I too have had this experience recently, with comments and links left on posts that bear no relation to gardening or plants. But I'm NOT going to stand down or be put off by people who get vicarious pleasure from attempting to post inappropriate rubbish on my posts, or give links to sites that have nothing to do with the simple pleasures like gardening that I enjoy.
So, just a couple of words of advice to fellow bloggers - DO enable comment moderation so you can actually delete inappropriate words before others see them and DO check your followers column (if you have one), because sometimes people slip in amongst your genuine friends and you don't realise. You can always block followers, just as you can delete comments.
I'm not going to say more ... but if you're wondering about the choice of pictures today - it's to do with stormy weather and clear skies!