Mr. Larry A. West asserts that a shield grounded at only one end is resonant to RF frequencies at its quarter wavelength and will induce voltage to internal conductors at that frequency. He neglects to mention that a shield grounded at both ends also has resonant frequencies and can induce voltage to its internal conductors. No configuration of grounding results in the shield always being a low-impedance path to ground across its entire length, for anything but DC and low frequencies.
Hahahahaha. Sure, it'll still have resonances (odd multiples of 1/2 wavelength, namely). He fails to note that
those resonant modes DO NOT couple into the signal-to-ground propagation mode. With an open shield, they do (at odd 1/4 wave multiples).
The impedance of the signal, with respect to the inside of the shield, remains constant when the shield is grounded at both ends. That's a better way to speak of a "low impedance shield", since there's no such thing as an arbitrarily low impedance anyway, and what we're really concerned with is the impedance being consistent (a stable ~50 ohms or whatever), and the isolation between outside fields (currents running on the outside of the shield, or for balanced line, equal (common mode) currents on the lines) and inside fields (differential currents running inside the shield, between the conductor pair) being good.
Both the impedance and the coupling get all fucked up (the common mode impedance of the whole cable is inserted in series) when ground is broken.
This is a whole lot easier to illustrate with a diagram, but alas I don't have one handy.

The soil sensors are used to monitor indoor potted plants, and the sensor itself (the metal probes that go into the soil) is connected to ground. Since the hub is the power source, I assume there's no way for me to achieve a balanced ground between the hub and the sensors (peripherals). So wouldn't leaving the sensor end of the shield disconnected make sense? But as you've said, since my clock frequency is slow, I may not have to worry too much about this at all. However I do find this an interesting topic.
If you worry about low frequency (DC and mains, usually) ground loops, a very different circuit is needed, regardless (high impedance differential amplifier? isolator?).
You might not need to connect the cable shield and ground, to soil ground (earth, as it were). The probe leads can be high impedance (indeed, should be..?), and RF filtering, differential sensing or isolation can be applied there. That way, the digital signals can be fully shielded (or whatever you wind up doing).
Tim