Gordon Johnson, Extension Ag Agent, Kent Co.; gcjohn@udel.edu
We have more growers that are producing tomatoes in high tunnels. The following are fertilizer recommendations for spring grown high tunnel tomatoes from Penn State University:
Fertility Recommendations – Spring High Tunnel Tomato Crop
| Weeks After Transplanting | Fertilizer and Amount Applied per 100 Plants in 50 Gallons of Water |
| 1 and 2 | Water only, no fertilizer |
| 3 through 6 | 3 lbs calcium nitrate |
| 7 | 6 lbs potassium nitrate |
| 8 | 6 lbs calcium nitrate + 0.25 lbs chelated iron |
| 9 | 5 lbs potassium nitrate |
| 10 | 5 lbs 20-20-20 |
| 11 | 5 lbs calcium nitrate + 0.25 lbs chelated iron |
| 12 | 5 lbs potassium nitrate |
| 13 | 5 lbs calcium nitrate |
| 14 | 4 lbs 20-20-20 |
| 15 | 5 lbs calcium nitrate |
| 16 | 4 lbs potassium nitrate |
| 17 | 4 lbs potassium nitrate |
| 18 | 4 lbs 20-20-20 |
| 19 | 3 lbs calcium nitrate |
| 20 | 3 lbs potassium nitrate |
| 21 | 3 lbs potassium nitrate |
| 22 | 2 lbs 20-20-20 |
| 23 | 2 lbs calcium nitrate |
| 24 | 2 lbs calcium nitrate |
Go to http://hortweb.cas.psu.edu/vegcrops/vegetable_gazette/2007/May2007.pdf for more information.