The name nemesia refers to a genus of plant species that includes annuals, perennials, and subshrubs. The most common nemesia are the species of annuals that are cultivated for gardens around the world. There are numerous different varieties and hybrids cultivated in a wide range of colors. It is a type of plant that blooms frequently, particularly in cooler weather of spring and fall.
Originally from South Africa, nemesia grows best in mild, cool weather. It does not tolerate frost or high heat conditions well, preferring temperatures that range between 55 to 75 degrees Fahrenheit (13 to 28 degrees Celsius). It thrives in areas with cool, dry summers or warm, mild winters, as well as during spring and fall. Temperature extremes cause it to stop blooming, and may permanently damage the plant.
Most varieties of nemesia grow to about 2 feet (0.6 m) tall, and branch out to a width of approximately 1 foot (0.3 m). They have sturdy upright stems, with flowers near the top, and are often pleasantly scented. Flowers are small and delicate in appearance, but grow in larger clusters. Many people compare these to snapdragons, which are a distant relative. A huge number of different colors are available, including white, pink, yellow, purple, dual color varieties.
Easy to grow, nemesia does well planted in the ground, or potted in containers. Gardeners often plant it in borders and edgings, in flower beds, in rock gardens or walls, and other places. It is also frequently planted in decorative pots and containers, and is used as a cut flower as well.
Full sun to partial shade is preferred. Nemesia should be planted in rich soil containing organic matter, with vermiculite to promote drainage. It should be watered frequently enough to keep the soil moist, but not so much that the soil becomes saturated. Fertilizer should be applied regularly, the liquid types absorb well. Finished blooms should be pinched off the plants, this encourages abundant, full growth of new flowers.
Nemesia seedlings can be purchased ready to plant, or it can be cultivated from seeds. When planting seeds, it is often easiest to start them indoors about two months before the last expected frost. The seeds need lots of sunlight and water, and should take about one to three weeks to germinate. Once the danger of frost has passed, the seedlings can be transplanted outdoors.