Spacing Vegetables Correctly in Your Garden Plan

Vegetable spacing is one of the least glamorous aspects of garden planning but one of the most consequential. Crowded plants compete for light, water, and nutrients, produce smaller harvests, and are more prone to fungal diseases that spread easily in still, humid air between dense foliage. Conversely, plants spaced too far apart waste ground and allow weeds to dominate the gaps. Getting spacing right also makes rotation planning more accurate — you can calculate how many plants fit each bed and whether your available space is genuinely sufficient for each group.

Spacing Guidelines for the Main Crop Groups

Brassicas need the most generous spacing. Cabbages and broccoli should be planted 45 to 60 centimetres apart in rows 60 centimetres apart. Brussels sprouts need even more room: 75 centimetres each way for a full season of growth. Kale is slightly more flexible at 45 to 60 centimetres square. Potatoes are planted in rows 60 to 75 centimetres apart with tubers 30 to 40 centimetres apart within the row. Onions and shallots are much more compact: sets planted 10 centimetres apart in rows 25 centimetres apart. Garlic is typically planted 15 centimetres apart in rows 25 to 30 centimetres apart. Peas and beans in double rows 20 centimetres apart, with rows 60 centimetres from each other to allow for support structures.

How Spacing Affects Disease Risk

Spacing is directly linked to disease management, particularly for foliar and fungal diseases. Brassicas planted too close together develop brassica downy mildew, grey mould, and ring spot more readily because the dense canopy prevents airflow. Leeks and onions planted in tight rows are more vulnerable to leek rust and neck rot because moisture cannot evaporate from the foliage as quickly. Giving plants room to dry after rain and dew is one of the simplest ways to reduce disease pressure without any chemical inputs. When planning your rotation beds, always calculate spacing requirements and be honest about how many plants will actually fit rather than squeezing in more than the recommended number.

Block Planting Versus Row Planting

Most traditional spacing advice assumes row planting — single lines of plants separated by paths. Block planting (also called equidistant spacing) places plants at the same distance in all directions, producing a more efficient use of bed space because there are no wide paths between narrow rows. Block-planted beds typically produce 20 to 30 percent more yield per square metre than row-planted equivalents. For rotation purposes, block planting works well in raised beds where the entire bed is one growing group — you simply move the whole block to the next bed the following year. The key is to stick to the same spacing distance in all directions rather than simply pushing rows closer together, which creates the crowding problems described above.

Using Spacing to Estimate Bed Requirements

When planning how many beds each rotation group needs, work backwards from spacing requirements. Calculate how many plants of each type you want to harvest, then calculate the bed area required at the correct spacing. For example, if you want 30 cabbages at 45 centimetres square spacing, you need approximately 6 square metres of brassica bed. If your brassica bed is only 3 square metres, you will need to either reduce the number of cabbages or accept that a portion of the brassica bed will hold smaller crops such as kale or radishes at a closer spacing. This calculation step prevents the common problem of planning a rotation that looks fine on paper but leaves you short of room for the groups that need the most space.