The monsoon downpours have begun, and your orchids will get a fresh lease of life when you make the most of the season and allow them to soak in its goodness. Rich in Nitrates, phosphorus, and Vitamin B12 producing bacteria floating in the air, rainwater also comes with a balanced pH optimal for the growth of your orchids, thereby helping them thrive and bloom during their cycle. But the trick here is to expose your orchids in the right way, for the right time, and to check thereafter that they are growing well and not facing issues of rot.
Read on to learn more about my six orchid care tips for the rainy season to take full advantage of the rains. An added benefit would be that we can look forward to some respite from our regular watering and fertilizing schedule, and focus on other orchid related projects.
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After the hot and dusty summers, your orchids will welcome the rains with gusto. The first shower will drench your orchids and invigorate them to produce new growths and roots in abundance. The spurt in growth is significantly noticeable, some shooting up by almost a centimetre in a single day. As the leaves and stems get drenched and water trickles down the stems and into the roots, you notice visible changes such as a bright green colour, turgid leaves and new growths that are almost bursting out of their sheaths. Well that’s not all. Rain water will swell up the buds on the nodes, which develop into spikes in the case of vandas, oncidiums and phaenopsis, just as you will find buds pushing themselves out of their sheaths, as in the case of cattleyas. Such is the amazing impact of the rain on your orchids.
This should come as no surprise to you, knowing that most orchids, in their natural habitat grow in the rain forests, where there are frequent downpours and a predominantly humid environment. Epiphytic orchids (orchids that grow on trees) get drenched in the rains and spread out their roots on the tree trunks. Since the roots are exposed to air, they tend to dry off quickly and therefore roots do not rot even with repeated downpours. The leaves and crown are so arranged that water that falls on them just slips away and falls down or trickles down all the way down along the stem. Also the breeze following a downpour quickly dries off the plants, preventing collection of water and microorganisms in the crown and other nooks and crevices.
I strictly avoided wetting the leaves and only watered the orchids in the root region earlier. I did face crown rot and stem rot issues. So I decided to make the orchids resistant to crown rot by spraying them down with my gardening spray pump.
I took this step as I have a west facing windows, which allow good air circulation. So if you do not have good air circulation in your grow area or do not have a fan to circulate air, then this is best avoided.
Initially, when I begun spraying water, I found water pooling in the crown even after hours after i was done with watering. So I used to tip the pots to drain out the water from the crown. But after some days, I noticed the orchids draining out water from the crown automatically. Talk about adaptation! 🙂 I have never faced crown rot issues after that, even during the rainy season when there is a continuous downpour.
However, growing orchids in your home environment or in a greenhouse is quite another story. The growing conditions you provide in terms of potting media, light and air movement will vary based on your climatic conditions. Growing phalaenopsis orchids with their crown positioned vertically to provide an aesthetically pleasing display, may not exactly be conducive for exposing your orchids to the rain. To remove the tediousness of everyday watering, we have also modified our care routine by growing orchids in moisture retentive medium. While this can work well during the warm dry summers, it can adversely affect your orchids if they are continuously exposed to the rain during the monsoons.
I grow my orchids on my windowsill, in my tropical grow conditions using organic potting mixes of pine bark and sphagnum moss. Warm summers are followed by the rainy season. While I make some superficial changes to provide a conducive environment for growth during various seasons, additional care needs to be taken so that the orchids don’t develop issues such as fungal and bacterial rot. Taking care of these issues will help you provide the right amount of exposure to rain, which will stimulate growth and blooming in your orchid.
Let us begin with the commonly faced issues when our orchids are exposed to rain:
- Crown Rot – This is one of the most common issues faced by orchid hobbyists when their orchids are exposed to rain. When rain water collects in the crowns of monopodial plants such as phalaenopsis or vanda orchids, the long exposure to moisture, along with the bacteria and fungi that are on the surface of the leaves, tend to create an unhealthy environment for the orchid, wherein the bacteria and fungi start multiplying due to excessively moist conditions. This leads to rotting of the tender tissue in the crown of the plant. The infection spreads to the other portions of the stem and the plant slowly begins to lose its leaves. Timely intervention can help you save the orchid, but it will set back its growth and blooming to some extent.
- Rotting of leaves – Rain drops often collect in the base of the axil of the leaves. These regions are snugly bound to the stem and can allow moisture to accumulate. This again leads to an environment conducive for bacterial and fungal growth. Since the leaves are arranged on either side of the stem or pseudobulb in the case of vanda, phalaenopsis, oncidium and tolumnia, dendrobium and other such orchids, the infection spreads quickly to the stem and other parts. Sometimes, soft water-filled black spots appear on the leaves. If left untreated, they quickly spread and destroy the whole leaf and subsequently the stem. Only timely intervention and appropriate remedial measures can save the plant.
