How to Grow Asparagus From Seed
Asparagus is one of the favorite vegetables of Spring. This is a vegetable that when picked from the garden and prepared immediately is so far superior from the asparagus purchased from the grocery, you’ll feel like you’ve never had real asparagus before. Asparagus should have a sweet nutty delicate flavor. The longer the time between picking and eating, the sharper the flavor becomes.
Asparagus is actually pretty easy to grow from seed or from the rootstock, but there are some considerations you must take. Your asparagus bed will be a permanent feature of your garden for years. Asparagus plants produce abundantly for 15 to 25 years, but it will be two to three years before you can grow a full harvest. Let’s talk about how that affects how you grow your asparagus.
Starting Seeds
Starting asparagus is much the same as starting your usual varieties of organic vegetable seeds. If you have a seed starting kit, use it to start your seeds indoors. You can also use peat pots or other seed-starting containers. Asparagus seed will germinate best if the soil is kept warm. Use bottom heat and keep the temperature in the high 70s. Asparagus takes about three weeks to germinate, so have patience.
Once the seeds have germinated, you can lower the temperature to 60-70 degrees. Move the plants outside once the danger of frost is past. They will need to be hardened off. Plant them 2-3 inches deep in a temporary nursery bed.
Asparagus is monoecious. That means that each plant is either male or female. The female plant wants to put most of its energy into producing seeds. For the highest yields, you want to plant only male asparagus. Some varieties of asparagus, such as Jersey Knight or Jersey Supreme, produce mostly male plants. If you want your asparagus bed to be only male, you will be able to differentiate the plants by the flowers. The flowers are tiny, so you will probably need to use a magnifying glass. The female plants have well developed three-lobe pistils, while the male flower is longer and larger than the female.
Location of the Asparagus Bed
You have one chance to make your asparagus bed the best environment for your plants. They will be growing there for 25 years, so this is very important. Choose your location carefully. Asparagus will tolerate some shade, but there will be a decrease in productivity, as full sun is preferable.
Many gardeners prefer to use raised beds. Asparagus roots do not like standing water, and raised beds eliminate that problem. Raised beds also make it easier to keep your bed weed-free and make it easier for you to pick the asparagus. Having a row of asparagus in a traditional garden is also acceptable, but remember that the asparagus plant will grow quite tall after you’ve finished harvesting and could shade the plants adjacent to it.
Preparing the Asparagus Bed
Once you’ve chosen the site, it’s time to prepare the soil. Asparagus likes lighter soil, so amend your soil if necessary. You want to deep dig the soil and add lots of compost and aged manure. Remove any stones or other debris and remove all weeds. This is very important and will continue to be for the life of your asparagus bed. It is easy to spend a few minutes removing any weeds when the weeds are seedlings. Once the weeds start growing, it is more difficult to remove them without damaging the spear growing underground.
Planting the Asparagus
Dig a trench in the prepared bed 12 inches wide and 6 inches deep. Plant the asparagus about 11/2-2 feet apart and cover with about two inches of soil. Two weeks later, add another 2 inches of soil. Continue periodically adding soil until the soil is mounded over the ground level. Keep the bed well-weeded and water regularly.
Maintenance
A good clean mulch will help keep down the weeds and keep the moisture level of the soil consistent. Fertilize your bed in the Spring and Fall. After harvesting asparagus each year, allow the plants to grow. This gives them time to reenergize the rootstock. Remove the dried plant material in late Fall and clean the bed of any debris that could be harboring pests.
While growing asparagus seeds isn’t difficult, you might not want to wait three years for that first taste. You can cut down the wait by a year if you purchase asparagus plants. Park Seed offers one-year-old bare-root crowns ready to go into their permanent home. Consider planting both and purchase an heirloom variety asparagus seed to start germinating. Then, plant your main crop with one-year-old plants.