Growing Tomatoes

Tomatoes have a minor reputation for stubbornness but have no fear! You’ve come to the right place to learn how to start growing tomatoes in your own backyard! We have broken down the tomato growing guide into sections to better help you find the information you are looking for. Whether you want to know the best time of year to plant your seeds, or the best way to prevent pests – we’ve got you covered.

Start Growing Tomatoes

Remember as with any crop, you’ll want to rotate where you grow your tomatoes throughout your garden each season. “You want to avoid growing tomatoes – or similar crops such as peppers, eggplant, potatoes, tomatillos, ground cherries, etc. – in the same place two years in a row,” says Common Sense Home. This helps keep your soil more fertile, and helps you learn more about your growing space.

One way to make this more convenient is to build raised beds. This also helps with drainage, which is especially beneficial with a crop like tomatoes, which are prone to rot. While you do not have to plant your tomatoes in a raised bed, keep in mind that it bears many benefits. Planning out your garden, including the type of beds you intend to utilize, is ultimately the first step to growing healthy plants.

When and Where You Should Grow Tomatoes

Tomatoes like sunlight.

So, the first consideration should be your type of tomato and its particular sunlight needs. If you are growing cherry tomatoes, for example, you can get away with a minimum of six hours of sunlight daily.

For other types of tomatoes, you will want to consult the tag on the plant or the directions on the seed packet. For the most plump varieties, ideally you’ll want to aim for upwards of ten hours of sunlight per day during summertime.

Secondly, you want to ensure that you wait until well after the last frost to plant your tomato transplants outdoors. You can consult this guide and obviously follow your local weather patterns, but err on the side of caution. Your tomato plants will be relatively fragile once first transplanted and each hair on the stem will be creating part of a delicate root system. The plant will not be able to sustain a cold snap soon after transplant.

Usually, this means your seed should be started indoors in late winter to early spring. You should begin to harden off your transplants roughly eight weeks later. This means moving them outside to cool weather for about an hour each day to help them acclimate.

Additionally, you may also gently run your hand over the plants occasionally to help simulate wind. This will help strengthen the roots and stems, but be careful, as the young plants are still quite fragile.

Once early spring arrives, transplants can be moved to the garden. Then, you can start looking for fruit to harvest either all at once or throughout the summer season up until frost. Although, this is heavily dependent on whether your plant is a determinate or an indeterminate variety.

Understanding Seed Germination for Tomatoes

Tomatoes are a sprawling vine when left to grow undisturbed. Due to this, it is important to recognize the necessity of a tomato trellis, cage or stake placed immediately upon transplant. Attempting to place these implements after your plant has begun its root formation will disturb and likely sever some of its vital roots. Placement of your support device is up to you but bear in mind the nature of your plant and likely wind directions, as well as whether you can make use of any existing structures to help block wind or support the plant or trellis.

When we begin our transplants, we want to make sure to bury about 75% of the plant under the soil. To do so, you bury to the bottom-most set of true leaves. You can clip off any baby leaves that are in the way. Each tiny hair on the tomato stem is going to become a root, so the more stem buried underground, the stronger and healthier your tomato plant will be.

Also, you may hang your tomato plant upside down, but be sure to invest in a strong planter and hook system as your fully grown plant will be quite heavy, especially once it begins bearing fruit.

Determinate tomato varieties tend to be smaller plants. If you are interested in indoor growing, we recommend a determinate variety as they will only grow to a certain, determined point, and then their roots will extend no further. They bear all of their fruit over the course of about two weeks and then begin to die off. Many will still require support, and every plant will have its own size expectations.

Be sure to check the tag or seed packet when you make your purchase to ensure you have the space required. If your space is truly limited, you may want to look in growing a dwarf” variety of the tomato plant.

On the other hand, indeterminate tomato varieties will grow as large as they are able, provided they are properly cared for. They are not genetically programmed to stop growing at any particular point. These plants tend to become quite sprawling and are best grown outdoors with a cage or trellis for support.

Additionally, they bear fruit throughout the summer season. If you are someone who enjoys having a steady supply of tomatoes available all season long, an indeterminate crop might be your best choice. By far, most tomatoes we are familiar with – including heirlooms, beef steak and many cherry tomatoes are indeterminate varieties.

