How to Grow Garlic in Minnesota – Harvest Huge Hardneck Bulbs
To succeed at how to grow garlic in minnesota, plant hardneck varieties like “Music” or “Chesnok Red” in mid-October. Ensure the cloves are buried 3-4 inches deep in well-drained soil and covered with 6 inches of straw mulch.
Hardy bulbs require a period of cold vernalization during the winter to form cloves, followed by a harvest in mid-July once the lower leaves turn brown.
Growing your own gourmet garlic in the North Star State is incredibly rewarding. While our winters are famous for being brutal, they actually provide the perfect environment for certain types of garlic to thrive.
You might think our frozen ground is an obstacle, but for the right cultivars, that deep chill is a biological necessity. By following a few specific steps, you can produce bulbs that are far more flavorful than anything found in a grocery store.
In this guide, we will walk through the entire lifecycle of a garlic crop in the Upper Midwest. We will cover everything from selecting hardy cloves to the final curing process that ensures your harvest lasts through the next winter.
Choosing the Best Varieties for the Minnesota Climate
When learning how to grow garlic in minnesota, the most important decision you will make is selecting the right variety. Garlic is generally divided into two categories: hardneck and softneck.
In Minnesota, hardneck garlic (Allium sativum var. ophioscorodon) is the undisputed king. These varieties are much hardier and can easily withstand USDA Hardiness Zone 3 and 4 winters.
Hardneck varieties also produce “scapes,” which are delicious curly flower stalks you can harvest in early summer. Popular hardneck types for our region include Porcelain, Rocambole, and Purple Stripe varieties.
Recommended Hardneck Cultivars
- Music: A porcelain variety known for its massive cloves and easy-to-peel skin. It is exceptionally cold-hardy and reliable.
- German Extra Hardy: This variety produces large, pungent bulbs and resists overwintering stress better than almost any other.
- Chesnok Red: A purple stripe variety that is widely considered the best for roasting due to its sweet, mellow flavor.
- Siberian: As the name suggests, this variety loves the cold and produces a very high oil content for a sharp bite.
Softneck garlic, while common in grocery stores, often struggles in the North. It lacks the hardiness required for a deep freeze and often fails to produce large bulbs in our short, intense growing season.
Optimal Timing for a Northern Harvest
Timing is everything in a Minnesota garden. If you plant too early, the garlic may send up too much green growth that gets killed by the first hard frost, wasting the plant’s energy.
If you plant too late, the roots won’t have enough time to establish themselves before the ground freezes solid. The “sweet spot” for Minnesota is typically between October 10th and October 30th.
Your goal is to get the garlic in the ground about 2 to 4 weeks before the soil freezes. This allows the clove to develop a strong root system while keeping the green shoot tucked safely below the soil surface.
Keep an eye on the local weather forecast. If a sudden deep freeze is predicted early, move your planting date up. Conversely, if we are having a “long fall,” you can wait until early November.
Preparing Your Soil for Pungent Results
Garlic is a heavy feeder that requires well-drained soil rich in organic matter. Because garlic stays in the ground for nine months, the soil structure is critical for preventing rot during the spring thaw.
Start by testing your soil pH; garlic prefers a range between 6.0 and 7.5. If your soil is heavy clay, common in many parts of Minnesota, consider adding compost or aged manure to improve drainage.
Avoid planting garlic in spots where water pools after a rainstorm. Excess moisture during the winter or early spring is the primary cause of bulb rot and fungal diseases.
Essential Soil Amendments
Before planting, incorporate a balanced fertilizer into the top six inches of soil. A fertilizer with a slightly higher phosphorus count can help with initial root establishment.
Many “pro” gardeners also add a bit of bone meal or blood meal to the planting trench. This provides a slow-release source of nutrients that the garlic can tap into the moment it wakes up in April.
If you are looking to how to grow big garlic, focusing on soil fertility in the fall is the most important step you can take.
How to Grow Garlic in Minnesota: Step-by-Step Planting
Once your soil is prepared and your “seed” garlic has arrived, it is time to get your hands dirty. Never use garlic from the grocery store, as it is often treated with growth inhibitors and may carry soil-borne diseases.
