Once a site has been selected, the next task should be the actual design of the garden. For this purpose, graph paper works very well to draw and lay out the size, shape, and location of the planting as well as other physical features that will influence the prairie garden such as shrubs, trees, fences, buildings, roads, or ponds (Figure 7 and Figure 8). Also determine the size of the area to be planted in square feet. This will help to determine how many plants are needed for the site and where they should be placed in order to achieve proper balance.
The prairie planting should also be placed at a location away from wooden fences, electrical wiring, gas storage tanks, utility poles, telephone system installations, or other structures that could be harmed by fire if it is used in the management of the site. The wooden structures burn easily, especially utility poles that have been treated with creosote.
Do not use straight lines or blocks in the design of the garden. Straight lines are not found in nature. They will detract from your prairie planting by creating an unnatural border. It is much better to use curves and undulating edges in the prairie planting. Such edges are much more pleasing aesthetically than straight lines. The same concept should also be incorporated into the planting of the prairie plants. Planting in polygons should be adopted instead of rows.
Remember that most prairie grasses are bunch grasses that do not form a sod or turf. They are also warm season plants, meaning that they will grow and flower during the warm summer months unlike Kentucky bluegrass which grows best during the cooler months of the spring and fall. All prairie plants will become larger as they mature, so this needs to be kept in mind as the plant selection takes place.
It is also important to maintain proper balance in the planting. Place tall plants at the sides or back of the garden where they will not obstruct the view of the small ones. If a tall plant is used on one side of the planting, one should be used on the other side to match it.
If the site is going to be managed using prescribed fire, fire breaks should be considered in the planning process. Roads, mowed areas, ponds, or other bodies of water can all be used as firebreaks. It may be necessary to plan for a four to six foot wide firebreak at some location to help contain the fires.
One of the mistakes made in the design and planting of prairie gardens is placing the plants too close together, causing the plants to be crowded and not allowing each plant room to grow and display their graceful forms. Crowded plantings also project a rough, coarse appearance to the visitor of the prairie garden. Individual plants must retain their distinctiveness or gracefully combine with others of the same species in a group.