If you’re planning your Ohio garden, knowing when to plant potatoes is the first step to a successful harvest. Getting the timing right makes all the difference between a bumper crop and a disappointing one.
Potatoes are a rewarding cool-season crop, but they need careful scheduling. Ohio’s varied climate means your planting date depends heavily on where you live and the whims of spring. This guide will walk you through the simple signs to watch for, so you can get your spuds in the ground at the perfect moment.
When to Plant Potatoes in Ohio
For most of Ohio, the ideal potato planting window is from late March to mid-April. You need to watch the weather and soil more than the calendar, though. The traditional rule is to plant your potatoes about 2-4 weeks before your area’s last expected spring frost date.
This timing allows the plants to establish roots and begin growing in the cool, moist soil they love. Planting too early in cold, wet soil can cause seed pieces to rot. Planting too late exposes the developing tubers to the peak summer heat, which can halt growth and affect quality.
Ohio’s Climate Zones and Planting Dates
Ohio spans USDA hardiness zones 5b to 6b, which creates a range of last frost dates. Here’s a general breakdown by region:
- Southern Ohio (Zone 6b): Last frost around mid-April. Aim to plant from late March to early April.
- Central Ohio (Zone 6a): Last frost around late April. Target early to mid-April for planting.
- Northern Ohio (Zone 5b): Last frost around early May. Plan for mid to late April planting.
Always use your local frost dates as a guide, not a guarantee. Spring weather can be unpredictable from year to year.
The Best Soil Conditions for Planting
Soil temperature and moisture are more critical than the date on your phone. Before you grab your shovel, check these two factors:
- Soil Temperature: It should be at least 45°F (7°C). A simple soil thermometer is a great investment. When you can comfortably bare your hand in the soil for a minute, it’s usually ready.
- Soil Moisture: The soil should be moist but not waterlogged. Grab a handful and squeeze it. If it holds together in a muddy ball, it’s too wet. If it crumbles freely, it’s perfect.
Choosing and Preparing Your Seed Potatoes
Never use potatoes from the grocery store. They are often treated with sprout inhibitors and can carry disease. Always buy certified disease-free seed potatoes from a garden center or reputable supplier.
How to “Chit” or Pre-Sprout Your Potatoes
Pre-sprouting, or chitting, gives your potatoes a head start. About 2-3 weeks before your planned planting date, follow these steps:
- Place your seed potatoes in a single layer in a cool, bright spot (like a sunny windowsill).
- Arrange them with the “eyes” (the small dimples where sprouts form) facing upward.
- Allow short, sturdy green sprouts to grow about ¾-inch long.
Cutting and Curing Seed Pieces
Large seed potatoes should be cut into pieces. Each piece needs at least one or two strong eyes. Here’s how to do it right:
- Use a clean, sharp knife to cut the potato a day or two before planting.
- Ensure each piece is roughly golf-ball sized, about 1.5 to 2 ounces.
- Let the cut pieces cure in a well-ventilated, cool place. This allows the cut surfaces to dry and form a callus, which prevents rot once planted.
Step-by-Step Planting Guide
Once your soil is ready and your seed pieces are prepped, it’s time to plant. Potatoes thrive in loose, well-draining soil with plenty of organic matter.
- Choose a Sunny Spot: Select a site that gets at least 6-8 hours of full sun daily.
- Prepare the Soil: Loosen the soil to a depth of 12 inches. Mix in a generous amount of compost or aged manure. Avoid fresh manure, as it can promote scab disease.
- Dig Trenches: Dig straight trenches about 6-8 inches deep and space them 2.5 to 3 feet apart.
- Plant the Seed Pieces: Place the pieces cut-side down, with the eyes facing up, in the trench. Space them about 12 inches apart.
- Cover and Water: Cover the seed pieces with 4 inches of soil. Water the trench thoroughly to settle the soil around them.
The Importance of Hilling
Hilling is the process of mounding soil around the growing stems. This protects developing tubers from sunlight (which turns them green and toxic) and encourages more potatoes to form along the buried stem.
- When the plants are about 6 inches tall, gently hill soil around the base, leaving just the top few leaves exposed.
- Repeat this process every few weeks as the plants continue to grow. Stop hilling when the plants begin to flower.
Caring for Your Growing Potato Plants
Consistent care through the season is key for healthy plants. Potatoes need about 1-2 inches of water per week, especially during tuber formation (when they flower). Water deeply at the base of the plants to keep the soil evenly moist but not soggy.
A layer of straw or shredded leaf mulch can help retain moisture, suppress weeds, and keep the soil cooler. It also makes harvesting a bit cleaner later on.
Fertilizing and Pest Watch
Potatoes are moderate feeders. A balanced, low-nitrogen fertilizer applied at planting and again at hilling is usually sufficient. Too much nitrogen leads to lots of leaves and few tubers.
Keep a eye out for common pests like the Colorado potato beetle. Hand-pick them and their orange egg clusters off leaves. Crop rotation is also vital—don’t plant potatoes in the same spot where you grew them, tomatoes, or peppers the previous year.
Harvesting Your Ohio Potatoes
Your harvest time depends on the type of potato and what you want.
- New Potatoes: For tender, small “new” potatoes, you can carefully dig around the plants about 2-3 weeks after they stop flowering.
- Mature Potatoes (for storage): Wait until the plant vines have completely yellowed and died back. This usually happens in late summer or early fall.
To harvest, use a digging fork on a dry day. Insert it carefully about a foot away from the plant to avoid spearing tubers. Gently lift the soil and sift through it with your hands to find all the potatoes.
Curing and Storing Your Harvest
Proper curing is essential for long-term storage. After digging, let the potatoes dry on the soil surface for a few hours. Then, move them to a dark, well-ventilated, and humid place (like a garage or basement) at about 55-60°F for 10-14 days. This allows the skins to toughen.
After curing, store your potatoes in a completely dark, cool (38-40°F), and humid place. Check them periodically and remove any that show signs of spoiling.
FAQ: Planting Potatoes in Ohio
Can I plant potatoes in the fall in Ohio?
Fall planting is generally not recommended for Ohio. The winter freeze comes to early for a second crop to mature. However, you can sometimes get a very late summer planting in for a fall harvest of new potatoes if you use a fast-maturing variety.
What are the best potato varieties for Ohio gardens?
Many varieties do well here. For early season, try ‘Yukon Gold’ or ‘Red Norland’. For mid to late season and storage, ‘Kennebec’ and ‘German Butterball’ are excellent choices. Always choose varieties that resist common diseases.
How late is too late to plant potatoes?
Aim to have your potatoes planted by late May at the absolute latest. Planting in June risks the tubers developing during the hottest part of summer, which stresses the plants and leads to poor yields. The soil can also become to dry.
My potato plants are flowering. Is that normal?
Yes, flowering is a normal part of the potato plant’s lifecycle. It often signals that tuber formation is happening underground. It’s not necessary for production, but it’s a good sign your plants are healthy.
Why are my potato leaves turning yellow?
Yellowing leaves at the end of the season is normal as the plant matures. However, yellowing early on can indicate overwatering, a nutrient deficiency, or disease. Check your soil moisture and look for other signs of pests or illness on the plant.
Following these guidelines for when to plant potatoes in Ohio will set you up for a productive season. Paying attention to your local conditions and giving your plants consistent care is the real secret. With a little planning, you’ll be enjoying homegrown potatoes from your own backyard.