Do tea-like drinks typically require the plant material be dried or processed? Many of the plants in my garden have leaves or flowers that are, in various places, described as being good for making a herbal tea. A couple of examples are lemon balm leaves (Melissa officinalis) and strawberry guava leaves (Psidium littorale). I also have a number of different varieties of mint.

When you buy herbal teas, the leaves or flowers (or bark) that the tea is made from are obviously dried. Is the drying process an essential aspect of the tea preparation, or is that simply for storage and preservation? If you have access to the raw ingredient, do you need to dry or process it in some way first or can the tea be made satisfactorily without any drying or processing?
Dried vegetation usually suffers cell wall degradation. So when rehydrated all the oils and flavours will easily leach out. This is very desirable for vegetation you want to extract oils and flavours from

Many "teas" are also partially fermented for additional flavour. This processes need to be stopped otherwise the whole plant will be consumed. Drying is the simplest way to stop fermentation, and make the product storable and transportable