Spacing your vegetables
Raised beds are well suited to growing intensive vegetable crops, because you don’t need paths between the rows of plants. You can plant your vegetables in grids, with sprawling varieties spaced 60 cm apart, average spreaders, 30 cm apart, and compact varieties, 10 to 15 cm apart. Raised beds do well with the square-foot gardening method, in fact.
Using the space efficiently
The following growing techniques will give you the best yields.
Sow seeds of fast-growing vegetables (arugula, mizuna, rapini, bok choy, radishes, turnips, curly lettuce, spinach) every 2 to 4 weeks to obtain several harvests.
Some greens and herbs (kale, chard, parsley, basil) can be cut back every 4 to 6 weeks and harvested all season long.
You can regularly harvest the outer leaves of rosette-forming plants like parsley, lettuces and chard. Just keep the centre of the plant, so that new leaves will continue to appear.
You can also plant fast-growing vegetables (radishes, spinach and other greens) between rows of slower-growing vegetables (cabbage, tomatoes, peppers, cucumbers, squash, etc.).
Maintaining your raised vegetable garden
A raised vegetable garden requires much the same care as a regular vegetable patch, with a few exceptions.
You can often sow seeds or set out seedlings a bit earlier than in a regular vegetable garden, because the soil will warm up and dry more quickly in spring. You can also get a head start by using mulch and row covers.
The soil mixtures used for raised bed gardens tend to dry out faster, so they need to be watered more often. You can use soaker hoses or drip irrigation systems, which give good results and are more efficient than sprinklers. It is also an excellent idea to add mulch to keep the soil cool and moist in summer.