How to Grow Tomatoes
Updated: Sep 15, 2022
Tomatoes are probably the most popular garden vegetable in North America, and yet how to grow them at home feels like a mystery for many. Lets change that!
Here's everything you need to know to transform yourself into a tomato-growing expert. As GI Joe liked to say, ‘Knowing is half the battle’! Topics I'll cover are:
• The best tomato varieties for your space
• Starting seeds, properly preparing containers& growing medium
• Growing strong seedlings
• When to fertilize and not
• How to transplant tomatoes to avoid shock
• Support structures
• Pruning, feeding & fertilizing
Solutions to common tomato plant pests & diseases
Good companion plants & what to avoid
Harvesting and storing tomatoes
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Glossary of Tomato Terms
How to grow tomatoes is a little easier once you know the terms. So, get yourself a tea or a coffee (or a glass of wine—I won’t judge!) and get to know your tomato terms.
A term often used interchangeably with ‘variety’ and ‘strain’ (two other tomato-related terms), a cultivar is a specific tomato type propagated by dividing or replanting, or from a cutting—it is ‘cultivated.’
DAYS TO MATURITY
The number of days from transplanting a tomato plant seedling in the garden to its first mature fruit.
EARLY VARIETY TOMATOES
A tomato that matures in 50 to 60 days, these early varieties are prized for early harvests and late summer planting for a fall crop. Sometimes we refer to tomatoes that mature in more than 60 days as ‘early,’ but only in comparison to their peers.
For example, the earliest beefsteak type is only early compared to other beefsteaks. Beefsteaks typically take longer to mature than different tomato types because they are so big!
This refers to a process in which you gradually acclimatize your tomato seedlings to outdoor temperatures, sunlight, and wind to prepare them to be transplanted out into the garden.
Any tomato variety is at least fifty years old and is not a hybrid.
A tomato bred by crossing varieties. Hybrids tend to offer better disease resistance and a higher crop yield.
A tomato plant that has been pollinated by wind, insects, birds, humans, or some other naturally occurring way. All heirloom varieties are open-pollinated. Not all open-pollinated tomato plants are heirloom varieties.
The process in which pollen is transferred from a male part of a plant to a female part of a plant, enabling fertilization.
A term often used interchangeably with ‘variety’ and ‘cultivar,’ a strain is a specific type of tomato that has demonstrated particular characteristics and has then been developed or improved for that characteristic.
A foliage leaf of a tomato plant, as opposed to a seed leaf. Seed leaves are usually smooth-edged, almost looking like a perfect oval. True leaves for a tomato have jagged edges. Seed leaves are the first two leaves that the seedling produces and will be the lowest ones on the stem. Once there are a few more leaves on the stem, you will see the difference.
A term often used interchangeably with ‘cultivar’ and ‘strain,’ a tomato variety is a specific tomato type grown from seed.
A big part of knowing how to grow tomatoes is choosing which kind of tomato is right for your plate and your space. Did you know there are over 700 tomato varieties?! Should you get red, yellow, orange, or maybe even purple? Do you want to grow tiny and sweet tomatoes or big as a melon? Juicy or pulpy?
If the thought of making a choice on which seeds to buy gives you decision paralysis, you're not alone. Often your local garden center expert is happy to help; however, I know what it's like to want to just go dream a little by flipping through tomato seed packets yourself, so here's what you need to know to self serve a bit.
First, it’s worth considering what you’re going to want to use your tomatoes for; for example, do you want cherry tomatoes, slicers for sandwiches, or tomatoes for making sauce or paste?
I like to grow a variety to suit all needs: cherry tomatoes in a pot near the kitchen for salads and two larger varieties in raised beds.
However, if you don’t have room for all 3, here are a few things to consider when choosing the right type for you.
TOMATO PLANT SIZES
Some tiny seeds can grow into huge garden companions, so if you don’t have much room for growth, you might need to limit yourself to considering smaller varieties.
Cherry tomatoes can quickly be grown in a planter. There are even dwarf varieties that can be grown in pots as small as 6 inches (15 cm) deep, making them ideal on a sunny windowsill.
You won’t find these smaller growing options with slicing tomatoes or pasta sauce-loving varieties, so available space may cause your tomato seed selection for you.
Determinate tomatoes grow to about 2-3 feet (60-91 cm) tall, need little to no pruning, can be supported with simple stakes, and are an excellent choice for containers and large pots.
Determinate tomatoes have a growth habit of setting fruit and then ripening all that fruit in one giant wave.
Most varieties of paste tomatoes are determinate because most of the fruit ripens within two or three weeks.
Determinate tomato varieties are also suitable for cold-climate gardeners who need to harvest their whole crop within a couple of weeks.
Indeterminate tomatoes, also known as vining tomatoes, can get very large, some growing up to 10 feet (305 cm) tall and 6 feet (183 cm) being about the average.
These are not optimal for you if your gardening space is at a premium, as they don’t thrive in a pot or planter like some of the other options.
The growth habit of indeterminate plants keeps growing taller and taller, setting and ripening fruit as they grow until the tomato plants are killed by frost.
These varieties require more cage and stake support and more of your attention.
So, if you have plenty of space, prefer to pick your tomatoes over several months, and are prepared to provide sturdy support with stakes, cages, or ladders, then an indeterminate variety may be a perfect match for you.
Most beefsteak tomatoes are indeterminate, but there are also lots of cherry tomatoes and other varieties in this tomato plant style.
