Background: I’ve been growing orchids for over 10 years and have learned many things over that time. When I first started growing orchids, I was a nut about semi hydro. EVERYTHING I grew was immediately transferred into S/H and ultimately I found flaws that inhibited my success with that method in my environment. All said and done, all the orchids I bought in my first three years died. It wasn’t until my 5th year of growing orchids that I finally started to experience real success; and that happened because I started ACTIVELY breaking all the “common orchid rules”—you know, things like: “high humidity is a big deal”, “always use pure water”, “don’t give orchids bright light”, “don’t get water in the crown”, “don’t let them soak in water”, etc. Now that I’m a better grower and understand orchid care a LOT more, I want to share some of my core care advice with you (so that you can get the insights I never had at the start). I’m also writing this because the advice I gave in a previous post was met with some friction by fellow growers. Apparently it was “click-bait” and wasn’t very secret revealing. Now it’s time to set the record straight; here’s a list of things I’ve learned that have greatly improved my orchid growing…
10+ Things I’ve Learned About Growing Orchids
1. Humidity (rH) is not as big of a deal for orchids as everyone claims it is.
I know this is true, because I grow all 250+ orchids in my condo with an average rH of ~18-40%; on a good rainy day outside my humidity jumps to an impressive 65%—but that’s extremely rare.
Some claim that having many plants on a shelf creates a, “micro climate” around the plants. If you know anything about physics and gasses, you know that they move to achieve equilibrium within a space. Humidity (air with a higher percentage of H2O molecules) isn’t gummy, thick, and sticky; it doesn’t cluster closely around your plants; it disperses quickly to reach equilibrium within your room. Further exacerbating that situation, I run multiple fans in my grow area (because it ensures heat from direct sun doesn’t burn the leaves), AND I run the A/C all summer! That’s a LOT of air movement in an already dry climate. This idea that many plants inherently increases humidity simply isn’t accurate and my humidity gauge is backing that up.
Don’t believe me? No prob. Here’s some helpful proof: I grow Macodes petola (jewel orchids) on my windowsill – today the humidity was 35%. I grow bulbophyllums there. I grow seedling orchids…most without a humidity dome. I grow all of my orchids and I don’t have a single humidifier. Yes, for some species humidity is vital and yes, for all orchids it’s generally better; however, if you live in a place (like a condo with central heating or A/C) where the humidity is low, you don’t HAVE to buy a bunch of humidifiers and destroy your walls and window frames trying to get your humidity up to 75%. You also don’t need a greenhouse, or terrarium to grow most of the common orchids (Phals, paphs, oncidiums, miltoniopsis, etc). The key to successfully growing orchids in a low-humid environment is to keep your orchids hydrated. A severely dehydrated orchid is as bad as a water-logged, root-rot orchid. Once a root system is too dry for too long, it dies…that’s a big (and often under emphasized) problem.
How do you keep an orchid hydrated? The same way you keep any plant hydrated…through its roots. Water religiously and NEVER skip an orchid that needs water by more than a few days. I used to think “dry” between waterings meant DRY and “orchids don’t like being wet or soaking in water” meant they don’t like water at all. I was very wrong. Be mindful of this fact: orchids that “need to dry out” do not need to go BONE DRY like they can in your low-humid environment. They need to lightly dry. Leaves can be bone dry…roots? NOT BONE DRY!
2. Wet Leaves are not the downfall of orchids – stagnant air is
Orchids live in rainforests…this idea that you shouldn’t get the leaves wet is dumb. Wet leaves for a brief period are good because orchids are actually foliar feeders. Wet leaves for a long period are only bad because they give bacteria and fungus the opportunity to grow and invade your plant. Think about your home…would you leave pools of water all over your kitchen counters? Na…because bacteria would grow; but you might give those counters a good wipe down once a day to clean them, right? In nature orchids get rained on. Rain is not poison. You can read more about this here.
3. Low Light does not REALLY mean “low light”
Your eyes are very good at detecting light…your eyes are not very good at interpreting the difference between light that’s good for seeing, vs good for growing a plant. Many new growers in my experience, miss calculate how much light an orchid actually needs, and that SUCKS for inexperienced growers because an orchid can live a very long time with just a little bit of light, but they won’t grow and flower very well. The problem with that is that the average grower may wait YEARS and think they’re doing well because the orchid is still alive, but they reach a point where they get fed up with a pair of leaves on the table, and they toss the plant.
4. Cycles affect growth (temperature and dryness)
Temperature: transitions from warm to cool, and cool to warm are often responsible for inducing growth and flowering cycles on orchids. It’s not the case with ALL ORCHIDS (so do your research), but definitely a good percentage of plants have a seasonal rhythm dictated by temperature.
