How to Repot an Orchid

Yes, you can do this. It's not rocket science. Repotting is fun. And your orchid will thank you, especially if it's been two or more years since it was repotted. Never repotted an orchid before? We can fix that. Come on into our greenhouse and I'll show you how.

1. Gather your materials.  A good basic orchid mix consists of equal parts fir bark, charcoal and sponge rock (aka coarse perlite). You can buy these products online from OFE International and Tropical Plant Products. They also sell high quality ready-to-use packaged orchid mixes. Grower's Tip: The organic component -in this case the bark- can make or break the quality of an orchid mix, because that's the part that breaks down with repeated watering. The bark should be Douglas Fir or Pinus radiata, and should be mold-free. Pinus radiata (sold as Orchiata) and kiln-dried Douglas Fir bark (sold as Rexius bark) last longer than regular Douglas Fir bark. Fir bark often needs to be rinsed beforehand in order to remove dust and sediment.

2. Select a plant. The best time to repot an orchid like Cattleya is when the new shoot is about the length of your pinkie finger. The new shoot indicates that the plant has started a new cycle of growth, the perfect time to provide new roots with fresh medium. We repot every two years, because that's the lifetime of fir bark mixes in our greenhouse. Any longer is asking for trouble -a waterlogged mix that kills roots. Grower's Tip: Keep your eye on that new shoot while repotting! It is as fragile as new asparagus and if you break it, you lose an entire season's growth, including the flowers.

3. Invert the plant, tap the rim of the pot against the table and remove the plant. Keep the new shoot well away from the table when you do this. Grower's Tip: Water your plant the day before to make it easier to dislodge.

4. Remove the old mix. Hold the plant by the pseudobulbs (not the roots!) with one hand and gently prod the mix with your other hand in order to loosen it. Grower's Tip: Expect to find new yellow-tipped roots emerging near the base of the new shoot. Be careful not to break them.

5. Remove the dead roots. Healthy roots are white and firm. Dead roots are grey/black and squishy. You can use pruners for cutting, but remember that viruses in plant sap can be spread by using the same tool on consecutive plants. Grower's Tip: That's why we use one razor blade per plant. We wrap used blades in duct tape before discarding them. When I divide a large plant, I use a kitchen knife and sterilize it with a propane torch between plants. Grower's Tip #2: Notice the new shoot face up on the table? Don't rest the plant on its new shoot. Grower's Tip #3: Orchid roots can absorb tannins from the bark in the mix and appear brown on the surface. A brown root can be healthy. When in doubt, cut a cross section--a healthy root will have a white core.

6. Wash the roots. I like to do this under a gentle stream of water at the sink. It gently removes the old bark hiding in inaccessible places. And it often reveals more dead roots that need to be cut away. If the roots are healthy you don't need to remove all the mix --only about three quarters. If the roots are in poor shape, remove as much old mix as possible. Grower's Tip: This is a great time to observe how your plant is constructed. Notice how the vertical shoots (the pseudobulbs) are connected by a horizontal stem (or rhizome, pronounced rye-zome). This will become important in a few minutes.

7. Choose a pot size based on the size of the root mass, not the top growth. One inch bigger all around is plenty. Orchids like to attach their roots to their surroundings. Let them. Grower's Tip: A step up in pot size isn't always necessary. Sometimes fresh mix and a clean pot of the same size is all that's needed.

8. Center the new shoot in the pot. See how I'm holding the older part of the plant against the rim of the pot? That's because I want the new shoot in the center where it will have plenty of room to grow over the next two years. Looks asymmetric, right? Absolutely. The new shoot goes in the center. Hold the base of the new shoot about a half inch below the top rim. That's your imaginary fill line.

9. While holding the plant in place with your left hand, add mix with your right hand, small amounts at a time.

Where do I cut my Cattleya after it blooms?

I'm glad you asked! It's important to know where to cut your Cattleya spike after it flowers. Cattleya anatomy is a little quirky and it is easy to make a mistake. The good news is that there's really just one bit that requires an introduction--the bud sheath. Once you are able to recognize a bud sheath, deadheading a Cattleya or its close relative Laelia is a snap.

So grab your favorite cutting tool and follow along!

1. Locate the bud sheath. Have a look at the photo above. Both flowers are supported by a vertical spike. The upper part of the vertical spike is visible emerging from the top of a green bud sheath.  The sheath is sealed on two sides and open at the top. The lower part of the spike is faintly visible in silhouette through the backlit bud sheath.

The purpose of the bud sheath is to protect the young flower buds as they develop. It remains in place even after the flowers are spent. Bud sheaths are green or papery brown. Cattleyas and laelias are stealth bloomers--in many species the bud sheaths appear months before blooming, with the buds emerging just a week or so before opening. The flowers often take me by surprise.

2. Look carefully! If no flowers or old spikes are visible, carefully examine the bud sheath to make sure that it is an old sheath. You don't want to accidentally remove a sheath full of young buds.  Gently squeeze the sheath to make sure that there are no buds inside. The color of the sheath is not a reliable indicator. Some orchids, like the Laelia pictured above and below, have sheaths that remain green after the flowers are spent. Others produce bud sheaths that turn papery brown while the buds are still developing inside.

Each mature shoot--the pseudobulb, leaf and bud sheath--produces just one flush of flowers during its lifetime.  If you can still see the old spike with its spent flowers you needn't look for a second flush of buds inside the sheath. The show is over. It's time to remove the spike and sheath.

3. Find the spot where the bud sheath meets the stem. The bud sheath and its flower spike originate at the top of the stem (pseudobulb) and they are surrounded by one or two leaves.

4. Position your cut as close as possible to the base of the leaf. 

5. Make the cut through the sheath and spike.

6. Examine your plant for more old sheaths. Any pseudobulb that matured recently could have a sheath. You can use the same cutting tool to remove all the old sheaths on that plant. That's it! Don't forget to safely discard or clean your cutting tool before cutting another plant.

Why is it important to remove old sheaths?

Prompt deadheading of cattleyas and laelias is a high priority in our greenhouses. Old bud sheaths often fill with water and bacteria, becoming bags of icky aqueous goo. You can get away with being lazy about deadheading your Oncidium, but not your Cattleya.

Wondering where to cut your Dendrobium? Find out here.
Click here to find out where to cut your Oncidium spike.
Go here to learn where to cut a Phalaenopsis spike.

Cattleya maxima, Flor de Navidad

Late summer is a great time to see Cattleya maxima at the Fuqua Orchid Center. Dozens of plants spill from the branches of epiphyte trees and pose in pots around the reflection pools, just waiting to have their pictures taken. They are glorious.

Cattleya maxima is native to Venezuela, Colombia, Ecuador and Peru. It flowers under long day conditions, so in the southern hemisphere it flowers in December--hence the common name  Flor de Navidad,  the Christmas Flower.