When to Plant Leek in Sweet Valley, Pennsylvania (18656)

Location

Sweet Valley, Pennsylvania

ZIP Code

18656

USDA Zone

Last Frost

Monday, April 20, 2026

📅 Your 2026 Planting Dates

Start Seeds Indoors

Monday, February 9, 2026

Transplant Outdoors

Monday, May 4, 2026

Based on last frost Monday, April 20, 2026 · Zone 6a

Pro tip: Start Leek seeds indoors 10 weeks before your last frost date, then transplant outdoors around Monday, May 4, 2026.

Add to Calendar (.ics)

🌿 Plant Details

Scientific Name Allium ampeloprasum

Days to Maturity 120 days

☀️ Growing Requirements

☀️

Sun

Full Sun

💧

Water

Regular

Seeds typically germinate in 1-7 days

Ready to Plant Leek in Sweet Valley?

Get your seeds now so they're ready by Monday, February 9, 2026.

🛒 Buy on Amazon 🌿 True Leaf Market

* Affiliate links — we may earn a small commission at no extra cost to you.

🤝 Good Companions

CeleryAppleCarrot

⚠️ Avoid Planting Near

Swiss Chard

🤝

Full Companion Planting Guide for Leek

See which plants help Leek thrive, which to keep away, and raised bed layout tips →

🛠️ Supplies You'll Need

🌱 Seed Starting Trays 🪴 Seed Starting Mix 💡 Grow Lights 🌡️ Heat Mat 🪵 Raised Garden Bed 🌍 Vegetable Garden Soil 🛠️ Hand Trowel Set 🚿 Watering Can

* Affiliate links — we may earn a small commission at no extra cost to you.

🌾 Seed Saving Guide

🟡 Moderate

✅ Open-pollinated — seeds grow true to parent

When to Harvest Seed

Biennial — allow flowering in year 2. Harvest seed heads when seeds are black and ripe.

Processing

Cut seed heads into bags when most seeds are black, dry 1 week, thresh gently.

Seed Viability

Up to 2 years when stored cool, dark, and dry.

Pro Tip

Leeks cross-pollinate with onions via insects. Isolate by at least a mile for truly pure seed.

Frequently Asked Questions

When should I plant Leek in Sweet Valley, Pennsylvania? +

In Sweet Valley (Zone 6a), start Leek seeds indoors around Monday, February 9, 2026 and transplant outdoors around Monday, May 4, 2026.

What is the last frost date for Sweet Valley, Pennsylvania? +

The average last spring frost date for Sweet Valley, Pennsylvania (ZIP 18656) is around Monday, April 20, 2026. This is based on NOAA climate normals for USDA Zone 6a.

How long does Leek take to grow? +

Leek typically matures in about 120 days from transplanting. In Sweet Valley, that means you can expect harvest around Monday, May 4, 2026 plus 120 days.

Should I start Leek indoors or direct sow in Pennsylvania? +

Leek should be started indoors 10 weeks before your last frost date. In Sweet Valley, that means starting around Monday, February 9, 2026.

📚 More Leek Planting Guides

🗺️

Leek in Pennsylvania

Zone-by-zone breakdown · Full state guide

→ 🌡️

Zone 6a Leek Guide

All cities in your zone · Avg dates

→

Other Plants for Sweet Valley

Blackberry Blueberry Raspberry Strawberry Basil Chamomile Chives Cilantro Dill Lavender Lemon Balm Marjoram Mint Oregano Parsley Rosemary Sage Tarragon Thyme Acorn Squash Artichoke Arugula Asparagus Beefsteak Tomato Beet Bell Pepper Bok Choy Broccoli Brussels Sprout Butternut Squash Cabbage Cantaloupe Carrot Cauliflower Cayenne Pepper Celery Cherry Tomato Chili Pepper Collard Green Common Bean Cucumber Eggplant Endive Fennel Garlic Grape Tomato Green Bean Habanero Pepper Head Lettuce Heirloom Tomato Honeydew Melon Jalapeño Pepper Kale Kohlrabi Leaf Lettuce Lima Bean Mustard Okra Onion Parsnip Pea Poblano Pepper Pole Pea Potato Pumpkin Radicchio Radish Rhubarb Roma Tomato Rutabaga Serrano Pepper Shallot Snap Pea Snow Pea Spaghetti Squash Spinach Squash Sweet Corn Sweet Potato Swiss Chard Tomato Turnip Watermelon Zucchini Sunflower Marigold Zinnia Nasturtium Cosmos Echinacea (Coneflower) Petunia Black-eyed Susan Apple Tree Pear Tree Peach Tree Plum Tree Sweet Cherry Tree Lemon Tree Borage Lemongrass Ginger Stevia Tomatillo Edamame Fava Bean Mâche Mizuna Sorrel Shishito Pepper Banana Pepper Watermelon Radish Napa Cabbage Popcorn Broccoli Raab Catnip Valerian Lemon Verbena Bee Balm Anise Lovage Chervil Summer Savory Dahlia Snapdragon Pansy Sweet Pea Morning Glory Hollyhock Larkspur Bachelor Button Columbine Impatiens Salvia (Annual) Sweet Alyssum Celosia Lupine Verbena Elderberry Grape Vine Red Currant Gooseberry Serviceberry Fig Tree Avocado Tree Persimmon Tree Olive Tree

Growing Leek in Zone 6a

Leek (Allium ampeloprasum) is a popular garden vegetable. In Sweet Valley, Pennsylvania, which is in USDA Hardiness Zone 6a, you should start seeds indoors around Monday, February 9, 2026.

Your average last frost date is Monday, April 20, 2026. Plan to transplant your Leek seedlings outdoors around Monday, May 4, 2026, about 2 weeks after your last frost date.