Fan flower (Scaevola aemula), also known simply as scaevola, is a warm-weather perennial or small shrub that is often grown as an annual flower. It is an excellent plant for any region with warm summers. Scaevola is a sprawling plant with oval or lance-shaped leaves and, given a hot humid climate, it will produce a nearly non-stop display of dark blue fan-shaped flowers from early summer right up to frost. Scaevola plants fill a niche for gardeners seeking a heat-tolerant plant for their summer containers: its thick stems ensure drought tolerance in full sun locations, even in triple-digit temperatures.
Scaevola is a fast-growing plant that is normally planted from purchased nursery seedlings in the spring after soil temperatures are fully warmed, or from seeds started indoors in early spring.
|Common Name||Fan flower, scaevola, fairy fan flower|
|Botanical Name||Scaevola aemula|
|Plant Type||Evergreen perennial/shrub, often grown as an annual|
|Mature Size||9–18 in. tall, 1–2 ft. wide|
|Sun Exposure||Full, partial|
|Soil Type||Average, well-drained|
|Soil pH||Acidic (5.5-6.0)|
|Bloom Time||Late spring to fall|
|Flower Color||Blue, purple, white, pink|
|Hardiness Zones||10–11 (USDA)|
Scaevola plants earn brownie points in hot climates for powering through the dog days of summer without any blossom drop, and for requiring very little in the way of tending. Scaevola plants don't need much pinching or fertilizing, and if a Scaevola plant fails, it's usually due to excessive irrigation or poor soil drainage. Your plants will be low-maintenance performers as long as you give them warmth and sunshine, and an occasional drink.
Like many Australian natives, Scaevola is a tough specimen that doesn't suffer from any serious pest, disease, or cultural problems. Plants stressed by lengthy drought may attract thrips, and mealybugs may be occasional nuisances. Avoid spraying Scaevola for insects, as these plants are an important source of nectar for butterflies.
Choose a site with full to partial sun for best Scaevola performance—six to eight hours of sun is optimal. Plants growing in hot, dry desert areas may remain more pert if they are planted in a site with dappled shade.
Rich soil isn't necessary for thriving scaevola plants. A soil of average fertility is fine, with good drainage the most important factor in healthy plant growth. Container plants do fine when planted in a standard commercial potting mix, perhaps with some sand blended in. When planted in the garden, heavy clay soil should be amended to make it more porous; or you can grow Scaevola in raised beds filled with amended soil.
Scaevola plants prefer to be on the dry side, but they are not true xeriscape plants and so do need occasional watering. Plants growing in wet soil may attract fungus gnats, or may experience root rot. Wait until the soil surface is dry to water. Wilted plants will perk up quickly after irrigation.
Temperature and Humidity
Scaevola plants grow vigorously in warm to hot weather. Temperatures below 60 degrees Fahrenheit will cause flowering to slow or stop. Temperatures between 70 and 85 degrees yield the happiest plants with compact growth, but hot temperatures are also well tolerated. High humidity is welcomed by the Scaevola.
Accustomed to the lean growing conditions of its native Australia, Scaevola plants require only a light feeding. Choose a balanced flower fertilize and apply it once a month during the growing season.
Types of Scaevola
The pure species plant, Scaevola aemula, is a somewhat large plant, growing to as much as 18 inches with a growth habit that is almost shrub-like when planted in zones where it is hardy. The native plant certainly has a role in the landscape, but more often gardeners choose one of the named cultivars. The many cultivars are generally shorter plants, more appropriate for containers and other garden uses.
- ´Blue Wonder´ has blue flowers, growing 6 to 8 inches tall and 3 to 4 feet wide.
- ´Bombay' series offers blue, pink, and white types. The plants grow 8 to 12 inches tall and 12 to 18 inches wide.
- ´Fairy' series offers blue, pink, and white flowers on plants that grow 6 to 10 inches tall and 18 to 24 inches wide.
- 'Whirlwind' series offers plants in several colors. These vigorous growers will spread to fill containers and fill in borders.
- 'Purple Fanfare' delivers loads of lavender-blue blooms throughout the growing season.
- 'Carpet' series offers plants in several colors, ideal for creating a dense ground cover.
Like most trailing annuals, Scaevola benefits from a little snipping here and there to keep it tidy and to encourage the plant to grow in a branching habit, rather than developing long, lanky stems. Scaevola is self-cleaning and does not need to be deadheaded, but you can cut it back by half after the first big flush of blooms to encourage new growth and spur even more flowering.
