Some Of the Spears On My Asparaguses Have Developed Poorly. What Is Causing This And Can I Do Anything About It?

Have the spears of your asparaguses grown small in size?

Are there any visible damages and unusual colors on small spears?

Are the small spears girdled or with brown streaks at soil line?

Have the spears turn brown, got soft or dry?

Have the spears turn brown near the soil line?

Are the spears crooked and deformed, some may be brown or scarred and are the leaves chewed or missing?

Was there a mechanical injury done to the asparaguses during cultivation?

Are there any visible 1/4 of an inch long, blue-black beetles on the crops?

Are the spears chewed at the soil line?

Small asparagus spears with no visible damages are caused by low soil fertility or by overharvesting. Add lots of compost into the soil as asparagus loves nutrient-rich soils. Harvest lightly during the first few years of growing asparaguses so plants can develop strong roots.

Small girdled spears or spears with brown streaks at soil line are caused by insects Asparagus miners. Larvae are small, white maggots and adults are small black flies. Infested spears should be destroyed to control miners' numbers.

Small spears with large lesions or at the soil surface are caused by Fusarium wilt. Leaves may turn yellow and the whole plant will die. There is no cure for Fusarium wilt, so the infected plants should be destroyed. Do not plant new asparaguses or any susceptible plants to Fusarium wilt in the same spot for several years.

Freeze injury causes spears to turn brown, some may get soft, wither and dry up. Cut and discard damaged spears. Cover plants with mulch during frosty nights.

Most likely cause for this is a fungal disease - Crown rot. The disease can't be cured so remove and destroy all diseased plants, including their roots. You can prevent crown rot by planting asparaguses in a raised bed and maintaining good soil drainage. Soil pH should also be above 6.0.

If the plants have been damaged during cultivation they will not develop properly and may not develop foliage. Be careful when cultivating as asparaguses can be damaged easily.

Asparagus beetles are a common pest on asparagus crops. They are most active during colder weather. Apply a commercial pyrethrin spray or dust to control beetles. Fertilize soil to encourage new leaf growth.

Asparagus fern caterpillar is a 1.5 inches long caterpillar that feeds on the asparaguses leaves. To control it pick them by hand and dispose off them. Spraying with BTK insecticide will also remove them from your crops.

Cutworms cause spears to be chewed at the soil line. These caterpillars can be 1-2 inches long, brown or gray. They feed at night and during the day, they are hidden below the soil surface. Control them by introducing parasitic nematodes to the ground. Using diatomaceous earth around your plants can also encourage them to leave your garden and find some other feeding ground.

Excessive heat can cause asparagus spears to bract open prematurely. Harvest spears daily when they are 8 inches high, especially when temperatures are above 95°F.