Rutabaga (Brassica napus var. nopobrassica): The optimum pH is 5.5 to 7.0 on eastern soils and up to 7.5 on western soils. Rutabaga has a relatively high need for boron. This medium long-season, cool-weather plant produces a surprisingly large and deep root system. For best plant development, the soil should be at least 4 to 5 feet deep. Loams and silt loams are preferred. Sandy loams are generally a little less productive. Clays tend to cause the marketable roots to be misshapen and to make harvest difficult.

Salsify (Tragopogon porrifolius): The Optimum pH is 6.0 to 7.5. Other soil requirements are the same as for carrots. It is less difficult to get good stands of salsify than of carrots.

Shallots (Allium ascalonicum): The optimum pH is 5.5 to 7.0. This minor cool-weather plant, similar to the "bunching" type of onion, is seldom grown commercially except in southern Louisiana. The plant is relatively shallow rooted and is grown best on loam soils, although sandy loams and silt loams are also good. Sandy soils and clays are undesirable.

Sorrel (Rumex acetosa): It tolerates a PH of 4.0 to 7.0. This minor greens "vegetable" is a perennial kin to dock (a common perennial weed) and is sometimes called "sour grass." It will grow in soils too acid for other vegetables, ranging from sandy soil to clay and muck. Like most plants, it grows better in rich soils than in poor ones.

Spinach (Spinacia oleracea): The optimum pH is 6.0 to 7.0. It is rather highly tolerant to high salt content and boron content in the soil and is very sensitive to high acidity. Additions of manganese may be needed to correct chlorosis on strongly alkaline soils. The root system is shallow; the soil need not be more than 1.5 to 2 feet deep, but it must be well drained and highly fertile for good yields. Sandy loams are satisfactory for early market crops, but the more fertile, deep loams, silt loams, clay loams, and mucks are preferred where earliness is not important. Clay soils can be used where moisture in the soil is under control.

Squash (Cucurbita pepo, C. moschata, and C. maxima): (See cucurbits.)

Sweet corn (Zea mays): (See also corn). Optimum pH is 5.5 to 7.0. Sweet corn is moderately tolerant to high salt and to high boron content of the soil. It grows well on any well-drained soil that produces good yields of other crops. Deep, naturally rich soils that are easy to work are preferred but are not essential. Sweet corn requires relatively heavy manuring and fertilizing of soils that are not naturally highly fertile. Fine sandy loams and sandy loams are best for crops for early market; loams, silt loams, clay loams and clays can be used for later crops.

Sweetpotato (Ipomoea batatas): The optimum pH is 5.5 to 6.5; good yields are possible in a pH range of 5.2 to 7.0. Sweetpotato is best adapted to slightly acid soils and has little tolerance to either high salt or high boron content of the soil. Loamy fine sand, loamy sand, and sandy loam surface soils are suitable for sweetpotatoes when they are well fertilized and underlaid by firm, well-drained subsoils of finer texture at approximately 1 foot depth. Sandy or gravelly subsoils tend to be infertile and droughty and to cause too deep penetration of the enlarged roots; the results are poor shape of the roots and difficulty of harvest. Friable, moderately deep loams and silt loams, such as Lintonia silt loam, are very desirable. Clay loams and clays are conducive to poor root shape and difficult harvest; they are not recommended. Muck soils cause poor root shape, although large tonnages can be produced on them in the South. Sweet-potato requires high potash, medium phosphorus, and medium to low nitrogen supplies.

Swiss chard (Beta vulgaris var. cicla): The optimum pH is 6.0 to 7.5. This leafy form of beet is highly tolerant to high salt and high boron content of the soil. It can be grown successfully on any good garden or truck-crop soil from loamy sands and sandy loams to clay loams and muck, if the soil is not strongly acid.

Taro (Colocasia esculenta): This tropical tuber-bearing plant is a form of elephant's ear and is suited only to the warmest parts of this country. It requires 7 months of warm weather to make a crop. Best results are obtained with a very moist, preferably well-drained soil, although taro will tolerate longer periods of flooding and wet soil than most garden crops. Deep, rich, sandy loams and loams are best, but mucks can be used. Prolonged excessive wetness of soil impairs the eating quality of the tubers. High organic matter and high fertility of the soil are essential for good results.

Tomato (Lycopersicon esculentum): The optimum pH is 5.5 to 7.0 in the East and up to 7.5 in the West. The tomato has medium high tolerance to both high salt and high boron content of the soil. It is one of the most widely adaptable of vegetables. Most varieties produce a large root system that will fill the soil to a depth of 4 feet if the soil is suitable. It is grown commercially on soils ranging from fine sands to marls and clays. It is rarely grown on mucks. Manganese additions are necessary on marls. On the sands and sandy loams, heavy to very heavy fertilization is necessary.

The tomato has a high requirement for phosphorus and potassium. Nitrogenous fertilizers and manures must be used judiciously because excess nitrogen often causes excessive plant growth, dropping of blossoms, and consequent low yields. Tomato is very sensitive to fluctuations in water or in nutrients, which commonly cause blossom end rot of fruit and dropping of blossoms. The best yields are obtained on deep (4 feet or more), rich loams, silt loams, and clay loams that are well supplied with moisture.

Turnips (Brassica rapa): The optimum pH is 5.5 to 6.8. Turnips tolerate a high boron content in the soil. Roots for early market and greens for market and processing are commonly grown on sandy loams. Roots for storage and forage are better grown on the more fertile loams and silt loams. Rich clays can produce heavy yields if the soil moisture is under control.

Watercress (Radicula nasturtium-aquaticum): The optimum pH is 6.0 to 8.0. Watercress is grown commercially in running spring water, chiefly in limestone regions where the water is high in calcium and carries adequate amounts of other nutrients, including nitrates. The plants are set in 2 to 4 inches of compost on carefully graded bottoms of flooded beds. Other than preparation of compost, no fertilization is commonly given.

Watermelons (Citrullus vulgaris): The optimum pH is 5.5 to 6.5. (See also cucurbits).

Watermelon, a warm-weather plant, is grown chiefly on loamy sands, sandy loams, and well-drained loams. The plant is a gross feeder and responds well to heavy applications of manure and other organic matter and to fertilizer, but it is not adapted to mucks. Certain friable silt loams are satisfactory, but clay loams and clays are not recommended.