Q&A: Can You Identify Mystery Weblike Substance?

Reader Christina shares some photos of a white web like substance appearing in her terrarium. I am not familiar with this particular affliction but I share in hopes that someone else might have experience with this fungus or insect problem.  The best course of action for a mystery fungus is removal of the afflicted areas.  If the problem persists, you may need to empty out your terrarium and try building it again with new plants and soil.

Christina says "I've been noticing a strange white almost weblike thing growing on the branch points of some of my plants. The plants seem to be growing well but I was just wondering if you would happen to know what it is and how I can fix it. I've just been trimming it off hoping it goes away. I haven't had any problems with bugs in it so I don't think it's a nest of any kind. I've attached some pictures of the 2 plants that seem to be affected. My terrarium has quite a large opening at the top that I never cover and it gets a good amount of sunlight."

Q and A: Twigs in Moss

Fall is a great time to build a terrarium, to capture a bit of greenery in a bottle before things turn cold outside. My question for today comes from reader Kate:

Question: I bought some moss online. It's very healthy - I've just got it in a cookie sheet with some soil and pebbles, the whole affair sitting in a Ziploc bag that I can keep closed for humidity and then open it for awhile every day to get air. Now that I'm about to use it for a terrarium though, I see it has loads of (what look like) small brown decayed needles, and some tiny twigs. If I try to clean all that stuff out, I'm afraid that the entire sheet of moss will come apart (which I don't want to happen.) I'm thinking that all this detritus is decayed matter that's feeding the moss and keeping it healthy. Besides which, I'd never be able to pick it all out. So what do you think? Ok to just leave everything as is?

Answer: Your moss sounds healthy and well cared for! Storing it under plastic is a great method for quarantining your moss, to observe for insects or signs of mold. If the twigs and needles are in the dirt under the moss, wrapped up in the roots etc, it is probably fine to leave it there. It does sound like it is just part of the soil for your moss, and minimizing disruption of the moss while planting it in your terrarium will help it establish. Perhaps remove the larger pieces of twigs or pine needles if you do tear your moss into smaller pieces to place it in your terrarium.

Do you have a suggestion for dealing with twigs or pine needles in moss? Let's hear it in the comments?

Q and A: Can I Collect Moss in the Summer?

Whew, the heat is on here in Texas.  It is this type of heat that makes me want to dream of moss blanketing a cool forest floor. My question for today comes from reader Isabella:

Question: Can I collect the mosses in summer time from the forest?

Answer: I respond with a question again, does the moss you want to harvest look to be in peak health? If the moss in your area looks dry or dormant in the summer, you may want to skip collection until cooler months. You'll want to collect moss that is healthy, green, and thriving. In my experience, it can be challenging enough to transplant healthy moss harvested from the wild into a terrarium environment.  The moss receives a transplant shock from getting uprooted, it might dry out before you plant it, and it might be full of bugs or mold that might infest your terrarium (wash your moss!).  You may set yourself up for failure if you collect dry or dormant moss in summer months.

How to Make a Terrarium Last

I want to be honest with you about how long you can expect your terrarium to last and thrive.  Many blogs show fast and easy terrarium crafts in tiny glass vessels and bubbles, but they rarely show you what a tiny terrarium will look like after three months.  Probably dried out or moldy.  Tiny terrariums are cute if you think of them as a cut flower arrangement.  But part of the thrill of building terrariums is chasing the lasting terrarium, which sometimes means restarting, trying new combinations of plants, soil, and containers - until the ecosystem clicks and then plants thrive.  My longest-lasting terrarium was built in a wine jug and lasted about three years.  It looked a lot like the photo above from thedebrief.uk. Note the deep moss roots, and appearance of algae type stuff in the bottom layers of the soil. This is what a slice of the outdoors looks like under glass!

