Hi. I’ve been growing Thyme for about two months now, maybe a bit longer. I think I cut it back strongly like weekly… but it still keeps growing back like crazy. It says that it should last for 3 months, but mine has no signs of deterioration or aging at all.
Roots growing through the wick is not a real problem and that is nothing to worry about and it should be left like that as long as the plant grows. Though, if it happens multiple times it may reduce wicks’ longevity and reduce the ability to transport water to pods. Also, the water tank should be cleaned much more often if new pods are planted.
If plants are grown successfully longer than it says on the package… well… it is absolutely wonderful! Also, Thyme root growth is not so aggressive, it is quite modest plant and we see quite often that it last longer than promised.
In my experience the longevity or lifespan of a plant also depends on the time of year. During dark and cold months plants tend to finish their life-cycle in a hurry.