Best Time To Plant Arugula In Missouri

Missouri’s unpredictable spring temperatures require careful soil temperature monitoring before sowing arugula seeds. Knowing the best time to plant arugula in missouri can mean the difference between a crisp, peppery harvest and a crop that bolts to seed in a heat wave. This guide walks you through exactly when and how to plant arugula for success in the Show-Me State.

Arugula thrives in cool weather, making it a perfect early spring or fall crop. In Missouri, the window for planting is narrow but rewarding if you time it right. Let’s break down the ideal planting dates, soil conditions, and tips for a continuous harvest.

The absolute best window for planting arugula in Missouri is early spring, as soon as the soil can be worked. This usually falls between mid-March and early April, depending on your specific region. The key is to get seeds in the ground when soil temperatures are consistently between 40°F and 55°F.

For a fall harvest, plant arugula again in late summer. Aim for late August to mid-September. This timing allows the plants to mature during the cooler days of autumn, avoiding the intense summer heat that causes bitterness and bolting.

Understanding Missouri’s Climate Zones

Missouri spans USDA hardiness zones 5b in the north to 7a in the south. This means planting dates vary by about two weeks across the state. Northern Missouri gardeners should plant a week or two later in spring and earlier in fall compared to those in the south.

Check your local frost dates. The average last spring frost in Missouri ranges from late March in the south to mid-April in the north. Arugula can tolerate light frosts, so you can plant a few weeks before the last expected frost date.

Soil Temperature Is Your Best Guide

Don’t rely solely on the calendar. Use a soil thermometer to check the temperature at a depth of 2 inches. Arugula seeds germinate best when soil is between 45°F and 55°F. If the soil is too cold (below 40°F), seeds may rot. If it’s too warm (above 70°F), germination drops sharply.

Here is a quick soil temperature checklist:

Below 40°F: Too cold, wait.
40°F to 45°F: Marginal, but possible if weather is warming.
45°F to 55°F: Ideal for germination.
55°F to 70°F: Acceptable, but germination slows.
Above 70°F: Too warm, wait for fall.

Spring Planting: Step By Step

Follow these steps for a successful spring arugula crop in Missouri:

Prepare the bed: Choose a sunny spot with well-draining soil. Remove weeds and rocks. Add a 1-inch layer of compost.
Sow seeds directly: Arugula does not transplant well. Scatter seeds thinly on the soil surface. Cover with a 1/4-inch layer of fine soil.
Water gently: Use a spray nozzle to avoid washing seeds away. Keep the soil moist but not soggy.
Thin seedlings: When plants are 2 inches tall, thin them to 4-6 inches apart. You can eat the thinnings.
Mulch lightly: A thin layer of straw or shredded leaves helps keep soil cool and moist.

Succession Planting For Continuous Harvest

To enjoy arugula for weeks, plant a new row every 10 to 14 days. This is called succession planting. Start your first batch in mid-March, then plant another in late March, and a third in early April. Stop planting by mid-April to avoid summer heat.

Each planting will mature in about 30 to 40 days. You’ll have fresh arugula from late April through late May. After that, the heat will make the leaves too spicy and tough.

Fall Planting: A Second Chance

Fall is actually the best season for arugula in Missouri. The weather cools down, and the leaves stay tender and mild. Plant arugula for fall harvest about 4 to 6 weeks before the first expected fall frost. In Missouri, that means planting from late August to mid-September.

Here is a fall planting timeline for Missouri:

Southern Missouri: Plant in early to mid-September.
Central Missouri: Plant in late August to early September.
Northern Missouri: Plant in mid to late August.

Fall arugula often tastes sweeter because cool temperatures reduce bitterness. You can also plant arugula in a cold frame or under row covers to extend the harvest into November or even December.

Overwintering Arugula In Missouri

If you have a cold frame or a greenhouse, you can try overwintering arugula. Plant in late September. The plants will grow slowly through winter and provide an early spring harvest. This works best in southern Missouri where winters are milder.

Protect plants with a thick layer of straw or a floating row cover. On very cold nights, add an extra layer of frost cloth. Arugula can survive temperatures down to 20°F with protection.

Soil Preparation For Arugula

Arugula grows best in loose, fertile soil with a pH between 6.0 and 7.0. Before planting, test your soil pH. Missouri soils are often acidic, so you may need to add lime. Add 2 to 3 pounds of lime per 100 square feet to raise pH by one point.

Work in 2 inches of compost or well-rotted manure. This improves drainage and provides nutrients. Arugula is a light feeder, but it appreciates organic matter. Avoid heavy nitrogen fertilizers, which can make leaves taste bitter.

Watering And Care

Arugula needs consistent moisture to stay tender. Water deeply once or twice a week, providing about 1 inch of water per week. In hot weather, water more frequently. Mulch helps retain moisture and keeps soil cool.

Watch for pests like flea beetles and aphids. Flea beetles leave small holes in leaves. Use row covers to protect young plants. If aphids appear, spray them off with a strong stream of water or use insecticidal soap.

