Southeastern U.S. Vegetable Crop Handbook - 2023 - 43

pact the soil over the newly planted furrows, however; or emergence
of the spears will be severely delayed or reduced. With
good soil moisture, the new spears will break through the soil in
1-2 weeks.
ASPARAGUS PLANTING DATES*
AL North
AL South
AR North
AR South
GA North
GA South
LA
KY East
KY Central
KY West
MS
NC East
NC West
OK
SC East
SC West
TN East
TN West
VA East (coastal)
VA West (mountains)
* After the last frost date for your area of the state.
Planting Dates
2/15-4/15
1/15-3/15
3/1-5/1
2/15-4/1
2/15-4/15
1/15-3/15
3/15-4/15
3/20-4/1
3/15-3/25
3/10-3/20
3/15-4/15
2/15-3/31
4/1-5/31
3/15-4/15
2/1-3/15
3/1-4/15
3/1-3/31
2/25-3/15
3/1-4/15
4/1-5/31
Asparagus Beetle adults chew on ferns reducing photosynthesis.
Any reduction in leaf area causes a loss of stored food
reserves in the crown which is needed for next year's crop. Asparagus
beetles also lay eggs on the spears during harvest and
will result in further damage. During this period, the best way
to manage the beetle is to pick on a timely basis preventing any
spear getting tall and spindly, or allowing them to fern out.
Cercospora Needle Blight is a fungal disease that produces
spores that are wind-blown during the summer when hot and humid.
Cercospora Needle Blight turns the needles of the fern yellow,
then brown, and then they fall off. This severely reduces the photosynthetic
capability of the ferns to manufacture carbohydrates
which are critical for next year's spears. Spray an approved fungicide
to manage Cercospora when reddish-brown, football-shaped
lesions on the fern stalks are first noticed. Research in NC has
demonstrated that spraying once every 7 days from early July
through September, alternating with chlorothalonil and mancozeb
weekly successfully manges Cercospora. Spray once every 7 to 10
days through September. Neglecting to spray might reduce spear
yields up to 40% the following year. Burning the old ferns off instead
of mowing them off and letting the residue remain on the
ground will not prevent Cercospora. Be prepared to spray, regardless
if the old ferns are burned or not.
SPECIAL NOTES FOR PEST MANAGEMENT
WEED MANAGEMENT
Weed control is critical in asparagus. If young plants compete
with weeds, these young plants will become stressed preventing
them from developing good fern growth. Cultivation is not
recommended as there are effective herbicides labeled for use.
Research shows that even the shallowest of cultivations between
asparagus rows cuts and injures roots, predisposing them
to Fusarium root rot fungus that eventually will kill the asparagus.
Apply a pre-emergence and post-emergence herbicide over
the entire field after planting crowns and again after the old fern
growth is mowed each spring. Apply an herbicide three weeks
prior to the emergence of new spears and ferns, so that these
newly emerging spears and fern growth will not compete with
weeds.
Although asparagus is highly salt tolerant and salt can be
used to control weeds, salt will cause severe soil crusting; impeding
water infiltration and percolation. Additionally, salts can
leach horizontally through the soil killing other vegetables adjacent
to the asparagus which are not as salt tolerant.
INSECTS AND DISEASES MANAGEMENT
Cutworms feed on the spear tips at night before emerging from
the soil. They feed on one side of the spear, causing the tip to
bend over. Cutworms can easily be managed with approved insecticides.
2023
Vegetable Crop Handbook for Southeastern United States
Fusarium Crown and Root Rot are the major destructive diseases
of asparagus and the ones that usually take fields out of production.
There are no controls once the plants succumb to these diseases.
The main way to prevent infection is to prevent stresses from occurring
to the plant. These stresses include: overharvesting; low
soil pH; low soil fertility; frost damage to spears; waterlogged soil;
and insect, disease, and weed pressures.
HARVESTING AND STORAGE
During the second year about 3 weeks before the spears emerge,
mow off the dead ferns and spray a tank-mix of an approved
pre-emergence and post-emergence herbicide. Mow the dead
ferns off as close to the ground as possible. Do not cut ferns down
in the fall because the dead ferns will capture moisture in the winter
and will keep the soil temperature about 5 degrees colder than
the temperature of bare soil. This colder soil temperature will
delay spear emergence in the early spring when warm day temperatures
force the growth of new spears in bare soil causing frost
injury on spears.
With air temperatures (<70ºF), harvesting might be done
once every 2 to 3 days, harvesting a 7 " to 9 " tall spear with tight
tips. Air temperatures over 70ºF will cause the tips of the spears
to open up or " fern out " at a shorter height causing fiber development
in the spears making them tough. Fiber development is
determined by the tightness of the spear tip but has no bearing on
spear toughness. Harvesting under warm temperatures forces the
grower to pick shorter, 5 " to 7 " tall spears before the spear tips
fern out. Otherwise, the spears will lack tenderness and quality.
This involves harvesting in the morning and evening of the same
day as spears elongate rapidly under high temperatures.
Asparagus can be harvested safely for 2 weeks during the
second year (the year following initial establishment of crowns),
4 weeks during the third year, 6 weeks during the fourth year,
43
Southeastern U.S. Vegetable Crop Handbook - 2023

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