Soil preparation

Asked April 15, 2020, 9:55 PM EDT

I have a 1/4 acre I would like to plant shallots and garlic on in fall

the area is covered with grass, not a lot of invasive weeds, a few. Soil test show acidic soil 6-6.2, nitrogen depleted

My Plan:
1) cover the entire area with tarps
2)in 4 months remove tarp and till the dead grass into the soil
3)add cow manure for nitrogen,
4)till again, and create raised rows with wood chips between
5)plant garlic and shallots in late October

I live in SE Portland, I am near sea level

Does this sound like a reasonable plan? What would you suggest?
Stephen Ingram

Multnomah County Oregon

1 Response

You have a very well thought out plan.

The OSU Oregon Vegetable Shallot webpage suggest a fall planting date of September 15 for a mid-June harvest. Garlic can be planted between September and November.

Here is the OSU Shallot page:
https://horticulture.oregonstate.edu/oregon-vegetables/shallots-0

Here is the OSU Garlic page:
https://horticulture.oregonstate.edu/oregon-vegetables/garlic-1

Will the cow manure be composted or fresh?

You could do a side-dress Nitrogen fertilizer application in March as the plants begin to grow again.

Here are fertilizer recommendation for Shallots:

The following are general recommendations. It is advisable to use a soil test for each field to be planted.

Nitrogen: 50 lb N/acre applied at planting time for fall planted fields. Apply an additional 60-90 lb N/acre in spring, or use that amount for spring planted fields.


Here are the fertilizer recommendations for Garlic:
Apply 50-75 lb N/acre in the fall. Band the fertilizer 4-5 inches below the soil and 1-2 inches to the side of the row together with the needed P (see below). Care in the timing of N applications is important. Witches-brooming is believed to be caused by heavy manuring or extended periods of high soil N levels during the short days of winter, lasting for about one or more months, and starting just before lateral-bud formation.

In the spring, apply 100-175 lb N/acre split into 2 or 3 applications as plants begin to grow. See also the comments in the section on N liquid fertilizers having herbicidal effects: