Bulb vegetables like garlic thrive in full sun. Garlic plants will tolerate indirect sunlight or partial shade as long as they receive more sun than shade. When garlic can’t receive full sunlight, gardeners will need to make a few adjustments to soil composition to give garlic the extra nutritional support they need.
Garlic requires well-drained, loamy soil to prevent excess accumulation of moisture around the roots. Planting garlic in this type of soil is especially important if full sunlight conditions aren’t available. Add compost or manure to the soil prior to planting bulbs in the fall. Studies show that the best soil pH for garlic is between 6 and 7.
How Many Hours of Sun Does Garlic Need?
Garlic reaches its optimum growth capacity when it receives six to eight hours of sunlight per day. However, garlic will also develop normally if it can get at least four hours of sunlight per day. As long as soil conditions and temperature ranges remain stable, garlic will grow in partial sunlight.
- Garlic grows best when it receives 6–8 hours of sun per day.
- Some types of garlic can grow with as little as 4 hours of sun per day.
- Hardneck garlic varieties can grow with less sunlight than softneck varieties.
Depending on the garlic variety planted, air temperature is just as important as sunlight. For example, hardneck garlic tolerates cold winters better than softneck garlic. Alternatively, softneck garlic doesn’t tolerate cold weather and should be planted in warmer climates. Hardneck garlic types include purple stripe, Creole, and marbled purple stripe. Softneck garlic types (which need more sunlight than hardneck garlic) include Corsican red, silver rose, and silver white.
Can Garlic Grow in Indirect Sunlight?
Garlic can grow in indirect sunlight as long as it receives enough direct sunlight (at least three hours) to perform necessary photosynthesis processes. Again, soil composition heavily influences the growth rate and development of garlic bulbs. When garlic receives only indirect sunlight, the soil should be richly fertilized and have an appropriate pH level maintained throughout all growing seasons.
- Garlic can grow in indirect sunlight as long as it receives at least 3 hours of direct sunlight daily.
- Garlic will not grow if it receives only indirect sunlight.
When plants receive indirect sunlight, that means they are receiving sunlight that isn’t landing squarely on their leaves, flowers, stems, etc. Instead, indirect sunlight is landing on something else first, bouncing off that surface, and then landing on a plant. Very few plants can grow in indirect sunlight alone. Most need at least a few hours of direct sun each day, and this includes garlic.
Can You Grow Garlic in Shade?
Garlic should not be grown in shade. To produce a large head of garlic with big, flavorful garlic cloves, make sure your plants are not in a shady spot. If your garlic receives partial shade during the day, it will produce smaller individual cloves of garlic.
- Garlic growth is weakened by shade.
- Grow garlic in full sun without any shade in order to get the biggest head of garlic per plant.
Garlic needs full sun or partial sunlight to provide healthy, edible garlic bulbs. Also, remember that garlic is a “heavy feeder”, meaning it needs plenty of organic fertilizer to avoid being starved. Garlic should also be watered regularly to keep the soil slightly moist and promote the largest cloves. Gardeners can stop watering their garlic plants about two weeks before harvesting garlic since bulbs are no longer ripening and extracting water from the soil.
What Happens if Garlic Doesn’t Get Enough Sun?
Lack of sufficient daily sunlight may cause unhealthy garlic plants to be highly susceptible to any one of the following diseases:
A fungal disease common to garlic and onion, pink root causes roots to turn pink then dark red before shriveling and dying.
A pathogen responsible for garlic leaf and root decay, white rot is typically caused by planting infected seed cloves. Garlic plants subjected to minimal sunlight and poor soil conditions are vulnerable to developing white rot if seed cloves contain the pathogen.
Mainly a disease affecting garlic, onions, and leeks, rust (also called “leek rust”) produces red to dull orange lesions on older leaves first before it spreads to newer leaves. Severe rust infections will reduce the quality and size of garlic bulbs.
Garlic affected by botrytis rot will be mottled with a fuzzy, grayish fungal growth that is accompanied by dark, sunken, water-soaked stems. Botrytis rot usually emerges during or after a period of warm, humid weather.
Bottom (Basal) Rot
Although the fusarium fungal pathogen lives in all types of soils, it can be a secondary attacker of garlic plants that have been compromised by lack of sunlight, insects, or poor soil pH. Signs of bottom rot resemble signs of white rot, although bottom rot is not as fatal to garlic plants as white rot.
Can Garlic Get Too Much Sun?
Since garlic flourishes in six to eight hours of direct sunlight per day, it really can’t get too much sun. As long as garlic plants are given sufficient water and have been planted in the right type of soil, they’ll absorb as much sunlight as they receive without suffering any adverse effects.
- Garlic does not suffer from too much sun exposure.
- Provide garlic with sufficient water to prevent sun and heat from drying out your plants.
Garlic planted in a sunny location should be watered every 7 to 10 days if no rainfall occurs. Give garlic enough water so that the soil is moistened to one inch in depth. No watering is needed during the winter months because a mulch covering over garlic prevents dehydration. Newly sprouting garlic requires watering that soaks the top 3 inches (8 cm) of the soil.
How Much Sunlight Should Garlic Get?
Garlic will grow in full or partial sunlight as long as soil conditions are optimal. Studies involving garlic cultivation have found that organic fertilizers, such as humic acid, increase and improve the quality and yield of garlic bulb crops. This is especially important if your garlic patch receives less than 6 hours of direct sunlight each day.