Plan your Zone 3 planting calendar
Get a month-by-month schedule of when to start, transplant, and harvest.
Zone 3 Coverage
Planting Timeline — All Varieties
Growing Herbs in Zone 3
Zone 3 presents unique opportunities and challenges for herb gardeners. While the short growing season and late spring frosts can be limiting, the intense summer sun and cool nights actually concentrate essential oils in many herbs, giving you incredibly flavorful harvests. The key is choosing varieties that can either handle light frosts or produce quickly enough to give you multiple harvests before September's first freeze.
When selecting herbs for Zone 3, prioritize cold-hardy perennials like English Lavender, Common Thyme, and Garden Sage that can overwinter with protection, along with fast-maturing annuals like Cilantro and Dill that can be succession planted throughout the season. Basil varieties, while frost-sensitive, grow vigorously in Zone 3's warm summers if you time plantings correctly and provide protection during cool snaps.
The herb varieties listed here have been specifically chosen for their ability to thrive in Zone 3's climate. From hardy perennials that return year after year to quick-growing annuals perfect for succession planting, these selections will give you a continuous supply of fresh herbs from late spring through early fall.
Variety Comparison
| Variety ↑ | Days | Difficulty |
|---|---|---|
| Angelica | 365 | Easy |
| Arat | 75 | Easy |
| Arterner | 400 | Easy |
| Asia Ip | 80-85 | Easy |
| Borage | 50-60 | Easy |
| Bouquet Dill | 40-60 | Easy |
| Brilliant | 75 | Easy |
| Britton | 80-85 | Easy |
| Bronze | 50-60 | Easy |
| Catnip | 75-85 | Easy |
| Chocolate Basil | 65-75 | Easy |
| Chocolate Mint | 65-75 | Easy |
| Cilantro | 16-25 | Easy |
| Common Chamomile | 60-65 | Easy |
| Common Mint | 70-80 | Easy |
| Common Valerian | 500-550 | Easy |
| Creeping | 90-95 | Easy |
| Cumin | 100-115 | Easy |
| Curly Parsley | 55 | Easy |
| Cutting Celery | 80-85 | Easy |
| Dandelion | 95 | Easy |
| Darki Green | 75 | Easy |
| Dragon | 75 | Easy |
| Ellagance Purple | 100-110 | Easy |
| Fernleaf Dill | 40-50 | Easy |
Variety Details
Angelica
Large, lobed leaves and thick, hollow stems. Leaves and stalks have sweet flavor. Because Angelica is a biennial, flowering begins early spring of the second year. Large, numerous blooms. Seeds are cold-stored to ensure viability. Blooms make a lovely addition to fresh or dried bouquets. Attracts and feeds beneficial insects and pollinators, including bees, parasitic wasps, lady beetles, minute pirate bugs, syrphid flies, and tachinid flies.
Arat
Enjoy the flavor of fresh parsley for soups, salads, and stews throughout the winter. Keeps several months when stored in cool conditions. Once roots are established, tops can be used for cooking, with stronger flavor and tougher texture than traditional leaf parsley. Roots are 5-8" long.
Arterner
Easy to grow once established. White umbel flowers form in spring of second year, attracting beneficial insects, such as hover flies. Harvest seed heads when plump and light brown, hang to dry. Thresh to remove seeds. One plant produces approx. 5 Tbs. of seed. Used in breads and savory dishes to lend an earthy, mild anise flavor.
Asia Ip
Leaves are similar to Britton type in shape and size, but are medium green with pink tinge on undersides. Stronger flavor than standard green shiso with uniform, full habit. Edible Flowers: The flowers are a flavorful addition to salads and Asian dishes. Pairs well with fish, rice, noodles, and cucumbers. The minty, basil-like flavor has hints of clove and cumin.
