Gordon Johnson, Extension Vegetable & Fruit Specialist; gcjohn@udel.edu
The following are minimum pHs for various vegetable crops.
| Crop | Min. pH |
| Cucumbers, cantaloupes, squash, pumpkins | 5.8 |
| Watermelons | 5.5 |
| Tomatoes, peppers, and eggplant | 5.8 |
| Cole crops (broccoli, cabbage, cauliflower, Brussels sprouts, kale, collards) | 6.0 |
| Spinach, beets, chard | 6.0 |
| Snap beans and lima beans | 5.8 |
| Sweet corn | 5.8 |
| Peas | 6.0 |
| Potatoes (scab resistant) | 5.5 |
| Carrots | 5.5 |
| Sweet potatoes | 5.5 |
| Onions | 5.8 |
Below these pH levels, crop performance will be affected, and yields will be reduced. Lime should be applied immediately if soil pH has dropped to these values. Target pHs for vegetable crops can be found in Table B1 in the Mid-Atlantic Commercial Vegetable Production Recommendations.