Secrets to a Long-Lasting Terrarium

1. Use a large enough glass container. A general equation seems to be, the larger the container, the better the chance the terrarium has to thrive.
2. Use an adequate amount of soil. If plants are to grow, they will need some space.
3. Use healthy plants and moss that have been inspected for insects and washed if needed. Select plants that have similar light and water requirements (e.g. woodsy ferns with moss, succulents with cacti.) See 19 of the most popular terrarium plants.
4. Keep up with terrarium maintenance! This includes managing water and temperature levels (e.g. water occasionally and don't leave it in full sun all day).  You might need to put a lid on your terrarium occasionally to help keep water in the system.  You might need to remove dead leaves or scrub the sides of the container of algae fuzz.
5. If all else fails, try again. Don't be afraid to restart your terrarium if mold takes over, plants die, or insects infest.  Shake it all out, scrub out the container with water and a bit of bleach, and try again when it is dry.  Fresh plants and soil!

How long has your healthiest terrarium lasted? 53 years?

Tarantula Terrariums Just in Time for Halloween

I swear I was going to post a photo of a tarantula at the top of this post- but I really couldn't do it to you all!  I don't even bat an eye when I have to deal with small spiders in the house.... but the big hairy guys  freak me out!  So the photo is near the bottom if you'd prefer to skip through it.

With THAT SAID!  You might love tarantulas!  And terrariums!  So perhaps you might consider trying a vivarium and keeping a tarantula in your terrarium?  Don Moyer at the Manteca Bulletin shares his experiences keeping tarantulas and other local critters in a terrarium.  **I do not advocate stealing living creatures out of the wild and keeping them in captivity forever - but when we were kids we enjoyed keeping insects or lizards for a few days and then turning them loose.  Don reiterates this idea:

"Almost all of our terrarium guests were, just that, short term visitors who would reside with us for a few weeks or months so that we could learn more about them and their habits. Eventually the horned toads, lizards, snakes and turtles got returned to the wild places from which they came. We did learn a healthy respect for wild creatures."

Oklahoma brown tarantula (Aphonopelma hentzi), Picket Wire Canyonlands, Colorado, U.S.A.  From WikiCommons Media, by Zenhaus **This photo is for viewing purposes only, I do not advocate or condone keeping this species of spider in a terrarium.

Q & A: Mold on Terrarium Walls

Photo from forums.gardenweb.com

Here is a question I answered on the terrarium forum of gardenweb.com.

Q: Have a terrarium with a fern, would be about 2 months old & have noticed spots of mould on the glass.  Has anyone else had this problem?  The walls are covered in condensation even though I air it out at least once a week.
A: If the opening of your terrarium is narrow you may need to let it air out more frequently than once a week. I also see that you have a layer of sphagnum moss over the soil - this may contribute to trapping more moisture in the terrarium than is desirable. I would suggest removing it.

Q & A Update: Ant Invasion Reversed

Photo by Natalie K.

You may recall reader Natalie sharing a plea for advice on how to best deal with an infestation of ants in a large succulent terrarium.  I am happy to report that Nat has reported apparent success with some of the treatments that you, fellow readers, suggested.  Awesome!

"Thank you for your help with my ant infestation for my desert terrarium! A good soaking and light application of a pesticide got rid of them! The terrarium is now outside on the sunny days which my succulents are enjoying a lot!"

Lime Deposit in a Terrarium: a Tip from Chill Designs Terrariums

Photo courtesy of Chill Designs Terrarium

Chill Designs Terrarium offers a detailed terrarium care information via their ebay account.  I found this tip on how to clean lime deposit from a terrarium very informative.  This method would also be useful to clean bits of soil that cling to the glass as the layers settle in a jar.

"Terrariums are prone to developing a white line of lime-scale just above the soil line. To keep your terrarium looking like new, you'll need to clean this every now and then. How much lime-scale forms will depend on your water supply. To clean lime-scale from your glass container, take a wood satay stick and wrap a piece of moist kitchen paper (either moisten with water or a little non-toxic cleaner) and wipe around the inside of the container, cleaning away the lime-scale."

Q & A: Ants in Terrarium

Image from Wikipedia Commons, by Fir0002/Flagstaffotos

I've never had the misfortune to find ants in a terrarium - let alone an entire colony moving in!  Does anyone have any ideas for Natalie K.:

"I have a 2.5 gallon desert terrarium that sits on my window sill It has a screentop lid to keep the humidity low and allow an extra light to sit on top. Ants have moved in though and are nesting in the soil. I don't know how long they've been there but I just noticed them moving pupae in. I dumped a bunch of water in(there's a layer of marbles and moss to allow drainage) and that seems to have scattered them out for now. How do I get them out for good??? Short of dumping the entire thing and starting over?"