Borage
Large plants bear hundreds of small edible flowers, mostly blue and some pink. Long harvest period. Borage flowers attract bees and butterflies. Also available in organic seed.Edible Flowers: Add the flowers to salads or use to garnish cold drinks and desserts. Freeze as ice cubes. Mild cucumber flavor.
Bouquet Dill
Early flowering plants produce large blooms, seed umbels, and foliage on long stems, making Bouquet the preferred dill for cut-flower use and pickling. Also an economical, fast-growing choice for baby-leaf production. Edible seeds, flowers, and greens flavor many foods. Popular addition to sauces, salads, and soup. Foliage known as dill weed. Edible Flowers: The flowers are used to garnish potato salad, green salads, and pickles. When broken into florets, they can be mixed into a cheese spread or omelet.Also available in organic seed.
Brilliant
Brilliant is an easy-to-grow hybrid herb variety reaching maturity in 75 days under full sun conditions. This cultivar thrives in well-drained loam with moderate fertility, making it an excellent choice for novice gardeners. Brilliant delivers a distinctive sweet and juicy flavor profile with classic, mild undertones and a refreshing finish. The variety exhibits strong vigor but requires vigilant pest management against cucumber beetles, squash vine borers, aphids, and spider mites. Its balanced flavor and reliable productivity make it ideal for fresh use and culinary applications where a mild, refreshing taste is desired.
Britton
Good salad mix item, or use larger leaves as sushi wraps or garnishes. Larger leaf and plant than our 'Red' and 'Green' shiso. Mild mint/basil aroma. Also good for ornamental use. Leaves show best color contrast when grown in temperatures below 85°F (29°C). Also known as perilla. Edible Flowers:The flowers are a flavorful addition to salads and Asian dishes. Pairs well with fish, rice, noodles, and cucumbers. The minty, basil-like flavor has hints of clove and cumin.
Bronze
Bronze is an heirloom fennel variety prized for its distinctive copper-bronze foliage that sets it apart from traditional green fennel. This productive herb reaches maturity in 50-60 days and develops a sweet anise flavor that evolves from mild in young plants to rich and intensely fragrant when fully mature. The bronze coloring becomes more pronounced as the plant matures, making it visually striking in gardens. Bronze fennel is valued both as a culinary herb for its superior flavor depth and as an ornamental addition to herb and perennial gardens, thriving in full sun with well-drained soil.
Catnip
Cat-attracting perennial with gray-green leaves and white flowers. Markets for catnip include cat toy crafters, herbal tea companies, and retail plant sales. Flowers are very attractive to bees.
Chocolate Basil
Chocolate Basil is a heirloom herb variety known for its distinctive dark purple-tinged leaves and rich, complex flavor profile. Maturing in 65-75 days, this basil combines traditional sweet basil character with pronounced chocolate, cinnamon, and warm spice notes that become more pronounced as the plant matures. The foliage is dense and aromatic, ideal for culinary applications where its unique flavor complexity elevates dishes, teas, and infusions. Best grown in full sun with rich, well-drained soil, this easy-to-grow variety is prized by gardeners seeking distinctive flavor experiences beyond standard basil varieties.
Chocolate Mint
Chocolate Mint is a distinctive heirloom herb variety that matures in 65-75 days, featuring aromatic green foliage with soft, velvety texture. This unique mint hybrid stands out for its exceptional flavor profile: a refreshing cool mint taste with prominent chocolate undertones and a subtle sweet finish, making it ideal for both culinary applications and specialty beverages. Despite its rich flavor complexity, Chocolate Mint remains easy to grow, thriving in full sun with well-drained, moist soil. The plant tolerates heavy clay conditions well, making it adaptable to various garden settings.
Cilantro
Cilantro is a delicate leafy herb with feathery, triangular green foliage that reaches harvest maturity in 16-25 days. The plant produces thin, lacy stems bearing distinctive serrated leaves with a bright, citrusy flavor profile that carries subtle soapy notes and fresh herbal undertones. Cilantro thrives in full sun to partial shade and prefers well-drained, fertile soil. As a quick-maturing heirloom variety, it's ideal for succession planting throughout the growing season. Widely used in Latin American, Asian, and Mediterranean cuisines as a fresh garnish and flavor component in salsas, curries, and chutneys.
