Tomatoes are one of the most popular crops grown by home gardeners. The Brandywine tomato is often credited with starting the entire grow-it-yourself movement thanks to its superior flavor.
But unfortunately, growing tomatoes is not as easy as many other vegetables. So, in this article, I’ll share our method for growing tomatoes in raised beds. These plants do require a bit more effort than other crops, but the payoff is always worth it.
From Seed or Store Bought Plants?
The first question is whether you want to start your plants from seed or store bought plants. We usually do a mix of both, starting more unique varieties from seed, and then purchasing a few hybrids from the nursery.
This guide will begin at the point of transplanting into the raised beds. If you need to learn how to start tomatoes from seed, read this guide.
However, a quick note on timing. Tomato plants are usually ready for transplant around 4-6 weeks after sowing the seeds. So, if you are planting seeds, make sure you time it right to align with the weather in your area.
Preparing Your Raised Beds
Before you go transplanting your tomato seedlings into your raised bed, you should make a few preparations. Namely, the soil likely needs some attention to set the plants up for success.
Preparing the soil
In early spring, about 2-3 weeks before transplanting into the garden, I recommend amending the soil. The best way to do this properly is to get a soil test, which will tell you exactly what your soil needs (and what it doesn’t need).
If you’d rather skip the soil test, you can amend the soil with a slow-release all-purpose fertilizer. We’ve had great results with this brand for many years.
If you have it, compost makes a perfect amendment for all soil types. Apply a 1-2″ layer of finished compost to your soil’s surface, gently scratching it in. Don’t over-do it with the compost, as too much can lead to less blooms later in the year.
When to plant tomatoes outside
With your beds prepped and ready for the incoming tomato plants, you’ll need to watch the overnight temperatures in your area. Wait until the temperatures are consistently above 55°F before transplanting tomatoes outside.
Here in zone 6a, we typically transplant tomatoes outdoors around Memorial Day, or the end of May. It is typically safe to move tomatoes outdoors a few weeks after the last frost date.
If you have protective covering (floating row cover or greenhouse plastic), you can transplanting outside sooner. Just make sure to watch the overnight temperatures and cover the plants whenever it dips below 55°F.
How To Plant Tomatoes In Raised Beds
Once you’re in the clear weather-wise, you should transplant your tomatoes as soon as possible! The more time they have out in the sun, the better your overall yield will be.
Steps:
- Choose a good location.
Tomatoes thrive in full sun, so ideally your raised beds get plenty of sunshine. More importantly, the tomatoes will grow to be very tall and wide. Make sure each tomato plant has at least 2 feet of space from the next nearest plant.
- Prepare the seedling.
Since we recommend planting tomatoes deep, you may need to remove some of the lower leaves. I like to take off 1 or 2 of the lowest branches, ideally a day before transplanting (though this isn’t required).
- Dig a deep hole.
Dig out a hole that is about 2x the depth of the pot that your tomato is currently in.
- Amend the soil with fertilizer (optional).
Tomatoes are hungry plants, so it doesn’t hurt to add a small handful of all purpose fertilizer and/or bone meal to the planting hole.
- Remove the seedling from its pot.
Gently squeeze the tomato plant’s container to release it. You should see a nice, healthy root system filling out the soil. Don’t worry about teasing the roots apart, as this may do more harm than good.
- Plant the tomato plant deep.
Place the rootball into the pre-dug hole an align it upright. Backfill with the surrounding soil, burying part of the stem underground. This buried stem will quickly grow roots, helping the plant establish faster.
- Create a circle trench around the stem.
I like to dig out a shallow, circular trench around the base of each tomato plant. This helps water collect and drain down into the root-zone. Otherwise, the water may run away from the plants as your irrigate.
- Mulch the plant.
Optional but recommended is mulching your tomatoes. Straw, shredded leaves, or pine needles all work great to help retain soil moisture, prevent soil splashing, and suppress weeds.
- Water deeply and thoroughly.
The final step is to water your seedling into its new raised bed home. Water slowly and thoroughly to ensure the roots are well-saturated. This will help the plant establish properly over the coming weeks.
Tomato Cages
With your tomatoes planted, there are a few additional steps you can (and should) take at this point. While the plants are still small and manageable, I recommend adding support and removing lower leaves.
Tomatoes grow to be huge plants. Even if you’re growing small cherry tomatoes, the plants themselves can be massive. So, it is important to add support early on before they are too big.
Try to find the largest tomato cage you can from the store (these tend to be better suited for peppers than tomatoes). If you’re feeling crafty, you can make a sturdier version of a tomato cage using cattle panels.
As the tomatoes grow, the cages will keep the plants upright. The braces will also help support heavy branches as the fruits begin to form. This is especially important if you are growing larger tomato types.
Companion Planting With Tomatoes
Tomatoes can benefit from having other types of plants nearby in your raised bed. There are classic pairings, such as basil, but my favorite companions are flowers.
Flowers may not always be edible (though many are!), but they are an invaluable gardening tool. They attract beneficial insects, such as pollinators and predatory insects.
| Good companions | Bad companions |
|---|---|
| Basil | Fennel |
| Alyssum | Corn |
| Alliums (garlic, onions, etc.) | Brassicas |
| Cosmos | Potatoes |
| Zinnias | |
| Nasturtiums | |
| Lettuce | |
| Tomatoes! |
With a diverse range of crops planted with your tomatoes, your plants will have greater resilience to pests and disease. While it may be tempting to group your tomatoes all in one raised bed, it is better to inter-crop with many other plants.
This can be tricky to plan, so consider trying one of our raised bed plans.
Watering Tomatoes in Raised Beds
Once your plants are established, one of the most difficult tasks is watering properly. It turns out that it is easy to over-water tomato plants. But, it is also easy to under-water. So, how much water do tomato plants need in raised beds?
