Growing Pesto Ingredients
Classic pesto is made with basil, garlic, olive oil, cheese and nuts. Nuts and olives require a lot of time and the right climate to grow, but the other two ingredients are easy for home gardeners.
Basil is a warmth-loving, frost-sensitive annual herb. Frost kills it, and temps in the upper 30s will cause temporary yellowing and arrested development. Northern growers may want to start basil inside 4-8 weeks before the last frost date and set transplants out 2 weeks after the last spring frost for early harvest. Basil can also be direct-seeded 1/4″ deep and 12″ apart.
It wants full sun, plenty of warmth (Northern growers might consider planting it along a south-facing wall), and not too much fertilizer. Excessive nitrogen can weaken the flavor of the leaves. Pinch off the tops of basil plants when they’re about 6″ high to encourage branching. Keep pinching branch tips to harvest. Don’t let the plants flower.
Garlic is an unusual annual crop. It’s planted in the fall, starts growing, goes dormant over the winter, starts again in spring and is harvested in midsummer. Plant garlic cloves in rich well-drained soil, 3″ deep and 6″ apart, in a grid around the time of your first fall frost. Mulch the bed with hay or straw for protection through the winter. Keep it weeded and watered through the spring and summer. Harvest when lower leaves are turning brown and dying but 5 or 6 green leaves remain on the plant.
How to Make Pesto
Pesto recipes vary. Experiment and find out what flavors you like best.
Here’s a basic starter recipe:
4 cups basil leaves
4-6 cloves garlic
1/2 cup olive oil
1/3-2/3 cup nuts (pine nuts are traditional, but other nuts will do; mild-flavored options like almonds, walnuts and sunflower seeds are commonly used)
Combine basil and nuts in food processor. Pulse several times. Add garlic and pulse again. Scrape down the sides of the food processor if needed. Add olive oil in small amounts between pulses. Remove pesto from processor and season with salt and pepper to taste.
If you want to serve pesto fresh, add grated cheese to taste (Parmesan or Romano is traditional; recipe suggestions for a batch of pesto this size range from 1/3 cup to 1 cup of cheese) along with basil. If you want to preserve your pesto, leave the cheese out for now.
Pesto cannot be safely canned, but it can be safely and easily frozen. Make pesto without cheese (it’s safe to freeze it with cheese, but the cheese texture deteriorates in freezing). Line a cookie sheet with waxed paper. Pile pesto, in the amounts you’d use in a meal, on the waxed paper (or ice cube tray) and freeze. Once pesto piles have solidified they can be put into freezer bags. Label with the date. After pesto thaws, mash cheese in with a fork.
Making Pesto with Parsley, Cilantro, Spinach and Arugula
Sometimes other leaves are substituted for some of the basil in the recipe above. Popular partial substitutions include parsley, cilantro, arugula and spinach.
Parsley is a slow-growing biennial. Plant it indoors 4-6 weeks before frost and transplant outside after the last spring frost, or direct-seed 1/4″ deep outside in late spring. Seeds germinate better if they’re either chilled in the freezer or soaked for 24 hours before planting. During its first year parsley produces abundant leaves. During its second year it grows leaves again and then flowers. Pull plants with mature seeds and lay them down on the garden bed; next year you’ll get volunteer parsley.
Cilantro is a self-seeding short-lived annual. Plant like parsley, and plant again in mid-summer. Leave some cilantro plants to go to seed to ensure next year’s crop.
Arugula and Spinach
Arugula and spinach are quick-growing cool-season vegetables which may be ready to harvest 4 weeks after planting. They’re best planted in early spring or in fall and tended like lettuce.
Garlic mustard is an edible invasive plant which can be made into pesto; it is substituted for all the basil and most of the garlic in the classic recipe. Google offers several recipes for garlic mustard pesto.
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