At the bottom of your thread is the Quick Reply feature. At the bottom right of this is a 'Go Advanced' button. Click that. A new screen opens with a preview of your post so far (if you started one) and underneath is a section title 'Your Message'. Just above the text box where you type in your message you will see a row of buttons. About the 6th one from the right, you'll notice one that looks like a square picture with a tree on it. Hovering over the button should reveal the message 'Insert Image'. Click that button. A little pop-up window should come up, if not may be your browser is not allowing it. On the popup, click the 'Select Files' button. Select your files then click 'Upload File(s)'.Viola!
As far as your hempy bucket grow and plant prob, I got nothing for ya. Sorry. Somebody will pop in with that knowledge sooner or later, though. Good luck!