Expert: Sarracenia Northwest - 10/6/2011

Question
QUESTION: Hi, I am growing a few Mexican Pinguiculas and a Drosera binata on my windowsill and under fluorescent lights in the winter. I am in Brooklyn NY.

The peat moss in some pots seems a little muddy and the Pings. in those pots are not growing so lushly.

I found Perlite and deser sand with no fertilizer but the onnly peat moss i am seeing around is the Miracle Gro that contains fertilizer.

SO I was wondering one of these options:
- recycle the peat moss in the pots by boiling it, cooling and mix it with perlite and / or sand 50 %

- substitute with Sphagnum moss, chop it and mix it with perlite and sand.

- use just straight perlite and sand.

I also have horticultural charcoal and diatomaceous earth. are these 2 components ok for Drosera and Pinguicula mixes?

thanks
stefano

ANSWER: Yes, many growers are having trouble finding fertilizer-free peat moss.  Your situation is quite common, unfortunately.

I have to admit, I've never recycled peat moss, so I can't say for certain if boiling it will work.  Boiling it will kill off fungal spores, algae and bacteria, but it may break down the peat moss further.  Whether this is good or bad, I'm not sure.  I haven't tried it myself, though my instincts tell me that it's a bad idea.  I'll need to experiment with it before I can give you the thumbs up or thumbs down.

As for desert sand, I'm not sure about using that either because usually desert sand is high in calcium, which is good for succulents.  You should use horticultural sand or washed sand.  It should have those words on the package.  

Chopping or milling sphagnum moss is a very good alternative to peat moss.  Just make sure you mill the sphagnum moss as finely as possible.  I've never milled my own sphagnum moss, so I can't give you any recommendations on how to do it.  

With that said, you could also order peat moss through our website.  We have it available, along with perlite and other appropriate soil additives.  You could also check Amazon for milled sphagnum moss if you get tired of milling your own.  

As for charcoal and diatomaceous earth, they're OK to use with your Mexican butterwort, but avoid using diatomaceous earth with your sundew.  Diatomaceous earth contains some calcium, which the butterworts will appreciate, but not the sundew.  Charcoal is a fine substitute for perlite for drainage, but it really doesn't keep the soil clean as many garden experts claim.  Only activated charcoal can remove particulates, but the activated charcoal will fill up quickly in the soil.  (Activated charcoal is used among aquarium enthusiasts, and it's useful when filtering water or air, not soil.)

Good growing!
Jacob Farin

---------- FOLLOW-UP ----------

QUESTION: Thanks for the thorough answer.
I am looking more for local options since ordering medium usually implies high shipping costs due to weight / volume of the packages. I buy plants online as the shipping is not as high. But will check your offerings.

The sand I have is by Hoffmann "Western Desert Sand". I bought it at the Brooklyn Botanic Garden, so somehow it is an horticultural product, but as you say I do not know the mineral content. MAybe you know the product. It is pretty coarse.

I was thinking of just chopping teh Sphagnum moss. I have seen photos of Droseras growing in bogs on moss... SO I wonder even if not milled if that could be ok.

I have a small Cuisinart food processor anyway but I wonder if it may be a health hazard to process Sphagnum in a kitchen tool. It can for sure turn hot peppers to dust.

If I do not boil the existing peat moss I wonder if I could still mix it with new perlite and it could still be good for another year.

It is unfortunate that Better Gro that has almost a monopoly for soils here in NY, adds fertilizer to Perlite and Peat Moss. I understand adding it to more mainstream mixes but I wish they offered neutral specialized products.

Answer
With specialty items, sometimes you just have to bite the bullet and pay for shipping.  That's the nature of business nowadays.  They tend to specialize in certain products, such as we do.  Amazon offers free shipping, depending on the item.

I don't know much about desert sand, only that a lot of it is actually desert sand, which is often high in calcium.  For this reason, I recommend avoiding it.  

You could always reuse the peat moss.  When push comes to shove, you're better off reusing the peat moss until you could get milled sphagnum moss.  Adding more perlite will help improve aeration and keep the soil healthy longer.  Another alternative to boiling the soil is to simply pour boiling water over the soil before potting up your plants.   If you choose to make your own milled moss, wear a dust mask.