Garlic bulbils need a cold period to develop, so plant them in fall for harvest the following summer. Knowing when to plant garlic bulbils is the key to turning those tiny aerial cloves into full-sized bulbs. Unlike regular garlic cloves, bulbils take two years to mature, but they offer a disease-free way to multiply your garlic stock.
This guide covers everything you need to know about timing, from soil temperature to seasonal cues. You will learn the exact planting window, how to prepare bulbils, and what to expect during their long growing cycle.
When To Plant Garlic Bulbils
The best time to plant garlic bulbils is in the fall, about 4 to 6 weeks before the ground freezes. This timing allows the bulbils to establish roots before winter dormancy. In most climates, that means planting between late September and mid-November.
Garlic bulbils are the small, pea-sized cloves that form in the scape (the flower stalk) of hardneck garlic. Each bulbil contains the genetic material to grow a new plant, but they are much smaller than regular cloves. Because of their size, they need a full year in the ground to develop into a single clove (called a round), and then a second year to become a full bulb.
Why Fall Planting Works Best
Garlic is a cold-hardy crop that requires vernalization—a period of cold temperatures—to trigger bulb formation. Bulbils are no different. When you plant them in fall, they experience natural winter chilling, which signals the plant to start growing in spring.
- Fall planting gives bulbils time to root before winter
- Cold temperatures break dormancy and promote healthy growth
- Spring-planted bulbils often fail to form bulbs because they miss the cold period
If you live in a region with mild winters, you can still plant in fall. Just ensure the bulbils get at least 6 to 8 weeks of temperatures below 40°F (4°C). In warmer climates, you may need to refrigerate bulbils for 6 weeks before planting in late winter.
Soil Temperature For Planting
Check your soil temperature before planting. The ideal range is between 50°F and 60°F (10°C to 15°C). If the soil is too warm, bulbils may sprout prematurely and get damaged by frost. If it is too cold, they may not root before the ground freezes.
Use a soil thermometer to measure at a depth of 4 inches. Plant when the temperature consistently stays below 60°F but above freezing. This usually coincides with the first few light frosts in autumn.
How To Plant Garlic Bulbils Step By Step
Planting bulbils is similar to planting garlic cloves, but with a few adjustments due to their small size. Follow these steps for the best results.
Step 1: Prepare The Bulbils
Harvest bulbils from the scapes in late summer, after the scape has dried and turned brown. Store them in a cool, dry place until planting. Do not remove the papery husk—it protects the bulbil during storage and planting.
- Select the largest bulbils for faster growth
- Discard any that are shriveled or moldy
- Keep bulbils in a breathable bag or paper envelope
Step 2: Choose The Planting Site
Garlic needs full sun and well-drained soil. Bulbils are more sensitive to waterlogging than cloves, so raised beds or loose, sandy loam work best. Test your soil pH—garlic prefers a range of 6.0 to 7.0.
Add compost or aged manure a few weeks before planting. Avoid fresh manure, which can burn the tiny bulbils. If your soil is heavy clay, mix in sand or perlite to improve drainage.
Step 3: Plant At The Right Depth
Bulbils are planted much shallower than cloves. Place them about 1 inch deep and 2 to 3 inches apart. If you plant them too deep, they may not have enough energy to reach the surface. Too shallow, and they risk frost heave.
- Make a furrow or use a dibber to create holes
- Drop one bulbil per hole, pointy side up
- Cover with soil and pat gently
- Water lightly to settle the soil
Step 4: Mulch For Winter Protection
After planting, apply a 4 to 6 inch layer of organic mulch, such as straw or shredded leaves. Mulch insulates the soil, prevents heaving during freeze-thaw cycles, and suppresses weeds. Remove most of the mulch in early spring when growth begins.
Regional Planting Times For Bulbils
Your local climate determines the exact planting window. Here is a general guide based on USDA hardiness zones.
| Zone | Recommended Planting Window |
|---|---|
| 3-4 | Late August to mid-September |
| 5-6 | Mid-September to mid-October |
| 7-8 | October to mid-November |
| 9-10 | November to December (with refrigeration) |
In zones 9 and above, winters are too warm for natural vernalization. Refrigerate bulbils at 35-40°F for 6-8 weeks before planting. Then plant in late fall or early winter, and expect slower growth.
What If You Miss Fall Planting?
If you miss the fall window, you can still plant bulbils in early spring. However, they will not receive enough cold exposure to form bulbs in the first year. Instead, they will grow into small rounds that you can harvest in fall and replant the next year.
Spring planting is less reliable, but it works if you simulate winter by refrigerating bulbils for 6 weeks before planting. Plant as soon as the soil is workable in spring.