Some tomatoes also come in a semi-determinate variety, which means the crop won’t grow quite as large or produce quite as frequently. It’s best to assess your needs and your garden’s available space before deciding which tomato variety – or two, or three! – are right for you.

Starting Seeds Indoors

Tomato plants can be started from seed, or purchased as a transplant.

If you choose to start your tomato plants from seed, you may wish to start the seed germination process indoors. If so, you will want to begin approximately six to eight weeks before the last frost of the season.

  • Your tomato seeds may be started in a window box, or a small flat designed for seed planting under proper lighting, in seed starting soil or moistened peat pellets.
  • Plant two seeds in each container as only half of seeds can be expected to germinate.
  • Plant the seed approximately ⅛ to ¼ inch deep, or approximately three times deeper than the size of the seed.

Some growers recommend placing your pots or flats on a heated surface in the beginning as tomato plants love warmth.

Once the tomato plant begins to germinate, transfer it to a container with adequate drainage holes. Remember that your plants still want to remain in a warm environment. Keep them under bright lights and keep the soil moist. Tomatoes prefer to be watered as close to the soil as possible, so do not spray the plant, but rather direct the water towards the soil.

According to Gardening Know How, tomato seedlings can be given quarter-strength fertilizer once they develop leaves. However, beware of some common issues seedlings have, which include:

  • If the plant gets “leggy” (too tall and droopy), the most likely issue is a lack of light.
  • If the plant takes on a purple color, they may require additional fertilizer.
  • If they begin to fall over, they are suffering from “damping off.” This is a sudden death of seedlings caused by soil-borne fungus. The best way to prevent damping off is to thoroughly clean out all pots before use, maintain good draining of soil, and ensure plants are never overcrowded.

Preparing a Tomato Bed

There are few things more important than the health of your soil. For this reason, it is vital to your crop that you maintain the best possible conditions in your tomato’s bed. Whether you choose to plant directly in your soil or to build raised bed, remember that drainage is one of your primary concerns.

The first step in preparing your tomato bed is to prepare the soil. Just remember, you should begin preparing your bed a few weeks before your intend to move your seedlings outdoors. If you already have a space ready, then great. If not, you’ll want to amend the soil with any known missing nutrients.

Another great option for tomatoes is to build raised beds. Since you can build these practically anywhere, they are great for gardens of all shapes and sizes. But, the real benefit of raised beds for tomatoes is the level of drainage provided by them. With tomatoes being prone to blossom end rot, the additional drainage from raised beds helps in preventing this.

Once you have prepared your soil (in a raised bed or not) and let it “cook” for a week or two, test the acidity. Remember your tomato plants prefer a pH of around 6.5. If anything seems off in your tests, add amendments as needed.

Note: You will want to make sure that your soil is free of any clumps, and not overly sticky. You can remove the clumps when putting new soil into a raised bed. However, if you are planting directly into the ground, you may break up some of these clumps, but be sure not to disturb the ecosystem within the soil too much.

Remember your soil is a living ecosystem on its own, and needs to be cared for year after year in order to provide healthy crops.

Moving Outdoors

Begin to harden off your transplants one to two weeks before planning to move them outdoors. You can do this by bringing them outdoors on days when the weather is nice for approximately an hour to start. As you move closer to the time you’ll be putting the plants outdoors permanently, you may  begin increasing their daily time outdoors.

Just be sure to avoid days with high wind or low temperatures. And, do not forget about your plants! Even one night outdoors during a cold snap can easily kill your your plants.

It is critical that you choose an area in your garden that will get maximum sunlight. Your tomatoes will require at least six hours, many varieties will thrive with much more. If you live in the Southern Hemisphere, or a region with extreme heat, choosing an area with afternoon shade can be beneficial.

Don’t forget that your tomato plants also require excellent soil drainage. If your garden’s landscape doesn’t naturally provide this, consider preparing a raised bed.

Prior to moving your plants outdoors, many growers also recommend sprinkling crushed eggshells into your soil for an extra dose of calcium, which helps prevent blossom end rot in tomatoes.

Note: Throughout the growing season, you may find that you need to test your soil’s pH again. Tomatoes thrive at about 6.5, so if they seem to not be doing so well, go ahead and test it to start finding out what’s going on with your tomatoes.

Direct Seeding

Tomatoes are one of several crops that require a long growing season and have specific germination needs. Due to these factors, it is typically not recommended to “direct seed” or “direct sow” your tomato plants.

