Growing Tips:Water: The plants need regular watering, about 1 in. per week, more while first getting them established and during hot, dry spells.
Soil: Soil: Gerbera do best in a slightly acidic soil pH of 5.5 – 6.5. Higher pH levels can cause chlorosis which manifests as yellow stipes on the leaves. Too low a pH and you will see black spots or patches.
Fertilizer: Feeding depends on the quality of your soil. Start with a rich soil, high in organic matter. Since they will be repeat blooming all summer, monthly feeding with a water soluble fertilizer is advised.
Gerber daisies are not often sold as small seedlings in cell packs and the individual plants can be expensive. Some varieties can be easily grown from seed, but be warned, even the seed is pricy.
Starting from Seed: Gerber daisies are slow to develop, one of the reasons they are so expensive. Start seed indoors, about 12 – 18 weeks before your last frost date. Sow the seed in peat or paper pots, because they do not like to have their roots disturbed by transplanting.
The seed needs light to germinate, so press the seeds on top of the soil mix. Do not cover with more soil. Covering the container with plastic will help to keep the soil and seed moist. Place in a warm spot, 70 – 75 F (21 –24 C) and expect to wait 2 –4 weeks for germination.
Note: Double varieties to not always grow true to type. You will probably get a good many that turn out to be singles.
Planting: Transplant outdoors after all danger of frost has past. Choose a well-draining site with good light exposure. Plant so that the crown is ½ in. (1.25 cm) above the soil line. If you are planning on bringing the plants indoors for winter, you can simply sink the pot and all and lift it in the fall. It will be less disruptive to the roots.
Caring for Gerber Daisies
To keep the plants in flower, deadhead spent blooms. Make sure that sunlight can reach the center of the plants. If the plants get too bushy, you can remove some of the leaves clustered in the center, to allow more light in.
Bringing Plants Indoors: Gerber daisies will continue growing and blooming indoors. They prefer a cool winter temperature of about 45 – 50 F (7 – 10 C) and full, bright sun. Do not over-water during the winter. Water only when the soil is dry an inch or 2 below the surface.
Plants can also be overwintered dormant, if the pots are kept cool and not allowed to freeze. Water lightly every month and allow to dry.
Pests and Problems:Insects: Aphids, whiteflies, spider mites and thrips will all feast on gerbera leaves. They are attracted to stressed plants, but will also be drawn to large swathes of plants. Monitor regularly and treat at the first sign of trouble. Small populations can be blasted off with a strong spray of water. Larger populations can be controlled with insecticidal soap or neem.
Leafminers can also infest the leaves. Remove any that show the telltale tunneling.
- Powdery mildew can become a problem, if the plants remain wet for long periods and in high humidity.
- Crown and root rot can affect the plants when they are continuously in wet soil. Allow the soil to dry between waterings, but do not leave them unwatered so long that they wilt and look dry.
Design Tips:The bold colors of Gerber daisies can be hard to integrate into a flower bed with more subtle colors. These work best when contrasted with just a few other plants, with more delicate blooms or airy foliage. Complementary colored Calibrachoa and Diascia make a nice contrast. To really play up the bold colors, pair them with yellow foliage plants, especially short grasses like Hakonechloa macra 'Aureola' or 'All Gold'. . Small or spiky blue flowers, such as sages and lobelia, also bring out the boldness of Gerber daisies.
Of course, you can always grow Gerber daisies all on their own. They can easily fill a pot and make a statement.
Cut Gerber daisies when the flowers are fully opened, but the center remains tight. The stems will take up as much water as you give them, but too much water will shorten their display time. Place them in only ½ to 1 in. of water and add more as necessary. If the base of the stem begins to discolor, make a fresh cut.
Suggested Varieties:Gerbera jamesonii, the Transvaal or Barberton Daisy, is the most commonly grown species and there is a great deal of variety within it. Most of the seed sold is for Gerbera jamesonii. Jaguar is one of the most popular series. You can purchase seed of individual colors or in different combinations.
A smaller flowered Gerbera, Gerber minis, are becoming increasingly popular. They also come in a good selection of colors and can be grown from seed.
There is more selection when you purchase them as plants, because a lot of Gerbera breeding is done through tissue culture.
Resources: Year of Gerbera, at the National Garden Bureau.