Monthly Inspection of Orchids: Where It All Begins

The orchid enthusiast who wants to improve their skills will need to dedicate time to observing its collection. In fact, this is the beginning of any good horticultural practice. In this column, I suggest a monthly orchid inspection method that is easy, quick, and quite enjoyable.

The Three Objectives of Orchid Inspection

First, you need to check that the plant’s four basic needs are being met. You probably remember the column on photosynthesis which explained the importance of:

• 1.1 sufficient light; suitable for the cultivated species;
• 1.2 abundant hydration; only when the plant has dried well;
• 1.3 daily variation of ambient temperature (day/night);
• 1.4 gentle and regular ventilation at all times (24/7).

Secondly, we will try to determine the progress of the plant in its annual cycle which will allow us to adapt the care. We will be particularly attentive to the emergence of:

• 2.1 new roots indicating the beginning of a new growth cycle;
• 2.2 new leaves in deployment;
• 2.3 inflorescences in formation;
• 2.4 flower buds which are particularly fragile.

Finally, we will take the opportunity to identify any need for additional horticultural care, such as:

• 3.1 cleaning of any debris (old leaves, flower sheaths, etc.);
• 3.2 assessment of substrate degradation;
• 3.3 redirection of aerial roots towards the substrate;
• 3.4 the straightening and staking of inflorescences and leaves when needed;
• 3.5 detection of diseases and pests.

How To Proceed To Avoid Missing Anything and To React Correctly

This may seem complicated at first, but it only takes a little method to achieve it quickly and effectively. Here’s a simple “generic” routine that you can adapt to your needs.

A. Inspection

It is best to choose a well-lit and fairly open area. It is recommended to inspect one plant at a time, preferably holding it in your hands when possible. You will need to examine it from all angles. Before beginning the actual inspection, it is recommended to wash your hands (as well as any work tools) to avoid any contamination during the process.

B. Cleaning

We should start by cleaning up plant debris. It is normal for a growing plant to shed some old leaves, which will turn yellow before turning brown and falling off. These should be removed, as should dried flower sheaths, which no longer contribute anything to growth but represent a certain risk of contamination (ref. 3.1). If you are using a layer of sphagnum moss as a topdressing, make sure that it is not too deteriorated. Generally, the layer of sphagnum moss should be replaced every six months (ref. 3.2).

C. Examination of New Growths

We will continue by examining the new growths, that is the new roots, the new leaves and the new inflorescences. These are the most fragile tissues since they have not had time to harden like the older plant tissue. Problems should normally appear on the young tissue first unless it is degradation caused by aging, of course.

D. Inspection of Growth Abnormalities

Any growth abnormalities that could indicate a deficiency in basic needs should be looked for. For example, deformation and/or abnormal coloration may be caused by inadequate light. Well-erect, rigid, and soft-green foliage normally indicates good lighting conditions (ref. 1.1). Excessive light may be manifested by reddening of the foliage (often at the tips) or by localized burns in the case of exposure to direct sunlight.

Shrivelled and Wrinkled?

If the pseudobulbs shrivel and wrinkle, it is very likely that the plant is lacking water (ref. 1.2). You will then need to review your watering routine and/or the sponginess of the substrate to correct this type of problem. Too much water will lead to rotting of the substrate and possibly asphyxiation of the roots. The entire plant will then quickly die. For better water management, review the column on roots.

Lack of Inflorescences?

When an orchid refuses to produce an inflorescence, it may mean that it lacks light and/or that the nighttime temperature drop is insufficient (ref. 1.3). The full explanation was given in the May 2025 column.

Brown Spots?

If brown spots appear on the foliage, they are probably caused by the presence of bacteria and/or fungi; often symptomatic of insufficient air circulation, especially in the evening when the risk of condensation is higher (ref. 1.4). It is advisable to avoid watering your orchids at the end of the day to avoid contributing to the condensation process in the evening. Morning watering is much preferable! To limit the damage caused by bacteria and fungi (often difficult to distinguish), it is possible to spray the foliage with a chelated copper solution which will contain both pests simultaneously. Ask a specialist at a garden center near you for advice.

