Steamboat Springs Basil sits high on the list of essential herbs for a kitchen garden and although it is easy to grow, it is a little trickier to have it flourish in our climate. Basil is one of those herbs that romances cooks with its versatility and warm spicy flavor so there is nothing more frustrating than tending a puny under-performing specimen.
Basil is a tender warm weather annual that germinates best at high temperatures - above 85 degrees. It needs warm soil (so don't rush springtime planting) and will not grow well at temperatures below 60 or 65 degrees, while a period of weather in the 50s (our usual summer night time temperatures), will set the plant back significantly.
With that in mind, I left mine in a "Wall of Water" (a type of plant protector available at nurseries) the entire summer and was able to harvest my lushest and most prolific crop ever. I encouraged branching on the young seedlings by cutting back the stems to just above the first set of leaves after the plants had developed three pairs of leaves. Every dicot - a plant that has two seed leaves at the sprout stage - has a hormonal message system by which the topmost bud on the plant tells the side buds not to grow. By cutting off the tip of the basil plant and thus stopping the signal, all of the side sprouts on the plant will begin to grow, with those closest to the missing top growing the fastest. Later removing developing flowers (they are edible, so sprinkle them in a salad) preserves the flavor and prolongs the harvest.
The best location to plant basil is in rich, well-drained soil in full sun, protected from cooling winds and driving rain. If your soil needs upgrading, add compost, which improves the texture and water retention of the soil and at the same time adds a balanced amount of nutrients. Because basil is a leaf crop, some gardeners are tempted to fertilize heavily, but even though you may get bigger plants, it will be at the expense of flavor. If you need to fertilize, do so with a weak solution of a liquid fertilizer well before harvest. Basil needs room to bush out, so give each plant a square foot of space to grow into and either purchase as a pot plant or grow from seed. For best success with seeds, sow them thinly and snip out unwanted seedlings to avoid disrupting the roots of the ones you keep.
A native of Africa and Asia, basil has been cultivated for at least four thousand years, and in 19th century Europe, more than 60 varieties existed. Although most of these have disappeared, there are more than 16 varieties cultivated for culinary use - sweet basil (Ocimum basilicum), the main culinary variety, takes many forms - dwarf, opal, lettuce-leaved (perfect for pesto), napoletano and flavors such as cinnamon, licorice, lemon or clove. So, choose for looks (Purple Ruffles) as well as for flavor (Licorice) and enjoy. Even though basil has long been revered and is the stuff of diverse legends it is because of the poetry it produces in the kitchen that it has engendered such a faithful following.
Jane McLeod is a master gardener with the Colorado State University Cooperative Extension office in Routt County. Questions? Call 879-0825 or e-mail firstname.lastname@example.org