When To Plant Potatoes In Missouri

If you’re planning your Missouri garden, knowing when to plant potatoes is key to a great harvest. Getting the timing right gives your spuds the best start in our variable climate.

Potatoes are a cool-season crop, and Missouri’s springs can be tricky. Plant too early, and a late frost might damage them. Plant too late, and the summer heat can stunt your crop. The goal is to let them grow during the cool, moist days of spring.

For most of Missouri, the prime planting window is from mid-March to mid-April. You need to watch the weather and soil more than the calendar, though.

A good rule is to plant your potatoes about 2-4 weeks before your last expected spring frost. The soil temperature should be at least 45°F (7°C). If the soil is too cold and wet, your seed potatoes may just rot instead of sprouting.

Breaking Down Missouri’s Planting Zones

Missouri spans USDA hardiness zones 5b to 7a. This means planting times shift as you travel across the state.

Northern Missouri (Zones 5b-6a): Aim for early to mid-April. Cities like Kirksville and St. Joseph should wait until the soil has warmed up a bit.
Central Missouri (Zones 6a-6b): This includes Columbia and Jefferson City. Here, late March to early April is usually safe for planting.
Southern Missouri (Zones 6b-7a): Around Springfield and Branson, you can often plant as early as mid-March. The warmer winters allow for a slightly longer growing season.

Signs Nature Gives You

Old-time gardeners follow natural cues. These signs can be just as reliable as a soil thermometer.

When the first dandelions start to bloom in your lawn.
When the redbud trees are in full flower.
When the soil is dry enough to crumble in your hand, not clump into a muddy ball.

Preparing for a Successful Potato Patch

Good preparation makes all the difference. Start by choosing certified disease-free seed potatoes from a garden center. Don’t use potatoes from the grocery store, as they are often treated to prevent sprouting.

Chitting Your Seed Potatoes

About 2-3 weeks before planting, “chit” or pre-sprout your seed potatoes. Place them in a cool, bright spot (like an egg carton on a windowsill). This encourages strong, short sprouts and can give you a harvest a week or two earlier.

Soil is Everything

Potatoes need loose, well-drained soil. Heavy clay soil, common in parts of Missouri, can lead to misshapen tubers. Work in plenty of compost or aged manure to improve texture and fertility. A slightly acidic soil pH of 5.0 to 6.0 is ideal to help prevent scab disease.

The Step-by-Step Planting Process

Cut and Cure: A day before planting, cut larger seed potatoes into pieces. Each piece should be about the size of a golf ball and have at least 1-2 “eyes” (sprouts). Let them sit out so the cut surfaces dry and form a callus.
Dig Trenches: Dig straight trenches about 6-8 inches deep and 3 feet apart.
Plant and Feed: Place seed pieces cut-side down, 10-12 inches apart in the trench. Sprinkle a balanced, low-nitrogen organic fertilizer in the trench before covering.
Cover Gently: Cover the seed pieces with 4 inches of soil. Leave the remaining soil beside the trench for later.

Caring for Your Growing Potatoes

Once the plants are about 6 inches tall, begin “hilling.” Mound soil from between the rows around the base of the plant, leaving just the top few leaves exposed. This protects developing tubers from sunlight (which turns them green and toxic) and encourages more potatoes to form. Repeat hilling every few weeks.

Keep soil consistently moist, especially when plants are flowering, as this is when tubers are forming. Uneven watering can lead to knobby or cracked potatoes. A layer of straw mulch can help retain moisture and suppress weeds.

When to Harvest Your Missouri Potatoes

You can harvest “new” potatoes about 2-3 weeks after the plants finish flowering. For mature, storage potatoes, wait until the plant vines have turned yellow and died back completely, usually in late summer. Use a garden fork to carefully dig up your bounty on a dry day.

Common Problems and Solutions in Missouri

Colorado Potato Beetle: Hand-pick the orange larvae and adults off plants. Row covers early in the season can prevent them from laying eggs.
Early/Late Blight: Promote good air flow by not overcrowding plants. Rotate your potato patch to a new spot in the garden each year.
Poor Yields: Often caused by planting in soil that’s too cold or by using to much high-nitrogen fertilizer, which encourages leaves instead of tubers.

FAQ: Your Missouri Potato Questions Answered

Can I plant potatoes in the fall in Missouri?

In southern Missouri, you can sometimes plant a second crop in late summer (early August) for a fall harvest. In northern areas, the growing season is usually to short for a reliable fall crop.

What are the best potato varieties for Missouri?

Good all-purpose choices include ‘Yukon Gold’ (great yield), ‘Red Norland’ (early, good for our springs), and ‘Kenebec’ (excellent storage). For something fun, try the purple ‘All Blue’.

How do I store my harvested potatoes?

Cure them in a dark, well-ventilated place for 1-2 weeks. Then store in a cool (40-50°F), dark, and humid place. A basement or root cellar is perfect. Don’t store them near onions, as they release gases that can spoil eachother.

Is it possible to plant potatoes from last year’s harvest?

It’s not recommended. Saving your own seed potatoes can lead to a buildup of viral diseases in your soil over time. It’s best to buy new certified seed potatoes each year for a healthy crop.

Getting your potato planting timing right in Missouri sets the stage for the whole season. By following these simple guidelines and watching your local conditions, you’ll be well on your way to digging up a plentiful and delicious harvest from your own backyard garden.