouts are up, light and watering live on How to Grow Gloxinia.

How deep do I plant the tuber?

Set it so the top sits at the mix surface, or is barely covered. Do not bury it several inches deep.

Which side of the tuber goes up?

The hollow, concave side. If sprouts are already showing, those face up.

How to plant gloxinia

Fill a draining pot with dry African violet mix, set the tuber hollow-side up, water until it drains, then wait for sprouts.

  1. Choose a four- to five-inch pot with a hole. One tuber fills that pot. [2]
  2. Fill it with dry African violet mix, or another light houseplant mix. Pack dry mix around the tuber; do not ram wet mix onto it.
  3. Set the tuber hollow-side up so the top sits at the surface, or is barely covered. If sprouts are already there, keep them facing up. [3]
  4. Water until the mix is wet through, then let it drain. Water sparingly after that until new growth shows, because a wet rest is how a dormant tuber rots. Keep the pot warm, around 70°F. [4]

Divide extra tubers when you pot them in spring

A large tuber sometimes splits into sound pieces, each with a sprout. Separate those at potting time, and give each piece its own small pot. Throw out a soft or moldy piece.

  1. Lift the clump when you change the mix in spring.
  2. Break or cut apart only pieces that each have a sprout or a clear growing point.
  3. Pot each piece hollow-side up in fresh mix, barely covered, and water as for a whole tuber.

What fails at planting

A tuber planted hollow-side down, or several inches deep in wet mix, sits in a pocket of water and rots before it sprouts. A cold windowsill in January does the same. Wait until you can keep the pot around 70°F, water once to settle the mix, then keep it only barely moist until leaves show.

Set the tuber hollow-side up at the mix surface, water once, and wait for sprouts before you water again.

FAQ

Can I plant the tuber outdoors in the ground?

This is a houseplant tuber. A summer porch pot in bright shade is fine. Do not plant it as a hardy bed perennial.

Do I soak the tuber before planting?

No soak is required. Set it in dry mix, water until the pot drains, then wait for sprouts.

Recommended plants

References

  1. [1] Clemson HGIC - https://hgic.clemson.edu/factsheet/gloxinias/
  2. [2] University of Missouri Extension - https://extension.missouri.edu/publications/g6511
  3. [3] Guide to Houseplants - https://www.guide-to-houseplants.com/gloxinia.html
  4. [4] Iowa State Extension - https://yardandgarden.extension.iastate.edu/faq/how-do-you-care-gloxinia

This note is part of Sinningia Guides.

More planting notes by plant are gathered in Planting Guides.

Updated: Reviewed by Bosquelle Editors

This guide is written for real gardens, not perfect climates. Results vary with site, season, and plant choice. We draw on multiple sources and practical experience; treat the steps here as honest guidance, not a promise that every bed will behave the same.