As a gardener you’re very much aware of the importance of sunlight for the plant growth, and how low light exposure can impact the yield.
Asparagus takes 2-3 years to be harvested. However, this will pay off with delicious and nutritious shoots year after year.
This means the plant will reside in its initially spot permanently, so you must choose wisely. Right location that gets ample amount of sunlight, adequate amount of water and well-drained soil are essential for good yield.
Do asparagus need full sun to grow? Or can they be grown in partial shade?
Asparagus plant requires 8 hours of direct sunlight to ensure high yield. However, this perennial plant can grow in partial to full shade but you can’t expect high yield.
If you’re growing asparagus in backyard, choose a location that gets morning sunlight for 8 hours and for rest of the day this plant can be in shade.
Also, you shouldn’t plant this vegetable plant next to tree that shade asparagus or compete for nutrients.
To understand in detail we must know its temperature and light requirements.
Asparagus Sunlight Requirements
If grown with proper care, asparagus crown can last for about 15 years.
Proper care doesn’t mean the plant is alive; it should be healthy to be harvested every year.
At optimal day temperature between 75 F to 85 F asparagus spear grows 3-6 inches per day. At night time the temperature can drop to 60 F to 70 F.
However, higher than 85F or lower than 55F will result in slowing of root and shoot growth. Higher temperatures results in poor quality yield with premature shoots.
Check weather conditions in your region and note that ideal temperature for growing asparagus is 75F to 85F. (Source)
Asparagus plant does well in full sun; low sun exposure will result in weak and thin spears. Sometimes, the asparagus may turn white due to no sun exposure.
Choose a spot where it gets eight hours of morning direct sunlight. Also, ensure to water the plant in early hours. So, the plant gets essential substances to produce its food.
How Much Sunlight Does Asparagus Need?
Gardening experts say asparagus plant does well in full sun, but it can tolerate partial shade as long as it gets 8 hours of sun exposure.
As the asparagus plant grows taller, it can shade other near-by plants. Remember this while planting.
Plant needs sun exposure for yielding and to protect itself from pests.
Low sunlight exposure results in white asparagus due absence of chlorophyll. Though they are edible, it has less fiber content compared to green asparagus.
If your garden area is shaded part of the day, even then you can try planting asparagus. Just make sure the plant gets required amount of sunlight.
But, you must ensure that the temperature isn’t more than 85F as mentioned above. Else, higher temperature will damage the plant’s yield.
If you see the plant is producing premature shoots, then this is the sign of high temperature.
To protect your plant from hot and longer exposure towards rises temperature, you can mulch using hay grass. (Source) Water asparagus plant regularly to prevent underwatering issue.
Asparagus does well in hot days and cool nights.
But, if the night temperature falls below 55 F, the shoots produced will be discolored.
According to this research, prolonged cold temperatures will damage the spear and crown.
If the temperature is below 20F, then the plant will eventually die.
Signs of Insufficient Sunlight for Asparagus
Due to lack of sunlight, the plant doesn’t produce chlorophyll. So, the plant turns yellow and then white. White asparagus is the major sign of insufficient sunlight.
Apart from this the yield quality and quantity will be compromised with low sun exposure.
Adequate amount of sunlight is very essential for the plant growth. Though you can make-up for lack of natural sunlight by using grow lights, it might not be easy in case of asparagus.
Growing asparagus indoors in containers isn’t a good choice. Because of the adult asparagus reaches 5 feet tall and it takes 3 years to start producing yield. Along with full sun, it required adequate space. (Source)
Also Read: How to Grow Asparagus from Cuttings?
How to Grow Asparagus in Partial Shade?
This edible perennial plant can thrive in full sun, but can tolerate partial shade.
However, for the quality yield you must ensure the plant gets at-least 6-8 hours of sun exposure.
Dappled shaded part in your garden can help you to grow asparagus.
Plant Spot Selection
Choose location that is free from weed and that gets ample amount of sunlight. As asparagus grow several feet tall, it will shade neighboring plants.
If you’re living tropical regions, then planting in shade will save asparagus plant from hot summer days.
Asparagus plant bed must be towards the edge of the garden, where the plant doesn’t get disturbed by other gardening activity.
Also Read: How Deep to Plant Tomato Seedlings?
Asparagus does well in sandy soil. You can opt for well drained soil mixture that includes sand, soil and compost.
Preferred soil pH to grow this plant is 6.5 (neutral to slightly acidic).
While planting loosen the soil by 12 to 15 inches deep, so that root system grows easily.
Raised bed or garden soil must be well drained and shouldn’t lock water.
Along with using compost while planting, you must fertilize the plant in growing season.
Use balanced organic fertilizer to enrich the soil with required nutrients.
Check this out: Is Bone Meal Good for Tomatoes?
Adequate watering in growing season will help the plant to thrive.
Often new gardeners may end overwatering or underwatering the plant.
Touch the soil for moisture. Don’t water if it’s wet. If the soil is bone dry, then you must water immediately.
Drooping and yellowing are signs of inadequate watering.
Must Read: Should I Cut Off Yellow Cucumber Leaves?
Use straw or hay grass mulch around the plant to lock moisture and to protect from hot summer.
When you see the mulch is decomposed into the soil, replace with new straw mulch.
Start harvesting after 2 years of planting crowns to allow the roots to grow firm.
Use sharp knife to harvest 7 inch long spear.
If the diameter of spear is less than 3/8 inch, then stop harvesting.
Varieties of Asparagus
Recommended asparagus include male and female asparagus.
Female asparagus plant produce berries, whereas male asparagus don’t produce expend berries. So, male asparagus grows 3 times more productive than its female plants.
According to weather conditions in your region, you can opt for the best asparagus.
- In warmer regions, heat tolerant varieties like Apollo and UC-157 are preferred.
- Guelph Millennium asparagus variety does well in colder climates.
- Other varieties like Jersey Giant, Jersey King, and Jersey knight are male asparagus that does well in hardiness zone 4 to 6.
Can you grow asparagus in full shade?
Yes, but you’ll not love the harvest. Growing in no sun will result less fruitful yield.
How much sunlight does asparagus need? The bottom line is, this perennial plant does well in full sun and in partial shade but it must get adequate sunlight for about 8 hours.
Low sunlight will impact the harvest and result in poor quality.