Gerbera daisy

Identification and origin

Gerbera jamesonii belongs to the family Asteraceae. It is native to northeastern South Africa, in the former Northern Provinces, and neighboring Eswatini. The genus honors the German naturalist Traugott Gerber; the species is named for Robert Jameson, who collected it near Barberton.

It is a stemless herbaceous perennial that forms a clump in a rosette. Its dark green leaves are spoon-shaped, lobed or deeply cut, up to 18–20 in long, with woolly undersides. From the center rise bare, hairy flower stalks, each topped by a single flower head about 4 in across, sometimes up to 5 in. In the species, the outer ray florets are red, orange, or yellow around a bronze-yellow center; the flowers are single or semi-double. The fruit is a small brown achene. In cultivation the plant usually stands 12–18 in tall and 10–16 in wide, and its roots run deep.

It is the main parent of the hybrid gerberas sold in stores, which come in a much wider range of colors. Cultivars offered under this name include ‘Orange Palmaria’, orange with a black center, ‘Pink Kimsey’, pink with a green center, and ‘Green Kermit’, with green petals. The flowers last a long time in a vase.

Light

Gerbera daisy needs strong light. Indoors, choose the brightest spot in the house, but beware of summer sun through glass: it builds up heat and can scorch the leaves. Outdoors it blooms in full sun or part shade; where summers are hot, morning sun and afternoon shade is ideal.

Watering

The crown, the point where the leaves meet the roots, is the most sensitive part: it must dry out between waterings. Before watering a pot, check that the surface of the mix has dried slightly. The safest method is bottom watering: set the pot in a tray of water until the mix is moist, then pour off what is left. Do not wet the center of the rosette or the leaves, and never leave the pot standing in water.

In the garden, water at the base and in the morning so the foliage dries before night. In summer, keep moisture steady but never excessive. In winter, keep the mix on the dry side, especially in an unheated room: just enough that the root ball never dries out completely.

Potting mix

In a container, use a rich, peat-free, very free-draining mix: an all-purpose potting mix or a loam-based mix with added fine grit. In the ground it needs fertile soil enriched with compost and well drained; in heavy soil that stays soggy, use a raised bed or a pot instead. Always set the crown level with the soil or slightly above it, never buried, and keep mulch off the center.

In spring and summer, apply a liquid fertilizer every two weeks, or a controlled-release fertilizer two or three times in the season; a high-potassium feed, such as tomato fertilizer, encourages blooming. In pots it is prone to iron and manganese deficiencies, so choose a fertilizer that contains these micronutrients.

Temperature

It blooms best when cool: indoors, between 50 °F and 68 °F. Below or above that range, flowering stops, then resumes as soon as temperatures return to it. It likes mild days and cool nights. Never let it drop below 41 °F.

To overwinter a plant grown outdoors, bring it in before frost to a bright, well-ventilated room at 45–50 °F, with the mix barely moist. Move it back outside in spring once nights stay above 41 °F and the danger of frost has passed. In the ground it lives for several years only in mild regions, USDA zones 8a to 10b; elsewhere it is grown as an annual.

Repotting

Gerbera daisy dislikes disturbance: its deep roots do not take well to being dug up. When roots fill the whole pot, repot in spring into a container just one size larger, gently loosening any circling roots. Keep the crown at exactly the same height.

Over the years the plant tends to sink, and the crown eventually gets buried, which invites rot: lift it and replant it at the right level. For a garden plant you want to bring in for winter, grow it in a pot sunk to the rim, which is easy to lift in fall.

Pruning

No structural pruning is needed. Deadhead regularly by removing the whole flower stalk at the base: the plant then produces new ones. Also remove damaged or yellowing leaves, which can become a breeding ground for mold.

Propagation

Division is the easiest method. In spring, at the first signs of new growth, unpot an older clump and cut the crown into four or five pieces with a clean, sharp knife; each division must keep at least one bud and plenty of roots. Remove dead roots, old leaves, and half of the lower mature leaves, replant right away, and keep moist until established. A divided plant can take a year to bloom fully again.

In spring you can also take a vigorous shoot from the base, as close to the crown as possible, and root it in a sandy mix in a closed, humid propagator. In late summer, basal offsets from a favorite plant can be rooted in pots and overwintered under cover.

Sow seed in late winter, using fresh seed. Mix sand into the seed-starting mix and set the seeds upright with the feathery end showing, without burying them. At 68–77 °F, they germinate in two to three weeks; water carefully, as seedlings rot easily. The first flowers appear four to six months after sowing.

Common problems

• Crown or root rot: soggy mix, buried crown, water standing in the saucer.
• Gray fuzz, white powder, or dark spots on leaves: gray mold, powdery mildew, anthracnose, or leaf spot, encouraged by humidity, wet foliage, and poor air circulation.
• Iron and manganese deficiencies: common in pots; a fertilizer containing these micronutrients prevents them.
• No more flowers: temperatures outside 50–68 °F, too little light, or spent flowers left on the plant.
• Pests: whiteflies, aphids, thrips, leaf miners, and spider mites, especially under cover. Insecticidal soap or neem oil keeps them in check; spray late in the day, never in full sun or above 90 °F.

The same symptom can have several causes: always check watering, light, temperature, and the condition of the crown before drawing conclusions.

Toxicity

Gerbera daisy is listed as non-toxic to dogs, cats, and horses, and no toxicity has been reported in people.