Undercrop Guide

What Is Undercropping

Undercropping is the agricultural technique of growing one crop below or underneath another. It is a subset of intercropping - the technique utilizing two or more species grown together to forma polyculture.

A few examples of this to give you a visual:

• Carrots growing underneath broccoli
• Radishes growing underneath cilantro
• Alfalfa growing underneath tomatoes & cucumbers
• Amaranth growing underneath corn
• Pumpkins growing underneath a peach tree

Why Use an Undercrop?

Undercropping With Cover Crops

My personal favorite technique, using cover crops as your undercrop.

If you can get this right, you can combine all the benefits of a cover crop cycle with a main crop, in a small space, while maximizing your land usage.

I love growing nitrogen-fixing cover crops at the foot of main crops, simultaneously taking and adding nitrogen. These cover crops are chopped and dropped every couple weeks throughout the season to provide constant mulch and to add that nitrogen to the soil.

You're setting yourself up with the nitrogen that will power future grow cycles all while still growing any of the main crops you want.

This all hinges upon choosing low-growing cover crops and/or intentionally trimming your cover crops low while letting main crops grow tall.

Cover Crop Growth Habits

The growth habit of your covers makes a big difference here if you'd like to grow it underneath your main crops. You'll want to consider how your main crops grow and whether a chosen cover will work well as an undercrop with it.

Managing Covers Under Main Crops

Undercropping Cover Crops

Some cover crops such as clover have a wonderfully low growth habit. This allows them to carpet the soil while not crowding out any tall plants.

Utilizing clover as an undercrop below your main crops is a great way to add nitrogen to the soil without sacrificing a season to cover crops alone.

Cover Crops With Low Growth Habits

The following is the list of cover crops which will remain short enough to be grown underneath the main crops:

• Clover
• Oilseed Radish (commonly Daikon)
• Flax
• Buckwheat
• Alfalfa
  • will out-compete short crops, but can undercrop taller crops or be pruned short
• Vetch
  • will out-compete short crops, but can undercrop taller crops or be pruned short

It's worth noting that some of these *may* get too tall at times.

Vetch may climb partially up main crops.

I love trimming cover crops down below main crops, as they provide a quick and constant source of chop & drop to feed my soil microbiome.