See the solution to the ants in a terrarium.

How to Make String Gardens or Kokedama

Head over to Dennis' 7 Dees for a brief tutorial on constructing kokedama.  I am really hankering to try this out but - I can't really fathom keeping them out doors and they seem like potential gnat magnets if you keep them indoors.  Have you cared for kokedama and do you have any tips?

Removing Dead Plants from a Mature Terrarium

The internet is chock full of glossy photos of brand new terrariums in all their leafy glory.  But what about the old terrariums, with dying plants or problem spots?  Kudos to yellowbrickhome.com for sharing some tips and photos of removing some dead plants from a mature terrarium.  I highly recommend popping over to the post to see the ingenious use of household tools to fix up an ailing terrarium.

The Grabber: the Ultimate Terrarium Tool?

This unceremonious photo depicts one of my favorite terrarium tools, purchased for me by my sister at a hardware store.  We refer to it as "the grabber" and I believe it is a tool for plumbers.  It is about 18" and contains a claw at the end that can be opened and closed using a push lever at the other end.

The grabber is a bit much for everyday terrarium maintenance or planting.  The true worth of the tool comes through when it comes to extraction situations: removing moldy or dead plants, removing fallen dead leaves, removing the miniature ceramic kitten you now decide is ruining the terrarium ambiance.  I'd link out to a place to purchase this magical tool online but alas, I know of none.

Have you ever seen a "grabber" for sale online?

Diluting Hydrogen Peroxide for Garden and Terrarium Use

As part of our ongoing discussion about the utility of treating terrarium mold or fungus with diluted hydrogen peroxide, I've found a new resource that may answer some more questions.  The aptly-named www.using-hydrogen-peroxide.com  has a wealth of information on using hydrogen peroxide to fertilize plants, sprout seeds and - you guessed it- treat mold and fungus.

I've grabbed an image of the suggested dilution ratios for treating sick or fungus-attacked plants above.  However, if you are interested in preventing mold or fungus in terrarium moss and plants, and are washing your moss prior to use, you may want to review the additional chart "To water or mist plants, to soak seeds, to add to water used to wash sprouts."  The dilution ratio is about half of that suggested for treating a mold outbreak and seems to be the right fit for a mold prevention attempt.  

The evidence I've discovered so far has motivated me to test including dilute hydrogen peroxide as a step for washing and preparing moss and plants for use in a terrarium.  I'll report back on how things go! 

Can You Combat Terrarium Mold With Diluted Hydrogen Peroxide?

I'd like to say this is a Q & A feature but I only have the "question" part and I'm looking for your answers.  As you may or may not know, I strongly recommend washing moss before putting it in your terrarium.  It gets rid of foreign contaminants that may be in the soil or the moss and, in my experience, minimizes the chances of mold developing in the terrarium-ensconced moss.  When mold appeared - I would remove the affected moss/plants/soil and if it became rampant - I'd start the terrarium over again.

Recently someone suggested that diluted hydrogen peroxide can also be used to eliminate mold on soil. Has anyone tried this before?  Any tips or tricks for approaching mold removal with hydrogen peroxide?  Or any other solutions for removing mold?

Q & A: Can I use spanish moss instead of sphagnum moss in my terrarium?

Image courtesy of http://www.orchidsandtropicals.com/

This week I received an excellent question in my post "How to Make a Terrarium: Adding Soil Layers."

Question: Can dried spanish moss be used in lieu of the spaghnum moss as a filter?

Answer: Sphagnum or peat moss is a commonly used element in gardening and container gardening but I have never seen spanish mossed used in the same capacities (i.e. to line a hanging wire flower basket).  I did some research online and found an ehow article that may help us.  The author points out that while sphagnum moss is a great water absorber, spanish moss is actually an air plant in the tillandsia family and will not act the same way when used in gardening.