Common Chamomile
Good yields of small, sweet-smelling, daisy-like flowers. Tea made from the flowers aids digestion and acts as a gentle sleep inducer. Harvest using the Chamomile Rake. Also known as German chamomile and Hungarian chamomile.Edible Flowers: The flowers can be used to garnish salads, desserts, and drinks. Flavor is slightly sweet and of chamomile.
Common Mint
Use to flavor salad mix, main dishes, ice cream, and drinks. Variety not stated since mint does not grow true-to-type from seed. Edible Flowers: The flowers add a minty flavor to salads, soups, desserts, and drinks.
Common Valerian
Common variety, naturalized in some areas. Root used for anxiety, insomnia, and pain relief. Also known as garden heliotrope, cat's valerian, setwell, and St. George's herb.
Creeping
Creeping is an heirloom herb variety characterized by its low-growing, spreading growth habit that makes it ideal for ground cover or container cultivation. Reaching maturity in 90-95 days, this easy-to-grow herb thrives in full sun and well-drained soil while tolerating poor soil conditions remarkably well. The creeping form sets it apart from upright varieties, offering both ornamental appeal and practical utility in herb gardens.
Cumin
Fragrant, ferny foliage is similar to dill. Young leaves make a nice addition to salad mixes. Grows best in warmer climates, but will produce seeds in northern areas if started early. Medicinal: Seed aids digestion.
Curly Parsley
The finely curled dark blue-green leaves can be harvested with one cut. The compact plants produce leaves that are very uniform, resist yellowing, and have good flavor. Short internodes allow for high yields despite compact habit. Perfect for harvesting the whole plant at 12-18".
Cutting Celery
Easier to grow than standard celery. A versatile ingredient for salads, soups, stews, and vegetable medleys. Can be marketed in bunches or salad mixes. Also known as leaf celery. Also available in organic seed.
Dandelion
Young leaves are used in salads. Roots are roasted for a coffee substitute.
Darki Green
A very dark green selection of the Moss Curled type. Use it for garnishes, salads, and cooking. It performs well in containers and the field, allowing for multiple cuttings per season from one planting. Upright leaves make harvesting easy. Tolerates light frost. Curled-leaf type. Ht. 12-16".
Dragon
Well-known for its beautiful magenta-purple skin and broad, Chantenay-type shoulders. Slicing reveals a surprise of orange or yellow interior, sometimes both. Very thin, smooth skin makes Dragon easier to wash and serve unpeeled than other purples. Roots hold well in the field. Tops are strong and vigorous in early growth to compete with weeds. Internal color will vary. Avg. 5-7" long. Originally bred by the late Dr. John Navazio. Kuroda x Chantenay type. Also available with NOP-compliant pelleting.
Ellagance Purple
Deep purple flowers bloom the first year on large dense spikes. Plants are bushy, uniform, and well-branched. An alternative to vegetative varieties. Winter hardy in Zones 5-7. FleuroSelect Gold Award Winner. Edible Flowers: The flowers can be used to garnish desserts and as a distinct flavor element in baked goods. Flavor is sweet and floral and pairs well with citrus, berries, nuts, mint, and cinnamon.
Fernleaf Dill
Abundant dark blue-green foliage. Great in containers or in small spaces. AAS Winner. Ht. 6-8".
Flat-Leaf Parsley
Also known as Italian parsley, this variety offers superior flavor compared to curly parsley with its clean, bright taste that doesn't overpower dishes. The flat, deeply-cut leaves are easier to chop and provide a fresh, grassy flavor that's essential in Mediterranean cooking. This hardy biennial is incredibly productive and continues growing through light frosts, making it a kitchen garden staple.