- Root rot – Moisture retentive medium such as sphagnum moss, when added to the potting medium tends to hold copious amounts of water. This is utilised by the the plant and the medium dries off after a couple of days. But when your orchids soak up rain water, the medium remains damp for prolonged periods, then fungal and bacterial infections become rampant. The roots become soggy and begin rotting. The first sign of root rot is when the leaves become thin and dehydrated despite moisture in the pot. This is indicative of a damaged root system. If not treated on time, the infection quickly travels up the root, to the rhizome and the pseudobulbs. This further causes the leaves and stem to turn yellow and black, and decay.
- Rot of new growths – Just as with crown rot, rain water that remains trapped in new growths of oncidium and cattleya orchids can also lead to bacterial and fungal rot. As the water travels into the crevices, it collects bacteria and fungi on the surface of the plant and its narrow vertical structure does not allow air to enter and dry up the moisture. The prolonged dampness promotes bacterial and fungal attack on the roots, leading to rotting of the delicate tissue. Losing a new growth to rot can lead to setback for the plant as these new shoots are the ones that would mature and bloom in the coming season. Moreover, orchids put out new roots through these new growths. If the orchid does not have a healthy root system, then this could prove to be a major setback for the plant. So, these delicate new growths need to be protected from rainfall.
Advantages of rain water for your orchids
Now you must be wondering that if there is so much of risk involved, then why you should even consider placing your orchids in the rain. Well, for the simple reason that rain water has manifold benefits on your orchids. The first and foremost being that it has the right pH of around 6.5, which is suitable for healthy orchid growth and blooming.
During rains, Nitrogen from the atmosphere is converted to oxides of Nitrogen by lightning. Oxide gases of nitogen and sulphur , along with carbon-dioxide from the atmosphere, are brought down to the earth by rain. The Nitrogen is converted to nitrates when it dissolves in rainwater.
As the rainwater comes down, some of the nitrates are converted to metabolic by-products such as Vitamin B12 by bacteria in the air and on the surface of plants. This is rich in Nitrogen and Phosphorus (If you check out the structure of Vitamin B12, you will find several nitrogen atoms and a phosphate group in each molecule). Vitamin B12 cannot be absorbed by plants directly, so it is broken down by bacteria and fungi to form soluble nitrates and phosphates. These are then readily absorbed by the plants, resulting in the insrant greening effect on plants seen after rainy showers. I allow my orchids to soak up the rain. The results are simply amazing. They develop a lush green hue that is incomparably beautiful and healthy.
Another advantage of rainfall is that it can help your dehydrated orchids become hydrated and healthy once again. Since rainwater is readily absorbable, you can place your severely dehydrated orchid in rain and the leaves and pseudobulbs will plump up again. I have revived quite a few orchids that were dehydrated due to an inadequate root system. The plant basically gets a new lease of life and will begin producing new roots and growths when it gets soaked in the rain.
Healthy plants thrive in the rain by shooting up to almost a centimetre in length of new growths, leaves and roots. Spikes and sheaths also begin to develop as a result of rain. I have known cases where a vanda orchid did not bloom for ten consecutive years, but bloomed in the eleventh year, when the hobbyist allowed the vanda to soak up the rain during monsoon. Such is the power of rain water. In fact, experienced orchid hobbyists often collect rainwater in large clean storage tanks and water their orchids with it throughout the year.
Now let us understand how you can effectively provide the above advantages without adversely affecting or damaging your orchids. A little care will help you keep your orchids safe while exposing them to the rain. While most of your orchids will thrive in the rain, you may face issues in some orchids based on their health. You need to watch over them with a keen eye, for any signs of susceptibility.
Six care tips for your orchids during the rainy season:
Follow these six cautious care tips to protect your orchids when you expose them to rain:
- Prepare your orchids for the rainy season
My tropical grow conditions are ideally suited for warm growing orchids. During summers, the climate tends to get very warm and dry, increasing my frequency of watering. To increase humidity, I superficially line up the periphery of the pot with sphagnum moss. This provides humidity and keeps the orchids cool. But come rainy season, and I remove this top layer of moss and replace it with bark chips. This prevents excessive moisture retention, which would lead to rotting of the orchid roots and stems.
Along with this, I also clean up the leaves of the orchids with a soft cloth or sponge dipped in mild dish-wash solution and allow them to dry under a fan. This removes any superficial dust and mites.
When it begins to rain, I use small polythene bags to cover the new growths and protect them from holding moisture. I followed this tip from the YouTube channel, My Green Pets, and it has worked just fine for me.
- Prevent retention of moisture for a prolonged period
Since we grow orchids upright as opposed to how they grow in the wild, water tends to pool up in the crown area of the pseudobulb, leading to rot. To prevent this from happening to your orchids, you can allow them to soak in the rain and once it is saturated, tilt the pot slightly and allow the excess water to run off along the axil of the youngest leaf. This will allow minimal moisture to remain in the crown, which can easily be dried up by air-drafts.