I'll paraphrase some of the key points here:

"Spanish moss is home to small insects and other organism. Spanish moss requires treatment or sterilization before use.... Because sphagnum moss grows in highly acidic waters, peat moss is usually germ free.  Because of its water-retaining ability and lack of most pathogens, it is ideal for seed-starting mixes or use as a soil amendment.  Spanish moss, does not incorporate easily into soil, but does act as an effective mulch, especially for indoor potted plants."

Read more: Spanish Moss Vs. Peat Moss

The idea of the Spanish moss potentially containing contaminants makes me hesitant to suggest using it as a terrarium soil layer.  You'll want to minimize the inclusion of any mold or germs in your terrarium.

Moss Monday: Mold on Moss (Q & A)

Thanks to reader Kelly for her question on the post Prevention and Dealing with Pests, Fungus and Disease in Terrariums.

Question: My terrariums lately have grown a type of fungus and even tiny mushrooms. Will this kill my irish moss? Is there anything that can be done to "clean" the moss? Or is this harmless?

Answer: I do not think mushrooms could kill your moss but if the fungus is web-looking you may be facing trouble. You may try removing the fungus or mushrooms with tweezers or chopsticks to clean it out. Next time you build a terrarium you may want to wash the moss first and watch it for a few days before putting it in your terrarium.

To recap my general advice to prevent or at least minimize the chance of mold or pests appearing in a terrarium:


1.) Rinse all containers with a bleach/water mix before planting (with a day or two to dry out).

2.) Wash newly harvested moss and look for pests or unwanted plants in the chunks.

3.) Quarantine new plant specimens in a "holding tank" for a period of time so you can observe their behavior and adaptation to the terrarium environment.

Have you had problems with fungus or mold in your moss terraria?

Q&A: Insect Infestation

An insect infestation can be the bane of a terrarium ecosystem.  While an errant earthworm, ant or snail may not do severe damage an entire host of winged insects can spoil your tiny garden.  Here's another Q & A about this common problem.

Question: I recently made a moss terrarium with live moss bought from Idaho. After a week or two after I placed everything in my glass jar, I noticed very small white mite looking insects crawling on the glass. I researched for hours and couldn't find anything pictures of the insects. They don't jump or fly, and seemed to be in the hundreds crawling on the glass. I tried putting a cottonball soaked in pesticide in the closed terrarium for a week plus. I didn't see the bugs again. I bleached the terrarium, put new substrate in and within 2 weeks the white tiny mite looking bugs were back. I threw everything out in fear the bugs were crawling in my house and not being able to identify them was scary to say the least. I just went back to my homestate of Illinois and went moss hunting so I can try once again. I'm going to go through all your steps and quarantine the pieces to see if anything happens. Have you had this problem before? Do you have any advice on how to treat them if I do have another problem? Thanks so much!

Answer: I believe that washing your moss and observing it under quarantine should prevent the insect infestation from taking place again.  I would recommend observing the moss for two weeks in quarantine just in case the insects are taking that long to hatch or mature.  Two weeks is a long time to quarantine moss so make sure to not over/under water or let it suffocate in a poorly ventilated container.

If the insects are not native to your moss - I can imagine two other potential problems:

• Your soil may be contaminated if you are not using fresh, bagged potting soil.  There are methods to "sterilize" soil by baking it on a cookie sheet in an oven at low temps.  It may be something to consider trying and here are some further instructions at Tipnut.  

• If you fear that the insects may enter your terrarium from elsewhere in your house (another houseplant perhaps)?  You may want to lid your terrarium for 80% of the time or consider rubber banding a piece of gauze or cheesecloth over the opening of your terrarium to prevent insect colonization.  

Q and A: Quarantine for Large Plants

Chemical Safety Signs - MySafetySign.com

Reader CJ left a couple questions in the comments of my post about keeping new plants in quarantine before adding them to a terrarium.  I'm sharing a version of my reply in this post to clarify the circumstances for which I recommend the quarantine process for terrarium plants.