Harvesting Arugula Leaves

You can start harvesting arugula when leaves are 3 to 4 inches long. Pick outer leaves first, leaving the inner rosette to continue growing. This method gives you multiple harvests from the same plant. Cut leaves with scissors or pinch them off at the base.

For the best flavor, harvest in the morning when leaves are crisp. Avoid harvesting in the heat of the day, as leaves wilt quickly. If you let plants flower, the leaves become very spicy and tough. Remove flower stalks as soon as they appear to prolong harvest.

Common Mistakes To Avoid

Many Missouri gardeners make these mistakes when planting arugula:

Planting too late in spring: Arugula bolts when temperatures exceed 75°F. Plant early.
Planting too early in fall: August heat can kill seedlings. Wait until late August or September.
Overcrowding: Thin seedlings to 4-6 inches apart. Crowded plants grow slowly and are more prone to disease.
Poor drainage: Arugula hates wet feet. Plant in raised beds if your soil is heavy clay.
Ignoring soil temperature: Guessing leads to poor germination. Use a thermometer.

Best Arugula Varieties For Missouri

Choose varieties that are heat-tolerant or slow to bolt for Missouri’s variable weather. Here are some reliable options:

Astro: Fast-growing, mild flavor, good for spring and fall.
Rocket: Classic peppery taste, heat-tolerant.
Wild Rocket: More intense flavor, slower to bolt.
Apollo: Very heat-tolerant, good for late spring planting.
Esmee: Slow-bolting, tender leaves, ideal for succession planting.

Companion Planting With Arugula

Arugula grows well with many garden vegetables. Plant it near carrots, onions, lettuce, and spinach. Avoid planting arugula near strawberries or pole beans, as they can compete for nutrients. Arugula also repels some pests when planted near tomatoes and peppers.

Interplant arugula with slower-growing crops like broccoli or cabbage. The arugula will be harvested before the larger plants need space. This maximizes your garden area.

Extending The Arugula Season

With a few simple techniques, you can enjoy arugula from early spring to late fall in Missouri. Use row covers to protect plants from frost in spring and fall. In summer, plant arugula in partial shade to keep it cooler.

Consider using a cold frame or a low tunnel. These structures trap heat and protect plants from harsh weather. You can start arugula in a cold frame as early as February in southern Missouri. In northern Missouri, start in early March.

Growing Arugula In Containers

If your garden soil is poor or you have limited space, grow arugula in containers. Use a pot at least 6 inches deep with drainage holes. Fill with quality potting mix. Sow seeds 1/4 inch deep and water regularly.

Containers warm up faster than garden soil, so you can plant earlier in spring. Place the pot in a sunny spot but move it to partial shade if temperatures rise above 75°F. Container-grown arugula may need more frequent watering, especially in summer.

Harvesting Seeds For Next Year

Let a few arugula plants go to seed at the end of the season. The flowers are edible and attract pollinators. After the flowers fade, seed pods form. Let them dry on the plant, then collect the seeds. Store them in a cool, dry place for next year.

Arugula seeds remain viable for 3 to 4 years. Saving your own seeds saves money and helps you select plants that perform well in your Missouri garden. Over time, you’ll develop a strain adapted to your local conditions.

Frequently Asked Questions

Can I plant arugula in Missouri during summer?

It is not recommended. Summer heat above 80°F causes arugula to bolt and become bitter. If you want summer arugula, plant it in a shaded spot and keep it well-watered, but expect lower quality.

How late can I plant arugula in Missouri for fall?

You can plant arugula as late as mid-October in southern Missouri if you use a cold frame. In northern Missouri, plant by mid-September for best results. Arugula needs about 40 days to mature before heavy frost.

Does arugula need full sun in Missouri?

Arugula prefers full sun in spring and fall but benefits from partial shade in late spring or early fall. In Missouri’s hot summers, afternoon shade helps prevent bolting. Morning sun with afternoon shade is ideal.

What is the best soil temperature for arugula germination?

The best soil temperature is between 45°F and 55°F. Seeds will germinate slowly at 40°F and may not germinate at all above 70°F. Use a soil thermometer to check before planting.

Can I grow arugula indoors in Missouri?

Yes, you can grow arugula indoors year-round. Use a shallow container with drainage, place it in a sunny window or under grow lights, and keep the soil moist. Harvest leaves when they are 3-4 inches long. Indoor arugula is milder in flavor.

By following these guidelines, you can enjoy fresh, peppery arugula from your Missouri garden for many months. The key is to plant at the right time, monitor soil temperature, and provide consistent care. With a little planning, you’ll have a bountiful harvest of this delicious leafy green.

Remember to check your local frost dates and adjust planting times accordingly. Keep a garden journal to track what works best in your specific location. Over time, you’ll develop a planting schedule that maximizes your arugula yield.

Happy gardening in the Show-Me State. Your taste buds will thank you when you bite into that first crisp, peppery leaf of homegrown arugula.