pH needs of plants in soil or hydroponics
15 years ago hydroponics, pH, water
With the exception of some of my acid loving plants and flowers I normally do not have to worry much about the pH of my soil. This is because I have amended my gardens with nutrient rich soils in raised beds over my alkaline clay I get naturally in my area. This and the fact that due to natural and manmade causes the rainfall is slightly acidic and given the average range for the sweet spot of most edible vegetables (see table below) is 5.8 to 6.0 having your soil slightly acidic this is perfect.
Now when it comes to hydroponics this is entirely different. My tap water has a pH of around 7.5 and the fluctuation of plant using nutrients and transpiration can cause great havoc on the pH on your hydroponic system. Now this creates a challenge but also an opportunity to have control with great precision your pH and keep your plants growing in the sweet spot for the healthiest plants and the greatest yields.
So whether you are growing hydroponically, or simply trying to figure out why your Fennel didn’t do so well last year take a look at the table below, hopefully for some hints of what happened.
Recommended pH Ranges of Vegetables/Herbs
| Plant | Low | High | Plant | Low | High | |
| Artichoke | 6.5 | 7.5 | Millet | 6.0 | 6.5 | |
| Asparagus | 6.0 | 8.0 | Mint | 7.0 | 8.0 | |
| Average | 6.3 | 7.8 | Mushroom | 6.5 | 7.5 | |
| Basil | 5.5 | 6.5 | Mustard | 6.0 | 7.5 | |
| Bean | 6.0 | 7.5 | Okra | 5.5 | 6.0 | |
| Beanroot | 6.0 | 7.5 | Olive | 5.5 | 6.5 | |
| Beet | 6.0 | 6.8 | Onion | 5.5 | 6.5 | |
| Broccoli | 6.0 | 6.8 | Paprika | 7.0 | 8.5 | |
| Brussel Sprouts | 6.0 | 6.8 | Parsley | 5.0 | 7.0 | |
| Cabbage | 6.0 | 6.8 | Parsnip | 6.0 | 6.8 | |
| Calabrese | 6.5 | 7.5 | Pea | 5.8 | 7.0 | |
| Carrot | 6.0 | 6.8 | Peanut | 5.0 | 6.5 | |
| Cauliflower | 6.0 | 6.8 | Pepper | 5.5 | 6.0 | |
| Celery | 6.0 | 6.5 | Peppermint | 6.0 | 7.5 | |
| Chicory | 5.0 | 6.5 | Pistacio | 5.0 | 6.0 | |
| Chinese Cabbage | 6.0 | 7.5 | Potato | 4.5 | 6.5 | |
| Chives | 6.0 | 7.0 | Potato, Sweet | 4.5 | 6.0 | |
| Corn Salad | 6.0 | 6.5 | Pumpkin | 6.0 | 6.8 | |
| Corn, Sweet | 5.8 | 6.8 | Radish | 6.0 | 6.8 | |
| Courgettes | 5.5 | 7.0 | Rice | 5.0 | 6.5 | |
| Cress | 6.0 | 7.0 | Rosemary | 5.0 | 6.0 | |
| Cucumber | 6.0 | 6.8 | Rutabaga | 6.0 | 6.8 | |
| Eggplant | 5.5 | 6.0 | Sage | 5.5 | 6.5 | |
| Fennel | 5.0 | 6.0 | Shallot | 5.5 | 7.0 | |
| Garlic | 5.5 | 7.5 | Sorghum | 5.5 | 7.5 | |
| Ginger | 6.0 | 8.0 | Soybean | 5.5 | 6.5 | |
| Horseradish | 6.0 | 7.0 | Spearmint | 5.5 | 7.5 | |
| Kale | 6.0 | 7.5 | Spinach | 6.0 | 6.5 | |
| Kohlrabi | 6.0 | 6.8 | Squash | 6.0 | 6.8 | |
| Leek | 6.0 | 8.0 | Swede | 5.5 | 7.0 | |
| Lentil | 5.5 | 7.0 | Swiss Chard | 6.0 | 6.5 | |
| Lettuce | 6.0 | 6.5 | Thyme | 5.5 | 7.0 | |
| Marjoram | 6.0 | 7.5 | Tomato | 6.0 | 6.5 | |
| Marrow | 6.0 | 7.5 | Turnip | 6.0 | 6.8 | |
| Melon | 6.0 | 6.8 | Upland Cress | 6.0 | 6.5 |
Tags: garlic bulbs, herb garden, outdoor plants, pepper plants, peppermint plant, tomato plants, vegetables