In short, tomato plants need even and consistent watering. Try to water once per week, deeply and thoroughly. Less-frequent, deep watering is much better than frequent, shallow watering. To avoid spreading disease, always water at the base of the plant, not over the tops of the leaves.
Water slowly and for a longer duration to ensure that the root system is well-saturated. It is important that the water penetrates deeply and doesn’t just flow away from your raised bed. Watering too fast may cause this.
It can help to water once, take a short break (10-15 minutes), and then water again. This intermittent watering gives the water time to seep into the soil instead of just flowing like a river.
Drip irrigation is a great way to ensure deep, slow watering. The emitters are rated to release a certain amount of water per hour. They can be used with a hose timer to water evenly, every time.
Blossom end rot
Believe it or not, blossom end rot is most often caused by improper watering. Namely, allowing your plants to become overly dry, followed by a heavy watering. Protect your plants from blossom end rot and cracked fruits by keeping the soil evenly moist.
Pruning Tomatoes (Is It Necessary?)
Pruning is what makes growing tomatoes a bit more challenging than other crops. However, it is important if you want healthy plants that produce optimal yields.
Pruning indeterminate tomatoes
Chances are, you’re growing indeterminate tomatoes. Check your seed packet or plant tag to see whether your plant is indeterminate or determinate.
Indeterminate plants should be pruned regularly to avoid too many “sucker” branches. Suckers are side shoots that form at nodes. They will steal energy from the main stem and often produce smaller tomatoes than those on the main stem.
Prune away suckers regularly, keeping 2-3 main leader branches. Be sure not to prune the flowering trusses, as these also form at nodes. Let the suckers get about 2-3 inches long before pruning to be sure they are not fruit-bearing.
The exception is if you are growing indeterminate cherry tomatoes. In this case, we don’t recommend pruning the suckers, as they can add to the overall yield. Instead, prune away any sprawling or dense foliage to maintain good airflow through the plants.
Pruning determinate tomatoes
If you happen to be growing determinate tomatoes, then pruning is a bit different. Instead of pruning suckers, you want to prune away some of the leaf branches. Suckers should be left alone to produce a larger crop.
As the plants grow larger, look for excessively dense foliage and prune away 1-3 branches every couple weeks. The goal is to improve air circulation through the bushy plants. This helps stop the spread of disease, which can be a major issue later in the season.
Bottom pruning
As the season goes on, I highly recommend removing lower foliage from your tomatoes. This helps avoid soil from splashing up onto the leaves which can lead to disease.
Bottom pruning also helps save energy and ripen lower fruits more quickly. Most importantly, it provides good airflow around the base of your tomato plants, helping to prevent disease.
Fertilizing Tomatoes
Another important part of growing bountiful tomato plants in raised beds it fertilizing. If you prepared your soil properly in the early spring, then you may not need to do much.
However, if your plants seem to be slowing down (sparse growth, yellowing foliage, etc.), then you may want to top-dress your tomatoes.
If you are seeing signs of nutrient deficiency, I recommend a liquid fertilizer, such as seaweed fertilizer. These nutrients will instantly feed your plants.
In addition, add a top-dressing of slow release fertilizer to carry the tomatoes through to frost. Avoid fertilizers with too much nitrogen, as this can lead to abundant green growth, at the expense of blooms and fruits.
Is Epsom salt good for tomatoes?
It is common advice to add epsom salt to your tomato plants. However, it is largely a myth that this actually helps the plants.
Epsom salt is just magnesium sulfate (water-soluble magnesium). Unless your soil needs magnesium (as suggested by a proper soil test), then adding magnesium is not going to help your plants.
In fact, adding magnesium when it isn’t needed may cause issues with calcium uptake. So, unless you’re sure, don’t bother using epsom salts in your raised beds!
When to Harvest Tomatoes
After a few months of caring for your tomatoes, you should start to see fruits. All tomatoes start off green and eventually turn red, yellow, or orange when ripe.
The best time to harvest tomatoes is when they are mostly finished changing color. The tomatoes will finish ripening off of the plant in a warm location like a window-sill or on the kitchen countertop.
If you wait too long before harvesting, the tomatoes become more vulnerable to pests and hungry animals. They are also very susceptible to cracking during heavy rain or irrigation.
So, for the best flavor, pick your tomatoes promptly when they are almost done changing color.
Pests and Disease Common Among Tomatoes
Unfortunately, tomatoes are common targets for pests and disease. Early and late blight, septoria leaf spot, tobamoviruses, aphids, white flies, thrips, and more.
If you follow the tips in this article, you can control many of these pressures naturally. Mulching right after transplanting, bottom pruning, and properly spacing your tomatoes in the garden makes all the difference.
However, if you notice a serious issue, you may need to intervene.
Pests
My best advice against pests is to plant flowers. Alyssum is my personal favorite companion for the entire veggie garden, as they attract hover flies. These feed of aphids and other sap-sucking pests.
If pests get out of control, you can introduce your own predatory insects. Or, you can spray your plants with an insecticide. Do this at night, and try to avoid spraying opened flowers.
Disease
For disease, your best bet is to avoid it all together. Diseases can cause a variety of problems, from brown leaves, to spots on fruits, and even dying plants. Planting disease-resistant tomato types helps tremendously, especially if you know which diseases are a problem near you.
The other major factor against disease airflow. Prune excessive, dense foliage throughout the year. You should be able to see through your plant from all angles.
Finally, never water your tomatoes over the top. Water on the leaves will help spread any pathogens that may be on your plants. Always water at the base of the plants if possible.
I hope this article helps you with growing tomatoes in raised beds. These plants are some of our favorites to watch grow every season. They offer impressive growth, and rewarding results!