Gladiolus Leaves Turning Yellow or Black: Find the Cause, Cut the Diseased Leaves and Spray

Gladiolus is a very easy-to-grow indoor flowering plant, but if your care method is wrong, the gladiolus leaves will turn yellow or black. Previously we covered how to grow gladiolus, how to water-culture potted gladiolus, and what to do with the corms after gladiolus blooms. Now let us look at what to do when gladiolus leaves turn yellow or black and the reasons gladiolus leaves turn yellow. If the leaves turn yellow or black, the care method must be wrong.

1. Reasons Gladiolus Leaves Turn Yellow: Related to Light and Watering Amount

Gladiolus is a very easy-to-grow potted flowering plant; leaves turn yellow or black only when the care method is wrong. Many people do not know what to do when gladiolus leaves turn yellow or black. In fact, the biggest factors are insufficient sunlight or overwatering. Let us first look at the reasons gladiolus leaves turn yellow.

1. Light Too Strong or Too Weak

Gladiolus is a sun-loving plant, but summer light is too strong, and at this time it should not be placed outside in strong sun! Neglecting shade or providing insufficient shade makes the light too strong, causing gladiolus leaf tips to scorch. If the orchid is shaded too much during growth and the light is too weak, long-term growing in shade will also make gladiolus leaves thin and weak; if the orchid is suddenly exposed to strong light, it easily causes scorched tips and shrunken leaves.

2. Overwatering

Watering too frequently causes root rot and leads to scorched tips. Spraying water in sunlight lets water collect at the leaf tips, and strong light then scorches the tips. If the water quality used for watering is polluted, or the orchid is exposed to acid rain, it will also cause scorched leaves.

3. Temperature Too Low

Being too lazy to water makes the potting medium too dry, unable to meet the orchid plant's water needs, forming empty roots; the orchid leaves cannot get a normal water supply, and water loss causes gladiolus leaf tips to scorch. Another point is that too low a temperature causes it; gladiolus leaves turning yellow or black are closely related to temperature, and if the temperature is too low it will inevitably cause orchid leaf tips to scorch. The several causes of gladiolus leaves turning yellow described above, caused by natural factors or improper management, are usually called physiological tip scorch. This kind of tip scorch is usually black, and there is no black horizontal line at the edge of the disease; it will not advance rapidly forward, the course is relatively slow, and the degree of harm is not great.

2. Leaf Yellowing or Blackening Caused by Pathogens

1. Bacterial Brown Spot Disease

Gladiolus leaf brown spot disease is caused by bacterial infection. It is the most vicious tip scorch disease among orchid leaf diseases and is relatively easy to identify. Its lesions are brown. In the early stage of the disease, the leaves have water-soaked faded spots that look as if they have been scalded by boiling water, and they quickly join into one patch and advance forward, causing an entire section of leaf to die. It is extremely contagious, spreads rapidly, and is extremely harmful.

2. Anthracnose

Gladiolus anthracnose is caused by fungi. It is the most common tip scorch disease and is relatively easy to identify. Its notable feature is that after the leaf tip is damaged and dries up, there are several wavy transverse black bands. If the scorched-tip leaves are cut off and no fungicide is applied, it will still continue to advance forward. It is a relatively serious tip scorch disease.

3. Black Spot Disease

Gladiolus black spot disease is caused by fungi and is relatively easy to identify. Its notable feature is that the lesions are round, scattered on the leaf surface and leaf margins, and in severe cases can also join into one patch, causing the entire orchid leaf to lose its ornamental value.

4. Leaf Blight

Gladiolus leaf blight is caused by fungi. It is one of the more vicious tip scorch diseases and is relatively easy to identify. Its notable feature is that in the later stage the leaf tip turns grayish-white and the entire section dies, the junction of the diseased leaf is dark brown, and it continuously advances forward, even causing the entire leaf to dry up rapidly. It is extremely harmful. Pathogens can also be the reason gladiolus leaves turn yellow. Let us now look at what to do when gladiolus leaves turn yellow or black, and the solutions.

3. Methods for Handling Gladiolus Leaves Turning Yellow or Black

1. Diseased leaves must be cut off: once the leaf tips have scorched, there is no regret in cutting them off; they must be resolutely cut away, with no need to hold back at all. Remove diseased leaves thoroughly, and the cut should be more than 1 cm away from the lesion. If an old plant is severely affected, the whole plant can be cut away without mercy. Then spray with thiophanate-methyl. After cutting off diseased leaves, burn them or bury them deeply. Never leave the cut diseased leaves among the gladiolus. Diseased leaves that fall on the ground during pruning must also be picked up, to prevent them from becoming a source of infection again.

