Plant Height. Basil usually grows to a height of 12 to 18 inches (30 - 45cm). Basil plants should be spaced between 9 and 12 inches (22 and 30 cm) apart. Basil will grow in a very wide pH range between 5.1 (strongly acidic) and 8.5 (alkaline) with a preferred range of 5.5 (strongly acidic) to 6.5 (mildly acidic).Sow seed indoors before last frost or direct sow outdoors after last frost.referred pH Range. Basil will grow in a very wide pH range between 5.1 (strongly acidic) and 8.5 (alkaline) with a preferred range of 5.5 (strongly acidic) to 6.5 (mildly acidic).
Ocean spring temperatures range from an average of 60 degrees Fahrenheit (16.5 degrees Celsius) in southern California to 50 degrees F (10 C) off the state's northern beaches.
In May, the average temperature in Calistoga is 64 degrees, with an average high of 78, and an average low of 46 degrees. The average rainfall in Calistoga for May is 1.4 inches. Although it is still technically spring, May in Napa Valley often feels like summer. In May 2014, for example, high temperatures were generally in the 70âs and 80âs with the temperature exceeding 90 on five days. Rainfall is practically non-existent in May, with average monthly rainfall of just a half inch. There is hardly a cloud and the sun shines 11 hours a day.