Dryness: Or wetness? often dictates seasonal changes too. Daily cycles can promote growth. Seasonal cycles can promote blooming (just like temperature). Again…this does not apply to all orchids so DO YOUR RESEARCH and make sure you know which of your orchids are seasonally dry, or seasonally cool.
5. Fertilizer basics
1/4-3/4 tsp per gallon of water is generally a good range for orchids (which is a quarter or half strength) once per week. Urea free fertilizers are generally better; but urea fertilizers will work…though they can burn your roots at higher percentages (as long as you don’t overdo it – also it’s not a HUGE problem to have a few burnt roots). You want something with higher nitrogen and potassium ratios (13-3-15) during active growth, and a well-balanced formula (20-20-20) leading up to flower production.
6. pH and hard water – It’s not important
As long as you leach your pots at every watering, the pH of your tap water is generally good enough to keep your orchids alive under average conditions. I’ve kept the core of my collection for well over 2 years using my “crappy water” (pH of 7.5-8, TDS of 250ppm) and only had a few instances of possible issues which to this day, I can’t say those issues were a result of my water. If you’re interested in more about this topic, I’ve covered my perspectives on pH in detail here.
7. pH – I Lied, pH is a little important
In the world of orchids there are lithophytes (grow on rocks), terrestrials (grow in decaying matter on the ground) and epiphytes (grow on the trunks and branches of trees).
Orchids which are lithophytes come from areas where they grow on or between basalt, limestone and granite rocks. These rocks are alkaline and they constantly buffer the pH of acidic rain water water up (remember that vinegar-baking soda volcano in the science lab? The reaction between acidic rain and alkaline rock and substrates is similar to that…but less aggressive). Lithophytic orchids (along with many species of “regular plants” that grow in high pH environments) have adaptations to better-absorb nutrients in those high-pH environments. Putting alkaline-preferring plants into a low pH environment can actually lead to nutrient toxicity—generally by iron—because their adaptation to better utilize nutrients is not adapted to deal with LOTS of that nutrient (which happens when the pH is low and nutrients are more freely available to the plant via water). This may be why some paphs, phrags and select phalaenopsis are intolerant of lower pH conditions (see phal lowii, chinese paphs, and phrag besseae and kovachii).
Epiphytes are watered with rain which has a slightly acidic pH, and is very low in dissolved salts/minerals. These species tend to deal poorly with high pH water; it’s better to stick to the golden number of 5.8pH for these plants, which is the “ideal nutrient availability pH.”
In 2018, I began altering the pH of my tap water with phosphoric acid and fairly quickly noticed little changes, and improved growth in specific types of orchids. Granted, it was also the beginning of spring…but things like lightly yellowing leaves transitioned to deep green leaves. Oncidiums which previously often had root burn, started getting roots that crawled out of the pot, my seedling phals darkened in color and started to get growth on the few that had stalled, and overall it seemed to work better on the select plants I was pH adjusting.
I say it’s a “little important” because at the end of the day, prior to pH adjusting, I was still able to keep all of these species alive with less than ideal tap water…and so can you (if you’re not ready to become a water chemist).
8. Pick the growing medium that works for you:
Organic media is better – it supports and nurtures beneficial bacteria, fungi (which can out-compete pathogens), and insects that can kill pests; that ecosystem in the pot can convert urea-based fertilizers to usable nitrogen. Plus, you can use organic fertilizers (blood meal, feather meal, kelp meal and bone meal) at reduced amounts, which work REALLY well for orchids (especially paphs and phrags). But you need to use them in combination with organic media, otherwise you’ll lack the microfauna required to break down the organic ferts. Also…don’t use organic ferts at high concentrations.
Inorganic works for some orchids in some climates – If your humidity is high, inorganic probably makes a lot of sense. If your humidity is low…the upper layers of inorganic media can be so dry that they actually pull water from the roots that are in contact with the leca. If you want to know more about my opinions and experience with S/H, click here.
Water Cult(ure) – It’s a fad and if your goal is truly to have healthy orchids that respond well, grow robustly, and produce lots of flowers…then it’s not the most effective growing method. Also… like inorganic medium, Full Water Cult (FWC) is specifically bad for certain types of orchids (paphs, seasonal / cool-blooming phals, repiculous laelias, etc.)
9. An orchid collection should take you years to curate
I once read the biggest downfall of new orchid growers was getting too many plants, too fast. At the time I laughed, but now I get it. If you become a true orchid collector the aspect of acquiring new plants is exciting and addictive. The problem is, a collection can quickly become so large it feels like a burden. Plus mastering care for each type can often take years. Select plants you really love, and expand your collection slowly. Seriously though… good luck with this; three years ago I had under 50 plants…now I’m over 250 lol.
10. It’s good to be passionate, but people don’t like “Know-it-Alls”
That’s what I’m often told at any rate… 😉