FAQ #1 Watering your moss garden
Since I just finished watering my moss garden, I'll address one of the top FAQs – how much and how often should you water your mosses? First, bryophytes are unique in the plant world for a variety of botanical reasons. No bryophyte or true moss has roots, only rhizoids; therefore, you do not need to drench the soil or other substrate to reach any roots. Mosses have no cuticle – the waxy substance that covers other leaves (good visual image is a rhododendron leaf). The leaf is able to absorb moisture immediately because of this feature. Most mosses absorb 10 times their weight in a matter of minutes. Given these factors, water frequently but not too much.
Mosses will change their appearance as they become rehydrated. Some dramatic differences in color saturation occur as with Leucobryum (pincushion moss) where it can shift from almost white to a “moss” green. Other mosses have more subtle clues but an attentive eye will learn the nuances of recognizing when your mosses have absorbed all the water they can at the moment.
On dry, hot days (even in spring), you may need to water more than once a day. You can water at any time of the day or night. However, the best time to water is in the late afternoon, not the morning. Mosses don't seem to burn or ever mold from an erratic watering time frame. For years, I've watered my moss garden when it looks thirsty, sometimes at high noon on a lunch break or even at midnight under the moonlight.
Of course, you can always use your tactile senses and if the moss feels really dry, most likely, it's time to water again. With all that said, some mosses NEED to dry out like Bryums (sidewalk moss). And, the majority of soil-type mosses (with the exception Sphagnums and Bartramia) will not tolerate constant, soggy conditions or “wet feet.”
Beware of overwatering your mosses!
So, if it doesn't rain, it is important to consistently water mosses. Even if it rains the day before, your mosses may want a drink the next day. Watering and walking on your moss garden are my main recommendations for establishing a successful moss garden.