If you want a robust garlic harvest next summer, knowing when to plant garlic in Minnesota is the most critical step. Getting the timing right in our state’s unique climate makes all the difference for healthy cloves that survive the winter.
Planting garlic in the fall allows the cloves to establish roots before the ground freezes. They then go dormant over winter and are ready to explode with growth in early spring. This process, called vernalization, is essential for forming large, well-developed bulbs.
When to Plant Garlic in Minnesota
The ideal window for planting garlic in Minnesota is relatively short. You need to hit the sweet spot between summer’s heat and winter’s deep freeze.
Aim to plant your garlic cloves about 4-6 weeks before the ground typically freezes solid in your area. For most of Minnesota, this falls between mid-September and mid-October. A good rule of thumb is to get them in the ground after the first light frost but well before a hard, killing frost.
Here’s a quick regional guide:
* Northern Minnesota: Target late September to early October.
* Central Minnesota (Twin Cities metro area): Target early to mid-October.
* Southern Minnesota: Target mid to late October.
Always check your local frost dates and observe the weather. The goal is for cloves to develop strong roots but not send up green shoots above the soil line before winter.
Why Fall Planting is Non-Negotiable
Spring-planted garlic rarely succeeds in Minnesota. The cloves won’t undergo the necessary cold period and often produce small, single-clove bulbs called “rounds.” Fall planting gives them that crucial cold trigger. It also gives them a head start, so they mature during the longer days of early summer, which is perfect for bulb formation.
Choosing the Right Garlic for Minnesota
You have two main types to choose from, and your choice impacts flavor and storage.
Hardneck Garlic:
This is the best choice for Minnesota’s cold winters. It’s extremely cold-hardy and produces a central stalk called a scape.
* Flavor: Complex, often spicier or more robust flavors.
* Cloves: Larger, but fewer per bulb, arranged around the hard central stem.
* Bonus: You harvest edible scapes in early summer.
* Good Varieties: Music, German Extra Hardy, Russian Red.
Softneck Garlic:
Less winter-hardy and better suited to milder climates. It can work in Minnesota with heavy mulch, but hardnecks are more reliable.
* Flavor: Generally milder, great for raw uses.
* Cloves: More cloves per bulb, often in multiple layers.
* Storage: Usually stores longer than hardneck types.
* Good Varieties: Inchelium Red, California Early (with extra protection).
Always source your seed garlic from a reputable nursery or garden center. Do not plant garlic from the grocery store, as it may be treated to prevent sprouting and isn’t adapted to our climate.
Preparing Your Planting Site
Garlic thrives in full sun and well-drained soil. Soggy soil will cause the cloves to rot over winter.
1. Choose a Sunny Spot: At least 6-8 hours of direct sun daily.
2. Amend the Soil: Work in several inches of compost or well-rotted manure. Garlic prefers fertile, loamy soil.
3. Check pH: Aim for a soil pH between 6.0 and 7.0. A simple soil test can tell you if you need to add lime to raise pH.
4. Ensure Drainage: If you have heavy clay soil, consider building a raised bed to improve drainage.
A Step-by-Step Planting Guide
Follow these steps for success:
1. Break the Bulbs: A day or two before planting, gently break the garlic bulbs into individual cloves. Keep the papery husk on each clove.
2. Select the Best Cloves: Plant only the largest, healthiest-looking cloves. The size of the clove directly influences the size of the harvested bulb. Use smaller cloves for cooking.
3. Plant Pointy-End Up: This is crucial. The pointed end is where the shoot emerges, and the flat root end goes down.
4. Depth and Spacing: Plant cloves 2-3 inches deep. Space them 4-6 inches apart in rows that are 12-18 inches apart.
5. Water Thoroughly: Give the planted bed a good drink to settle the soil around the cloves.
The Essential Mulching Step
Mulching is not optional in Minnesota; it’s your garlic’s winter blanket. It prevents frost heave, moderates soil temperature, and suppresses weeds.
