The sphag and bag method is designed to improve the condition of an orchid’s roots when you notice signs of rot or decay or have very few to no healthy roots. When we talk about sphag, we are referring to the use of sphagnum moss (also known as peat moss) for horticultural purposes.
Due to the fact that sphagnum moss is acidic and good at absorbing moisture, it inhibits the growth of bacteria and fungi. By using sphagnum moss with your orchid and placing the plant inside a nearly-sealed bag, you can help to remove excess moisture that is actually preventing plant roots from taking in water.
Carefully remove any unnecessary organic material from the roots. This includes any damaged or dead roots that may be present as they will inhibit the recovery of your orchid. Make sure to use a sterile blade when trimming the roots.
Soak the plant for about one hour in a gallon of warm water. Some people choose to add a tablespoon of root stimulant, but this is optional. You may find that this helps to dislodge any organic matter that you were unable to remove during the first step.
Get a clear plastic bag. Make sure that the bag you are using is clear, free from any holes and can be sealed in some way.
Take a small amount of sphagnum moss and place it in the corner of the bag. Make sure to give the moss about a teaspoon of moisture. This will help the bag stay humid and will provide ideal growing conditions for your recovering orchid. The humid environment means that your plant can dedicate resources to re-growing its roots, rather than focusing on its surface features.
Put your orchid inside the bag. Place it such a way so that it is still growing in its natural direction. A common mistake at this point is to place it in contact with the sphagnum moss. As we have discussed above, sphagnum moss is very absorbent and will quickly strip your orchid of the water it so desperately needs. Similarly, make sure that it is not in contact with any water inside the bag. Again, you are trying to clear the roots of their excess moisture and this will hinder the process.
Seal the bag while allowing for some air movement. If you have purchased your bag from a gardening store, then such bags tend to come with a Ziploc®-type seal, making this step simple. Anyone using their own bag should fold the bag over at the top before sealing it with a bulldog clip or similar. You can allow a corner to stay unsealed. The aim is to prevent excess moisture or pollutants from entering the bag. You are trying to control the humidity so make sure the bag is secure. You don’t want it to be completely air tight because you’ll get mold. Make sure there is room for air movement and the bag is not sealed off completely.
The final step is to position the plant in a warm, shaded area. It is important for the humidity to remain at an acceptable level for a number of weeks to allow the roots to grow. A shady space will provide enough light for the plant to grow, without causing the inside of the bag to turn into a tropical climate. The warmth allows the moisture to circulate around the bag and encourages cell development within the orchid.
If the bag is causing problems with mold, you can try using two plastic pots. Put the moist sphagnum moss in the bottom of the taller first pot and then put the orchid into the shorter second pot. Put the second pot inside of the first pot (on top of the sphagnum moss). The height difference of the pots will allow for a moist environment inside the pot around the orchid.
Check in on your orchid once a week. After a few weeks (or even a month) have passed, you should notice that the roots of your orchid have returned to a healthy state. Be patient with the process and repot the orchid when the root system has properly developed.
Mary Ann Berdak is a Garden & Greenhouse contributing editor and the publisher of OrchidCareZone.com an online destination for orchid growing tips and advice. For more information on caring for your newly purchased plants, download her totally free report, “The 5 Biggest Orchid Mistakes (and How to Avoid Them!)”, at OrchidSecretsRevealed.com.
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