When To Plant Potatoes In Colorado

If you’re planning your garden in the Centennial State, knowing when to plant potatoes in Colorado is the first step to a succesful harvest. Getting the timing right is crucial because our unique climate, with its late springs and early frosts, presents a specific challenge for this cool-season crop.

Plant too early, and your seed potatoes might rot in cold, wet soil. Plant too late, and the summer heat can stop tuber development before they reach a good size. This guide will walk you through the optimal timing for planting, tailored to Colorado’s diverse elevations and regions, so you can enjoy a bounty of homegrown spuds.

The general rule for planting potatoes in Colorado is to get them in the ground 2-4 weeks before your area’s last average spring frost date. Potatoes can handle a light frost after they emerge, but the soil temperature is the real key.

You should aim for a soil temperature of at least 45°F (7°C). A good sign is when the soil is workable and not longer waterlogged from spring snowmelt. For most Front Range cities like Denver, Fort Collins, and Colorado Springs, this window typically falls from late March through mid-April.

However, Colorado’s varied geography means your schedule changes with altitude:

Lower Elevations (Below 6,000 ft): This includes the Front Range urban corridor and Western Slope valleys. Target early to mid-April. You can often do a second planting in late July for a fall harvest.
Mid-Elevations (6,000-8,000 ft): Think foothills communities. Here, aim for mid to late May, as frosts persist longer.
High Elevations (Above 8,000 ft): In mountain towns, the growing season is short. Wait until late May or even early June, and choose fast-maturing varieties.

How to Prepare Your Seed Potatoes

Start with certified disease-free seed potatoes from a garden center, not grocery store potatoes. About 2-3 weeks before your planting date, you’ll need to “chit” or sprout them. This gives them a head start.

Place your seed potatoes in a cool (50-60°F), bright spot, like a windowsill.
Arrange them with the “eyes” (the small dimples where sprouts form) facing upward.
Let them develop short, sturdy green sprouts about ½ to 1 inch long.

On planting day, you can plant small potatoes whole. For larger ones, cut them into egg-sized pieces, making sure each piece has at least 1-2 strong sprouts. Let the cut pieces dry and form a callus for a day or two to prevent rot—this step is easy to forget but really helps.

Step-by-Step Planting Guide

Potatoes thrive in loose, well-draining soil with plenty of organic matter. A sunny spot is essential.

Prepare the Soil: Work the soil to a depth of 10-12 inches. Mix in several inches of compost or aged manure. Colorado soil often benefits from this added organic material.
Dig Trenches: Dig straight trenches about 6-8 inches deep and space them 2.5 to 3 feet apart.
Plant and Fertilize: Place seed pieces cut-side down, with sprouts facing up, every 12 inches in the trench. Sprinkle a balanced, low-nitrogen organic fertilizer or some extra compost in the trench before covering.
Cover and Water: Cover the seed pieces with 4 inches of soil. Water thoroughly to settle the soil around them.

The Importance of Hilling

Hilling is the secret to a bigger harvest. It protects developing tubers from sunlight, which turns them green and toxic, and encourages the plant to produce more potatoes along the buried stem.

When green shoots reach about 8 inches tall, gently mound soil around the base, leaving just the top few leaves exposed.
Repeat this process every couple weeks until the plants begin to flower. You can also use straw or leaves for hilling, which is especially helpful in heavy clay soils.

Choosing the Right Potato Varieties for Colorado

Selecting varieties suited to our climate and your desired use makes a big difference. Early varieties mature fast, beating the heat, while late varieties store well.

Early Season (70-90 days): ‘Yukon Gold’ (all-purpose), ‘Red Norland’ (great for boiling), ‘Dark Red Norland’. These are excellent for higher elevations or for getting an early summer crop.
Mid-Season (90-110 days): ‘Kennebec’ (reliable, good storage), ‘Purple Majesty’ (antioxidant-rich), ‘German Butterball’ (flavorful).
Late Season (110+ days): ‘Russet Burbank’ (classic baking), ‘Canela Russet’ (disease resistant). These need the longest, warmest season, best for lower elevations.

Seasonal Care and Troubleshooting

Consistent moisture is vital, especially during tuber formation (when plants flower). Water deeply once a week, aiming for about 1-2 inches of water. Avoid overhead watering to keep foliage dry and prevent disease.

Watch out for Colorado potato beetles—their orange larvae can defoliate plants. Hand-pick them off daily or use an organic pesticide like spinosad. Crop rotation (not planting potatoes in the same spot for 3 years) is crucial to prevent soil-borne diseases.

Harvesting and Storing Your Crop

You can harvest “new” potatoes carefully by hand about 2-3 weeks after plants stop flowering. For your main harvest for storage, wait until the plant vines have completely died back.

Use a digging fork on a dry day, starting well away from the plant to avoid spearing tubers.
Gently lift the plant and sift through the soil for potatoes.
Let potatoes cure in a dark, well-ventilated place at 50-60°F for about 10-14 days. This toughens their skin for storage.
After curing, store them in a cool (38-40°F), humid, and completely dark place. Properly cured and stored potatoes can last for months.

FAQ: Planting Potatoes in Colorado

Can I plant potatoes from the grocery store?
It’s not recommended. They are often treated with sprout inhibitors and may carry diseases that can persist in your soil for years.

What if a late frost is forecast after my potatoes have sprouted?
If the green foliage is above ground and a hard freeze (below 28°F) is expected, you can cover the plants with frost cloth, old blankets, or a thick layer of straw. They can usually recover from a light frost on there own.

Can I grow potatoes in containers on my Colorado patio?
Absolutely! Use a large container (at least 15 gallons) with excellent drainage. Follow the same planting and hilling steps, using a quality potting mix. Container potatoes may need more frequent watering.

Why are my potato plants flowering?
Flowering is a normal part of the growth cycle. It often signals that tuber formation is beginning underground, so it’s a good sign! It doesn’t effect the edibility of the tubers.

My potato leaves look wilted or have spots. What’s wrong?
This could be a sign of blight, a fungal disease. Ensure good air circulation, avoid wetting foliage, and remove affected leaves. Choosing resistant varieties and rotating crops are the best preventions.

By following these timing and care tips, you’ll be well on your way to harvesting a plentiful supply of potatoes from your Colorado garden. The key is to work with our climate, not against it, and to always keep an eye on the soil temperature in spring.