If you grow your orchids outdoors in your balcony, patio or on your window-sill, the breeze will dry off the remaining moisture. But remember to tip the pots sidewards at a 45º angle so that excess water does not remain trapped in the pot. Alternatively, place the orchids under a fan. This will ensure that they dry off quickly. You could also draw out the moisture by rolling up absorbent paper and blotting out the moisture.
- Check on your orchids after they get wet in the rain
One way to ensure your orchids are safe, is to check them every day for signs of infections and rot, especially after you have exposed them to rainfall. Catching infections, rot and pest infestations early on will help you save your orchid by taking appropriate preventive measures. Look out for soft, damp, dark spots on the leaves. This is an indication of leaf rot. Also yellowing and soft rot in the crown region or the stem indicates crown rot and stem rot, respectively. These require immediate remedial action.
- Ensure a good wet-dry cycle
While it rains almost every day during the season, we cannot give our orchids the advantage of getting soaked day-after-day during the season. The reason being that we pot our orchids in moisture retentive organic medium like coconut chips, sphagnum moss and bark chips.
Excessive retention of rainwater can lead to a soggy environment. Orchid roots do not like prolonged soaking wet conditions and quickly begin to rot. Excessive moisture over prolonged periods in the medium makes the medium very acidic. This is either caused by excessive moisture retention due to moisture absorbent media or due to poor drainage and ventilation of the pots. You need to ensure that both these issues are set right before you think of soaking up your orchids in the rain. If not detected early on, the rotting can even spread to the pseudobulbs, and destroy the plant completely.
To prevent rot from setting in, you need to limit the exposure of your potted orchids to rainfall. Let your potted orchids reach near-dry conditions before allowing them to soak up rainwater again. If they are already moist, do not expose them to rain again as excessive moisture in the medium will promote rotting of roots and new growths.
If your orchids are potted in any inorganic material that is non-absorbent ar are bare root, you can go ahead and allow them to soak in the rain during the entire season. Just ensure they dry up after each soak so that no water pools up in the new growths and crowns. You can easily tip your mounts to one side to drain out any moisture that is trapped in new growths or sheaths.
- Take quick remedial action if you observe signs of rotting
Once you identify any rot issues in any of your orchids, you need to take quick remedial action to treat them at the earliest.
In the case of stem, crown and leaf rot, you may have to remove the rotted tissue by cutting or scraping away the affected portion. Apply cinnamon powder on the cut surfaces to prevent them from getting re-infected.
For root rot issues, you may need to cut away the affected portion of the roots and rhizome and apply 3% hydrogen peroxide to the healthy part of the rhizome and root system. In case the infection is severe, you may need to apply a suitable fungicide in below recommended proportions. This will help salvage the healthy portion of the plant.
Some hobbyists recommend a fungicidal spray (prophylactic) every fifteen days to prevent fungal and bacterial rot. Personally, I avoid spraying harmful chemicals and instead prefer much conservative and harmless methods to control rot issues. I use fungicides cautiously, only when there is a major problem with orchids. These are highly toxic and, therefore, should be applied with extreme caution and care, especially if you have children and pets around. Also, there is the issue of development of resistance to these fungicides, which will render the application ineffective. So please use them selectively to isolate and treat only the affected plant.
- Additional precautions to be taken
Once you wet your orchids in the rain, do not allow the excess water from the medium to drain out onto other pots. This can lead to rotting of the crown, stem, roots, leaves and also new growths of the orchid. The rot is mainly due to spread of infection from one pot to another. This can be prevented by placing a saucer under the pot to collect water or allowing it to drain out fully before hanging it up above your other plants.
Another reason for spread of infection can be attributed to the use of unsterilized equipment for trimming your orchid leaves and roots. This can get aggravated and lead to spread of the infection due to a prolonged moist environment. So always sterilize your cutters with rubbing alcohol and flame it with necessary precaution. Ensure all safety measures are taken during this procedure.
For instance, Fusarium Wilt is a fungal disease that is commonly spread by sharing of water and using unsterilized pruners or cutters for trimming your orchids.
For more information on orchid diseases, pest infestations as well as their treatment and preventive measures, you can read my post How to save your orchids from pests and diseases.
Armed with these tips, you can confidently allow your orchids to soak up in the rain and get all its inherent advantages. This will promote their healthy growth and blooming. And you get some respite from watering your orchids. Just watching them soak in the rain will make you very happy. After all, growing orchids is also about keeping ourselves peppy and happy.
Please leave a comment below if you have some more useful tips so that I can include the same in the post (and credit you for the same).
Till my next, happy growing!