How to choose the pot size for a Phalaenopsis orchid: is a big pot or a small pot better?

Ever since I started growing Phalaenopsis orchids, I've enjoyed browsing different community forums every day, just to see what everyone likes to talk about. Among the popular questions, I found the one most people ask: "When should I repot?" Today let's take a brief look at some of my hands-on experience since I started growing Phalaenopsis orchids.

Phalaenopsis orchids have a wonderful flower form. If you want a blooming season every year, then besides the usual reasonable steps (watering, light, temperature, moisture retention, fertilizing), repotting is also a key point. When it comes to repotting, the most overlooked thing is the size of the pot used. In fact, this is especially important for orchids. It's like people wearing shoes: they have to fit properly for the roots to be comfortable. So how do you figure out the right pot size?

Having grown orchids for so long, I've summed up an iron rule: if there are few roots, use a small pot. Don't go for that "a big pot looks impressive" approach. For example, some newly bought Phalaenopsis orchids have only a few roots to begin with and look sparse. At this point, using a big pot is purely digging a pit for yourself. Based on how I usually do it, I use a coffee cup with a 9.2 cm diameter as a flower pot at most. This size has the best breathability, dries quickly after watering, and won't easily smother the roots. If at this point you force it into a 15 cm big pot, the potting soil will stay wet for half a day, and after a few days the roots will rot.

Of course, it's not that you use a small pot in every situation. A 12 cm diameter Qingshan pot can also count as a "universal choice." Usually flower farmers also like to use this size. Whether it's a medium-sized Phalaenopsis orchid or one whose roots have grown fairly evenly, once you put it in, the roots can spread out, and there won't be empty space either. When watering, it's also easy to control the amount, and you won't end up with excess water collecting at the bottom of the pot.

To figure out the size of your own Phalaenopsis orchid, you can straighten out its roots and put it into a flower pot to take a look. From the side, if the roots are squeezed and wrinkled inside, with no room even to turn around, then you definitely need to go up one size. But if after putting the roots in, you can still fit two or three fingers around them, then that's about right. Don't choose any bigger.