When to Sow: Traditionally planted in the spring as the soil begins to warm. However some gardeners prefer to plant theirs in the autumn, leaving them to overwinter outdoors.
Growing garlic and onions can be extremely rewarding for any home gardener. These versatile vegetables add incredible flavor to dishes, and have numerous health benefits when consumed. However, timing is everything when it comes to planting garlic and onions. Choosing the right time to get them in the ground will ensure you have a bountiful harvest. In this comprehensive guide, we’ll cover everything you need to know about when to plant garlic and onions.
Understanding Garlic and Onion Growth Stages
Before deciding when to plant, it’s important to understand the growth cycle of garlic and onions Like many vegetables, they go through distinct stages of growth and development throughout the season
Garlic growth stages
- Planting – Garlic is planted by breaking bulbs into individual cloves. Each clove will grow into a new bulb.
- Root establishment – The planted clove starts to establish its root system and send up a green shoot.
- Leaf growth – The above ground shoot produces leaves to capture sunlight for growth. More roots also grow.
- Bulb formation – The bulb begins to swell as the plant directs energy toward it. This is the key stage for large bulbs.
- Maturation – Lower leaves start to dry out as the bulbs finish growing. Time to cure and harvest.
Onion growth stages:
- Planting – Onion sets or transplants are planted in the garden. Seeds can also be directly sown.
- Leaf growth – Leaves emerge and expand to gather sunlight. Roots establish.
- Bulb formation – The bulb starts to swell. Proper nutrition and water is critical now.
- Maturation – Tops fall over and dry out as bulbs finish growing. Ready for harvest.
Understanding how garlic and onions progress through their lifecycles will help determine the optimal planting time. The goal is to maximize growth during the crucial bulb formation stage by planting at the right time.
Factors That Influence Planting Time
Several key factors come into play when deciding when to plant garlic and onions. The most important are climate, the variety grown, and whether you want to plant in fall or spring.
Climate
Regional climate plays a major role in determining planting times. In warmer climates, garlic and onions can be planted earlier because soil warms faster. Colder climates require later fall planting or spring planting to avoid winter damage. Onions prefer cooler temperatures during their early growth stages.
- Warmer climates – Can plant garlic and onions in late fall/early winter
- Colder climates – Spring or late fall planting recommended
Variety
There are early, mid, and late season varieties of garlic and onions. Early varieties mature faster, while late ones require more time. This allows for staggered plantings to prolong the harvest.
- Early varieties – Best for areas with short growing seasons
- Late varieties – Recommended for longer seasons
Fall vs. Spring Planting
Both fall and spring planting have benefits, depending on your climate:
- Fall – Gives plants a head start on growth before winter. Recommended for mild winter areas.
- Spring – Avoids winter damage to plants. Best for locations with harsh winters.
Recommended Planting Times by Zone
To simplify determining the best planting times, here are general recommendations based on USDA Plant Hardiness Zones:
Garlic
- Zones 3-4: Mid to late September
- Zones 5-6: Late September to mid October
- Zones 7-8: Late October to mid November
- Zones 9-10: Late November to late December
Plant garlic in the fall 6-8 weeks before the ground freezes. Separate bulbs into individual cloves and plant with the tips facing up. Space 4-6 inches apart and 1-2 inches deep.
Onions
- Zones 3-4: Early to mid April
- Zones 5-6: Late March to early April
- Zones 7-8: Mid February to mid March
- Zones 9-10: January to mid February
For spring planting, choose onion sets, transplants or seeds and plant 1⁄2 to 1 inch deep, spaced 2-4 inches apart in rows.
Tips for Successful Fall Planting
For the best results from fall planted garlic and onions, keep these tips in mind:
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Select the biggest, healthiest bulbs and divide into individual cloves or sets. This gives plants the best start.
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Prepare soil in advance by mixing in compost and adjusting pH – aim for 6.5 pH. Smooth beds for even emergence.
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Plant in raised beds for improved drainage. Garlic and onions are prone to rot in wet soil.
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Apply a 2-4 inch protective mulch layer after planting. This insulates plants and prevents frost heave.
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Water thoroughly after planting and continue until the ground freezes. Prevent soils from drying out.
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Consider protective covers like low tunnels or cold frames in very cold climates. Add extra insulation if needed.
