Missouri’s mild spring weather permits an early planting of potatoes, often in March. Knowing the **best time to plant potatoes in missouri** is key to a big harvest. You want to get them in the ground when the soil is workable but not too wet.
Potatoes are a cool-season crop. They grow best when the weather is cool and the soil is moist. In Missouri, the window for planting is wide, but timing it right makes all the difference.
This guide will walk you through everything you need to know. From soil temperature to frost dates, we cover it all. Let’s get your spuds in the ground at the perfect moment.
Best Time To Plant Potatoes In Missouri
The short answer is: plant seed potatoes two to four weeks before your last expected spring frost. For most of Missouri, that falls between mid-March and early April. This timing lets the potatoes grow during cool weather and mature before summer heat arrives.
Missouri is split into USDA hardiness zones 5b to 7a. This means planting dates vary slightly by region. Northern Missouri (zones 5b-6a) should plant later. Southern Missouri (zones 6b-7a) can plant a bit earlier.
Check your local frost dates. The average last frost in St. Louis is around April 10. In Kansas City, it’s about April 15. In Springfield, it can be as early as April 5. Use these dates as a guide.
Soil Temperature Matters Most
Potato plants need soil temperatures above 45°F (7°C) to grow. Cold, wet soil can cause seed pieces to rot. Aim for soil temperatures between 45°F and 50°F at planting depth.
Use a soil thermometer. Insert it four inches deep in the garden bed. Take readings in the morning for the most accurate results. If the soil is too cold, wait a week and check again.
Warmer soil speeds up sprouting. Soil around 60°F is ideal for fast emergence. But don’t wait too long. Planting too late means harvest during hot, dry weather, which reduces yield.
Regional Planting Windows For Missouri
Here is a simple breakdown by region. These are general guidelines. Always adjust based on your local weather patterns.
- Northern Missouri: Plant from late March to mid-April. Focus on early to mid-April for best results.
- Central Missouri: Plant from mid-March to early April. This includes areas like Columbia and Jefferson City.
- Southern Missouri: Plant from early March to late March. The Ozarks and Bootheel can start earlier.
If you miss the spring window, you can plant a fall crop. Plant in late July to early August for a harvest before the first hard freeze. Fall potatoes are often sweeter and store well.
Signs The Soil Is Ready
Don’t rely only on the calendar. Check your garden bed for these signs. The soil should be dry enough to crumble in your hand, not form a muddy ball.
Walk on your garden bed. If your shoes pick up mud, the soil is too wet. Wait a few days for it to dry out. Working wet soil damages its structure and harms potato growth.
Dig a small hole. The soil at four inches deep should feel cool but not cold. It should not be saturated with water. If you see standing water, choose a different spot or wait.
Preparing Your Potato Bed
Good preparation leads to healthy plants. Start by choosing a sunny location. Potatoes need at least six to eight hours of direct sunlight daily.
Loosen the soil to a depth of 10 to 12 inches. Remove rocks, sticks, and large clumps. Potatoes grow best in loose, well-draining soil. Heavy clay soil can be improved with compost or aged manure.
Test your soil pH. Potatoes prefer a slightly acidic soil, between 5.0 and 6.0. A pH below 5.5 helps prevent common diseases like potato scab. Add sulfur if your soil is too alkaline.
Choosing The Right Seed Potatoes
Always buy certified seed potatoes from a garden center. Do not use potatoes from the grocery store. Store potatoes may carry diseases and are often treated to prevent sprouting.
Look for disease-resistant varieties. Some good choices for Missouri include:
- Yukon Gold: A popular all-purpose potato. It matures in about 80 days.
- Red Pontiac: A red-skinned potato that stores well. It matures in 90 to 100 days.
- Kennebec: A white potato great for baking and frying. It matures in 80 to 90 days.
- Russet Burbank: The classic baking potato. It takes 90 to 110 days to mature.
Cut large seed potatoes into pieces. Each piece should have at least two eyes. Let the cut pieces dry for 24 to 48 hours before planting. This prevents rotting in the soil.
How To Plant Potatoes
Plant seed pieces about four inches deep. Space them 12 to 15 inches apart in rows. Rows should be 30 to 36 inches apart. This gives the plants room to grow.
Place the seed piece with the eyes facing up. Cover with soil and water gently. Do not soak the soil. Keep it moist but not waterlogged.