French Tarragon
The aristocrat of culinary herbs, true French tarragon is essential for classic French cuisine with its distinctive anise-like flavor and sophisticated aroma. Unlike Russian tarragon, this sterile variety must be grown from cuttings and offers incomparably superior flavor. A must-have for serious cooks who want to create authentic béarnaise sauce and fine herb blends.
Garland Chrysanthemum
Garland Chrysanthemum is a tender, leafy herb with finely divided, feathery foliage that reaches maturity in 30-50 days. Also known as shungiku or edible chrysanthemum, this heirloom variety produces delicate, deeply lobed leaves with a distinctive mild, slightly bitter flavor. The fresh, herbal notes carry subtle hints of chrysanthemum flowers, making it prized in East Asian cuisines for both raw salads and cooked applications. This versatile herb thrives in cool seasons and is remarkably easy to grow, tolerating partial shade while preferring rich, well-draining soil enriched with organic matter.
German Chamomile
The classic tea herb beloved for its apple-scented flowers and gentle, soothing properties that have been treasured for centuries. This delicate annual produces masses of small, daisy-like flowers with white petals and bright yellow centers that can be harvested continuously throughout the growing season. Easy to grow and self-seeds readily, creating a charming cottage garden atmosphere while providing homegrown herbal tea.
Giant of Italy
Huge dark green leaves with great flavor. Strong, upright stems make Giant of Italy one of the best parsley varieties for fresh-market sales. Very high-yielding flat-leaf type. Ht. 18-20".
Gourmet Gold Dill
A stunning ornamental dill variety with bright golden-yellow foliage that adds both culinary value and visual drama to herb gardens. The vibrant color intensifies in cool weather while maintaining the classic dill flavor profile. Perfect for gardeners who want their herb garden to double as landscape decoration.
Green Shiso
Distinct cinnamon/clove flavor and aroma with the spiciness of cumin. Used in Asian cooking, sushi, and salad mix. Also known as perilla. Edible Flowers: The flowers are a flavorful addition to salads and Asian dishes. Pairs well with fish, rice, noodles, and cucumbers. The minty, basil-like flavor has hints of clove and cumin.
Grosfruchtiger
Nonbulbing type. We found Grosfruchtiger to be the most flavorful fennel in our trials. Leaves are a nice addition to salads, coleslaw, and dressings.Flavor in fennel develops and intensifies as plants mature. Very young plants (baby-leaf stage) will have a mild fennel flavor, while mature plants (8-12" tall) will have a fuller fennel flavor. Edible Flowers: The florets are used to garnish savory dishes, and pair well with fish, potato, tomato, and beef dishes. Flavor is of sweet anise.
Holy Basil
1 1/2" long green leaves, with purple stems. Known for its use in Hindu culture and Ayurveda. Also known as Tulsi. A common ingredient in Thai cuisine and in teas. Used medicinally for digestion and immune system support. Ht. 16-22".
Hyssop
Mint family plant has bright blue-violet flowers. Popular ornamental for the perennial bed. Tea has a soothing quality.
Kapoor Tulsi (Holy Basil)
Compact but very full, attractive plants. Mild spicy aroma with hints of sweetness. Faster growing than green holy basil, and its purple flowers also make it a nice beneficial and/or ornamental. For teas, culinary, and medicinal use. Appears to have some resistance to downy mildew in our trials. Also known as "Spice Basil" and often referred to as Ocimum sanctum, although sanctum is not botanically correct. Ht. 12-18".
Katinka
Upright, tall plants make Katinka easy to harvest. Dark green curled leaves with a uniform canopy. Suitable for field or container production. Mild and pleasant parsley flavor. Katinka is very similar to Wega with the primary difference being that Katinka is taller for optimal bunch harvest and productivity in the field. Curled-leaf type. Ht. 14-20".