Break the garlic bulbs into individual cloves just before planting. Leave the papery skin on each clove, as this acts as a protective layer against soil pathogens and pests.
- Sort your cloves: Only plant the largest, healthiest cloves. Small cloves will produce small bulbs, so save the tiny ones for your kitchen.
- Space correctly: Dig a trench or individual holes 6 inches apart. If planting multiple rows, keep the rows at least 12 inches apart to allow for easy weeding.
- Depth is key: In Minnesota, plant cloves 3 to 4 inches deep. This extra depth provides a buffer against the extreme temperature swings of a northern winter.
- Orientation: Always plant the clove with the pointed end up and the blunt (root) end down. Garlic planted upside down will struggle and produce misshapen bulbs.
- Cover and firm: Fill the holes with soil and lightly press down to ensure good soil-to-clove contact. Avoid packing the soil too tightly, as this can hinder root growth.
After planting, give the area a light watering. This helps settle the soil around the cloves and triggers the initial root development phase.
Winter Protection: The Power of Mulching
In more temperate states, mulching is optional. In Minnesota, it is mandatory. A thick layer of mulch acts as an insulator, preventing the soil from “heaving” during freeze-thaw cycles.
Heaving can actually push garlic cloves right out of the ground, exposing them to the killing air. For the best results, use straw mulch or shredded leaves, applying a layer 4 to 6 inches thick.
Do not use hay, as it contains weed seeds that will haunt your garden for years. Straw is generally cleaner and provides excellent air pockets for insulation.
Wait until the first light frost has “crusted” the soil before applying the mulch. This prevents rodents from nesting in the warm straw and snacking on your newly planted cloves.
The Role of Vernalization
One reason how to grow garlic in minnesota is so successful is vernalization. This is the process where the garlic clove is exposed to cold temperatures for an extended period.
This cold trigger tells the plant to stop focused leaf growth and start dividing into individual cloves. Without this “winter nap,” your garlic might only grow as a single large onion-like bulb called a “round.”
Spring Maintenance and Scape Management
As the snow melts in late March or early April, you will see the first green shoots poking through the mulch. This is an exciting moment for any Minnesota gardener!
You do not need to remove the mulch entirely. Simply pull it back slightly if the shoots seem to be struggling to break through. The mulch will continue to suppress weeds and retain moisture as the weather warms.
During the rapid growth phase of May and June, garlic needs plenty of nitrogen. Apply a liquid fish emulsion or a side-dressing of compost to keep the leaves vibrant and green.
If you are interested in variety, you might also consider harvesting green garlic early in the spring. These are immature plants pulled like scallions and offer a mild, fresh garlic flavor.
Removing the Scapes
By mid-June, your hardneck garlic will send up a central stalk that curls at the top. This is the scape. If left alone, the plant will put its energy into producing “bulbils” (tiny seeds) at the top of this stalk.
To maximize bulb size, you must cut these scapes off once they have formed one or two loops. Use clean garden shears and cut them at the base where they emerge from the leaves.
Don’t throw them away! Garlic scapes are a culinary delicacy. They can be grilled, made into pesto, or chopped into stir-fries for a wonderful early-summer treat.
A Minnesota Garlic Care Calendar
To help you stay on track, use this seasonal table to manage your garlic crop effectively throughout the year.
| Season | Month | Action Required |
|---|---|---|
| Fall | October | Plant cloves 4 inches deep; apply 6 inches of straw mulch. |
| Winter | Nov – March | Ensure mulch stays in place; avoid walking on the garlic bed. |
| Spring | April – May | Fertilize with high-nitrogen feed; keep the bed weed-free. |
| Summer | June | Remove garlic scapes to redirect energy to the bulb. |
| Summer | July | Stop watering; harvest bulbs when lower leaves turn brown. |
| Late Summer | August | Cure bulbs in a shaded, well-ventilated area for 3-4 weeks. |
Harvesting and Curing Your Minnesota Bounty
Knowing when to harvest is a delicate balance. If you dig too early, the cloves will be small and underdeveloped. If you wait too long, the protective skins will burst, and the garlic won’t store well.
