When to Plant Radish in Broad Top, Pennsylvania (16621)

Location

Broad Top, Pennsylvania

ZIP Code

16621

USDA Zone

Last Frost

Wednesday, April 15, 2026

📅 Your 2026 Planting Dates

Direct Sow Outdoors

Wednesday, March 4, 2026

Based on last frost Wednesday, April 15, 2026 · Zone 6b

Pro tip: Sow Radish directly outdoors 6 weeks before your last frost date.

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🌿 Plant Details

Scientific Name Rhaphanus sativus

Days to Maturity 25 days

Mature Height 6-12"

Spread 3"

Type Root

Fruit Size Small (1-2 inches)

☀️ Growing Requirements

☀️

Sun

Full Sun to Partial Shade

💧

Water

Regular (keep moist)

↔️

Spacing

2" apart

🌱

Planting Depth

0.5" deep

Seeds typically germinate in 3-7 days

Ready to Plant Radish in Broad Top?

Get your seeds now so they're ready by Wednesday, March 4, 2026.

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🤝 Good Companions

CarrotLettucePeaCucumberSpinach

⚠️ Avoid Planting Near

Hyssop

🤝

Full Companion Planting Guide for Radish

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

🛠️ Supplies You'll Need

🪵 Raised Garden Bed 🌍 Vegetable Garden Soil 🛠️ Hand Trowel Set 🚿 Watering Can

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Common Radish Varieties

Popular cultivars to look for at your local nursery or seed supplier.

Cherry Belle

spring 22d

Round, bright red radish that matures in just 22 days; the classic spring radish.

French Breakfast

spring 25d

Elongated red-tipped radish with milder flavor and crisp, white interior.

Watermelon (Shinrimei)

daikon 60d

Chinese daikon with green exterior and stunning magenta-pink interior; mild and sweet.

Daikon

daikon 60d

Long, white Japanese radish used fresh, pickled, or cooked; much larger and milder than spring types.

Common Radish Problems

What to watch for — and how to fix it before it spreads.

🐛

Pests

Flea Beetle

Tiny beetles make hundreds of small holes in leaves; seedlings can be badly damaged.

Fix:

Use row covers immediately after sowing; apply diatomaceous earth; sow densely and sacrifice outer rows.

Cabbage Root Maggot

Fly larvae tunnel into roots, leaving rusty tunnels and stunting plants.

Fix:

Use row covers from sowing; delay planting spring radishes until after peak fly emergence.

🍂

Diseases

Downy Mildew

Yellow patches on leaves with gray spores beneath; common in cool, wet springs.

Fix:

Improve airflow; avoid overhead watering; rotate with non-brassica crops.

Black Root

Interior of roots turns gray-black from Aphanomyces fungus; common in wet, acidic soils.

Fix:

Raise soil pH to 6.5–7.0; rotate crops; use certified disease-free seed.

💡

Common Mistakes

Sowing too late in the season

Radishes bolt immediately in heat, going straight to flowers without forming a root.

Fix:

Sow in early spring and again in late summer/fall; avoid sowing when temps will exceed 75°F.

Leaving in the ground too long

Radishes go pithy and hollow quickly after reaching mature size.

Fix:

Check spring radishes starting at day 20–25; harvest when roots reach pencil-width to marble-size.

🌾 Seed Saving Guide

🟢 Easy

✅ Open-pollinated — seeds grow true to parent

When to Harvest Seed

Let plants bolt and seed pods dry completely on the plant until papery and tan.

Processing

Thresh dried pods to release round seeds, winnow to remove chaff.

Seed Viability

Up to 5 years when stored cool, dark, and dry.

Pro Tip

Radishes cross readily between varieties and with wild radish — isolate by 1000 feet for pure seed.

🪴

Raised Bed Planting Guides

A 4×8 bed fits 36 per sq ft of Radish. See plant counts, spacing grids, and companion pairings for every bed size →

Frequently Asked Questions

When should I plant Radish in Broad Top, Pennsylvania? +

In Broad Top (Zone 6b), direct sow Radish outdoors around Wednesday, March 4, 2026.

What is the last frost date for Broad Top, Pennsylvania? +

The average last spring frost date for Broad Top, Pennsylvania (ZIP 16621) is around Wednesday, April 15, 2026. This is based on NOAA climate normals for USDA Zone 6b.

How long does Radish take to grow? +

Radish typically matures in about 25 days from direct sowing. In Broad Top, that means you can expect harvest around Wednesday, March 4, 2026 plus 25 days.

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

Radish does best when direct sown outdoors. In Broad Top, sow directly around Wednesday, March 4, 2026.

📚 More Radish Planting Guides

🗺️

Radish in Pennsylvania

Zone-by-zone breakdown · Full state guide

→ 🌡️

Zone 6b Radish Guide

All cities in your zone · Avg dates

→

Other Plants for Broad Top

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 Leek Lima Bean Mustard Okra Onion Parsnip Pea Poblano Pepper Pole Pea Potato Pumpkin Radicchio 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 Radish in Zone 6b

Radish (Rhaphanus sativus) is a popular garden vegetable. In Broad Top, Pennsylvania, which is in USDA Hardiness Zone 6b, you should direct sow seeds around Wednesday, March 4, 2026.

Your average last frost date is Wednesday, April 15, 2026. Radish grows well when direct sown, as it doesn't transplant well or germinates quickly outdoors.