The spacing of plants is one of most important decision a gardener can make because it determines how the soil volume available to each plant from which to draw on for nutrients and moisture. Intensive gardening allows maximum yield for minimum area using minimum soil volumes but there is a trade off. The soil must be deep and intensely fertile hold moisture. Even then, unless the rains are exactly perfect, irrigation will be necessary. Spacing the plants farther apart allows them to access to greater nutrient and moistures stores.
3 Spacing Types:
1. Semi-intensive- 90% of the yield of intensive but generally sustainable with Good Quantity compost (better with COF addition) and less irrigation.
2. Extensive (with good rain fall)- In North America generally east of the 98 meridian through Dallas, Texas and, barring drought, no irrigation is required and the soil is sustainable with Good Quantity compost. Based on Indian and pioneer techniques, on good rain years, yields are close to semi-intensive levels.
3. Extensive (with little rain)- For soil at least 4 feet deep with good winter snow or rain but little summer rain, like some semi-arid prairie states.
Note: See “Gardening When It Counts” chapter 6 for extensive dry land soil building, wind resistant dust mulching and “fertigation” techniques.
Soloman’s raised beds plant spacing ranges:
Semi-intensive to Extensive (w/ good rain fall) to Extensive (w/ little rain)
Plant Indoor sowing date Garden sowing date Spacing
P= plant spacing
R= row spacing Seed depth
Asparagus
N/A Perennial... plant in early spring P=18-18-18" R=48-60-72" 4-5"
Bush beans N/A April-May P=12-12-18" R=18-24-48" 1 1/2"
Beets N/A April and again in June P=4-4-8" R=18-24-48" 1/2"
Broccoli N/A April-May P=24-36-n/a" R=36-48-n/a" 1/2-1"
Cabbage, early Feb-March
Set out in May April P=16-18-24" R=24-24-36" 1/2"
Cabbage, late Feb-March
Set out in May April P=24-24-36" R=30-36-48" 1/2"
Carrots N/A April and again in July P=2-3-6" R=18-18-36" 1/2"
Corn (sweet) N/A May
every 2 weeks P=10-12-48" R=30-36-48" 1"
Cucumbers N/A May-June P=36-36-48" R=48-48-60"
3-4 plants per mound 1"
Endive April P=12-18-24" R=18-24-36" 1/4"
Garlic Set out in early November P=6-6-8" R=24-24-24" 4"
Kale P=24-24-30" R=24-36-48" 1/2"
Lettuce, looseleaf April P=10-12-n/a" R=18-18-n/a" 1/4"
Muskmelons N/A May P=48-48-48" R=48-72-72"
1-2 plants per mound 1"
Onions, multiplier Set in garden in November Plant onion bulbs in April P=2-2-n/a" R=12-18-n/a" 1/2"
Onions, topset Set in garden in November Plant onion sets in April P=4-4-n/a" R=18-24-n/a” 1/2”
Parsley April P=6-6-10" R=18-24-30” 1/2”
Parsnip April P=3-4-6" R=18-24-36” 1/2”
Peas N/A April every 2 weeks P=2-3-3" R=18-24-24" 1 1/2-2"
Peppers March
Set out in May May P=24-24-36" R=2436-48" 1/2"
Potatoes
N/A April-May P=8-12-16" R=24-36-48" 3-6"
Poc Choi May P=12-12-12" R=18-24-24" 1/2"
Pumpkins N/A May P=24-60-72" R=36-72-96" 3-4"
Radishes April P=1½-2-n/a" R=12-12-n/a" 1/2"
Rhubarb
N/A Perennial P=24-36-48" R=36-48-48" 3/4"
Rutabaga April P=8" R=24-36" 1/2"
Squash, Winter N/A May-June P=48-60-72" R=48-72-96"
3-4 plants per mound 1/2-1"
Tomatoes, indeterminate March Set out in May May P=48-48-60" R=48-60-72" 1/2"
Watermelons N/A May P=48-48-n/a" R=48-72-n/a"
1-2 plants per mound 1"