Why this happens (not actually a problem)
As older lower leaves are lost or removed, a length of stem can become exposed. A firm neck on an otherwise healthy plant is different from a soft, rotting crown. Leaf lifespan varies; there is no need to remove leaves on a yearly timetable.
First check the stem and roots. If tissue is soft, blackening or collapsing, do not simply bury it deeper. Seek advice on whether a healthy part remains that can be propagated.
Short neck: repot deeper in the same pot
A modest exposed neck can often be accommodated when refreshing the mix. Gently unpot the plant, remove loose old mix and check that there is room to position the stem lower while keeping the growing crown above the surface.
Use a pot suited to the roots and light African-violet mix. Preserve healthy roots where practical; do not automatically cut away a measured slice solely to match neck length. Water carefully, drain and monitor. Avoid packing wet mix around the crown.
Long neck: restart via the crown
A long neck may require rerooting the healthy crown, but a ruler alone does not decide that a drastic cut is necessary. Root condition and stem shape matter. If unsure, ask an experienced grower before cutting.
When restarting a sound crown, use clean tools and remove damaged or old outer material while retaining healthy central growth. Prepare the sound stem and set it in a small container of airy, lightly moist mix, with the growing centre above the surface. The linked African Violet Society of America demonstration explains crown preparation in detail.
Keep warm in bright, indirect light with humidity around the cutting, not saturated compost. Vent any cover if condensation persists; never place a covered cutting in direct sun. New roots take time, and pulling repeatedly to test them causes damage. A healthy leaf cutting can provide a separate backup.
Keep a short care record
Photograph the whole plant and any damage, and note moisture checks and recent changes. Compare later growth rather than expecting an old scar to disappear. Continuing collapse, expanding lesions or extensive decay deserves specialist help.
Reference material
Reference material consulted for this independently written guide. The publishers listed have not reviewed or endorsed it.
- RHS — African violets
- University of Maryland — watering
- University of Maryland — symptom checks
- University of Minnesota — African violets
- African Violet Society of America — repotting a long neck (demonstration)