watering and testing for dryness in pumice

M. Gastil-Buhl gastil.buhl@gmail.com
Sat, 30 Nov 2013 17:42:32 PST
Ina asked how to tell how dry a pot is which contains a lot of pumice.

Hi Ina,
For some pots, I weigh them at the time I pot them, before adding  
water, and then again when saturated and then later if I am unsure how  
dry it is, I weigh it again. Except for the weight of the plant, any  
difference is the loss of water. I only do this for a few special  
pots, such as my Lycoris sprengeri seedlings and my Ammocharis  
longifolia. The mass at the time of planting is with the potting mix  
only slightly damp, which is what I assume the bulbs prefer. Of course  
I cannot do this with the pots in the plunge bed so for them I just  
guess. I have one of those prong things but it only measures the most  
extreme dry and soggy. The pronged thing does hint at what depth the  
moisture changes. I do not stick the prongs into bulb pots for fear of  
spearing the bulbs but I do stick it into the sand of the plunge bed.  
If I am unsure, I guess based on how long it has been since it has  
rained or I have watered. My hope is that the potting mix with mostly  
pumice will not hold enough water to drown the bulbs. But I do not  
know this for certain.

This is a good question. I am curious what others do.

- Gastil

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