Tips for Spring Planting Success
When opting for spring planting, there are also some key tips to ensure your garlic and onions thrive:
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Choose the best quality seed, sets, or starter plants you can find. Check for signs of disease or damage.
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Prepare soil in advance by mixing in aged compost. Quick-maturing varieties may not need more fertilizer.
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Plant as soon as the ground can be worked in spring. Delaying leads to smaller bulbs.
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Water immediately after planting and continue consistent moisture during early growth.
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Use row covers at planting to boost soil temps and growth. Ventilate on warm days.
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Side dress with a balanced organic fertilizer or compost tea mid-season to support bulbing.
Avoiding Common Mistakes
While garlic and onions are relatively easy to grow, there are some common mistakes that can reduce yields:
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Planting too early – Leads to premature sprouting and winter damage.
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Allowing soil to dry out – Onions and garlic require consistent moisture for best growth.
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Crowded spacing – Cramped plants compete for nutrients and air circulation.
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Insufficient sunlight – Look for a site with full sun to partial shade.
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Poor nutrition – Regular, light feeding is needed for large bulbs.
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Failure to cure – Curing allows bulbs to fully mature and locks in storage potential.
By understanding garlic and onion growth stages, considering your climate, and following the zone-specific planting guidelines, you can determine the optimal time to get your crop planted. Pay close attention to fall and spring planting tips for success. Avoid common mistakes, and you’ll be harvesting bountiful, beautiful bulbs before you know it. Growing your own garlic and onions is very satisfying, not to mention delicious.
How to Grow Onion and Shallot Sets
Onions are an incredibly versatile vegetable for home cooking that are simple to grow and store well too. So, the experience of growing your own onion sets and shallot bulbs can be highly rewarding. In this growing guide, we’ll be detailing how to plant and grow onion and shallot sets with instructions for each growing step. There are various ways onions can be grown, with different advantages for each. So, first, take a look at our guide on the best way to grow onions to find out which best suits you. If you would prefer to grow onions from seed, our guide on how to grow onions and shallots from seed can help you with expert advice.
After unpacking your onion or shallot sets, put them into a cool, light, well-ventilated and frost-free place, away from direct sunlight.
You should choose a planting site with free-draining soil that will have plenty of exposure to sunlight. Once you’ve done so, prepare the soil by digging over and incorporating some general-purpose fertiliser. Then, work the soil down to a fine tilth as if preparing a seed bed.
How to Plant Onion and Shallot Sets
Remove any loose papery skins before planting the sets. Push the sets into the soil at the base of the drill, with their pointed tips upwards. Spacing can be anything from 2.5cm (1in) to 10cm (4in) apart, depending on the size of bulbs. Closer spacing results in large numbers of small bulbs, whereas wider spacing results in a smaller number of large bulbs; 5-7.5cm (2-3in) usually works well.
Fill in the drill with soil by running the edge of the rake along its edge to draw soil over the sets, or use the trowel in a similar fashion. Use the trowel to firm in the sets. When they are planted, the tips at least should still be protruding from the soil surface.
Watch This Before You Plant Garlic
FAQ
What month is the best to plant garlic?
However, the best time to plant garlic is from late September to late December, planting it at least a month before your region’s first frost. Most people who have been growing garlic for years, including me, plant garlic in October, and that goes for a wide range of growing zones!
What month is best to plant onions?
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Cool-Season Crop:Onions are a cool-season crop, meaning they thrive in temperatures that are not too hot or too cold.
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Planting Time in Los Angeles:In Los Angeles, with its mild winters, you can plant onions as early as late March or early April.
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Planting Methods:You can plant onions from seed, transplants, or sets (small, immature onions).
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Seed Starting:If starting from seed, you can start them indoors 8-12 weeks before the last frost date.
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Transplanting:Transplant seedlings or plant starters outside in early spring when the soil is workable, about 2-4 weeks before the last frost.
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Onion Sets:Onion sets can be planted as soon as the soil is no longer frozen and can be worked, typically in late March or early April.
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Soil Requirements:Onions need well-drained, fertile soil that is rich in organic matter.
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Sunlight:They also need a sunny location, ideally with at least 6-8 hours of sunlight per day.
What not to do when planting garlic?
Garlic needs consistent moisture, particularly in the early growth stages. Don’t Plant Too Early or Late: – Planting too early can lead to premature growth, while planting too late may not allow cloves to establish roots before winter. Avoid Overcrowding: – Give garlic enough space to grow.