3 × 8 raised bed planting layouts

A 3 × 8 ft bed holds 24 heads of lettuce, 96 spinach plants or 384 carrots if you fill it with one crop, at the spacings Colorado State University Extension gives for raised beds. Most people mix crops: here are four plans drawn to scale, from a salad bed to a kitchen bed with cucumbers, peppers and herbs, with every plant counted.

Salad bed

Greens to cut from spring into early summer, with quick radishes and onions between the slower crops.

8 ft × 3 ft inside, drawn to scale.

6 heads of lettuce12 in apart
8 leaf lettuce plants9 in apart
12 spinach plants6 in apart
8 chard plants9 in apart
36 radishes3 in apart
60 bunching onions3 in apart

Kitchen bed with herbs

Something for most meals: cucumbers on a trellis along the north side, then peppers, basil, leaf lettuce and chives in the sun in front of them.

8 ft × 3 ft inside, drawn to scale; the trellis stands on the north side.

10 trellised cucumbers9 in apart on a trellis
2 pepper plants15 in apart
2 basil plants12 in apart
8 leaf lettuce plants9 in apart
12 chive clumps6 in apart

Tomatoes and peppers

In a narrow bed the tomatoes take one end in a single row, the peppers and onions the rest.

8 ft × 3 ft inside, drawn to scale; the trellis stands on the north side.

2 trellised tomatoes24 in apart on a trellis
4 pepper plants15 in apart
18 onions6 in apart

Roots and onions

Crops that store: carrots, beets, onions and parsnips, with radishes to mark the rows while the carrots come up.

8 ft × 3 ft inside, drawn to scale.

120 carrots3 in apart
18 beets6 in apart
18 onions6 in apart
18 parsnips6 in apart
48 radishes3 in apart

How many plants fit in a 3 × 8 raised bed?

If the whole bed held one crop, at the wider spacing in each of Colorado State University Extension’s ranges:

Crop	Spacing (CSU)	Plants in a 3 × 8 bed
Head lettuce	10 to 12 in each way	24
Leaf lettuce	7 to 9 in each way	40
Spinach	4 to 6 in each way	96
Swiss chard	7 to 9 in each way	40
Kohlrabi	7 to 9 in each way	40
Beets	4 to 6 in each way	96
Onions	4 to 6 in each way (dry onions)	96
Garlic	4 to 6 in each way	96
Leeks	4 to 6 in each way	96
Carrots	2 to 3 in each way	384
Radishes	2 to 3 in each way	384
Bunching onions	2 to 3 in each way	384
Bush beans	4 in apart in rows 12 in apart	72
Peppers	15 in each way	12
Broccoli or cabbage	18 in each way	10
Potatoes	12 by 15 in	16
Tomatoes, trellised	at least 24 in apart in one row	4

How the plants are placed

Colorado State University Extension’s advice for raised beds is to plant with an equal distance between neighbouring plants in both directions, and to start with the wider spacing of each range, closing it up as you gain experience and the soil improves. Every count on this page uses the wider figure.

Plants sit half a spacing in from the walls, the way our plant spacing calculator counts them, so a 4-ft-wide bed takes two rows of broccoli 18 inches apart; CSU fits three by planting nearer the edges. Tomatoes go in one row on a trellis along a long side: put that side to the north and the trellis shades the rest of the bed least.

Before you plant

Most garden crops need at least 10 inches of soil, the University of Georgia Extension says. Filled 10 inches deep, a 3 × 8 ft bed takes 20 cubic feet of soil: 14 bags of 1.5 cubic feet. Soil for a 3 × 8 bed at every depth. The depth guide covers tomatoes and other deep roots.

To start the salad bed early or keep it going into autumn, the hoop cover calculator sizes the hoops and the cover for a 3 × 8 ft bed.

Raised garden bed ideas Plant spacing calculator Hoop cover calculator

Layouts for other bed sizes

2 × 4 ft 2 × 6 ft 2 × 8 ft 3 × 6 ft 4 × 4 ft 4 × 6 ft 4 × 8 ft 4 × 10 ft 4 × 12 ft

References

Block Style Layout in Raised Bed Vegetable Gardens (GardenNotes #713), Colorado State University Extension
Basil in the Garden, Utah State University Extension
How to Grow Chives in Your Garden, Utah State University Extension
Raised Garden Bed Dimensions (Circular 1027-4), University of Georgia Cooperative Extension