Great Magazines have "Gardening News" at just £1 per issue via subscription. It's a weekly publication, with 52 issues in the year. This is a saving of £41 on the cover price over a year's subscription. Delivery is free of charge.
This is payable by direct debit, so it's mega easy to cancel. If you don't cancel then you'll be sent the magazines until you do.
If you pay for a subscription of an entire year (£52) using a credit/debit card (rather than direct debit) then you can use the attached voucher for an extra £2.50 off.