Growing fennel (Foeniculum vulgare) can be a rewarding and aromatic addition to your garden. This herbaceous plant is known for its feathery leaves and fragrant, bulbous base, making it a popular choice for culinary uses as well as ornamental value. If you live in Washington State, where the climate varies from coastal temperate to mountainous terrains, understanding how to cultivate fennel effectively can help ensure a successful harvest. This article provides a comprehensive guide on how to grow fennel in Washington.
Before you begin planting, it’s essential to know that there are two main types of fennel:
Florence Fennel (Bulbing Fennel): This variety develops a swollen bulb that is used in cooking. It’s typically grown for its edible bulb and has a mild anise flavor.
Herb Fennel: This type is primarily grown for its leaves and seeds, which are used as culinary herbs and spices. It doesn’t form a bulb.
For growing in Washington, Florence fennel is generally favored for its unique flavor and versatility in dishes.
Washington’s climate can vary significantly depending on the region. Here are some specific factors to consider when growing fennel:
Western Washington: The coastal areas have a milder climate with higher humidity levels. The growing season here is typically longer, allowing for better bulb formation in Florence fennel. Frost dates usually range from late March to early April for spring planting.
Eastern Washington: This region experiences a much drier climate with more extreme temperature variations between summer and winter. Ensure adequate irrigation during hot spells as fennel prefers consistent moisture.
Fennel thrives in USDA hardiness zones 5-9, which covers most of Washington, but attention must be paid to local microclimates while selecting planting times.
Fennel prefers well-drained soil rich in organic matter. Here’s how to prepare your soil for planting:
Soil Testing: Conduct a soil test to determine pH levels and nutrient content. Fennel prefers slightly acidic to neutral pH (6.0 – 7.0).
Amending Soil: Based on your soil test results, consider adding compost or well-rotted manure to improve nutrient levels and moisture retention.
Tillage: Loosen the soil to a depth of at least 12 inches using a garden fork or tiller, ensuring good drainage and aeration.
Adding Mulch: Incorporating organic mulch can help retain moisture and suppress weeds.
Fennel can be started from seeds or seedlings:
Timing: In Western Washington, sow seeds indoors 6-8 weeks before the last expected frost date (around early March). In Eastern Washington, consider starting seeds outdoors directly after the frost has passed (usually late April).
Seed Depth: Sow fennel seeds about ¼ inch deep in seed starting mix or directly into prepared outdoor beds.
Spacing: Once seedlings emerge (approximately 10-14 days), thin them out so that they are spaced 12-18 inches apart for bulbing fennel; herb fennel may be spaced slightly closer.
If starting seeds indoors, transplant seedlings outdoors once they have at least two sets of true leaves and are hardened off to outdoor conditions:
Transplant Timing: Generally between late April and May in Western Washington or after any danger of frost in Eastern Washington.
Planting Hole Preparation: Dig holes large enough to accommodate the root ball without crowding.
Watering After Planting: Water newly transplanted seedlings thoroughly to help reduce transplant shock.
Ensuring that your fennel plants remain healthy requires diligent maintenance throughout their growing season:
Fennel needs consistent moisture especially during dry spells:
Feed your fennel plants with a balanced fertilizer every four weeks during the growing season:
Weeds can compete with fennel for nutrients and water:
Pests like aphids and caterpillars can also trouble fennel:
The timing of your harvest depends on the type of fennel you’ve planted:
Florence Fennel: Harvest bulbs when they reach about 3-4 inches in diameter, generally around 80-90 days after planting when they feel firm but not overgrown.
Herb Fennel: Leaves can be harvested throughout the growing season; cut them as needed while allowing the plant to continue growing.
When harvesting bulbs, cut them off at the base with a sharp knife, ensuring not to damage other plants nearby.
Freshly harvested fennel stores best under cool conditions:
Refrigeration: Store unwashed bulbs wrapped in a damp paper towel inside plastic bags in the fridge for up to two weeks.
Dry Herb Storage: For herb fennels, hang the leaves upside down in a dark, dry area until fully dried; store in airtight containers away from sunlight.
Growing fennel in Washington can be an enjoyable experience whether you choose the herbaceous variety or aim for a bulbing plant that adds flavor to your dishes. Adjust your practices according to local weather conditions, ensure proper soil health, provide adequate water and nutrients, and you’ll be rewarded with aromatic foliage and delicious bulbs ready for harvest! With patience and care, you’ll soon discover why this Mediterranean plant has gained popularity among gardeners across the state.