Can you write a love poem by showing and not telling and only describing the landscape? I am thinking you need to make it allegorical, but without mentioning animals and humans and clothes, etc, just describing the landscape, I am thinking this is impossible, so what are some ways this is done most of the time and is it even possible to do this with just the landscape? I am wondering if show don't tell means something different in poetry.
The meaning of show don't tell is independent of composition type.
Writing a poem about love as an allegory is a composition type. How to write the allegory itself is a matter of showing vs telling.
These hills are nice. The sun loves them and wakes them up every morning with light, caressing their tops, warming their body.
With a slow, timid pace, the sun's morning hand crawls from leaf to leaf, peeks between the branches and brushes away the dew from the drowsy tops of these sleepy hills.
1: Disclaimer -- I am no poet. These are crude illustrative examples.
Same allegory, just a different way of composing it. The allegory meaning is that of waking up next to the loved one.
In the telling example, we 'tell' what there is to know: the sun wakes up and cuddles with the hills.
In the showing example, we 'show' the waking up process, what it entails. In this case, showing is about conveying the same image through the feelings, the speed and the sensations involved.