In Minnesota, the harvest usually happens in mid-to-late July. Look at the leaves of the plant. When the bottom two or three leaves have turned brown, but the top four or five are still green, it is time to dig.
Never pull garlic by the stem, as this can damage the neck and lead to rot. Instead, use a garden fork to gently loosen the soil around the bulbs and lift them from beneath.
Avoid harvesting on a rainy day. Dry soil makes it much easier to shake off the excess dirt without damaging the delicate outer skins of the bulbs.
The Curing Process
Curing is the process of drying the garlic so it can be stored for months. Immediately after harvest, move the garlic out of the direct sun, which can “cook” the bulbs and ruin the flavor.
Hang the garlic in bunches or spread it out on a wire rack in a cool, dry place with excellent airflow. A garage, barn, or covered porch works perfectly.
Let the garlic cure for 3 to 4 weeks. You will know it is ready when the outer skins are dry and papery, and the roots are brittle. Once cured, you can trim the roots and cut the stalks to about an inch above the bulb.
If you want to compare this process to other regions, you might find our guide on growing in cold climates like Maine very helpful, as their conditions are remarkably similar to ours.
Troubleshooting Common Minnesota Garlic Issues
While garlic is generally hardy, Minnesota gardeners do face a few specific challenges. Being proactive can save your crop from total failure.
Onion Maggots: These small larvae can tunnel into the bulbs. To prevent them, practice crop rotation and avoid planting garlic in the same spot where onions or leeks grew the previous year.
Bulb Mites: These tiny pests thrive in moist conditions and can cause the garlic to appear stunted. Ensuring your soil is well-drained is the best defense against these microscopic invaders.
White Rot: This is a serious fungal disease that appears as a white, fluffy growth on the base of the bulb. If you see this, remove the infected plants immediately and do not compost them, as the spores can live in the soil for decades.
Always maintain high garden hygiene. Clean your tools after working in an area where you suspect disease, and never plant cloves that show signs of mold or soft spots.
FAQs About Growing Garlic in the North
Can I Plant Garlic in the Spring in Minnesota?
While you can plant in the spring, it is not recommended. Spring-planted garlic often fails to go through the necessary vernalization, resulting in smaller bulbs or “rounds” that haven’t split into cloves.
How Much Garlic Should I Plant for a Family of Four?
A good rule of thumb is to plant about 50 to 75 cloves. This usually provides enough garlic for fresh use throughout the summer and plenty of cured bulbs to last through the winter months.
Do I Need to Water My Garlic During a Minnesota Winter?
No. Once the ground freezes, the plant is dormant. The snow cover provides all the moisture the soil needs. You only need to resume watering in the spring once the soil thaws and active growth begins.
What Is the Best Way to Store Harvested Garlic?
Store your cured bulbs in a cool (50-60°F), dry place with good air circulation. A mesh bag or a woven basket works well. Never store whole garlic bulbs in the refrigerator, as the humidity and cold can trigger sprouting.
Final Thoughts on Growing Northern Garlic
Mastering how to grow garlic in minnesota is a badge of honor for any local gardener. It requires patience, a bit of physical labor in the chilly October air, and the discipline to protect your crop with heavy mulch.
However, the result is a kitchen stocked with high-quality, pungent, and medicinal garlic that puts supermarket varieties to shame. By choosing hardneck cultivars and respecting the northern seasons, you can ensure a massive harvest every year.
Now is the perfect time to start planning your garden layout. Order your seed garlic early, prepare your organic amendments, and get ready to enjoy the most flavorful crop your backyard has ever produced!
Taylor pairs an engineer's eye with years of hands-on work in soil, lawns and outdoor machinery. He tests ideas in his own garden, keeps tractors and mowers running himself, and speaks to local horticulture groups. Every Garden Aider guide is written to be practical, accurate and safe to follow.
“To bring life alive, you just need to mix some love with the compost, bedding, and gardening machines.”