What to do when orchids won't bloom? 10 key points for winter care

Quite a few flower enthusiasts report that the orchids they keep at home are slow to bloom - why is that? The low temperatures of winter easily cause problems in orchid cultivation, so enthusiasts need to be even more careful with their care. Below, let's talk about the 10 key points for winter orchid care.

1. Damage from pests and diseases

Common orchid ailments include anthracnose, leaf spot disease, leaf blight, and orchid scale insects. Without preventive measures in advance, pests and diseases can easily harm the entire plant. Therefore, a schedule should be set up and spraying should be done regularly.

2. Insufficient nutrient supply

If you pursue airiness and drainage one-sidedly, the growing medium will have poor water retention, and no matter how much fertilizer you apply, just as much will leach away. So the growing medium needs to be replaced appropriately, and fertilizer should be topped up in time, to help the orchid form flower buds.

3. The plant is too small

Many orchids fail to bloom because the seedlings are too small and have not yet reached the reproductive stage. Some young seedlings that have not yet formed pseudobulbs must grow for two years to form pseudobulbs before they can possibly bloom.

4. Improper dry-wet conditions

In winter, orchids are in a dormant period and suit a relatively dry environment. If the humidity is too high, it easily causes root rot in orchids and affects their blooming the following year.

5. Temperature too low

The roots of potted orchids are easily frostbitten in winter. Even if they don't die, they won't bloom. The ideal ambient temperature in winter should be 0~3°C.

6. Excess nitrogen fertilizer

If too much nitrogen fertilizer is applied, it causes the plant to grow leggy, with overly thick leaves, and reproductive growth is inhibited. The correct fertilization should be: from late April to early July, mainly nitrogen fertilizer with phosphorus and potassium fertilizer as a supplement; from mid-July to late August, mainly phosphorus and potassium fertilizer with nitrogen fertilizer as a supplement; no fertilizer in winter.

7. Nutrients dispersed

If an orchid plant blooms too much in the first year and also sets seed, and then produces too many new shoots the second year, the nutrients will be dispersed. Therefore, buds should be thinned promptly and shoots thinned, and seed-setting should be prevented, to ensure blooming the following year.

8. Dormancy period too short

After entering winter, orchids all enter a dormant period. But if orchids are moved indoors too early, dormancy will be delayed; and if the indoor temperature is too high, it will shorten the orchid's dormancy time, disrupt the plant's biological clock, and inhibit flower bud differentiation.

9. Air pollution

Orchids like to grow in a clean environment. If they are often exposed to pollution such as airborne dust and smoke, the plant will grow poorly and find it hard to bloom.

10. Improper fertilization season

If fertilizer continues to be applied in late autumn and winter, the orchid's vegetative growth will be stimulated and it will be unable to enter normal dormancy, weakening vernalization, causing its physiological functions to become disordered. Orchid fertilization is mostly carried out between Grain Rain and the Start of Autumn.

[Reasons orchids won't bloom] What to do when orchids won't bloom

There are many reasons why orchids won't bloom, and orchid enthusiasts need to investigate and analyze them. A normal mature orchid, as long as it has reached a connected plant of two or three seedlings or more, if cultivated properly, can generally bloom. But in reality orchids are not so easy to grow; during cultivation, the slightest mishandling easily leads to root rot, stem rot, or failure to bloom. Generally, if an orchid's stem buds rot and are left untreated, root rot and yellowing leaves follow, and in the end the orchid will certainly not bloom.

The orchid plant is still small and does not have the reproductive genes. Some young seedlings that have not yet formed pseudobulbs need two years of vegetative growth to form pseudobulbs, then sprout new shoots two or three times, and only when branches of three generations grow together is blooming possible.

Dividing and planting separately will destroy the orchid's habit of passing on reproductive genes through generations growing together. Therefore, orchids are best planted in clumps; single planting means fewer leaves, less accumulation of organic matter, and the reproductive genes cannot become active. Generally, without three pseudobulbs growing connected as three generations together, it is hard to bloom.

Improper dry-wet conditions. Late spring and summer-autumn are the orchid's vegetative growth period (but it needs to avoid the plum rains and the onslaught of heavy rainstorms). If autumn is too dry, it will hinder vegetative growth. Winter is its dormancy period and it should be kept on the dry side; if too wet, the potting soil easily freezes and expands, squeezing and injuring the root mass, affecting the sprouting of new shoots in the following spring and summer, and even more so affecting its normal reproductive growth.

Too little light means limited accumulation of organic matter, which cannot supply the needs of reproductive growth. Although orchids are shade-loving flowers, that does not mean they need no light at all; they only dislike direct strong light and long periods of light, and need diffuse, scattered light (semi-shade). Often, plants grown in dark places have lush dark green leaves but bloom with difficulty and only sparingly; while plants grown facing south and in half-shade in midsummer, although their leaves are slightly yellow-green, bear more flowers, and the flowers are showy and fragrant.

Orchids themselves have special reasons for not blooming, or rather there are a very few orchids that are not much inclined to bloom. This phenomenon has appeared in various orchid species, and I have encountered it myself: a Jianlan (Cymbidium ensifolium) with plain buds collected locally in 2004 has been cultivated in this garden for six or seven years and has grown to more than a dozen pots, yet to this day it has never once bloomed. This is probably the plant (orchid) phenomenon of infertility!

Generally, flower-appreciated Chunlan (Cymbidium goeringii) should not be split into single seedlings for propagation when repotting; it is best to plant three seedlings together in one pot, so that strong seedlings can be raised.

Light is the main factor affecting orchid growth and blooming. Plants rely on sunlight for photosynthesis, producing the nutrients indispensable for their growth. Both the growth of Chunlan and the formation of its flowers require ample light. Sunlight helps orchid leaves carry out photosynthesis and make "food" to support the growth and blooming of the orchid seedlings. Except that Chunlan must not be exposed to direct sunlight in summer and early autumn, more sunlight in the other seasons can not only make the seedlings healthy and sturdy but also strengthen the pseudobulbs and promote bud propagation. Vigorous-growing orchids are relatively prone to sending up flower buds.

Water is one of the material foundations of plant growth, but the amount of watering should have a limit. Watering should not be on a fixed schedule but should seize the right moment. Water when dry, and water thoroughly. When the potting medium is dry, water it - this is the basic principle of watering. When watering, note that the water temperature should be as close as possible to the temperature inside the pot at the orchid-growing site. In summer and early autumn, water in the morning and evening, while in winter water at noon; the aim is to reduce the temperature difference between the water and the orchid pot. Chunlan should generally be watered a little during the growth period, but watering should be strictly controlled before the flower buds have formed.

Why won't orchids bloom? What to do when orchids won't bloom