Beginner's Guide to Growing Tomatoes

Tomatoes are a staple crop of many backyard gardens. Almost everyone who gardens has grown them, and probably knows their favorite varieties by name. Gardeners can also tell you stories of years when their tomatoes just didn’t produce as well as planned.

Growing tomatoes doesn’t have to be difficult, but it can be overwhelming for a beginning gardener. Garden centers will try to sell you every type of fertilizer and supplement, convincing you that tomatoes need it all.

So what is the secret to growing tomatoes well? There really isn’t one; however, there are some things you should know ahead of time to ensure your greatest success.

Let’s take a look at what you need to get started, as well as how to handle some of the challenges you may experience while growing tomatoes.

Seed vs Seedling

The first question most beginners ponder is whether they should start their tomatoes from seeds or purchased seedlings. A lot of this will depend upon your timing and how much planning you've done ahead of time.

First of all, you need to know a few dates for your area. For most of the US, these dates will be the date of your last frost and the date of your first frost. For Florida, it's when temperatures usually stay below 90 degrees and when they stay above 90 degrees.

First lesson in tomatoes: they don't like cold weather AT ALL, but they generally don't dig extreme heat either. In fact, tomatoes will stop setting fruit when daytime temperatures are 85-90 degrees and nighttime temperatures are 75 degrees. So if you live up north, you will be transplanting tomato seedlings in early summer. If you live in zones 9 and south, then tomatoes are probably going to be a winter crop with cold protection as needed.

Knowing the length of your season, you can better determine how soon you'll need to start your tomatoes.

Most tomato varieties take 70-90 days from the time seedlings are transplanted to start producing ripe fruit. If you are starting from seeds, then you need to calculate another two months of growing time to get seedlings that are ready to transplant into the ground. This will probably mean starting your seeds a couple of months before your growing season technically starts.

In freezing climates, you'll need to start the seeds indoors under grow lights or in a greenhouse. In Florida, we start ours outdoors in the shade. It isn't difficult to start tomatoes from seed, but many gardeners opt for seedlings just because of the extra planning that is required for seeds.

Determinate vs Indeterminate

When choosing a tomato variety, you'll often see them labeled as determinate or indeterminate, but what does that mean? How do you determine which is best for you? How does growing them differ?

Determinate Tomato Varieties

A determinate tomato variety has a genetically pre-determined size and level of production. They will have more of a bush shape, and you'll prune them accordingly. They will typically produce and ripen all of their fruit at the same time, making them ideal for someone who wants to preserve their tomato products. Once they produce their fruit, the plant dies back.

Indeterminate Tomato Varieties

An indeterminate tomato variety has an undetermined size and level of production. It will be more like a vine and will continue to grow in height until it is pruned back. It will also continue to set fruit until something kills the plant. These are good for eating tomatoes since you're more likely to get one or two to ripen at a time and the harvest will be staggered through the season.

Plant Deep

When planting your tomatoes, you will want to bury the stem as deep as possible. Tomatoes have the ability to grow roots from their stems. The more of the stem that is buried in the soil, the more roots your plant will produce and the deeper its root ball will be. A deep large, deep root system allows the plant to find the moisture and nutrients it needs to produce a better crop.

Sunlight

Tomatoes need 4 to 6 hours of full sun a day to produce ripe fruit. Northern climates will typically grow them in full sun, while southern zones may find the afternoon sun to be too intense. Tomatoes that receive too much sun will wilt in the afternoon and their leaves will begin to burn.

If you notice your tomato plants wilting and receiving damage from the sun, you can build a lean-to with wood and shade cloth to help give them some relief. When planting, you may also want to consider structures and trees that could provide your garden with morning sun and afternoon shade.

Because tomato plants do grow so large, they can also be used to shade some more tender, shade loving plants. I typically plant herbs around the bases of my tomato plants. I've also found that my lettuces enjoy the shade tomato plants provide.

Nutrients: Finding a Balance

Tomatoes tend to need a lot of nutrients to produce really well. You'll hear a lot of wives tales about growing tomatoes with fish heads, eggs, and banana peels.

While these stories may sound far fetched, they have some truth to them. Personally, I prefer compost, manure, and deep mulch. Here's why:

Compost

In large part, I consider compost to be a pretty complete fertilizer. My compost is largely leaves, kitchen scraps, old eggs, and chicken coop bedding.

The eggs contain the calcium tomatoes need to prevent blossom end rot.

The leaves have the phosphorus needed to set fruit.

Chicken manure has nitrogen needed for stem and leaf growth.

Mixed together with all of my other kitchen scraps, and I have just about everything a tomato plants needs.

Read: 5 Little Known Ways to Find Cheap Compost

Manure

Our manure is dumped into a pile and then pulled from as necessary. This way it's well aged for when we need it. In large part, it's mostly nitrogen. This can work well when tomato plants are getting established because it provides for healthy leaves and stems.

At some point, you'll need something to bind some of that nitrogen and provide phosphorus so the plant will produce fruit. That's where deep mulch comes in.

Deep Mulch

I'm a big fan of Back to Eden gardening. Using a thick layer of mulch on your gardens keeps weeds down, roots cool, and retains moisture. This mulch will also break down over time and provide phosphorus for the plants.

