watering and testing for dryness in pumice
M. Gastil-Buhl (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