A Detailed Guide to the Latest Nasturtium Growing Methods, Easy for Beginners to Learn

Nasturtium (Tropaeolum majus) is a perennial semi-trailing or prostrate plant of the genus Tropaeolum in the family Tropaeolaceae. In southern China it can be grown as a perennial, while in North China it is mostly sown in autumn and potted indoors, and in the north it is often grown as an annual or biennial flower. Under suitable environmental conditions it can bloom all year round, with a sweet fragrance and brilliant colors, winning people's affection. Now let's take a look at how to grow nasturtium!

Nasturtium's Growth Habits

Nasturtium prefers a mild climate and cannot tolerate severe cold or intense heat. Its suitable growing temperature is 18 to 24 degrees Celsius, and it can endure short periods of 0°C. It likes warmth and humidity, and its overwintering temperature should be above 10°C. It does not bloom easily in high summer temperatures, and growth is inhibited above 35°C. It needs ample light in winter, spring and autumn, and potted plants should avoid direct sun exposure in summer. Potted plants need loose, fertile, well-draining potting soil; they like moisture but fear waterlogging.

Nasturtium's Propagation Methods

1. Sowing: Generally the sowing period is from March to June, with the flowering period from August to December. Sowing in late August or early September of autumn is also possible, and this will bring blooms around New Year's Day and the Spring Festival. The suitable germination temperature for nasturtium is 18 to 20 degrees. After sowing in individual spots, cover with about 1 cm of soil, water thoroughly and keep moist; germination occurs in 7 days. When there are 2 to 3 true leaves, pinch out the growing tips and pot up, and tidy the leaves and branches appropriately to improve ventilation and let the flowers show.

2. Cuttings: Take cuttings from April to June, selecting tender stems as cuttings, removing the lower leaves, shading them after insertion and keeping them moist; roots form in 2 to 3 weeks. As the stems and vines grow, bamboo strips should be used promptly to set up a trellis and tie up the branches and vines. Apply fertilizer once every 10 to 15 days, and maintain sufficient moisture and fairly high air humidity throughout the entire growing period.

Nasturtium's Growing Methods

1. Soil: Potted nasturtium likes soil that drains easily, is rich in nutrients and allows the roots to breathe. It fears waterlogging and must not sit in 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, but in summer it must not be exposed to direct sunlight; place it in a cool, well-ventilated spot. In North China, move it indoors in mid-October and place it where it can receive sunlight. Nasturtium grows according to the light conditions, so the plant should be rotated constantly to receive even light.

3. Watering: Nasturtium likes moisture but cannot tolerate waterlogging, so soil moisture should be kept at around 50%. During the growing period, water little but often: in spring and autumn water once every 1 to 2 days, in summer water once a day, and in the evening mist the nasturtium's leaves with water. Reduce watering frequency during the bud stage, and increase the amount as appropriate.

4. Temperature: The most suitable temperature for nasturtium is 18 to 24°C. It fears high temperatures, and does not bloom easily when summer temperatures are too high; above 35°C growth slows or stops. Nasturtium is not cold-tolerant and can only survive 0°C for a short time, so the winter temperature should be above 10°C to help it overwinter. Keeping the winter temperature at 12 to 16°C together with suitable fertilizer and water can keep nasturtium growing.

5. Fertilizing: During the growing 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. In late autumn, apply a compound overwintering fertilizer once, which helps with cold resistance and growth the following year.

Nasturtium's Pest and Disease Control

1. Leaf miner

[Symptoms] The larvae bore into the plant's new shoots and tender leaves, forming winding tunnels within the layer between the upper and lower epidermis, so that the entire new shoot and leaves cannot unfold and easily fall off; in severe cases, all the autumn shoots can turn yellow and wither.

[Control] In winter, prune off the larvae and pupae that overwinter on late-autumn shoots and winter shoots. In spring and early summer, remove scattered larvae and pupae causing damage, to reduce the source of the next generation.

2. Mosaic disease

[Symptoms] Infected leaves show original mosaic-type symptoms of alternating yellow-green and dark green, the leaves become smaller, and the whole plant looks somewhat stunted.

[Control] Spray insecticides to control the aphids that transmit the virus, and promptly pull up and burn infected plants when found.

3. Ringspot disease

[Symptoms] Ring-shaped mosaic or necrotic spots form on diseased leaves.

[Control] Control aphids promptly. Commonly used insecticides include 50% malathion emulsifiable concentrate at 1000 times dilution, or 40% dimethoate emulsifiable concentrate at 1000 to 1500 times dilution, or compound fruit emulsifiable concentrate (40% dichlorvos, 10% omethoate) at 2000 to 3000 times dilution, or 20% fenpropathrin emulsifiable concentrate at 3000 times dilution, etc. At the same time, pay attention to the weeds around the nasturtium and remove other virus-source plants.