Table 4. Maximum rooting depth for different plants (adapted from Allen et al., 1998)
| Plant | Root depth (in) | Plant | Root depth (in) | Plant | Root depth (in) |
|---|---|---|---|---|---|
| Small vegetables | |||||
| Broccoli and Brussel Sprouts | 16 - 24 | Cabbage | 20 - 30 | Carrots | 20 - 40 |
| Cauliflower | 16 - 28 | Celery, Garlic, Spinach, Radishes, and Lettuce | 12 - 20 | Onions | 12 - 24 |
| Big vegetables | |||||
| Egg Plant and Cucumber | 28 - 47 | Sweet Peppers | 20 - 40 | Tomato | 28 - 60 |
| Sweet Melons and Watermelon | 35 - 60 | Cantaloupe, Pumpkin and Winter Squash | 39 - 60 | Squash and Zucchini | 24 - 40 |
| Perennial vegetables | |||||
| Artichokes and Asparagus | 24 - 70 | Mint | 16 - 30 | Strawberries | 8 - 12 |
| Forages | |||||
| Alfalfa | 40 - 118 | Bermuda | 40 - 60 | Clover | 24 - 35 |
| Rye grass | 24 - 40 | Grazing Pasture | 20 - 60 | Turf Grass | 20 - 40 |
| Roots and Tubers | |||||
| Cassava | 28 - 40 | Turnip | 20 - 40 | Potato | 16 - 24 |
| Sweet Potato | 40 - 60 | Sugar Beet | 28 - 47 | Parsnip | 24 - 40 |
| Legumes | |||||
| Beans | 20 - 47 | Peas | 24 - 40 | Peanut | 20 - 40 |
| Lentil | 24 - 30 | Soybeans | 24 - 50 | Green Gram | 20 - 43 |
| Fiber Crops | |||||
| Cotton | 40 - 67 | Flax | 40 - 60 | Sisal | 20 - 40 |
| Oil crops | |||||
| Ricinus and safflower | 40 - 80 | Rapeseed, Canola, and Sesame | 20 - 40 | Sunflower | 30 - 60 |
| Cereals | |||||
| Barley, Oates, Spring Wheat | 40 - 60 | Winter Wheat | 60 - 70 | Millet and Sorghum | 40 - 80 |
| Field Maize | 40 - 67 | Sweet Maize | 30 - 47 | Rice | 20 - 40 |
| Fruit trees | |||||
| Almonds, Apples, Cherries, Pears, Apricots, and Peaches | 40 - 118 | Avocado | 20 - 40 | Conifer Trees and Pistachio | 35 - 60 |
| Kiwi | 28 - 50 | Olives | 47 - 67 | Walnut | 67 - 94 |
| Grapes | 40 - 60 | Berries | 24 - 47 | Pawpaw | 120 - 240 |
| Citrus (20% canopy) | 30 - 43 | Citrus (50% canopy) | 43 - 60 | Citrus (70% canopy) | 47 - 60 |