Kelvin
Thick, juicy, and succulent. Petioles and leaves are a healthy dark green and stalks hold well in the field. Kelvin performs well under heat and moisture stress and in soils of average fertility. Upright and uniform. Also available with NOP-compliant pelleting.
Lemon Balm
Lemon Balm is a vigorous perennial herb with soft, crinkled green leaves and small white or pale pink flowers. Reaching full maturity in 70 days, this heirloom variety thrives in full sun to partial shade and adapts well to most soil types. Distinguished by its intensely aromatic foliage releasing a powerful lemon scent when brushed, Lemon Balm delivers a refreshing citrus flavor with subtle minty undertones. Its strong essential oils naturally repel common pests like aphids and spider mites, making it exceptionally pest-resistant. Ideal for teas, cocktails, desserts, and fresh culinary applications.
Lemon Thyme
Lemon Thyme is a fragrant heirloom herb variety that grows as a low, spreading perennial with fine, narrow green leaves and delicate pink flowers. Reaching maturity in approximately 65 days, it produces harvestable foliage suitable for continuous picking. This variety distinguishes itself through its distinctive bright citrus aroma and flavor—a harmonious blend of classic thyme earthiness with zesty lemon notes. The herb thrives in full sun with excellent drainage and performs best in sandy or rocky soil. Its unique flavor profile makes it ideal for culinary applications in fish dishes, beverages, desserts, and Mediterranean cooking, while also serving ornamental and medicinal purposes.
Lovage
Young leaves taste like celery with a hint of anise, and are used in spring tonic salads and with potato, rice, soups, and poultry dishes. Roots and young stems are also edible. Young stems can be cut, peeled, and used in salads. Stems are smooth, hollow, and thick. Also available in organic seed. Attracts Beneficial Insects: If allowed to flower, provides pollen and nectar for beneficial insects such as bees, hoverflies, lacewing larvae, lady beetles, parasitic wasps, and tachinid flies.
Mammoth Dill
Mammoth Dill is a vigorous heirloom herb variety known for its tall, robust growth and abundant foliage. Plants reach full maturity in approximately 90 days, producing large, feathery fronds that tower above standard dill varieties. The distinctive flavor combines fresh, tangy notes with subtle caraway undertones and a hint of sweetness, making it exceptional for pickling, dill weed, and culinary applications. Mammoth Dill thrives in full sun with rich, well-drained soil and is remarkably easy to grow, making it ideal for both experienced and novice gardeners seeking impressive yields.
Menuette
The deeply incised, feathery, narrow leaflets are easy to chop during kitchen prep and make an elegant garnish or bunch. Delicate in appearance but firm enough to stand up to handling, packing, and plating. Standard parsley flavor. Suitable for field or pot production. Has shown some resistance to tipburn in our trials. Ht. 12-18".
Mrs. Burns' Lemon
Very bright green, 2 1/2" long leaves with white blooms make this basil both attractive and intensely flavorful. Ht. 20-24".Edible Flowers: Use the flowers in any recipe that calls for basil, or to garnish drinks, salads, soups, pasta, and desserts. Flavor is of intense basil and citrus.
Munstead-Type
A strain of English lavender with a compact, bushy habit. Nice range of bloom colors, from pale blue to dark violet. Usually begins flowering in the second year. Hardy in Zones 5-8, but can survive Zone 4 winters when mulched or grown in a well-drained, south-facing location. Also available in organic seed. Edible Flowers: The flowers can be used to garnish desserts and as a distinct flavor element in baked goods. Flavor is sweet and floral and pairs well with citrus, berries, nuts, mint, and cinnamon.
Orange Mint
Orange Mint is a vibrant heirloom herb variety that matures in 85-95 days, producing lush green foliage with aromatic leaves. This distinctive mint variety stands apart with its unique flavor profile—fresh mint paired with bright citrus notes reminiscent of orange and subtle bergamot undertones, making it exceptional for teas, cocktails, and culinary garnishes. Best grown in full sun (6+ hours daily) with rich, moist, well-drained soil, it thrives easily in most conditions. Watch for common mint pests including aphids, spider mites, and flea beetles.
