Culture guide

Usage

Plants for bedding, pot plants, beautiful plants, that attract bees and butterflies, plants for planting of bowls

Sow time

February-June

Sowing method

1 seed per plug, can be sown directly into final pot

Germination

7-10 days at 68-72 °F (20-22 °C). Higher temperatures can reduce germination and cause week seedlings. Sow seeds in a well-drained media low in nutrients with a pH between 5.8-6.2. Cover seed lightly with vermiculite.

Growing on

Grow on at 60-65 °F (15-18 °C) for 3-4 weeks. Temperatures below 60 °F (15 °C) delays flowering. Provide good ventilation.
Fertilize weekly at 200 ppm nitrogen in a well-balanced mix. Use of calcium nitrate will improve stem strength. For cut flower production, thin seedlings or plant plugs at 8-10″ (20-25 cm) in rows or
9-12″ x 12″ (23-30 cm x 30 cm) spacing in beds.

Media

Use a well-drained, growing perennial substrate with 15-30 % clay, 1-1,5 kg/m³ complete balanced fertilizer, iron-chelate, micronutrients, pH: 5.8-6.2.

Temperature

Grow at 15-16 °C. Temperatures below 10 °C support yellow leaves. Zinnia does tolerate high temperatures of 25 °C, but does not tolerate frost. For selling it is recommended to harden the plants slowly at 12-14 °C.

Fertilization

Moderate fertilization levels are required. Fertilize the crop weekly with 100-150 ppm nitrogen, using complete balanced fertilizer. Avoid high ammonium and high nitrogen levels, because high nitrogen level will result in soft stems. Stems are too soft will break underneath the flower. Prevent magnesium deficiency by applying magnesium sulphate (0,05 %) 1-2 times and in case of iron deficiency apply iron-chelate for 1-2 times. Nutrition deficiency supports a poor branching. The roots are sensitive to high salt levels in substrates.