Question
QUESTION: Hey Guys,
I've read your ebook and it says that it is beneficial to add a top layer of gravel to your pots to help retain moisture as well as keep the soil warmer. Last year I've tried this and I haven't 100% narrowed down a problem I had with new traps dying but I thought it could have been a problem with the gravel I chose. I thought it was the gravel because when I had a heavy rain the water inside the trays had a brown tint to it. So my thoughts were whatever type of gravel I bought (which was as a nursery) was leaching into the soil causing problems. But then it could have been the fact that we had alot of rain day after day and the roots started to rot. This year I went out and bought a bag of "Hoffman Alabaster Blend Stone Chips". They are white and seem to have a little bit of white "dust" on them probably from rolling around in the bag. I am a little weary about putting them on the pots and I wanted to ask you guys what types of gravel should I NOT put on the pots and whether you thought the Hoffmans bag I bought would be alright. What kind of gravel do you guys currently use at your nursery?

Best regards, Ken

ANSWER: Hi Ken,

First, don't use the Alabaster chips.  They are a form of marble/calcium carbonate and will make the soil alkaline; bad news!

When we use a gravel top dressing we use rainbow rock pea gravel.  Most of this comes from Montana and is usually available at rock/landscape supply companies.  Regular pea gravel is ok too, but ours in the Northwest is almost always from basalt which only adds a tiny amount of iron to the soil which isn't harmful.  I'm not sure what you have available in your area.  The important thing is to avoid any calciferous type rock like marble, limestone, gypsum, dolomite, etc...  Igneous and metamorphic rocks tend to be fine.

I also wanted to mention to be cautious with a gravel top dressing during hot weather.  When it's cool outside it is helpful, and does minimize splash erosion.  It can burn new foliage, however, during very hot weather.  Here in the Pacific Northwest it makes sense to use it because of our constant rain, and cool temperatures.  In other parts of the country you may need to use caution when the temperatures are above 90.

Good Growing!

Jeff Dallas
Sarracenia Northwest
http://www.cobraplant.com

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

QUESTION: Thank you very much for your feedback! When I got the Alabaster chips I did put them on top of some of my pots for the weekend but got nervous and took them off after about three days. Should I re-pot the pots that I put the chips on or just do a couple of top flushes with rain water and keep an eye on them?

Best Regards, Ken

Answer
Hi Ken,

If they were only there a short time just top water the them a few times.  If they are getting rained on regularly, they'll be fine.  It takes time for the calcium to break down and leach into the soil.  You shouldn't need to transplant them.

Good Growing!

Jeff Dallas
Sarracenia Northwest
http://www.cobraplant.com