Compiled from data presented by Jon Clements from material supplied by Joe Costante, and from a chapter by P. Heinemann in the Mid-Atlantic Orchard Monitoring Guide - D. G. Pfeiffer
These temperature ranges are only approximations, and are subject to environmental variables. Prolonged exposure to cool temperatures increases a bud's hardiness and lowers these critical temperatures.
| Bud Stage-> |
Silver Tip |
Green Tip |
Half-inch Green |
Tight Cluster |
First Pink |
Full Pink |
First Bloom |
Full Bloom |
Post Bloom |
| Ave. temp. for 10% kill |
12-15 |
15-18 |
20-23 |
24-27 |
25-28 |
25-28 |
27-28 |
28 |
28 |
| Ave. temp. for 90% kill |
0-2 |
5-10 |
10-15 |
16-21 |
18-24 |
20-25 |
22-25 |
23-25 |
23-25 |
| Bud Stage-> |
Scales separating |
Blossom buds exposed |
Tight cluster |
First white |
Full white |
First bloom |
Full bloom |
Post bloom |
| Ave. temp. for 10% kill |
15 |
20 |
24 |
25 |
26 |
27 |
28 |
28 |
| Ave. temp. for 90% kill |
0 |
5-6 |
15 |
18-19 |
22 |
23 |
24 |
24 |
* For Bartlett. Anjou is similar in hardiness but may bloom earlier and therefore may be more tender than Bartlett on the same date.
| Bud Stage-> |
First swelling |
Calyx green |
Calyx red |
First pink |
First bloom |
Full bloom |
Post bloom |
| Ave. temp. for 10% kill |
18 |
21 |
23 |
25 |
26 |
27 |
28 |
| Ave. temp. for 90% kill |
1 |
5 |
9 |
15 |
21 |
24 |
25 |
* For Elberta