Q: I recently decided to attempt a trio of open terrariums in my home. I bought a variety of different plants including irish moss, davalia trichomanoides (fern), hypoestes phyllostachya, and what I suspect to be a peperomia scanden (unlabeled), along with 2 other unlabeled plants from a local nursery. I am also buying a small orchid. I want to take the proper steps before beginning the process of planting them all. How do you quarantine medium sized plants? They range in height from about 3" to 10". Should they be separate from one another? 

A: If your open terrarium vessels are large enough to reach your hand into - I wouldn't worry about keeping them in quarantine prior to planting them.  If mold develops you can reach in and cut it out or scoop it out as it develops and a larger vessel isn't as likely to get quickly overrun by bugs or mold.  To recap my suggestion from the original post:

It is relatively easy to remove problem items from a large-opening terrarium such as a vase, fishbowl or dish.  But if you aim to plant a terrarium in an enclosed terrarium or a narrow-opening vessel like a wine bottle, test tube etc. it may save you time an energy in the long run if you can be patient enough to "quarantine" your plants and moss to see if any problems surface before you add them to your terrarium.

If you'd still like to quarantine your larger plants prior to planting them, you may be looking at a need for additional equipment.  Some terrarium enthusiasts invest in large aquariums or wardian cases in which they can enclose their plants prior to terrarium-planting.  You can keep several new plants in the quarantine vessel for a period of time.  Make sure to inspect each plant regularly for insects or mold and remove promptly if discovered so they don't contaminate each other.

Smaller plants can be sealed into a gallon ziplock bag, kept upright with a chopstick or popsicle stick as a stake.  Make sure to leave the bag slightly "unzipped" to allow for airflow.  Don't leave your plants in bags for longer than three days or so.

"Be careful what you put in there!"

The Crafty Collaborative and Better Homes and Gardens House and Hold teamed up to provide a pair of "reviews" of terrarium-crafting.  Both participants created the typical succulent-in-potting-soil-in-a-jar type terrarium - which is great for an afternoon craft but may not last in the long run.  One woman made a wise comment:

"Be careful what you stick in there… initially I had these little mushrooms from the craft store and within a couple of days they were totally furry with mold.  Gross."

She doesn't describe in detail what these craft store mushrooms were made of but I'm picturing those foam-looking mock mushrooms you see in the floral arrangement sections of craft stores.  Beware adding spongy decorative items as the moist terrarium environment is prone to encouraging mold growth on plants and nearly anything else.  When considering adding curios to your terrariums, think of hardier items that could handle semi-outdoor conditions like glass, plastic, clay or stone.

Q and A: Gnats in terrarium (from the archive)

I am at a conference and will be sharing posts from the archive this week.

Question: A few weeks ago I put together two terrariums: one with irish moss and african violet... recently I've noticed that they both have some tiny little whitish/yellowish bugs roaming around inside. I've only seen 5-6 in each one, but now I'm wondering if they're going to become a problem for the plants if they're not kept in check. I'm pretty sure that the bugs have begun to sprout wings, so I think they're probably fungus gnats that were stowed away in the potting soil.

My question is this: what's the best way to deal with these little guys?

Answer: The appearance of gnats might be the most difficult and disastrous problem for terrarium owners. Whether the gnats invade an established terrarium through an open top or appear in a freshly-planted terrarium they are very difficult to eradicate. Traditional methods for dealing with fungus gnats such as dish soap sprays and changing soil do not bode well for the delicate environment within the terrarium.

When my large jug terrarium showed signs of gnats I was desperate to try to save the arrangement. I used a sharp bamboo skewer to "turn" the soil in the terrarium to try to disrupt any of the juvenile insects or the eggs. I also used a the round end of the skewer to squash any of the flying gnats I could reach.

After careful monitoring and repeated gnat-attacks I seemed to have eliminated all but a few of the insects. I stuck some double-ended tape on the edge of the skewer to fish the last few gnats out on the makeshift fly paper.

I'm proud to say I finally saved the big terrarium from the gnat invasion and I'm happy to say it's till growing strong! However now I keep a bit of gauze over the top of the bottle to prevent any more new residents.

Good luck with the gnats and in the future- always use sterilized fresh potting soil to make your terrarium substrate.

Pests in terrariums