If you want to plant your raised bed with vegetables in a way that makes the most of it, you need to keep a few things in mind. Here is what you need to know.
Raised beds planted with vegetables and herbs are becoming increasingly popular among amateur gardeners. For one thing, they make gardening much easier on the back, eliminating the need to bend over. On the other hand, the harvest in a raised bed can also be richer than in a classic vegetable patch, but only if a few things are taken into account when planting.
In a nutshell: Planting raised bed
Due to the heat development in the raised bed, planting is possible as early as March. Vegetables can be grown in crop rotation, one after the other, or as a mixed crop, according to their nutrient requirements. Good planning is required when planting so that the vegetable varieties do not shade each other. Regrowing species offer a lot of yield with little space consumption. Raised beds are less well suited for space-consuming crops. A raised bed favors heat-loving vegetable varieties and allows for a longer growing season. Before each spring planting, a raised bed should be filled with soil; after 4 to 5 years, the raised bed filler should be replaced.
When should you plant your raised bed?
You can start planting a raised bed a little earlier than you would in a vegetable patch – the natural heat development makes it possible. If you add a cover to your raised bed, you can even use it as a cold frame as early as February and plant cold-sensitive vegetables such as lettuce. However, you don’t really start in the raised bed until March/April. In the following, you can see when you can plant which vegetables in the raised bed.
- March/April: parsley, lettuces, radishes, radish, arugula, spinach
- Late April: spring onions, leeks, onions
- May: eggplants, cucumbers, peppers, hot peppers, tomatoes, zucchini
- June: broccoli, cauliflower, kohlrabi, carrots
- August: endives, kale, radicchio, autumn salads
- September/October: arugula, celery
Before planting a raised bed: Proper planning
To make the best use of raised beds, different rules apply than in a normal flat bed. The first feature is crop rotation: it divides plants according to their nutrient requirements into heavy feeder, medium feeder and light feeder. In a bed with direct soil contact, the corresponding crops are rotated from year to year by one bed area at a time. In the raised bed, on the other hand, the nutrient consumption of the different species is used one after the other.
The first year belongs to the heavy feeders, because now they can draw from the full. If, for example, you were to start with a medium feeder like spinach in the first year, an undesirable amount of nitrate could accumulate in the green leaves. Light feeder like radishes would sprout heavily instead of forming beautiful tubers. Broad beans may even die from excess nitrogen. Light feeder ideally grow in the raised bed from the third year of cultivation. The time in between belongs to the medium growers.
This list shows which vegetables belong to the heavy, medium and light feeder.
- Heavy feeder: broccoli, cucumbers, potatoes, cabbage, pumpkin, leeks, melon, peppers, tomatoes, zucchini.
- Medium feeder: fennel, chard, carrots, beet, spinach
- Light feeder: beans, peas, lamb’s lettuce, herbs, radishes, onions
Many raised bed beginners, however, want a colorful mix of heavy and light feeder. You want to cultivate lettuce, a few herbs, maybe tomatoes and snack fruits. In this case, a mixed culture is a good idea. The soil requirements of the various crops can be met particularly well in a raised bed. When filling the raised bed, it is up to you how nutritious the top layer of soil should be. For hungry plants, such as cabbage, you can additionally fertilize a part of the bed. If plants like Mediterranean herbs such as thyme and sage like it less lush, you lean the soil in one place minerally, for example, with rock chips. You can also regulate nutrient consumption through plant density. Where more grows together in a small space, the nutrients are used up more quickly.
What can I plant in a raised bed?
Depending on the location of the raised bed, the highest crops are arranged so that they do not shade the others. At the edge there is space for climbing vegetables and nasturtiums. What you direct upwards elsewhere will tend to climb down in the raised bed, as in the case of climbing zucchini. This not only saves space and looks pretty, the airy position also prevents mildew. Regrowing species also offer a lot of yield while taking up little space. For example, only the outer leaves of chard can be harvested. Raised beds are less suitable for space-consuming crops such as cabbage. Fortunately, miniature versions of many vegetables are increasingly available. With snack vegetables and snack fruits, you make the most of the space.
With other species like broad beans, look for compact-growing varieties. With peas, for example, prefer delicacy varieties that can be eaten young with the pod on versus dry peas with a long growing season. To save yourself long growing times, take pre-cultivated plants. Because the area is limited, gaps should be filled quickly. For this purpose, lettuces are suitable because they grow quickly and do not leach the substrate. Suitable gap fillers are also edible flowers such as golden marigold or herbs. The useful beauties not only visually loosen up, but in some cases even protect against plant diseases and pests.
Inside the raised bed, the rotting not only continuously releases nutrients. It also generates heat. This is favorable for tomatoes, peppers and other heat-loving species. It also allows for a longer growing season, such as for Brussels sprouts and kale, which remain standing into the winter. Such vegetables, which stand on the raised bed for several months, form the main crop. Before planting, consider which pre- and post-crops will go well with them. For example, if you have decided on potatoes as the main crop, you could sow lamb’s lettuce as a secondary crop. If you want to plant the crops earlier, you can use a raised bed. This way you can turn the raised bed into a cold frame.
How do I plant a raised bed correctly?
Generally, you plant more densely in a raised bed than in a normal bed. This makes it all the more important that plant neighbors do not compete unnecessarily for space and nutrients. Crops that complement each other are therefore ideal. In terms of space, a row of peas that takes up a lot of height space is better next to a row of carrots that fills the root space than next to bush beans. But interactions also occur at other levels. Some plant species encourage each other, while others inhibit each other. Good and bad neighbors can be found in appropriate tables. As a rule of thumb, the more closely plants are related, the less suitable they are for growing together. Also, avoid growing plants of the same family consecutively away from each other in the same spot. Where there was arugula last year, there should not be another cruciferous plant next year.
Care tips for the raised bed
Every four to five years you need to refill a raised bed. The correct layering in the raised bed is important. Rotting in the lower layers of the raised bed causes the material to sag. Therefore, the top layer should be refilled at the beginning of each season. If you top up with quality planting soil, this usually contains sufficient slow-release fertilizer. Mature compost also contains all the nutrients. However, little nitrogen flows at the beginning, so that heavy feeder usually require additional fertilization in the summer months.
In raised beds, the soil dries out quickly in sunshine, especially at the edges. Because of the elevated position, the sun also shines directly on the walls and heats them up. Pay special attention to sufficient moisture here and water several times a day if necessary during dry periods. If you have the possibility to install automatic watering systems in the raised bed, this has great advantages. Regular water supply shortens the cultivation period. You can also add a layer of mulch to the bed, so the soil does not dry out so fast. Grass clippings with a mix of other plants, e.g. leaves of ashweed are suitable. Another advantage is, that this supports the soil with nutrients. Weeding is usually needed only at the beginning of the season. Since a raised bed is densely planted, unwanted growth is usually well suppressed.