Of course, if you are planning on keeping them indoors, go right ahead and direct sow into the planter.

Watering and Mulching Requirements

Tomato plants need to be watered close to the soil, so you’ll generally want to avoid spraying your plants. We advise allowing time for the water to absorb into the soil. You want to penetrate the top 5 or so inches of soil with water. However, watering too quickly will lead to runoff which just steals nutrients from your crops.

A good solution is using a drip irrigation system or drip hose. But, no matter what method you use, water early in the day to allow plenty of time for the roots to absorb the water during sunlight hours.

Next, you must remember the necessity of mulching your tomato plants. Although, you won’t want to mulch too early in the season. Depending upon your region, waiting at least 4-5 weeks before mulching is advised. This allows time for the ground to warm up. If you mulch too early in the season, you will hold in the cool temperatures. And, we all know our tomatoes do not like the cold!

When mulching, choose an organic substance such as hay or leaves. This provides additional nutrients to your plants as they decompose. However if you use a material, such as bark, the soil will likely require additional nitrogen from the soil during the decomposition process. This means you’ll need to use amendments to provide the additional nitrogen your soil needs.

Some gardeners prefer to use black plastic instead of mulch to protect the ground around their tomato plants. If you use this method, be aware of the ground temperature underneath the plastic. While our tomato plants do in fact like warmth, you do not want to literally cook your roots. We don’t really recommend this method. Mother nature gave us her bounties for a reason, right?

Companion Planting and Rotation Considerations

There are many plants that go well with tomatoes in the same garden bed. Below is a list of some we recommend due to their ability to protect the plants and/or prevent disease.

  • Garlic repels red spider mites.
  • Basil repels many insects and improves pollination and flavor.
  • Chives repel aphids.
  • Mint deters moths, ants, beetles, fleas, aphids and rodents. Beware though, mint can be invasive. We suggest planting it in a submerged container, so it can’t get too out of control.
  • Marigolds produce a substance which helps reduce root-knot nematodes, tomato worm, slugs and many other garden bugs.
  • Lettuce (leaf) and spinach can act as living mulch and protect the tomato plants from water and soil splash, which can spread disease.
  • Carrots, while not growing as large when planted with tomatoes, will taste great and are a space saver. Additionally the roots will help to break up the soil.

These are the plants that we do NOT recommend planting alongside your tomato crops.

  • Walnuts inhibit tomato growth by producing a substance that is toxic to tomatoes.
  • Brassicas (cabbage, cauliflower, broccoli, sprouts, kohlrabi) inhibit tomato growth.
  • Fennel inhibits tomato growth.
  • Corn and tomatoes both attract the same types of fruitworms/earworms.
  • Potato increases the tomato plants’ susceptibility to blight. This is a fungal infection that requires damp, warm weather and appears as black and brown spots on the leaves and leaf loss (septoria blight or leaf spot); target-shaped rings on the leaves and cankers on the stems, with eventual black spots that develop into bruising of the fruit itself (early blight); or pale, water-soaked spots on leaves that devolve into purple-black lesions and black stems (late blight).

You’ll want to rotate crops each season in order to optimize the quality of your soil. We recommend planting legumes and/or brassicas, such as cabbage, cauliflower, broccoli, sprouts or kohlrabi after tomatoes. These plants help add nitrogen back to the soil, which is used in great quantities by leafy vegetables like tomatoes. It is even advised to allow just a few of these plants to fall and rot, allowing the soil to gain those nutrients as well.

The best route is actually to rotate through each of the four vegetable groups (solanaceous, cruciferous, root and leguminous) and switch between above ground to below ground crops each season, to further your variety. Tomatoes are in the solanaceous vegetable family, and additionally should not be planted in the same spot for at least three years between harvests. If you plan to grow tomatoes annually, you’ll need to find enough variety of space in your garden – with adequate sunlight – to ensure that you are not depleting your soil in any one area.

Harvesting and Storing Tomatoes

Tomatoes ripen on the vine from the inside out. In most regions, it is beneficial to allow your tomatoes to remain on the vine until they have reached optimal coloring, depending upon their particular variety. Although, in regions where the temperature is very hot (over 85 degrees) or a cold spell is looming, it is advisable to pick your tomatoes and continue the ripening process indoors.

