When to sow nasturtium for flowering? Seed planting and yellow leaf treatment methods

Nasturtium (Tropaeolum majus) is a plant of the family Tropaeolaceae and the genus Tropaeolum, also known as "hanhe," "hanhe," "jinlianhua," "hanlianhua," "jinqianlian," "hanjinlian," and "dahongque." So when does it usually get sown and flower? How do you plant the seeds? What should you do when the leaves turn yellow? According to a flower base in Suqian, Jiangsu, depending on the region and climate, sowing nasturtium seeds can be divided into spring sowing, autumn sowing, and winter sowing.

When does nasturtium usually get sown and flower?

Sowing:

1. Spring sowing (East China region): High summer temperatures are not suitable for the growth of nasturtium, so spring sowing should be done early. Germination can be promoted from early February to early March; after sprouting, buds appear in 30-35 days and flowers bloom in 40-45 days. The characteristics of spring-sown nasturtium are broad leaves, slender stem nodes, fewer blooms than autumn sowing, a shorter single-flower period, and fewer and smaller seeds. The spring sowing growth cycle is short, 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 peak flowering period in February to March of the following year. The characteristics of autumn-sown nasturtium are thick leaves, sturdy branches, a compact plant shape, short stem nodes, abundant flowering, a longer single-flower period, and plump seeds. Because the autumn sowing growth cycle is long, it tests the patience and planting skills of flower enthusiasts.

Flowering:

Flowers are solitary or 2-3 in cymes, with five petals and 8-19 sepals, yellow, elliptical-obovate or obovate, petals equal in length to the sepals, narrowly linear.

In the north it is often cultivated as an annual or biennial flower. Under suitable environmental conditions, it can bloom throughout the year. A single flower can last 8-9 days, and the whole plant can open dozens of flowers at the same time, with a rich fragrance and brilliant colors, winning people's affection.

In southern China it can be cultivated as a perennial; in North China it is mostly autumn-sown and grown indoors in pots, as a spring-welcoming flower, made to bloom during New Year's Day and the Spring Festival.

The leaves are lush and the flowers beautiful, with flower colors including purplish red, orange-red, and creamy yellow. The nasturtium's trailing stems twine, and its leaves resemble those of bowl lotus; when the creamy yellow flowers are in full bloom, they look like a swarm of butterflies dancing. It is an important ornamental flower.

How do you plant nasturtium seeds?

1. Seed treatment: Because the seed coat of nasturtium is relatively 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 6-8 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, ventilating for 15-30 minutes each day.

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

What should you do when nasturtium leaves turn yellow?

1. Overwatering causes nasturtium leaves to turn yellow (water yellowing): If nasturtium is overwatered and drainage is poor, the roots are prone to rot from dampness; in mild cases the leaves turn yellow and fall off, and in severe cases the whole plant wilts and dies. (If the potting soil becomes waterlogged, it will cause the leaves to turn yellow.)

Solution: After flowering, reduce watering to prevent excessive growth of the branches.

2. Long-term lack of water causes nasturtium leaves to turn yellow (drought yellowing): Leaf tips or edges become withered and dry, and old leaves wither, yellow, and fall off from the bottom up, but new leaf growth is relatively normal.

Solution: Just water thoroughly and sufficiently.

3. Scorching sun causes nasturtium leaves to turn yellow (sunburn yellowing): Flower leaf tips and leaf edges become withered and dry, and yellow spots appear on the sun-facing parts of the leaves.

Solution: Just move it to a shaded place.

4. Insufficient sunlight causes nasturtium leaves to turn yellow (light-deficiency yellowing): If nasturtium is placed in semi-shade or a shaded place, the leaves are likely to turn yellow.

Solution: It needs to be placed in conditions with sufficient sunlight to grow well.

5. Too-low temperature causes nasturtium leaves to turn yellow: Exposure to cold winds and the dry hot air from heating or air conditioning can otherwise very easily cause leaf yellowing.

Solution: The temperature is best kept above 10°C, and the lower the temperature, the more the watering frequency should be controlled.

6. Overfertilizing nasturtium causes leaves to turn yellow (fertilizer yellowing): Excessive fertilizer will cause fertilizer damage. Especially when watering with fertilizer solution, prevent the fertilizer solution from splashing onto the leaves.

Solution: Place it in a cool, ventilated place, stop fertilizing, and water less.

7. Long-term lack of fertilizer causes nasturtium leaves to turn yellow (fertilizer-deficiency yellowing): The color of young leaves becomes lighter, appearing yellow or pale green, while old leaves are relatively normal or gradually turn from green to yellow.

Solution: Check the potting soil; if there are signs of drying out, replace the soil. Usually apply light fertilizer frequently, and water with some alum water at appropriate times.

8. Pests and diseases cause nasturtium leaves to turn yellow: If there are spider threads on your nasturtium leaves, or insects are hiding inside the plant's inner leaves, then the yellowing of the leaves must be caused by pests and diseases, and in severe cases it can cause all the leaves to wither and die.

Solution: Increase humidity, and you can also spray with a pesticide specifically for killing mites.

Appendix: Nasturtium care methods

1. For nasturtium cultivation, sandy loam rich in organic matter is suitable, with a pH of 5-6. Generally, during the growing period, fertilize once every 3-4 weeks, and after each fertilization loosen the soil promptly to improve aeration and facilitate root development.

2. Nasturtium likes moisture and fears waterlogging; keep soil moisture at about 50%. During the growing period, water with small amounts frequently; in spring and autumn, water once every 2-3 days, and in summer water every day, and spray water on the leaf surface in the evening to maintain relatively high humidity.

3. After flowering, reduce watering to prevent excessive growth of the branches. If overwatered and drainage is poor, the roots are prone to rot from dampness; in mild cases the leaves turn yellow and fall off, and in severe cases the whole plant wilts and dies.

4. Nasturtium likes sufficient sunlight and does not tolerate shade. In spring and autumn, it should be placed in a sunny place for cultivation. In summer, provide appropriate shading; in midsummer, place it in a cool, ventilated place. In the north, move it indoors in mid-October and keep it in a sunny place, maintaining a room temperature of 10-15°C and appropriately controlling fertilizer and water. At the same time, the flowers and leaves of nasturtium are strongly phototropic, so when cultivating or viewing it, change its position frequently so that it grows evenly.