After planting and watering, apply a 4-6 inch layer of loose, airy mulch. Excellent choices include:
* Straw (make sure it’s seed-free)
* Shredded leaves
* Grass clippings (only if not treated with herbicides)
In spring, as the weather warms, you may see green shoots poking through the mulch. Leave most of the mulch in place to suppress weeds. You can gently pull it back from the direct shoots if growth seems slow.
Spring and Summer Care
Your garlic will be one of the first green things in your garden.
* Spring Feeding: When plants are about 6 inches tall, side-dress with a nitrogen-rich fertilizer like blood meal or a balanced organic fertilizer.
* Watering: Keep the soil consistently moist, but not waterlogged, especially during bulb formation (May-June). Reduce watering as harvest approaches to let bulbs cure.
* Weeding: Keep the bed weed-free; garlic doesn’t like competition.
* Harvest Scapes (Hardnecks Only): In early summer, hardneck garlic will send up a curly flower stalk called a scape. Cut it off when it makes one full loop. This directs the plant’s energy into making a bigger bulb, and the scapes are delicious to eat!
Knowing When to Harvest
Harvest timing is almost as important as planting timing. Harvest too early, and bulbs will be small; too late, and the cloves may burst from their skins, reducing storage life.
Watch for these signs in mid-to-late July:
* The bottom 3-4 leaves have turned brown and dry.
* The top leaves are still partially green.
* The plant begins to look a bit “tired.”
Gently dig up a test bulb to check. The cloves should be well-formed and the wrappers tight.
How to Harvest and Cure
1. Use a garden fork to loosen the soil and lift the bulbs, being careful not to bruise them.
2. Do not wash them. Brush off excess soil gently.
3. Cure the bulbs in a warm, dry, well-ventilated, and shady place for 3-4 weeks. Hang them in bunches or lay them on a rack.
4. Once the necks are completely tight and dry and the outer wrapper is papery, trim the roots and cut the stalks. Your garlic is ready for storage in a cool, dark place.
Common Problems and Solutions
* Rotting Cloves: Caused by poor drainage or planting too early. Ensure your bed drains well and follow the recommended planting window.
* Small Bulbs: Often due to planting small cloves, insufficient sun, or not harvesting scapes from hardnecks.
* Frost Heave: Inadequate mulch can allow freezing and thawing cycles to push cloves out of the ground. Apply a thick mulch layer.
* Weeds: Mulch heavily to supress weeds, which compete with garlic for nutrients.
FAQ Section
Can I plant garlic from the grocery store in Minnesota?
It’s not recommended. Store-bought garlic is often from warm climates and may be treated with sprout inhibitors. It’s also more suseptible to diseases. For best results, buy certified seed garlic from a local source.
What happens if I plant garlic too late in the fall?
If planted too late, the cloves won’t have time to establish adequate roots before freeze-up. This can lead to poor survival over winter and weaker plants in spring. Try to get them in by mid-October at the latest for most areas.
Should I fertilize garlic when I plant it in the fall?
Avoid high-nitrogen fertilizers at planting time. Focus on amending the soil with compost. The main fertilizer application should come in spring when growth resumes.
Can I grow garlic in containers in Minnesota?
Yes, you can. Use a deep container (at least 12 inches) with excellent drainage. Insulate the container over winter by moving it to an unheated garage or wrapping it with burlap and straw. The mulch is still very important.
My garlic sprouted green tops in late fall, is it ruined?
Not necessarily. A little top growth is okay. The mulch will often protect it. The plants may experience some winter die-back, but they usually regrow from the clove in spring. Try planting a bit later next season.
Getting the timing right for when to plant garlic in Minnesota sets the stage for a successful harvest. By following these steps—choosing hardy varieties, planting in that crucial fall window, and using ample mulch—you’ll be rewarded with a bounty of homegrown garlic that stores well and tastes incredible.