Re: greenhouse advice needed
As with any new greenhouse, now comes the fun of fine tuning the climatic
conditions for your and the plants you dicide to grow needs. As you well
know, or will learn to know, the greenhouse climate control will change with
the seasons as well.
65% humidity is not too high, but just about right. In fact, 70 to 80% is
closer to optimum for tropical rainforest derived plants, but with some like
the filmy ferns, requiring over 95% RH. But the RH will depend upon the air
The mold on your soil may be due to too much watering. Watering is an art.
It could also be due to the temporary fungal decomposition of composted wood
or bark in your mix if your potting mix has that as a component. Most
likely the fungus is a saprophyte and not a pathogen unless you see the
plants under stress from root rot. But that too could be a symptom of over
If it bothers you, go ahead with a 1/4 to 1/3 concentration light soil
drench. Forget about the Benlate drenches, unless the problem gets really
out of hand, as it can have growth regulating effects on some species, i.e.
cytokinin like effects. Regardless of which fungicide you may decide to
try, test the application first on a couple of pots, wait for a week or so
to determine if there is any phytotoxicity, and then apply to the rest of
the afflicted pots per those results.
Good luck and happy growing! Tomorrow is the first day of spring, although
it already feels like summer here!
>From: Lester Kallus <firstname.lastname@example.org>
>Subject: greenhouse advice needed
>Date: Sun, Mar 21, 1999, 6:41 PM
> My greenhouse is finally operational. It's been a refreshing change
> walking into an area with high humidity and warmth where plants are
> actually growing rather than just hanging on in our usual cool dry conditions.
> A couple potential problems have come up and I'm hoping to get advice:
> 1. The humidity may be a tad too high. I've got a meter in the room
> saying that the humidity is up to 65%. Is that too high? Could plants
> suffer? I could fix it easily (and also humidify some of the house) by
> keeping one of the doors open slightly.
> 2. Probably because of the humidity, many of the pots have a fuzzy fungus
> growing on the soil surface. Should I be spraying it with Daconil, or
> pouring Benomyl onto it or is this type of fungus benign? If I should be
> trying to control it, what's the best control measure?