As the plants grow, mound soil around the stems. This is called hilling. Hill the potatoes when the plants are about six inches tall. Repeat every two to three weeks until the plants flower.
Hilling prevents sunlight from reaching the developing tubers. Sunlight turns potatoes green and produces solanine, which is toxic. Always keep the tubers covered with soil.
Caring For Your Potato Plants
Potatoes need consistent moisture, especially during flowering. Water deeply once or twice a week. Aim for about one to two inches of water per week.
Mulch around the plants to retain moisture and suppress weeds. Use straw, shredded leaves, or grass clippings. Mulch also keeps the soil temperature cool during hot weather.
Fertilize lightly when the plants are about six inches tall. Use a balanced fertilizer like 10-10-10. Avoid high-nitrogen fertilizers, which promote leaf growth over tuber development.
Common Pests And Diseases
Colorado potato beetles are a common pest in Missouri. They are yellow and black striped beetles. Hand pick them off the plants or use neem oil as a natural control.
Flea beetles are tiny black insects that chew small holes in leaves. They are more of a problem in dry weather. Row covers can protect young plants from flea beetles.
Late blight is a serious fungal disease. It causes dark spots on leaves and stems. Prevent it by watering at the base of the plants and spacing them for good air circulation.
Scab is a bacterial disease that causes rough, corky spots on the skin. It is worse in alkaline soil. Keep your soil pH below 5.5 to reduce scab problems.
Harvesting Your Potatoes
You can harvest new potatoes about two to three weeks after the plants flower. These are small, tender potatoes. Gently dig around the base of the plant to find them.
For full-sized potatoes, wait until the plants turn yellow and die back. This usually happens 90 to 120 days after planting. Stop watering two weeks before harvest to toughen the skins.
Dig the potatoes carefully with a garden fork. Start a foot away from the plant to avoid cutting the tubers. Let the potatoes dry on the ground for a few hours.
Do not wash the potatoes before storing. Brush off excess soil. Store them in a cool, dark, humid place. Ideal storage conditions are 40°F to 50°F with high humidity.
Fall Planting In Missouri
Fall planting is a great option for a second harvest. Plant in late July or early August. The soil is warm, so the potatoes sprout quickly. They mature as the weather cools down.
Choose early-maturing varieties for fall planting. Yukon Gold and Red Pontiac work well. Plant them the same way as spring potatoes. Keep the soil moist during the hot summer weeks.
Harvest fall potatoes after the first light frost. The cold weather improves their flavor. Fall potatoes often store better than spring potatoes because they are harvested in cooler weather.
Frequently Asked Questions
Can I plant potatoes in Missouri in May?
Yes, but it is not ideal. May planting means harvest during the hot summer. The plants may struggle with heat and produce fewer tubers. If you plant in May, choose early-maturing varieties and keep them well watered.
What is the best potato variety for Missouri?
Yukon Gold and Kennebec are excellent choices. They adapt well to Missouri’s climate. Red Pontiac is also a good option for storage. Choose disease-resistant varieties for the best results.
How deep should I plant potato seeds?
Plant seed pieces about four inches deep. This depth protects them from frost and keeps them cool. As the plants grow, mound soil around the stems to keep the tubers covered.
Do I need to water potatoes every day?
No, overwatering can cause rot. Water deeply once or twice a week. Aim for one to two inches of water per week. Consistent moisture is most important during flowering and tuber formation.
Can I grow potatoes in containers in Missouri?
Yes, containers work well for potatoes. Use a large pot or grow bag with drainage holes. Fill with loose potting soil. Plant seed pieces four inches deep. Water regularly and hill the plants as they grow.
Final Tips For Success
Rotate your potato crops each year. Do not plant potatoes in the same spot for at least three years. This prevents soil-borne diseases from building up.
Watch the weather forecast. If a hard freeze is predicted after you plant, cover the young plants with straw or a frost blanket. They can survive light frosts but not hard freezes.
Keep a garden journal. Write down your planting dates, varieties, and harvest results. This helps you refine your timing each year. You will learn what works best for your specific location.
Potatoes are a rewarding crop for Missouri gardeners. With the right timing and care, you can enjoy fresh, homegrown potatoes from spring through fall. Start planning your planting date today.
Remember, the best time to plant potatoes in missouri is when the soil is ready and the frost risk is low. Trust your soil thermometer and local frost dates. Your efforts will be rewarded with a bountiful harvest.