Propagating Scaevola is usually done by rooting stem cuttings. This is also the standard way to perpetuate a plant into the following spring: Take cuttings of scaevola at the end of summer:
- Using sharp pruners, Clip a 4- to 6-inch cutting from a non-blooming stem. Remove the bottom leaves, leaving at least two pairs of leaves at the top of the cutting.
- Dip the end of the cutting in rooting hormone, then plant the end in a small container filled with commercial potting mix. Place in a bright location and at a temperature of about 70 degrees Fahrenheit.
- Keep the cutting barely moist, but take care not to overwater, which can cause rot. Roots will form in about one month.
- When a good network of roots has formed, move the potted cutting into a warm, sunny location to continue growing until it's time to transplant outdoors. These are warm-weather plants that should not be planted outdoors until soil temperatures are reliably at 65 degrees Fahrenheit or higher.
How to Grow Scevola From Seed
Scaevola can be tricky to grow from seed, as the seeds are very tiny and germination is slow and not always reliable. But seed starting is sometimes the only option, as Scaevola plants are not offered by all local nurseries. It's best to buy packaged seeds from a commercial source rather than to collect seeds from existing plants.
Sow the seeds indoors about two months before the last frost date in a gritty potting mix. Just barely cover the seeds with a sprinkling of potting mix. Mist lightly, and keep seeds at about 70 degrees Fahrenheit and in a bright location, but out of direct sunlight. Germination usually occurs within a month, but be patient, as it can take as much as 60 days.
Once true leaves have sprouted, the seedlings can be moved into a warm, sunny location. But don't transplant them outdoors until soil temps are at 65 degrees or higher. Seedling plants should be hardened off by giving them daily visits to outdoor conditions over a period of a week or two before transplanting them into the garden or into their permanent outdoor pots.
Potting and Repotting Scaevola
Scaevola is an excellent outdoor container plant—either as an individual specimens or as a "spiller" plant in mixed containers. A lightweight potting mix with a good ratio of peat moss and perlite or vermiculite is ideal for container-grown Scaevola plants. Since they are normally grown as annuals, they will finish their life cycle with no need for repotting.
Clay pots with good drainage make good containers, though almost any container will suffice, provided it is well-draining.
In all but the warmest zones (10, 11), Scaevola plants are generally pulled up and discarded as winter cold approaches. Large, mature potted Scaevola plants usually don't adapt well to moving indoors for the winter, but some gardeners do have luck transplanting small bedding plants into containers to nurture through the winter in an indoor location.
If you want to try it, carefully transplant some selected garden plants into pots filled with standard commercial potting mix, place them in a sunny window, and protect them from cold for the winter. Watering should be somewhat reduced during the winter months, so as to encourage partial dormancy. Branches can be pinched back if they become sparse over the winter.
How to Get Scaevola to Bloom
Scaevola will normally bloom robustly from early summer right up to frost, provided it gets enough light, water, and warmth. Cold summer spells where daytime temperatures fall below 60 degrees Fahrenheit may cause the plants to temporarily stop blooming. If all other conditions are adequate, lack of blooms may be due to very poor soil conditions—feed the plants monthly to see if this improves blooming.
What is the difference between scaevola and lobelia?
Annual lobelia (Lobelia erinus) is indistinguishable from Scaevola plants from a distance. Up close, you can see that lobelia flowers are small, abundant, and have a similar fan shape (with three downward-facing petaloids rather than the five found on Scaevola blooms. The big difference between the two is that lobelia plants like cool weather and will die off as the summer heats up. If you replace your faded lobelia plants with Scaevola, your garden won't miss a beat.
How can I use scaevola in the landscape?
The outdoor container garden is where Scaevola plants really shine. Place them at the front of the pot, where they can drape over the side and hide the rim. They also work well as bedding plants or planted along retaining walls, where they can cascade over the edge.
Scaevola plants make good companions for other hot weather lovers of sun, like Mexican zinnias, zonal geraniums, and tropical hibiscus. Like the Scaevola, these flowers need good draining soil and don't like to be overwatered.
If I grow scaevola as a garden perennial in my warm climate, how long does it live?
In frost-free climates (zone 10, 11) scaevola planted in the garden will live indefinitely. The native species plant even makes a good low hedge plant or foundation planting, while the lower-growing named cultivars are often used as permanent ground covers.