Orange Thyme
Upright, branching plants produce gray-green leaves. The aroma is sharp and citrus-like. Orange Thyme is distinctly sweeter and less pungent than German Winter and Summer thyme. Growth habit and winter hardiness are similar to Summer thyme. Tender perennial in Zones 6-8. Also known as Orangelo thyme.
Orazio
Crisp and flavorful with a nice anise flavor. Highly uniform. Due to its heavier bulbs, Orazio has a higher yield potential than flatter, open-pollinated fennels. Suitable for late summer and early fall harvest in most areas. It also can be transplanted in January for an April harvest in areas with mild winters, such as coastal California. Also available with NOP-compliant pelleting.
Peppermint
Peppermint is a vigorous herbaceous perennial reaching 24-36 inches tall with dark green, lance-shaped leaves and purple-tinged stems. Mature leaves are ready to harvest at 60-90 days, though plants produce continuously through the growing season. The defining characteristic is its intense, cooling menthol profile with pronounced sweet undertones, making it ideal for tea, culinary applications, and medicinal preparations. More potent than spearmint, peppermint thrives in moist, rich soil and tolerates partial shade, though it prefers 4-6 hours of sun daily. This heirloom variety is notably easy to grow and propagate.
Petroselinum crispum 'Forest Green'
The ultimate curly parsley variety featuring exceptionally dark green, tightly curled leaves that maintain their vibrant color and crisp texture longer than standard varieties. This uniform, compact plant produces abundant harvests of premium-quality leaves perfect for garnishing and cooking, with superior bolt resistance extending the harvest season. Forest Green's attractive appearance and reliable performance make it a favorite among both home gardeners and commercial growers.
Porto Spineless
The midrib and leaf stalks of cardoon have a similar flavor to artichoke when boiled (not for eating raw). Both portions are commonly used as a side vegetable, addition to stuffing, or in soups and stews. Cardoon must be blanched before it can be eaten. To blanch, tie the stalks up firmly and wrap with black plastic or black-and-white newspaper. If left unharvested, the 3-4' tall plants will produce large purple thistle-like flowers. The sharply lobed and serrated silver-green leaves are a unique addition to flower arrangements. Significantly reduced spines. Perennial in Zones 6-10.
Red Shiso
Distinct cinnamon/clove flavor and aroma with the spiciness of cumin. Used in Asian cooking, sushi, and salad mix. Red shiso adds brilliant color to radish pickles and umeboshi plums. Also known as perilla. Edible Flowers: The flowers are a flavorful addition to salads and Asian dishes. Pairs well with fish, rice, noodles, and cucumbers. The minty, basil-like flavor has hints of clove and cumin.
Roman Chamomile
Low-growing, spreading plant with creeping rhizomes. Has similar uses for teas and medicine as annual chamomile varieties, but produces fewer blossoms.
Rue
Bushy habit is ideal for short hedges or borders. Unique and attractive foliage makes a useful cut flower filler, lasting for up to three weeks in a vase. Pungent aroma. Limited culinary use due to strong bitter flavor. Medicinal: Warming herb primarily used as an antispasmodic. Perennial in Zones 4-9.
Russian Tarragon
A hardy perennial herb that thrives in cold climates where French Tarragon struggles, though with a milder anise flavor. Russian Tarragon is incredibly easy to grow from seed and forms robust clumps that return year after year, making it perfect for beginning herb gardeners seeking a reliable tarragon experience.
Spicy Bush
Spicy/sweet basil flavor packed into 1" long leaves. Decorative plants are great for growing in small spaces, pots, or garden beds. Plants are about twice the size of Pluto. Ht. 8-14".
