How Much Water Do Basil Plants Need?

Moisture Needs

• Most herbs, including basil, have a reputation for being drought-tolerant plants that thrive in dry, infertile soils. Basil might survive under dry conditions, but it won't thrive and the leaves may have a bitter taste. Water the soil regularly to keep it evenly moist, but not soggy. Add 2 to 3 inches of organic matter, such as compost, peat moss or well-rotted manure, to the soil before planting the basil to improve drainage. Mulch basil plants with 3 inches of untreated grass clippings to conserve moisture.

Planting Basil

• Start basil indoors four to six weeks before the last expected frost. The seeds germinate quickly when the temperature is around 70 degrees Fahrenheit. Plant the basil outdoors only after daytime temperatures are above 70 F and nighttime temperatures don't dip below 50 F. Basil doesn't tolerate cold at all and becomes a black slimy mess if hit by frost.

Growing Conditions

• Basil thrives when planted in full sun and kept moist. Pinch the stems back if the plant gets leggy and don't allow it to produce flowers, which will change the flavor of the basil. Provide fertilizer only if growth lags or the leaves are pale green. Excess nitrogen fertilizer also alters the flavor of the leaves. Grow basil in pots next to your back door for easy access, but make sure to provide extra water since pots dry out quickly.

Harvest and Uses

• Pinch off a few leaves for use as a garnish or in pasta and sauces. Harvest basil only as needed because it doesn't store well, even in the refrigerator. At the end of the season, harvest all the basil and make it into pesto. Place the pesto in plastic freezer bags and freeze it for midwinter sauces. Thaw the frozen pesto in the refrigerator for six hours and heat it or serve cold.