How to Care for a Nemesia Aromatica Plant

Nemesias (Nemesia fruticans, syn. Nemesia caerulea) are known for their undemanding nature and abundant blooms, and the Aromatica series adds to that reputation. As their name suggests, these five easy-care cultivars boast intense fragrance, too. Typically grown as annuals in the United States, Aromatica nemesias are hardy in U.S. Department of Agriculture plant hardiness zones 9b through 10. In climates where mild winters follow cool summers, these low-maintenance lovelies keep the color coming year-round.

Full sun encourages the Aromaticas' everblooming tendencies. Like others in the series, Aromatica Rose Pink nemesia (Nemesia fruticans "Balarropi") flourishes with at least six hours of bright, direct sun each day. Unaffected by day length, the plants bloom well in every season. In the hottest climates, light afternoon shade helps extend the plentiful blooms. True to their South African roots, Aromatica nemesias prefer well-drained, compost-enriched soil. The plants grow 12 to 14 inches tall and 10 to 12 inches wide, with upright stems covered in colorful flowers and bright green leaves. Space Aromatica nemesias 8 to 12 inches apart in your garden.

Aromaticas like it cool and dry. Wet foliage and water-logged soil lead to fungal disease. To prevent these problems, avoid overhead irrigation and allow the soil to dry out slightly between waterings. Drier soil keeps Aromaticas compact and stimulates extra blooms. Adjust watering to meet the season -- cool seasons require less, summer heat calls for more -- but never leave plants soggy. Aromatica Scarlet nemesia (Nemesia fruticans "Balarlet") and Aromatica Sky Blue (Nemesia fruticans "Balarklu") broke new ground in nemesia colors. Generous amounts of organic compost worked into the soil at planting provide all the low-level, slow-release nutrition these colorful blossoms need. For perennial plantings, a 2- to 3-inch layer of compost each spring fulfills the ongoing need. Avoid high-nitrogen and phosphorus fertilizers, which can limit nemesia blooms.

The well-branched, mounded growth of Aromatica White nemesia (Nemesia fruticans "Balarwite") exemplifies the series. The plants need little care throughout the year and rarely require pruning. In hot climates, however, flowering may suffer when heat overcomes the plants. If flowers fade in heat, cut Aromaticas back to below the blooms; this stimulates growth and encourages new flowers. Use sharp garden scissors or shears, and sterilize the blades with household disinfectant before and after you prune. Proper watering and spacing prevents major disease problems, and pests rarely bother healthy Aromaticas. If aphids or other intruders appear, dislodge them with a sharp blast of water from your hose.

Aromatica nemesias are in their glory during cool seasons when frost threatens. Keep protective coverings close at hand to prolong annual blooms as much as possible. The flowers tolerate frost, but eventually succumb to cold. Plants die when temperatures drop below 25 degrees Fahrenheit. Aromatica Royal Blue nemesia (Nemesia fruticans "Balaroyble") and its series siblings survive winters where temperatures stay above that mark. The plants die to the ground, but their deep tap roots bring them back in spring. An extra layer of mulch provides added winter protection. Leave the stems until spring, and then prune them back before new growth begins. In frost-free climates, Aromaticas grace winter gardens with blooms.