The African Violet, or Saintpaulia, is a popular houseplant known for its vibrant, nearly constant blooms and compact size. Despite their appeal, these plants have a reputation for being temperamental, which often deters new owners. Successful cultivation requires understanding their specific needs, which are unlike those of most common houseplants. Mastering the nuances of their environment, watering, and soil is the path to enjoying a continuously flowering plant. This guide details the precise conditions and techniques required for long-term African Violet health and abundant flowering.
Light and Environmental Requirements
African Violets require bright, indirect light to thrive and produce consistent flowers. They must be shielded from the direct midday sun, which can scorch their fleshy leaves. An ideal location is near a north- or east-facing window, or a south- or west-facing window where the light is diffused by a sheer curtain.
If natural light is insufficient, the plants respond well to supplemental artificial lighting. African Violets can be grown entirely under fluorescent or LED grow lights, needing 600 to 1,000 foot-candles of light for 12 to 16 hours daily. They must also receive eight hours of uninterrupted darkness necessary to stimulate flowering.
These tropical plants prefer temperatures between 65 and 80 degrees Fahrenheit. Cold drafts must be avoided, as sudden drops in temperature can cause dark, water-soaked spots on the leaves. Moderate to high humidity (40 to 60 percent) is optimal.
Low humidity causes flower buds to shrivel and fail to open (bud blast). Localized humidity can be increased by placing the pots on a shallow tray filled with pebbles and water, ensuring the pot bottom does not touch the water.
Watering and Feeding Techniques
Improper watering is the most frequent cause of African Violet failure, often leading to crown or root rot. The soil should be allowed to dry slightly at the surface before rewatering, typically when the pot feels noticeably lighter when lifted.
Water temperature and type are important considerations. Water should always be at room temperature or slightly warmer, as cold water hitting the leaves can cause distinct yellow or bleached ring spots due to localized cell collapse. If using tap water, allowing it to sit out for 24 hours helps dissipate chlorine.
There are two primary watering methods, both aimed at keeping the sensitive central crown and leaves dry. Top watering involves pouring room-temperature water directly onto the soil, avoiding the crown, until water drains from the bottom. Bottom watering is often preferred, where the pot sits in a saucer of water for up to 30 minutes, allowing the soil to absorb moisture through capillary action.
After either method, any excess water remaining in the saucer must be discarded. This prevents the roots from sitting in standing water, which quickly leads to fungal crown rot.
African Violets require consistent, diluted feeding because their specialized, porous soil mixes do not retain nutrients well. A water-soluble fertilizer specifically formulated for African Violets should be applied at a reduced strength with almost every watering. This ensures a steady nutrient supply.
A balanced NPK ratio (like 20-20-20) or a formulation with slightly higher phosphorus (such as 15-30-15) is commonly used to encourage blooming. Phosphorus aids flowering and root health, while excessive nitrogen promotes foliage growth at the expense of flowers. Feeding should be regular during active growth (spring and summer) but reduced or stopped during the cooler winter months.
Choosing the Right Soil and Pots
The choice of growing medium is paramount, as standard potting soil is too heavy and dense for African Violets’ delicate root systems. A specialized mix must be light, extremely porous, and well-aerated to ensure proper drainage and oxygen flow to the roots. The ideal composition includes aeration materials combined with a moisture-retaining component.
A common and effective blend is a soil-less mix consisting of one part sphagnum peat moss or coco coir, one part perlite, and one part vermiculite. The peat moss or coir retains moisture and provides the slightly acidic pH (5.8 to 6.5) African Violets prefer. Perlite and vermiculite provide necessary air pockets and aid in drainage and moisture retention.
African Violets prefer to be slightly root-bound and perform best in small pots relative to their leaf span. The pot diameter should be approximately one-third the diameter of the plant’s leaf spread. Overpotting (using a pot that is too large) causes the soil to stay wet too long, increasing the risk of root rot.
Plastic pots are recommended over porous terracotta because they retain moisture more consistently. Repotting should occur every 6 to 12 months to refresh the growing medium, as the old mix compacts and degrades.
During repotting, African Violets often develop a bare, woody stem or “neck” from shedding older leaves. To address this, “neck scraping” is used: gently scrape the exposed neck to encourage new root formation. Then, trim the root ball and repot the plant so the scraped neck is buried in fresh, moist soil just below the rim of the pot, allowing it to quickly develop new roots.
Diagnosing Common Issues
Even with diligent care, African Violets occasionally exhibit symptoms related to light, water, or pests. A common problem is the failure to bloom, where the plant appears healthy but produces few or no flowers. This is usually caused by insufficient light intensity or duration. The solution is to move the plant closer to a bright window or increase the hours under a grow light.
Another issue is a tight, compacted center crown where the newest leaves appear small, brittle, and crowded. This signals either over-fertilization (mineral salts build up) or a pest infestation, most commonly cyclamen mites. If over-fertilization is the cause, the soil should be thoroughly flushed with plain water, and the feeding concentration reduced immediately.
The most serious problem is crown and root rot, a fungal infection caused by a perpetually waterlogged potting mix. Symptoms include yellowing, wilting outer leaves, a soft stem near the soil line, and a foul odor. Since there is no reliable cure for advanced crown rot, the infected plant must often be discarded.
Pests like mealybugs and cyclamen mites can cause significant damage. Mealybugs appear as small, cottony masses in leaf axils and can be treated by touching them with a cotton swab dipped in rubbing alcohol. Cyclamen mites are microscopic, inferred by severely stunted or deformed new growth. Disposal is often the most practical solution for heavily infested plants.