| Zone 8 Mar. 21 - Mar. 31 | Zone 9 Apr. 1 - Apr. 10 | Zone 10 Apr. 11 - Apr. 20 | Zone 11 Apr. 21 - Apr. 30 | Zone 12 May 1 - May 10 |
| Zone 13 May 11 - May 20 | Zone 14 May 21 - May 31 | Zone 15 Jun. 1 - Jun. 10 | Zone 16 Jun. 11 - Jun. 20 | Zone 17 Jun. 21 - Jun. 30 |
| Zone 18 Jul. 1 - Jul. 10 | Zone 19 Jul. 11 - Jul. 20 | Zone 20 Jul. 21 - Jul. 31 |
Plantmaps has derived zones indicating the average annual Last frost dates for Bulgaria