The Texas climate provides optimal growing conditions for asparagus as the plant thrives in a well-draining soil that has full sunlight. Some Texas soils are acidic and should be tested to verify to pH level and amended before planting. Asparagus spears should not be harvested until the third year of growth to give the plants an opportunity to spread and mature. Each established asparagus plant yields 8 to 12 spears each year.
Test the soil pH to verify it is 6.5 to 7.0, using your soil test kit. Work 2 lbs. of limestone into each 100 square feet of planting area if the pH is below 6.0.
Apply 3 to 4 inches of organic compost and 1/2 lb. of 10-20-10 fertilizer for each 100 square feet of planting area. Work the compost and fertilizer into the soil with a tiller to a depth of 10 inches. Dig a planting trench 10 inches deep and wide and spaced 3 feet apart.
Create a 2-inch-high mound made of half compost and half rotted manure at the bottom of the trench. Set the asparagus crown over the mound so the roots are spread out and the bud is facing upward. Space the plants 15 to 18 inches apart.
Cover the crowns with 2 inches of soil and water well. Continue to add soil over the crowns as they rise upward during the first growing season. Do not cover the asparagus foliage with soil.
Apply a 2-inch layer of organic mulch around the asparagus plants once the trench is completely filled with soil. Peat moss, compost or grass clippings work well for asparagus plants.
Apply 1 inch of supplemental water to the planting bed each week during the growing season when the rainfall is less than 1 inch per week.
Fertilize asparagus plants with ammonium sulfate in the spring before the spears emerge for the first two growing seasons. Apply at a rate of 1/4 lb. for each 100 square feet of planting area. Fertilize 3-year and older plants with 1/2 lb. of ammonium sulfate fertilizer two weeks before harvest is complete instead of at spear emergence.
Cut back asparagus foliage each fall to stimulate additional spear growth. Dig up female plants and replace them with male plants in spring. Female plants have red berries on the foliage.