Hi I can't fix all site problems, but I have a fix for the text editor so you can see what you are writing.
Webpages are basically content and style. html covers the words written and css controls how it is laid out on the page. Normally your web browser loads the content html and a css style file from the website.
For Gardeners World the current text size is 10px for the editor box.
Stylish is an extension for firefox which allows you to load and create styles for existing webpages which over ride the settings the webpage designer specified. Good news is you don't need to do any creating I have a style created and available to install.
Google Stylish and the name of your webbrowser in my case its firefox
Select install addon (some might have installed it already for styling other sites)
Once installed it will ask to restart your browser.
Go to the Gardeners World website and on the notification bar you on the bottom of your browser you should see an S in the corner left click on that and select 'find styles for this site' it should find the style I've uploaded click install and now you will be able to write your posts in 14 px instead of 10px.
If you don't like 14px you can select the style and choose edit and just change the font size to something better maybe 16px or even 20px
Simpler than it sounds honest. If anyone struggles with it just ask and i'll try to walk you through. There is always left 'Ctrl +' but that does the whole page where this is a fix for the textbox for entering your posts only
It just fixes this single problem, it should work for most browsers including internet explorer , chrome, opera, and safari