All living plants goes through normal cycles of life; fresh new growth matures into adult leaves, some leaves turn brown and drop off the plant, new growth then  emerges, etc. Moss is no different and just like any other houseplant will require some maintenance within the terrarium. Since mosses generally grow in dense mats, if one "stem" starts to turn it can quickly spread to the whole mat. In nature that isn't a problem since it will eventually renew itself with new growth. However in terrariums that renewal process seems to be much more difficult to achieve and therefore it is essential to the health of the mini ecosystem to nip any problem areas in the bud (pun intended). Keep your moss bright and healthy by doing a quick weekly inspection. Any pieces that may be turning yellow or brown should be removed using the following method:

What you will need

  • long aquarium tweezers (for terrariums with small openings)
  • sharp scissors (for terrariums with easy access)
  • moss fertilizer spray or distilled water

Start by doing a quick visual inspection. Note any moss stems or patches that are discolored. These will need to be pulled out of the mat. Also note if the tips are turning brown (or yellow) in any areas. If just the tips are discolored they can be trimmed with a scissors and need not be completely removed. Look at the example image and see if you can spot the areas that need attention:

Once you have spotted problem areas you can begin the pruning and removal process. Clip off yellowing tips anywhere your scissors will easily fit into the container. Use the long tweezers to gently pull out stems or portions that have completely turned brown/yellow:

If there are any gaps or holes left after maintenance removal simply fluff surrounding moss to cover the gaps. For large gaps you may need to use a small amount of replacement moss or fill with stones. After arranging the terrarium to your liking, thoroughly spray the moss with fertilizer spray or distilled water:

Now that your terrarium is looking as good as new, keep up weekly inspections so that you can detect any problems early which will keep them from spreading and ensure your terrarium stays in good health for many years to come. 

Read more about terrarium care here.

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