How to Plant Nasturtium Seeds? Latest Planting Method Explained

Nasturtium is also known as jinlianhua, hanlianhua, jinqianlian, hanjinlian, dahongque, etc. It is a perennial semi-trailing or prostrate plant of the genus Tropaeolum in the family Tropaeolaceae. In the north it is often cultivated as an annual or biennial flower, while in the south it can be grown as a perennial. Under suitable environmental conditions it can bloom all year round. Let us take a look below at how to plant nasturtium seeds!

Seed Soaking and Germination of Nasturtium

1. Seed treatment: Because the seed coat of nasturtium is rather thick, before sowing soak the seeds in warm water (about 40°C) or cold water for 12 hours, peel off the outer skin of the seeds, then continue soaking for 12 hours, with the water preferably not covering the seeds.

2. Seed germination: Take clean, unscented paper towels, fold them into 6 to 8 layers, place them on a small saucer, moisten with purified water (the paper towels should be thoroughly wet), place the soaked seeds in the middle of the paper towels and press lightly, then put the small saucer into a transparent food bag and tie it tightly, allowing air exchange for 15 to 30 minutes each day.

3. Sprouting and sowing: Seeds germinated with paper towels generally crack open and reveal the sprout tip within 2 to 7 days. When the sprout tip reaches 2 mm, it can be planted in soil for seedling raising. After planting in soil, the cotyledons will break through the soil within 2 to 5 days, and once the cotyledons have fully unfolded they can receive full light.

Sowing Time for Nasturtium

1. Spring sowing (East China region): High summer temperatures are not suitable for the growth of nasturtium, so spring sowing should be early. Germination can be started from early February to early March. After sprouting, buds appear in 30 to 35 days and flowers bloom in 40 to 45 days. The characteristics of spring-sown nasturtium are broad leaves, slender stem nodes, fewer flowers than autumn sowing, shorter single-flower blooming period, and fewer and smaller seeds. Spring sowing has a short growth cycle, so it is more suitable for beginners.

2. Autumn sowing (East China region): Autumn-sown nasturtium is carried out from late September to early October, with the full blooming period in February to March of the following year. The characteristics of autumn-sown nasturtium are thick leaves, sturdy branches, compact plant shape, short stem nodes, abundant flowers, longer single-flower blooming period, and plump seeds. Because autumn sowing has a long growth cycle, it tests the patience and planting skills of flower growers.

Planting Methods for Nasturtium

1. Soil: Potted nasturtium prefers soil that drains easily, is rich in nutrients, and is good for root respiration. It fears waterlogging and must not have standing water. The potting soil can be made by mixing garden soil, leaf mold, compost soil, and sand in a 4:4:1:1 ratio.

2. Light: Nasturtium needs sufficient light. In summer it must not receive direct sunlight and should be placed in a cool, well-ventilated place. In the North China region, place it indoors in mid-October, in a spot that receives sunlight. Nasturtium grows according to light conditions, so the plant should be rotated constantly to receive even light.

3. Watering: Nasturtium likes moisture but cannot tolerate waterlogging. Soil moisture should be kept at 50%. During the growth period, water less but more often. In spring and autumn, water once every 1 to 2 days; in summer, water once a day, and in the evening the leaves of nasturtium need to be sprayed with water. During the bud stage, reduce the frequency of watering and increase the amount as appropriate.

4. Temperature: The most suitable temperature for nasturtium is 18 to 24°C. It fears high temperatures, and when the summer temperature is too high it does not bloom easily. Above 35°C, growth slows or stops. Nasturtium is not cold-tolerant and can only survive briefly at 0°C. In winter the temperature should be above 10°C to help it overwinter. Keeping the winter temperature at 12 to 16°C along with suitable fertilizer and water can maintain the growth of nasturtium.

5. Fertilizing: During the growth period, nasturtium can be given 20% decomposed soybean cake water once a month. During the flowering period, apply 0.5% superphosphate or decomposed chicken and duck manure water once every half month. After the flowers fade, apply 30% decomposed soybean cake water once. Nasturtium does not need fertilizing in summer. Apply a compound overwintering fertilizer once in late autumn, which helps with cold resistance and growth the following year.

6. Pests: Nasturtium rarely suffers from pests and diseases. Diseases generally include leaf miners, which cause leaves to curl or fall off, as well as aphids and whiteflies, which can be controlled by spraying. Diseases generally include mosaic disease and ringspot disease. Insecticides can be sprayed to prevent aphids, weeds around the area should be cleared, and infected plants should be pulled up and burned.