2. Medication must match the symptoms: once gladiolus leaf tips have scorched, find out what caused it. If it is physiological tip scorch caused by improper management, then strengthen management according to the cause. If the tip scorch is caused by disease, first distinguish whether it is caused by bacteria or fungi. This point is very easy to distinguish: bacterial brown spot disease has an obvious symptom: in the early stage of the disease the lesions look like water-soaked marks scalded by boiling water. Diseases caused by bacteria are controlled with agricultural streptomycin, yekuning, and copper hydroxide; diseases caused by fungi are controlled with thiophanate-methyl, chlorothalonil, and tebuconazole. If it is difficult for a while to distinguish which disease it is, mix the bactericide and the fungicide and use them together, which can also achieve twice the result with half the effort.

3. Treatment must be timely: once the disease is discovered, medication must be used promptly for treatment. Never have the paralyzed attitude of "it does not matter if gladiolus leaf tips scorch," and even less the mistaken idea that "gladiolus leaf tip scorch is normal," delaying treatment and causing the disease to worsen and the scope to expand. Clearly recognize that diseases of gladiolus leaves spread very quickly; although they do not cause death, they cause loss of ornamental value.

4. Prevention must be ongoing: "prevention is more important than treatment." Prevention work must be carried out consistently without slack. Spray liquid medicine regularly. Preventive medication should start in early spring. Bactericides and fungicides should be used together, once every 10-15 days. Even if no disease is found, medication should still be used, to prevent trouble before it happens and eliminate the disease in the bud.

5. Spraying water must be strictly forbidden: once orchid leaves show tip scorch caused by pathogens, spraying water must be strictly forbidden. Spraying water wets the leaf surface and accelerates pathogen reproduction; at the same time, spraying water accelerates the spread of pathogens, causing vicious transmission. If there is too much dust on the leaf surface, affecting the orchid's photosynthesis and respiration, after spraying water and when the leaf surface is dry, immediately spray together with copper hydroxide and other fungicides, to prevent the spread and transmission of pathogens. The above is the complete analysis of what to do when gladiolus leaves turn yellow or black and the reasons gladiolus leaves turn yellow. We hope it can help everyone.

What to Do with Gladiolus Corms After Blooming: Refrigerate the Gladiolus Corms (Replant After Spring Begins)

Gladiolus is a flowering plant very suitable for growing indoors. Previously we discussed how to grow gladiolus, how to water-culture gladiolus, when gladiolus blooms, and so on. Now let us look at what to do with the corms after gladiolus blooms. Many friends who have grown gladiolus throw the corms away directly after the gladiolus flowers fade. In fact, gladiolus corms can be refrigerated. After refrigeration, the gladiolus corms can be taken out and replanted when the new year begins.

1. What to Do with Gladiolus Corms After Blooming: Refrigerate and Then Replant

Gladiolus flowers are beautiful, but no matter how beautiful a flower is, there is always a day when it fades. Many people do not know what to do with the corms after gladiolus blooms, and some directly throw the corms away. In fact, doing so is wrong. The gladiolus corms can be preserved, and then taken out to plant when spring begins or when you want to plant them. Refrigerated corms can be stored for one year. Let us look at the refrigeration method for gladiolus corms.

1. Dig out the corms: after the flowers fade in autumn, gladiolus corms have a natural dormancy period of 2 months. At this time, preserve the corms well to ensure they can sprout normally after dormancy. Normally, once winter has passed, plant the corms, and they can sprout in early spring in February. But the northern regions are relatively cold, so planting in March to April is fine. During this period, pay attention to ventilation and dryness.

2. Break off the small cormels beside the corms: gladiolus corms are corms, and many small cormels grow around the large corm. When storing the corms in autumn and winter, the small cormels can be broken off and planted in spring. Because gladiolus corms degenerate relatively quickly, they are mainly rejuvenated through propagating cormels.

Gladiolus has a dormancy period of 2-3 months each year; even if the environment is suitable, it will not grow. To make it bloom earlier, its dormancy period must be broken. Store the corms at 0-4°C for 30-50 days, or soak them in 39°C water for 2 weeks to break dormancy. With methods like these, as long as the corms are made to enter dormancy earlier, after the corms are planted they will bloom earlier than ordinary corms. What to do with gladiolus corms after blooming, now you know! Next let us look at the precautions for refrigerating gladiolus corms.

2. Precautions for Refrigerating Gladiolus Corms

1. Room-temperature storage: wrap the corms directly in newspaper or a mesh bag and place them in a cool, ventilated corner.