What To Expect After Planting
Garlic bulbils grow slowly. In the first year, they produce a single leaf and a small underground round (a single clove). This round is about the size of a marble or a small garlic clove. You harvest these rounds in late summer, cure them, and replant them in fall for full-sized bulbs the following year.
Here is a timeline of what happens after you plant bulbils in fall:
- Fall (first year): Roots develop, but no top growth appears
- Spring (first year): A single leaf emerges; the plant focuses on root and round growth
- Late summer (first year): The leaf yellows and dies back; harvest the rounds
- Fall (second year): Replant rounds like regular cloves
- Summer (second year): Harvest full-sized garlic bulbs
This two-year cycle is why many gardeners prefer planting cloves for quicker results. But bulbils offer a way to expand your garlic patch without buying new seed stock.
Common Mistakes To Avoid
Even experienced gardeners make errors when planting bulbils. Here are the most common pitfalls.
- Planting too deep: Bulbils are tiny; 1 inch is plenty
- Overwatering: Bulbils rot easily in wet soil
- Skipping mulch: Without insulation, bulbils may heave out of the ground
- Planting in shade: Garlic needs at least 6 hours of direct sun
- Harvesting too early: Wait until the leaf dies back completely
Caring For Bulbil Plants
Once planted, bulbils require minimal care. Keep the soil moist but not soggy during the growing season. In spring, remove most of the mulch but leave a thin layer to retain moisture and block weeds.
Fertilize lightly in early spring with a balanced organic fertilizer, such as fish emulsion or compost tea. Avoid high-nitrogen fertilizers, which promote leaf growth at the expense of bulb development.
Weed regularly, especially when the plants are small. Bulbils are poor competitors, and weeds can easily smother them. Hand-pull weeds to avoid disturbing the shallow roots.
Pest And Disease Management
Bulbils are less prone to soil-borne diseases than cloves because they grow above the ground. However, they can still attract pests like aphids and thrips. Use insecticidal soap if infestations occur.
Rotate your garlic planting location every year to prevent disease buildup. Avoid planting bulbils in soil where onions or other alliums grew recently.
Harvesting And Storing Rounds
In late summer of the first year, the single leaf will turn yellow and flop over. This is the sign to harvest. Gently dig up the rounds using a garden fork. Brush off excess soil, but do not wash them.
Cure the rounds in a warm, dry, well-ventilated area for 2 to 3 weeks. Then store them in a cool, dark place until fall planting. Rounds can be stored at 50-60°F with moderate humidity.
Select the largest rounds for replanting. Smaller rounds can be eaten like garlic cloves, though they are milder in flavor.
Using Bulbils For Seed Saving
One of the biggest advantages of growing from bulbils is disease-free seed stock. Bulbils form above the soil, so they avoid soil-borne pathogens like white rot and nematodes. By planting bulbils for two years, you can refresh your garlic supply without buying new seed.
Save bulbils from your healthiest, most vigorous plants. Choose scapes that produce large bulbils with good shape. Store them in a paper bag in a cool, dry place until fall.
Frequently Asked Questions
Can I plant garlic bulbils in spring?
Yes, but they will not form bulbs the first year. Spring-planted bulbils grow into rounds that you harvest in fall and replant the next year. Refrigerate them for 6 weeks before planting to mimic winter.
How deep should I plant garlic bulbils?
Plant bulbils about 1 inch deep. They are small and need to be close to the surface to emerge. Deeper planting can cause them to rot or fail to sprout.
Do garlic bulbils need to be peeled before planting?
No. Leave the papery husk intact. It protects the bulbil during storage and planting. Removing it can damage the bulbil and reduce germination.
How many bulbils does one garlic scape produce?
A single scape can produce 50 to 150 bulbils, depending on the garlic variety and growing conditions. Hardneck varieties like Rocambole and Porcelain tend to produce more.
Can I eat garlic bulbils?
Yes, bulbils are edible and have a mild garlic flavor. They can be used raw in salads, pickled, or roasted. However, they are best saved for planting if you want to expand your garlic crop.
Final Tips For Success
Planting garlic bulbils is a rewarding way to multiply your garlic without spending money on seed cloves. The key is timing—plant in fall, give them a cold winter, and be patient for two years.
Start with a small batch to learn the process. Once you see how easy it is, you can scale up. Keep records of planting dates, weather, and harvest results to refine your technique each year.
Remember that bulbils are more resilient than they look. They survive freezing temperatures, drought, and neglect better than most garden crops. With a little care, they will reward you with a steady supply of homegrown garlic for years to come.
So mark your calendar for fall, prepare your bed, and get those tiny bulbils into the ground. Your future garlic harvest will thank you.