E. Synchronizing Our Interventions

Knowing that orchids develop and flower in a fairly regular annual cycle, we will try to synchronize our more significant interventions with the needs of the plant. For example, the appearance of new aerial roots may require a slight “redirection” towards the substrate. Aerial orchid roots are much less effective in domestic cultivation than the substrate roots at absorbing water and nutrients (ref. 3.3 and 2.1). When the new foliage appears, we may apply nitrogen-rich fertilization until the emergence of an inflorescence, then use a less stimulating fertilization (ref. 2.2 and 2.3). Fertilizing orchids will be the subject of a future column. After the opening of the last flower of the season, we can radically reduce fertilization, because the rest period which will follow flowering will not require any additional nutrient input (ref. 2.4). Extra care should be taken when handling a flowering plant and it is recommended to stake the inflorescences before the flower buds become too heavy (ref. 3.4).

F. Repotting if Necessary

If the substrate gives off a bad smell (that of fungus or bacterial rot), it will be necessary to repot the plant at the next opportunity, that is at the beginning of the next growth cycle when new roots emerge. These young roots will be able to ensure the plant’s water supply despite the loss of old roots which is inevitable during repotting. Generally, the bark-based substrate will have to be replaced every 3 or 4 years to avoid the rotting of the root system (ref. 3.2).

Experienced orchid growers will pay particular attention to the tips of the leaves, which tend to blacken and dry out when the substrate is saturated with toxic minerals. This is often the case with an old, very deteriorated (or over-fertilized) substrate that should be rinsed under running water to remove the fertilizer salts.

Pests

Occasionally, we can detect the presence of pests in our orchids (ref. 3.5). Mealybugs and aphids are the most common. It is important to remain calm and methodical! First, eliminate all visible insects using a disinfectant wipe (e.g., Lysol or Clorox). Then, sprinkle diatomaceous earth around the base of the plant to block the passages of larvae that have developed in the substrate. Diatomaceous earth is a microscopic abrasive on which moving larvae cut themselves, causing fatal bleeding. You can also treat the infested plant with insecticidal soap, following the pesticide manufacturer’s instructions. It may be helpful to set up small sticky traps (yellow) and check them periodically. In case of recurrence, you should consult a specialist at a garden center or within an orchid association. Take a sample with you to help the advisor diagnose you.

G. Basic Hygiene for Observation

At the risk of repeating myself, wash your hands between each plant to prevent the spread of infestations. Using disinfectant wipes (e.g., Lysol or Clorox) can be very practical and very effective if access to a sink is difficult. They are safe and very effective. I recommend adding a little water to the wipe container so that there is always about one centimeter of water at the bottom of the container. This will ensure the wipes are moist and much more effective. It is recommended to empty the trash can after each orchid inspection and/or cleaning session.

With a Little Practice, This All Becomes Easy and Quick.

Obviously, the first inspections will take you a few minutes, but you’ll quickly gain experience and speed. After just ten inspections, you should be able to diagnose an orchid in seconds.

As a bonus, you’ll probably find some satisfaction in it. For the orchid lover, it’s truly enjoyable to watch a beautiful plant grow to bloom. Especially when you know you had a hand in it!

One last piece of advice: if you’re interested in the topic, don’t hesitate to join an orchid association. There are many across America and Europe. A simple online search should allow you to identify an orchid association that suits you. Note that many of these groups broadcast their meetings online (via Zoom), making them accessible to a wide, geographically dispersed audience. In addition to having access to lectures and workshops, you’ll be able to chat with experienced orchid enthusiasts who will guide you through the fascinating world of orchids.

Thanks

I would like to thank my friend Martin Rondeau for his patience and diligence in reviewing my orchid columns. His comments are very helpful and valuable. I also thank the blog readers who take the time to comment on my posts. Sincerely, thank you!