Summer Savory
Pepper flavor adds spice to dishes. For flavoring fresh and dry beans, cabbage, and sauerkraut. Long internodes create a tall, somewhat lanky plant.
Sweet Annie
Tall plants with fern-like dark green foliage dotted with tiny cream-yellow colored flowers. Use foliage for wreaths and as filler for mixed bouquets. Also known as sweet sagewort, sweet wormwood, and Chinese wormwood.
Topit
High leaf mass on thick, upright stems for easier harvest. Compared to the standard parsley Giant of Italy, Topit has larger and darker green leaves, a more uniform plant habit, and sweeter flavor. Very similar to, and from the same breeder as, Pieone. Flat-leaf type. Ht. 18-20".
Vertissimo
Excellent performance in our trials. Slow-bolting, vigorous plants. Mild, sweet, anise flavor. Popular for salads, microgreens, and garnishing. Edible Flowers: Chervil's flowers are edible, and used to garnish salads. Flavor is of mild licorice.
Wega
Wega's upright habit makes it easy to harvest the dark green leaves. Suitable for field or container production. Curled-leaf type. Plant Variety Protected. Ht. 12-18".
Wild Marjoram
Use leaves fresh or dried for culinary purposes. Blooms in shades of pink to purple from midsummer through fall. For cut-flower use, harvest flowers in bud stage for best color. Attracts Beneficial Insects: Provides pollen and nectar for beneficial insects such as bees, hoverflies, lacewing larva, parasitic wasps, and tachinid flies. Edible Flowers: Use the flowers, which have a mild and marjoram-like flavor, as you would the herb to garnish salads, soups, stews, sauces, and stuffing. Also pairs well with citrus, mushrooms, and fish.
Zaatar
Native to the Mediterranean, where it has flavored meals for thousands of years. Soft gray-green leaves on plants with a semi-upright habit. Flavor combines those of sweet marjoram, thyme and oregano. Not to be confused with Za'atar, an herbal blend of several ingredients. Grow as a tender perennial - start indoors and keep out of freezing temperatures. Harvest stems when they reach at least 4-6".
Zone 3 Growing Tips
Start tender herbs like basil, French Tarragon, and Chocolate Mint indoors 6-8 weeks before your last frost date (typically early to mid-March for a mid-May transplant). Hardy herbs like Cilantro, Dill, and Parsley can be direct seeded 2-3 weeks before the last frost, as they actually prefer cooler soil temperatures for germination. Wait until nighttime temperatures consistently stay above 50°F before transplanting warm-season herbs outdoors—usually late May to early June in Zone 3.
Season extension is crucial for maximizing your herb harvest. Use row covers, cold frames, or even simple plastic milk jugs as mini greenhouses to protect plants from unexpected late spring or early fall frosts. Many Zone 3 gardeners get an extra 2-4 weeks of growing time this way. For continuous harvests, succession plant fast-growing herbs like Cilantro and Dill every 2-3 weeks from late April through mid-August.
The biggest challenge in Zone 3 is the temperature swings—80°F days followed by 40°F nights aren't uncommon in late May and early September. Basil is particularly sensitive to these fluctuations, so consider growing it in containers that can be moved to protection, or invest in quality row covers for your herb garden.
Season Overview
With an average last frost around May 15 and first frost by September 15, Zone 3 gardeners work with approximately 120 growing days. This compressed season actually works in your favor for herb production, as most herbs prefer to grow quickly rather than slowly. Plan to have all tender herbs transplanted by June 1st to take full advantage of the growing season. Cool-season herbs like Cilantro and Dill can often be planted again in late July for a fall harvest that may extend into October with protection. The key is thinking of your Zone 3 herb garden in three phases: the cool spring season (May-early June) for hardy herbs, the warm summer season (June-August) for heat-lovers like basil and oregano, and the cool fall season (September-October) for second plantings of cilantro, dill, and parsley.