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If you want to know how to grow tomatoes in a raised bed, just keep these basic tips in mind and you will have an abundance of fresh juicy organic tomatoes to enjoy in summer. This growing season will be your best ever!
This blog post covers all the basics of how to grow tomatoes in raised garden beds, from selecting your plants to harvest.
While gardening in raised beds does differ somewhat from standard garden methods, if you give your tomato plants what they want and need, you will have a fantastic harvest this year. After all plants grow well when they are well tended, and raised bed tomatoes can easily get the best of care.
Location for A Raised Bed Tomato Gardening
The first thing you need to consider when growing tomatoes in a raised bed is selecting a location to plant. Like most vegetables, tomatoes thrive with abundant sun, so make sure you chose a sunny spot for your raised bed garden. Ensure the full sun hours are adequate throughout the growing season by avoiding spots shaded during portions of the day.
Tomatoes can produce the best harvest when placed on a deck, balcony, or patio with at least eight hours of light. Make sure the area you are planting your tomatoes in gets at least 8-10 hours of sunlight per day, has good drainage and is not highly trafficked by pets or children. If you have less light, avoid large-fruited tomatoes which need full sun to mature their fruits. Instead, plant cherry tomatoes which will still crop, although more modestly, when given 4 to 5 hours of daylight.
Soil Quality Control for Tomato Plants
Tomatoes prefer slightly acidic soil (pH 6.0-7.0), so it is important to do a soil test.
Plenty of nutrient rich organic matter in the soil is also essential for vigorous tomato plants.
One of the benefits of growing tomatoes in a raised bed vs. in ground planting is that you have complete control over the soil conditions from day one.
Good drainage and well aerated soil are also key to happy healthy tomato plants.
The soil also needs to be deep, so the raised bed either needs to partially utilize the soil beneath it or be somewhat taller.
Fertilizing Your Tomato Plants
Tomatoes are heavy feeders and appreciate a steady supply of nutrients all season long. With proper fertilizing tomatoes will grow bigger and produce more fruit. Tomato plants require higher nitrogen than most vegetables, so as mentioned above a test your soil is helpful, not just to ensure the PH is acidic for the plants, but to see if soil amendments are needed. I know I need to add bone meal regularly to my raised bed for my tomatoes.
Feed the soil with plenty of compost or aged manure, as well as slow-release organic tomato fertilizers. Apply a liquid organic fertilizer like fish emulsion or liquid kelp every three to four weeks during the growing season to encourage a generous harvest.
When to Plant Tomatoes in A Raised Garden Bed
Where you live will be the biggest factor in deciding what time of year to plant tomatoes. In general, once danger of frost has passed you can plant. Many wait a little longer and honestly, I have seen little difference in the time I get fruit whether I plant as soon as I can or wait an extra week or two. Your local gardening store can help you to determine the right time to plant them for your location.
If a freak frost does occur late in the season, simply cover your plants in the early evening before the expected frost event. They should be fine. Cut plastic bottles, leftover bubble wrap from packing materials or even a tented blanket will do.
Another point worth saying is that tomato plants have the lovely ability to form roots all along their stems. Planting each tomato seedling deeply encourages strong, deep-rooted plants. I bury the seedlings half deep in the potting mix, removing any leaves that would be under the soil.
Spacing The Tomato Plants in Raised Beds
Giving the plants in your tomato garden enough room to grow results in plants that are healthier, more productive, and less prone to diseases. There are four main reasons to aim for well-spaced tomato plants:
Disease prevention. Tomato plants are susceptible to many diseases and if spaced too closely, insufficient air circulation can elevate the risk of disease.
Adequate light. Heat-loving tomato plants need plenty of sunlight for healthy growth. If you crowd seedlings, the plants will cast shade on their neighbors as they grow.
Production. Use up all growing space leaving little open soil for weeds to grow. Spacing tomatoes too far apart means that you’re leaving space for weed growth, losing valuable growing space, and reducing your overall potential harvest.
Less competition. As noted above, air flow is decreased when plants are crowded, but it also means they’re competing for water and nutrients. Give tomato plants enough room to promote good air flow. This can help reduce the occurrence of tomato diseases.
Spacing depends on a few factors including the types of tomatoes you’re growing and how you intend to support the plants. Indeterminate tomatoes that are grown vertically on stakes can be spaced 18 to 24 inches apart. Compact, determinate varieties need 24 inches between plants.
However, spacing your tomato plants in a metal raised bed garden is pretty straightforward. You need one square foot of garden space for each plant. Of course, this assumes you will properly support and prune the plants. If you tend to get distracted midsummer and slack in this area, then give each tomato plant a little extra room. Ideally a 4x4 raised bed (16 square foot) could effectively grow 16 tomato plants though.
Staking and supporting tomato plants
There are so many reasons to support tomato plants. The biggest reason is that it promotes healthier tomato plants. Growing vertically allows better air circulation, less splashing of water onto leaves (therefore fewer occurrences of soil-borne diseases), and more light to reach the plants.
Tomato cages are widely available in garden centers and are fine for determinate, bushy varieties of tomatoes. Indeterminate or vining varieties, on the other hand can grow seven feet tall and require strong support. I like to use an eight-foot tall wooden or fiberglass stake which is inserted beside the seedling at planting time. As it grows, use twine to secure the plant to the stake. You can also buy or DIY tall square tomato cages for indeterminate plants. However, because I grow dozens of plants each season, these aren’t practical, easy to store, or economically feasible for me.
Just as with an in-ground garden, tomatoes in a raised bed will require some training and support. Keeping the plants off the ground not only assists in avoiding pests and disease, it also makes much better use of the confined gardening space.