Re: Xerophytic nepenthes?

From: Perry Malouf (pmalouf@access.digex.net)
Date: Fri Dec 12 1997 - 18:11:01 PST


Date: Fri, 12 Dec 1997 21:11:01 -0500 (EST)
From: Perry Malouf <pmalouf@access.digex.net>
To: cp@opus.hpl.hp.com
Message-Id: <aabcdefg4715$foo@default>
Subject: Re: Xerophytic nepenthes?

A. Hicks writes:

> ... I grow Nepenthes alata here in New Mexico with no special
> accomodations...Humidity on any given day ranges from 5-30%...

I'd be very surprised if any Nepenthes thrives under these conditions.
That's not to say they won't survive, or won't grow, but pitcher
production and pitcher longevity--that's another story.

By the way, ambient relative humidity is not necessarily what the
plant is exposed to, depending on how sheltered it is from
drafts and whether it's kept over a pan of water (or other source
of moisture).

Further on the subject of humidity, I've noticed some people referring
to the outdoor relative humidity but they keep their plants inside.
The outdoor relative humidity is often reported during news
broadcasts for the area.

There can be a big difference between the relative humidity outside, and
the relative humidity inside a house. Say it's 30 F outside and the relative
humidity is 50%. If the HVAC system in your home has a furnace with no
humidifier, then it'll heat the air without adding moisture. Air at 30 F
and 50% RH, when heated to 70 F with no moisture added, has a very low
relative humidity. I haven't done the calculation--I estimate it's
around 10% RH. Of course, any moisture in the house (adsorbed to the
walls, etc) will come out into the air and modify the RH somewhat.

Air conditioning, on the other hand, condenses moisture out of the air.
If it's 90 F outside with RH of 70%, the air conditioner might cool
the air inside to 70 F. If that's all it did, your house would be a
swamp because the RH would jump to 100%. But since water condenses
out of the cooled air, the RH doesn't skyrocket.

Physics can get kind of dry, can't it? :-) Low RH

Regards,

Perry Malouf



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