Activity 5.2: Stacking in Time and Space

This activity builds upon your research in Activity 5.1: Tree Research so you must do that activity first. 

The principle of stacking in time and space is a perspective that may prove to be one of the most critical in the successful implementation of agroforestry systems. This principle encourages a design that maximizes a range of yield times (annual vs. perennial vs. long term yields) and makes efficient use of vertical and horizontal planting space in the forest.

Here is an example of a Black Walnut polyculture that both spreads yields out over time (50 years to 10 years to 5 years to 1 year) and also stacks vegetation in the understory to maximize production per square foot. Note: All the species have expressed tolerance to juglone, which is exuded by the black walnut.

Species Vertical space occupied Years to mature yields
Black Walnut 80 – 100 feet 40 – 50
Paw Paw 15 – 30 feet 5 - 10
Currants 2 – 5 feet 3 – 5
Allium spp. 1  - 2 feet 1 – 5
Stropharia Ground level 1 – 2
Ducks Ground level 1
Ginseng Below ground 8-10 

1) Design a polyculture of trees, annual, and herbaceous perennial crops that meets your personal site goals.

This polyculture could be small enough to fit in a backyard, or it could be stamped across a field in repetition for increased production.

Choose between 3 and 6 species to include in the design. Make sure all your species can tolerate the same environmental conditions. Consider species that allow you to stack in space (vertical and horizontal) and in time (maturity, seasonal yields). 

2) On a letter-sized (8.5 X 11) sheets of paper create a color sketches that shows a top and side view of your polyculture.

3) Complete your assignment by photographing or scanning your color sketches and sharing via this week's Participant Forum: Polyculture and submitting it via this assignment page. You may want to iInclude a few clear and concise sentences clarifying details, comments or concerns about your sketch as necessary.