Monday, April 27, 2009

Asparagus Does Not Like Waterlogged Soils

Asparagus is a very interesting and exciting perennial vegetable crop. I have to admit, everything I learn about asparagus is new to me, but luckily we have some great asparagus growers here in WNC. Danny McConnell, a grower in Henderson County, was featured prominently in a recent article, Dana Farmer Spears New Market, in the Times-News.

On a recent visit to another area farm, we noticed that the asparagus crowns were wilting (see pictures below). The wilting spears were also hollowed out. The first thing that we noticed was the lack of internal drainage of the soil where the crowns were planted. The soil was very moist and from the reading I had done, I remembered that asparagus prefers well-drained soils.

Because of the wilting, I was tipped off that there was something going on underground. Upon digging into the soil, we noticed it was still very wet from the recent rains. There were also pillbugs or sowbugs present signaling very moist conditions. Luckily, at this point, the roots did not appear brown or unhealthy.

In order to learn more about this problem, I contacted another extension agent in Granville and Person Counties, Carl Cantaluppi (yes, indeed another Italian-American ag agent in NC- its an underground organization. I've already said too much). Carl has a lot of experience with asparagus and even authored and excellent factsheet from Ohio State Univeristy, Growing Asparagus in the Home Garden. After I explained the situation, Carl knew the cause.

The spears were in fact wilting because of the waterlogged soils. Excess nitrogen will only exacerbate the problem. Waterlogged soils will also lead to Fusarium root rot.

So what could this grower do?
  • Let the soil dry out, the plants will recover slightly
  • Do not replant the established crowns because they will become quite stressed resulting in crown death
  • For the recently planted (within the last month) crowns, transplant into raised beds or amend the soil with sand to improve the soil's internal drainage
Ultimately, because asparagus is a long-lived perennial, starting out with the correct soil conditions is key. Get your soil tested to determine phosphorous and potassium needs and to determine the pH. Asparagus requires a soil pH or 6.5-7.5.

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