When To Plant Mustard Greens In Zone 7

Knowing when to plant mustard greens in zone 7 is the key to a long and productive harvest. This cool-season crop thrives in the shoulder seasons of spring and fall, and timing it right means you’ll enjoy tender, flavorful leaves instead of bitter, bolted ones. Let’s break down the optimal schedule so you can plan your garden perfectly.

Zone 7 gardeners have a big advantage: two distinct planting windows. The goal is to grow mustard greens in cool weather, avoiding the intense heat of summer which makes them tough and prompts them to flower (bolt).

Spring Planting Window

For a spring harvest, you need to get seeds in the ground early. Soil temperature is more important than air temperature here.

Optimal Soil Temp: At least 40°F (4°C), but germination is best between 50-75°F (10-24°C).
Best Planting Dates: Sow seeds directly in the garden 4 to 6 weeks before your last average spring frost date. For most of zone 7, this falls between late February and mid-March.
Pro Tip: You can succession plant every two weeks until early April for a continuous spring harvest.

Fall Planting Window

Fall is often the best time for mustard greens in zone 7. The cooling temperatures create sweet, mild leaves.

Optimal Timing: Start sowing seeds in late summer, about 6 to 8 weeks before your first average fall frost date.
Best Planting Dates: For most zone 7 areas, this means planting from mid-August through late September.
Big Benefit: Fall-planted mustard greens often survive mild winters with minimal protection, giving you harvests into early winter and again in very early spring.

Using Your Frost Dates as a Guide

Your local frost dates are your best calendar. If you don’t know them, a quick search for your town and “frost dates” will give you the answer. Once you have them, mark your spring and fall planting periods on your calendar. It’s the simplest way to stay on track.

Preparing Your Garden Bed

Mustard greens aren’t fussy, but they do best in a well-prepared spot.

Choose a Sunny Location: Full sun (6+ hours) is ideal for fast growth, but they’ll tolerate light afternoon shade, especially as temperatures warm.
Amend the Soil: Work in 2-3 inches of compost or well-rotted manure. This improves drainage and fertility.
Check Soil pH: Aim for a slightly acidic to neutral pH, between 6.0 and 7.0. A simple soil test kit can confirm this.
Rake Smooth: Create a fine, level seedbed for sowing.

How to Plant Mustard Green Seeds

Direct sowing is the easiest and most effective method. Here’s how to do it step-by-step.

Sowing Depth: Plant seeds ¼ to ½ inch deep. They need darkness to germinate properly.
Spacing: Sow seeds about 1 inch apart in rows that are 12-18 inches apart.
Thinning: Once seedlings are a few inches tall, thin them to stand 6-12 inches apart (check your seed packet for the specific variety’s needs). Use the thinned seedlings as microgreens in salads!
Watering In: Gently water the seeded area and keep the soil consistently moist until germination, which usually takes 4-7 days.

Caring for Your Growing Mustard Greens

A little consistent care leads to a lush, leafy harvest.

Watering Needs

Mustard greens need about 1-1.5 inches of water per week. Use a soaker hose or water at the base to keep leaves dry and prevent disease. Consistent moisture is crucial to prevent stress, which can make leaves taste more pungent.

Fertilizing for Fast Growth

For a quick crop, a light feeding helps. Apply a balanced, water-soluble fertilizer (like a 10-10-10) about 3 weeks after planting. Always follow the label instructions to avoid over-fertilizing, which can harm the plants roots.

Managing Pests and Diseases

Common pests include flea beetles and cabbage loopers. Row covers right after planting are the best defense. For diseases like downy mildew, ensure good air circulation by proper spacing and avoid overhead watering. Rotating where you plant them each year also helps a lot.

Harvesting Your Mustard Greens

You can start harvesting in as little as 30-40 days for baby greens, or 40-50 days for full-sized leaves.

Cut-and-Come-Again: Harvest the outer, older leaves first, leaving the central growing point intact to produce more leaves.
Whole Plant Harvest: You can also cut the entire plant about an inch above the soil line. It may regrow for a second, smaller harvest.
Best Time to Pick: Harvest in the cool morning when leaves are crisp and full of moisture.

What to Do if Your Mustard Greens Bolt

Bolting is when the plant sends up a flower stalk. It’s triggered by lengthening days and warming temperatures. The leaves become bitter once this happens.

Spring Crop: Bolting is inevitable as summer approaches. Just pull the plants and replant the space with a warm-season crop.
Fall Crop: Bolting is less common, but if an unseasonable heat wave hits, provide shade cloth to cool them down.
Silver Lining: Let some plants flower! The yellow blooms attract beneficial insects, and you can save the seeds for next season.

Extending the Harvest Season

With a few tricks, you can enjoy mustard greens for even longer.

Use Row Covers: In fall, cover plants with a frost blanket or cold frame when temperatures dip below freezing. This can protect them through the winter.
Mulch Heavily: A thick layer of straw or leaves insulates the soil and plant roots in winter.
Succession Planting: As mentioned, sowing a few rows every couple weeks in spring and fall ensures you always have young, tender leaves ready.

Recommended Varieties for Zone 7

Some mustard greens handle zone 7’s fluctuations better than others. Here are a few reliable choices:

Southern Giant Curled: A classic, frilly, heirloom variety with excellent cold tolerance.
Red Giant: Beautiful purple-tinged leaves that are slightly more bolt-resistant and very cold-hardy.
Green Wave: A vigorous grower with peppery, curled leaves that’s resistant to bolting and cold.
Mizuna: A mild, feathery Japanese type that grows quickly and is very cold-tolerant.

FAQ: Mustard Greens in Zone 7

Can I plant mustard greens in the summer in zone 7?

It’s not recommended. Summer heat causes mustard greens to bolt quickly and become bitter. Focus on spring and fall plantings for the best quality.

How late can you plant mustard greens in zone 7 for fall?

You can plant up until about 4 weeks before your first hard frost. Later plantings will yield smaller leaves, but they can still be harvested as baby greens before a hard freeze.

Should I start mustard greens indoors for zone 7?

It’s usually unnecessary. They grow so quickly from direct-sown seeds that starting indoors doesn’t provide a significant advantage. Direct sowing avoids transplant shock, too.

Do mustard greens come back every year?

No, they are annual plants. However, if you let them flower and drop seed, you may get volunteer seedlings the following season that you can thin and grow.

What can I plant next to mustard greens?

Good companions include onions, beets, and herbs like dill and mint. Avoid planting them near other brassicas (like broccoli or cabbage) to help minimize pest issues.

By following this timing guide, you can enjoy multiple succesful harvests of spicy, nutritious mustard greens from your zone 7 garden each year. The key is simply working with the cool weather they love.