Garlic is a rewarding and relatively simple crop for home gardeners. Achieving a successful yield depends heavily on understanding the specific requirements of the growing environment. For gardeners in the Upper Midwest, particularly Wisconsin, success requires adherence to guidelines that account for the state’s severe winter climate and shorter growing season. Planting garlic in the fall ensures the cloves receive the necessary chilling period, which is fundamental to developing large, healthy bulbs the following summer.
Selecting the Right Garlic for Wisconsin
The initial and most important decision for a Wisconsin garlic grower is choosing the correct type of garlic, which is categorized into hardneck and softneck varieties. Hardneck garlic is distinguished by its stiff, woody central stalk, which contains a single ring of large cloves. These varieties are highly cold-hardy, making them ideally suited to survive the deep freezes of a Wisconsin winter.
Hardneck varieties naturally produce a flower stalk, or scape, which is an edible delicacy in late spring. Successful types for this region include the Porcelain group (such as ‘Music’ or ‘German White’), which produce large bulbs, and the Rocambole group, known for their complex flavor and easy-to-peel cloves. Softneck garlic, typically found in grocery stores, lacks the hard central stalk and is better adapted to milder climates, making it less reliable for overwintering in Wisconsin. The cold exposure is necessary for vernalization, which triggers the plant to form a bulb with distinct cloves instead of a single, undivided round.
Optimal Timing and Preparing the Planting Site
Planting time is a factor for success, generally falling between late September and the end of October in Wisconsin, well before the ground freezes solid. The goal is to allow the clove enough time to develop a strong root system before winter dormancy, but not so much time that it produces extensive green top growth. This root establishment anchors the plant and prepares it to grow rapidly once spring arrives.
The planting site must provide the best conditions for a long growing cycle. Garlic requires full, direct sunlight throughout the day. Well-draining soil is necessary, as cloves will rot if left sitting in standing water during the spring thaw. Amending the planting bed with aged compost or well-rotted manure improves soil structure and fertility. A slightly acidic to neutral pH, ideally between 6.0 and 7.0, supports optimal nutrient uptake.
Planting Technique and Winter Mulching
Separate the garlic bulb into individual cloves just before planting, ensuring each clove retains its papery wrapper. Only the largest, healthiest outer cloves should be planted, as these yield the largest bulbs. Plant the cloves with the pointed end facing up and the flat, root-end down.
Planting depth should be approximately two to three inches deep to provide insulation and prevent the cloves from being pushed out by freeze-thaw cycles. Space the cloves about six inches apart to allow sufficient room for the bulbs to swell without competing for nutrients. Once planted and watered, apply a heavy layer of winter mulch, which is important for gardening in this cold climate.
A thick layer of clean straw or shredded leaves, applied to a depth of four to six inches, provides the insulation necessary to keep the soil temperature stable. This layer prevents the freeze-thaw heaving that can eject shallowly planted cloves from the ground, causing them to dry out or freeze. The mulch also helps to suppress weeds and conserve moisture throughout the winter, protecting the newly established root systems until the spring growing season begins.
Spring Growth and Harvesting
Once the snow melts and temperatures warm in the spring, the first green shoots will emerge through the mulch, often in March or early April. The heavy mulch layer should then be slightly reduced or pulled back from the base of the plants to allow the soil to warm faster and promote growth. Spring is a period of rapid development, and plants benefit from consistent moisture, especially during dry spells.
Hardneck varieties begin to produce their characteristic scapes, the curling flower stalks, typically in June. Removing these scapes with a sharp cut just above the top leaf is important because it directs the plant’s energy away from flower production and into the developing underground bulb, increasing the final bulb size. Harvest time is signaled by the foliage: when the lower third of the leaves (about three to five leaves) have turned brown but the top leaves are still green, the bulbs are ready. Dig the bulbs carefully rather than pulling them by the stem. Move them to a dry, shaded, well-ventilated area to cure for two to three weeks until the outer wrappers are dry and crisp.