2. Low-temperature storage: place the corms in the refrigerator crisper for storage.

3. Try to replace with new soil for planting each year. If caring for them in the open ground, try to change the location. The planting depth must reach at least 5-8 cm, to ensure the healthy development of the new corms.

4. Small cormels harvested in autumn, sown the following spring, can produce new corms by October. However, for seed corms it is best to choose cormels the size of a soybean or pea.

3. Precautions for Replanting

Before planting, the corms should be disinfected. The method is to take the stored corms, remove the outer skin, soak them in clean water for 15 minutes, then soak them in a 500-fold solution of 50% carbendazim for 30 minutes and a 500-fold solution of 50% thiram powder for 10 minutes. Take out the corms, pile them together, cover them with plastic film for 1 hour, spread them out to dry, and only then plant them.

After the gladiolus corms are planted, if the soil is dry, irrigation should be carried out to prompt the corms to root quickly. During the growth period from the 3rd leaf to the 6th-7th leaf, it is the stage when the flower primordia form (the 3-leaf stage), and also the key period when the mother corm's root system begins to die and the new corm grows new roots. Special attention must be paid to the water supply, while combining management practices such as loosening the soil, weeding, and topdressing.

When Does Gladiolus Bloom: What to Do If Potted Gladiolus Does Not Bloom (Flowers in All Four Seasons Fill the House)

Gladiolus is a flowering plant very suitable for growing indoors. Previously we introduced gladiolus cultivation methods and precautions and how to water-culture gladiolus. Now let us look at when gladiolus blooms and what to do if gladiolus does not bloom. If gladiolus is grown well, the flowers it produces are absolutely more gorgeous than roses.

1. When Does Gladiolus Bloom: It Blooms in All Four Seasons

Gladiolus is a plant that very much loves light. They fear cold, and temperatures below 0°C may very likely freeze them to death, so sunlight and water are indispensable. Many people do not know when gladiolus blooms. In fact, potted gladiolus can bloom in all four seasons. They have different varieties, and well-grown gladiolus can produce flowers in 2 months.

Gladiolus flowering period: gladiolus is divided into two varieties, spring-flowering and summer-flowering, and different varieties have different growth cycles. Early-maturing varieties bloom in 50-601 days, mid-maturing varieties bloom in 65-80 days, and late-maturing varieties bloom in 80-120 days. The flowering period is generally from May to October, with May to June and October being the best for blooming. Because the planting season is different, the blooming season is naturally different.

If blooming is required in January to February, then plant in October to November. If planted in December, then it blooms in March to May. Generally, gladiolus takes 100-120 days from planting to blooming. Natural blooming is sometimes in spring and sometimes in summer, and it is relatively easy to keep alive. Now that we know when gladiolus blooms, let us understand what to do if potted gladiolus does not bloom.

2. What to Do If Potted Gladiolus Does Not Bloom

1. Improper Cultivation

If your gladiolus does not bloom, then your cultivation method must be improper; either there is not enough sunlight or not enough watering. First, before planting, the corms should be disinfected. The method is to remove the outer skin of the stored corms, soak them in clean water for 15 min, then soak them in a 500-fold solution of 50% carbendazim for 30 min and a 500-fold solution of 50% thiram powder for 10 min. Take them out, pile them up, cover them with plastic film for 1 h, spread them out to dry.

2. Planting

For flowers supplied in summer, they can be planted in the open ground in spring; for flowers supplied in winter and spring, they are cultivated in a greenhouse, and the growth period is more than 20-30 days longer than in summer. When planting, to prevent lodging and cormel growth, they should be planted somewhat deeply, and stakes should be inserted around the planting bed with ropes tied around them. The planting bed surface is 5-10 cm high and 1 m wide; in dry areas, flat beds can be made.

3. Sunlight

Insufficient light during flower bud differentiation will reduce the number of flowers. After flower bud differentiation is complete, short-day conditions help the formation of flower buds and earlier blooming. For potted gladiolus, mainly use phosphorus and potassium fertilizer, and apply light fertilizer more frequently.

3. What to Do After Gladiolus Blooms

After blooming in summer, the faded flowers should be cut off promptly, and water and fertilizer management should be strengthened, so that the nutrients of the aboveground part transfer underground and promote the swelling of the underground corms. After the corms mature in autumn, they should be harvested and stored promptly. Dig up the corms, remove soil clods and debris, cut off the dried stems and leaves, dry the corms, and store them indoors in a cool, ventilated place.

Generally, fully dried corms can be stored for 1 year when refrigerated at 1-3°C, and can still sprout normally after winter has passed. The above is the complete analysis of when gladiolus blooms and what to do if potted gladiolus does not bloom. We hope it can help everyone.