Just about anything can be used as mulch. I've heard of people using wood shavings and shredded paper, but I really like to use hay.

The most common mulch is wood chips. You'll hear naysayers claim that wood chips bind nitrogen as it breaks down. From my research, this is only an issue when the wood chips are mixed into the soil.

Personally, I have so much nitrogen in my soil mix already that it hasn't been an issue. My plants have loved the deep mulch.

Read: Low-Maintenance, No-Till Gardening

Providing Support

One of the biggest challenges to growing tomatoes is providing them adequate support as they grow tall.  Tomato cages are short and cannot support very much weight. Stakes work well for indeterminate varieties, but even they usually top off at 5-6 feet tall. It pains me when I have to cut off the top of a tomato plant because it's grown taller than the stake.

My recommendation is to set up a trellis for growing tomatoes. Even if the tomatoes aren't growing straight up, it gives you the flexibility to tie the tomato plant to the trellis as needed. It will also give you more space to tie individual branches to help support the weight of fruit.

If you can't do a trellis, use a combination of cages and stakes. The stake can support the main stems of the plant, but the cage is still there to support fruit and bushier determinate varieties.

Pruning

Pruning can make a big difference in tomato plant production, but it needs to be done correctly. Over pruning a determinate variety will result in fewer tomatoes, but not pruning indeterminate varieties can mean smaller and/or fewer tomatoes.

When it come to pruning either variety, it's best to keep the bottom 6" of the plant clean of leaves to avoid fungal issues. I've also heard it recommended to remove everything below the first flowering branch. You will want to have a good balance between leafy branches and fruiting branches so the tomatoes are protected and the plant can do enough photosynthesis to produce. But beyond that, you'll need to know if you have a determinate or indeterminate variety.

Pruning Determinate Tomatoes

Determinate varieties are designed to produce a lot of fruit at one time, ripen, then die. For this reason, any pruning will mean fewer tomatoes overall. They will usually get to a certain size before they start to produce, so you can get a good idea for which branches will be fruit producing before pruning.

If you do need to prune a low lying sucker to avoid fungal issues, you can root it to produce another plant. This way it can still go on to produce, but the original plant is kept in peak health.

Pruning Indeterminate Tomatoes

Indeterminate varieties are more vining than determinates, but do not have a pre-determined height. They will continue growing until they die. If left to their own devices, they will grow more vegetation than fruit, so they need to be pruned back if you want a decent tomato crop.

Indeterminates will put out "suckers" at almost every branch. You can allow 3-4 of these branches to grow, but the rest need to be removed while they are young.

These suckers can be rooted to make new plants though.

Keeping the plant pruned back will allow the plant to put its energy into producing more and larger tomatoes. You'll also want to cut off the tops of the plants about 30 days before the end of the growing season so the plant can focus on ripening the remaining tomatoes.

Avoiding Tomato Pests

You will find a variety of pests that like to eat tomatoes. Rather than getting into the wide variety of pests, let's focus on what you can do to keep them at a minimum.

Wire cages

I'm not talking about tomato cages. I mean cages you build out of fence wire around your tomato plants. As your tomatoes ripen, you'll find that all manner of animals want to eat those juicy, red fruits.

A wire cage that is clipped around the plants will help deter them from taking bites out of your tomatoes before you do. You can use clips to hold the fence so you can still access your plants for harvest.

Distractions

Birds can be a big culprit when it comes to damaging tomatoes, but they are easily distracted by shiny things.

Red Christmas ornaments hung before tomatoes are ripe will make your tomatoes look less appealing later. After trying to peck a few ornaments they'll learn that there is no food there and move on.

You can also scare them away by hanging pie pans or CDs that blow in the wind. The reflection and movement in the garden will make them want to seek shelter somewhere else.

Organic sprays

Two of my favorite sprays for the garden are neem oil and Bt (Bacillus thuringiensis). Bt is used to control caterpillar populations, which always seem to be a plague on tomato plants.

While I'll pick off caterpillars if there are only one or two, we have issues with tussock moth caterpillars which will completely defoliate a plant in a day. Spraying Bt on the plants as a preventative keeps destructive caterpillars under control and lessens their damage through the garden.

Neem oil is good for controlling most other pests and is a deterrent for a variety of flies, worms, and aphids. Be careful though, neem oil should only be applied in the evenings to avoid burning the plant.

Soapy water

A mixture of 2 tablespoon dish soap to a gallon of water can take care of a wide variety of pests in your garden. It can be used as a spray, but I actually like to use it as a dunk. As in, I dunk bugs in it and watch them drown. It works great on aphids.

Small seedlings can also be submerged in the mixture for heavy infestations. A swim in soapy water is the only thing I've found to kill stink bugs and leaf footed bugs.

Companion planting

I love companion planting with tomatoes. The most popular companion plants are herbs like basil, thyme, oregano, and rosemary. Not only will their fragrances deter a lot of pests, but they release a chemical into the soil that will strengthen the tomato plant. I also think it results in better tasting tomatoes.

Growing tomatoes doesn't have to be a struggle. With a good game plant and a few precautions, you can enjoy a tasty harvest of vine ripened tomatoes.