The Online Gardener's Handbook
Chapter 4: Vegetables
Table of Contents
- Asparagus Beetles
- Asparagus Rust
- Learn More
In this chapter, a description of various asparagus pests will
be provided along with suggested management options. These management
options will not include the use of pesticides. Some biopesticides
and certain reduced risk pesticides are still available to the homeowner
for controlling weeds and pests in lawns and gardens. For more information,
refer to Chapter 2
of this handbook and the Ministry
of the Environment's website. For suggestions on managing specific
weeds and pests, consult local horticulturalists, Master
Gardeners or your local garden supply centre.
Asparagus beetles occasionally damage both the spear and the fern
stages of plant growth. There are two species of beetles, one orange
with black spots, the other metallic blue-black with 6 yellow spots;
both are about 0.5 cm long. Larvae are olive-green or dark grey,
emerging from dark, bullet-shaped eggs, which are very visible on
the developing spears in late May, early June.
On small plantings, hand pick and destroy beetles. Cut and destroy
any spears when eggs are observed. Wash off eggs, larvae and beetles
with a strong spray of water. Destroy nearby wild asparagus, which
could harbour beetles. Remove dead fern growth.
Asparagus rust appears in the late spring as slightly raised, light
green, oval lesions. They turn creamy-orange and then reddish-brown
and blister as they mature. Severe rust infections stunt growth,
reduce plant vigour and may even kill young shoots.
Plant tolerant varieties. Remove and destroy infested crop residues.
Cut spears below the soil line during harvest. Water in the morning
to allow plants time to dry off before nighttime.