To remove ripe tomatoes, a single turn of the fruit from the stem, or a cut from a paring knife or pruning shear will work just fine. Just never tug or twist the fruit on the vine.

Once removed, wrap mature green fruit in newspaper to ripen in a dark space indoors, or place in a paper bag with a banana or apple for speedier ripening. The other fruit will release ethylene gas which speeds up this process. If you are ripening large volumes of darker green fruit, remove sections while still attached to the vine, and hang upside down indoors.

Remember that a tomato’s flavor deepens and develops as it ripens. Never place the unripened tomato in the refrigerator as it will halt this process and can cause the tomato to become mushy. In fact, most tomatoes will last longer on the countertop.

If a ripe tomato will not be used within a few days it can be placed in the back of the crisper drawer in the bottom of the refrigerator in a vented plastic bag to allow the ethylene gas to escape. Nevertheless, if you have a large amount of ripe tomatoes, we recommend storing them via drying or canning, which will allow them to be used up to a year or more later. You can even freeze then, which will allow the tomatoes to be used for up to eight months. For more instructions on how to dry, freeze, or can your tomatoes, follow this guide.

Saving Tomato Seeds

Tomato seeds are slightly more difficult to save than some of our other garden seeds. However, they are definitely worth every bit of the effort, as growing your own favorite tomatoes year after year is one of the most rewarding accomplishments for many gardeners.

To begin, you’ll want to select a couple of the best fruits from your garden to source your seeds. Only choose from open-pollinated plants, which includes all heirloom varieties. Slice down the middle of the fruit (stem end on one side, blossom end on the other) and scoop out the seeds including the gel surrounding them. This gel acts as a growth inhibitor which prevents the seeds from sprouting inside the tomato.

Some growers have had success planting an entire half of a tomato, or a cup of seeds encased in gel, in their gardens. Other growers will simply dry out these seeds including this gel substance, which works fine if you are only planning to save your seeds from one year to the next. However if you want your seeds to last four-six years or possibly more, you will want to remove this gel coating through “fermentation.”

  1. The gel coating around our tomato seeds is a breeding ground for tomato disease. We will start by squeezing all of the seeds and gel from our tomato into a glass jar.
  2. Label the jar with the variety of tomato and cover the top with cheesecloth.
  3. Set the jar out of the way for 2-3 days while the seeds drop to the bottom of the liquid, and a layer of mold forms on top. Do not allow the mixture to set more than three days as at this point the fermentation process may lead to germination.
  4. The mixture will have an unpleasant odor. Remove the layer of mold and use water to rinse off the large seeds which have fallen to the bottom of the jar.
  5. Dump the clean seeds onto a paper plate to air dry for about a week. Make sure to label the plate with the variety of tomato.
  6. Keep the seeds in a cool dry place.
  7. Do not try to speed up the process with heat. Gently shake the plate every day to keep the seeds from sticking together.
  8. When your seeds are dry, store them in a paper envelope or plastic bag labeled with their seed variety. You’ll know the seeds are dry and ready for storage when you can break one in half with a tweezer.

Choosing the Best Tomatoes for Your Climate

Regardless of where you live, there is a tomato variety that has been developed to thrive in your region. Most cherry tomatoes and “short-season” varieties are known for growing abundantly in almost any garden.

Of course, if you are looking for a specific variety that will do well in your region, we recommend using the list available here to make your selection.

Additional Growing Tips for Tomatoes

  • Remember never to grow tomatoes in the same spot each year. Allow at least three years rest for your soil before growing tomatoes in that area of your garden again.
  • Don’t underestimate the importance of tomato stakes and cages! Your tomato plants can grow to become quite sprawling and heavy vines. Plant these support systems before your crops begin their root formations. You do not want to destroy these necessary roots by planting stakes later.
  • Be very aware of your plants watering needs. Avoid spraying the leaves and do not allow water to sit on the fruit itself. Water directly at the soil and/or consider using a soaker hose.
  • If you notice sunken, water-soaked spots on your fruit, this is indicative of Blossom End Rot, which may be caused by fluctuating moisture conditions (either too wet or too dry), pH imbalance, excess nitrogen or calcium deficiency. Test your soil and add amendments as necessary to correct this issue. Also prune and dispose of affected fruit before the entire piece rots.