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.
The temperatures are state-wide averages calculated from temperatures recorded during the months of March, April and May. Spring temperature averages range from a high of 69.9 degrees Fahrenheit (21.1 degrees Celsius) in Florida to a low of 24.7 Â°F (-4.1 Â°C) in Alaska. For the entire United States, excluding Hawaii and Alaska, the season averages 52.0 Â°F (11.1 Â°C).