You can’t really start harvesting your asparagus until the third year after it’s been planted. They need that time to establish themselves and build their root systems. This is especially true in the first year of planting when the shoots will probably not be very large.
You can harvest a few spears in the second year of growth. The plants are not fully mature, so let them grow uninterrupted after the initial harvest.
In the third year, he begins to harvest spears the size of a finger and about 8 inches long. You can pluck the spears or cut them with a knife, just below the ground line. If you use a knife, be careful not to also cut the subsequent shoots that are still underground and have not yet penetrated.
Harvest for about four weeks in the third year. In subsequent years, the shoots will continue to emerge from the ground throughout the spring. After you’ve harvested for a couple of months and the weather starts to warm up, the shoots will start to get thinner.
At this point, allow the plants to grow into their mature fern foliage that will feed the roots for next year’s harvest. Asparagus plants can continue to produce for 20 years or more.
Be on the lookout for these pests
The slugs and snails emerging stems are eaten in the spring and can be particularly damaging. Apply slug pellets, use beer traps, or form sandy barriers around plants.
Asparagus beetle larvae, and adults as well, can feed on stems and foliage, weakening plants. Destroy them on the spot. Spray severely affected plants with a suitable natural pesticide.