Best Soil pH for Vegetables
Most vegetables grow best at soil pH 6.0 to 6.8. Potatoes want 5.0 to 5.2 and blueberries 4.5 to 5.5. Target and lowest-useful pH for 35 garden crops from...
Published by ThriveThyme
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Best Soil pH for Vegetables
Most vegetables grow best at a soil pH between 6.0 and 6.8, with 6.5 as the usual target. The exceptions are potatoes (5.0 to 5.2 if scab is a problem), blueberries (4.5 to 5.5), carrots and sweet potatoes (slightly lower), and asparagus (higher, around 6.8).
Enter your own pH in the Soil Test Desk to see every crop in your garden marked low, in range, or high.
How to Use the Table
- Target pH is the number extension labs aim for when they calculate lime.
- Lime below is the critical pH. Below it, acidity is likely to hurt growth and lime pays off. Between the critical pH and the target, plants usually do fine, and lime is optional.
- Values come from the University of Delaware and Rutgers soil testing programs and Cornell vegetable guidelines. Your state lab may use slightly different numbers. If it does, use theirs.
Vegetables and Herbs
| Crop | Target pH | Lime below |
|---|---|---|
| Asparagus | 6.8 | 6.2 |
| Beans (snap) | 6.2 | 6.0 |
| Beets | 6.5 | 6.2 |
| Broccoli | 6.5 | 6.2 |
| Brussels sprouts | 6.5 | 6.2 |
| Cabbage | 6.5 | 6.2 |
| Carrots | 6.0 | 5.5 |
| Cauliflower | 6.5 | 6.2 |
| Celery | 6.5 | 6.0 |
| Collards | 6.5 | 6.2 |
| Cucumbers | 6.5 | 6.0 |
| Eggplant | 6.5 | 6.0 |
| Garlic | 6.4 | 6.0 |
| Kale | 6.5 | 6.2 |
| Kohlrabi | 6.5 | 6.2 |
| Leeks | 6.5 | 6.0 |
| Lettuce | 6.5 | 6.0 |
| Melons (cantaloupe) | 6.5 | 6.0 |
| Okra | 6.5 | 6.0 |
| Onions | 6.5 | 6.0 |
| Parsley | 6.5 | 6.0 |
| Parsnips | 6.5 | 6.0 |
| Peas | 6.5 | 6.0 |
| Peppers | 6.5 | 6.0 |
| Pumpkins | 6.5 | 6.0 |
| Radishes | 6.5 | 6.2 |
| Spinach | 6.5 | 6.0 |
| Squash (summer and winter) | 6.5 | 6.0 |
| Sweet corn | 6.5 | 6.0 |
| Sweet potatoes | 6.2 | 5.5 |
| Swiss chard | 6.5 | 6.2 |
| Tomatoes | 6.5 | 6.0 |
| Turnips | 6.5 | 6.0 |
| Watermelon | 6.2 | 5.5 |
Fruit and Potatoes
| Crop | Target pH | Notes |
|---|---|---|
| Strawberries | 6.2 | Lime below 5.8 |
| Blueberries | 4.8 | Aim for 4.5 to 5.5. Never lime |
| White potatoes prone to scab | 5.2 | Lime below 5.0 only. Higher pH favors scab |
| White potatoes, scab resistant | 6.2 | Lime below 5.5 |
What to Do With Your Number
- Below the lime-below number for your crops: add lime at the rate on your soil report. Apply it in fall. See when and how to add lime to a garden in fall.
- Between lime-below and target: crops will grow. Lime if your lab recommends it, or if you want the best yield.
- At or above target but under 7.0: leave it alone.
- Above 7.0: do not lime. Use sulfur only on a lab recommendation.
Mixed beds are common. Pick the target of the crop that is hardest to please. If you grow tomatoes, brassicas, and onions together, aim for 6.5. Keep blueberries and potatoes in their own beds or containers.
Why It Matters
Soil pH controls which nutrients roots can take up. Oklahoma State Extension says most nutrients are most available in mildly acidic soil from 6.0 to 7.0. Soil tends to turn more acidic over time, which is why vegetable beds should be retested every 1 to 2 years (University of Georgia Extension).
Not sure what your pH is? Take a soil sample this fall, then read the results.
Sources
- University of Delaware Extension, Measurement and Management of Soil pH for Crop Production in Delaware
- Rutgers NJAES, Soil and Nutrient Management, Mid-Atlantic Commercial Vegetable Production Recommendations
- Cornell Nutrient Management Spear Program, Nutrient Guidelines for Commercial Vegetable Production
- Oklahoma State Extension, Soil Test Interpretations for Vegetable Crops
- Clemson HGIC, Soil Testing