How to grow tomatoes disease free
Next, you will want to consider disease resistance. Tomatoes are susceptible to several diseases that may or may not be common in your region. These diseases can weaken the tomato plant and reduce fruit yields, so look at the seed packet or plant label to see if the variety has resistance to those which are common in your area.
For example, Verticillium and Fusarium Wilt are two are very common soil-borne diseases that affect tomatoes, so seeds with resistance to these diseases are designated by a V or F after the variety name.
DISEASE RESISTANCE IS INDICATED BY THESE LETTERS:
Fusarium Wilt (two F’s indicate resistance to both races 1 and 2)
Alternaria Stem Canker
Tomacco Mosaic Virus
Stemphylium (gray leaf spot)
Tomato Spotted Wilt Virus
How to Grow Tomatoes Starting From Seeds
Tomato seeds are almost always started indoors—whether in a greenhouse or on a sunny window ledge—and are then transplanted to beds once they have at least a few leaves and an established root system.
Starting tomato seeds indoors is ideal, as tomato seeds need a constant soil temperature of at least 60 ºF (15.5 ºC) and preferably 80 ºF (26.5 ºC) to germinate. So, in temperate climates, it may be midsummer before the soil gets that warm, and by then, it’s too late for tomatoes to grow and mature before the end of the growing season. Therefore, we start the party inside.
Preparing containers and growing medium
You can start seeds in just about anything that holds soil and has drainage holes—I love starting them in a paper egg carton with holes poked in the bottoms.
Living in a small condo, I don’t have room to store many things when I’m not using them, so re-using items like this comes in handy. Plus, it looks pretty cute. That being said, you can also use purchased containers, such as biodegradable pots and seed-starting trays.
When it comes to the best kind of soil for planting your tomato seeds in, it’s super important to know that you should always avoid using garden soil if possible.
Note: Garden soil often drains poorly and may harbor disease organisms. The best growing medium for starting tomato seeds actually has no soil in it at all! Instead, choose a sterile, soilless mix that’s labeled as being specifically for seed starting.
How to plant tomato seeds
Now that you have your seeds, containers, and growing medium, it’s time to start! Here's a step-by-step walkthrough on how to grow tomatoes starting from seeds.
Thoroughly dampen your seed- starting mix before putting it into your container.
Once the medium is nice and moist, fill the containers within half an inch (1 cm) of the top.
Pat the medium down nicely into the container, but try not to pack it down too firmly. Note: make sure it’s still workable and loose for the soon-to-grow rooting system.
Place two or three seeds into each container and then cover the seeds with about a quarter-inch (6.5 mm) of soil.
Lightly tap down the seed- starting medium over the seeds to gently tuck them into their new homes. Remember, you’re tucking them in, not disposing of them, so be gentle.
To ensure there’s a good seed-to-mix contact, I find it helpful to water them after seeding. Ideally, use a plant mister or just dribble a light stream of water over the top. You don’t need to soak the ‘soil,’ just moisten the top layer. A mister is fantastic as it dampens the mix without disturbing the surface or the seed.
Place the pots in a warm spot, or ideally, on a heat mat. Never underestimate these heat-loving plants desire for warm soil. Warm though, not hot. A great little trick I learned once was to place the tray on top of your refrigerator. The top of your fridge is surprisingly warm, which the seeds love! At this point, the seeds don’t need light, and you won’t need to worry about taking up space if you live in a small apartment.
For the next few weeks, try to keep the mix moist but not soaked. A greenhouse top helps hold some moisture in; however, you can also achieve the same results by placing plastic wrap over the top.
As soon as you see sprouts, remove the covering and place the container in a sunny window or under grow lights. The seeds sprout quite quickly, so be sure to check your containers daily to be safe.
Continue to keep the soil moist but not saturated. Since dry seed-starting mix usually turns a lighter color when it dries out, so when you see this, it’s a good indication that your sprouting tomato babies need water.
GROWING STRONG SEEDLINGS
How to grow tomatoes once you have seedlings. Once your seedlings start popping up, you’ll want to do everything you can to help them become as strong and hardy as possible.
Here are some of my favorite tips for this stage of the growth cycle:
Put a fan on it! To develop strong stems, tomato plants need to move and sway in the breeze. That happens naturally outdoors, but when starting your seeds indoors, you’ll need to provide some type of air circulation to do this. Create a breeze by turning a fan on your seedlings for 5-10 minutes, twice a day.
If you’re growing plants on a windowsill, rotate your pots daily so that your plants grow upright instead of leaning toward the light.
If you’re growing your seedlings under lights, raise the lights as the tomato plants grow, keeping them just a few inches above the plants at all times.
Watering your seedlings from below helps you avoid disturbing the seeds and compacting the soil (which tends to happen when you water from above). To water from below:
Simply place your sprouting tray or container onto a tray of water.
Make sure that the bottom of your sprouting tray (or container!) is slightly submerged.
But don’t let the water go above the top of the planter, as the goal is to simply allow the soil and roots to absorb the water they need through the drainage holes at the bottom of your container.
If watering from below isn’t possible, use a mister to dampen the soil rather than directly pour water onto the surface.
As insufficient light can lead to weak, spindly plants, an adjustable grow light is ideal; however if you don’t have one (or if you like getting crafty), you can build a makeshift lightbox by placing a sheet of reflective tinfoil along with the seed tray on the side opposite the window. This will reflect daylight onto the darker side of the tomato plant.
By the way, to learn how to water tomato plants at each stage of growth, checkout this article on how, when and how much to water tomato plants.
Replanting tomato seedlings into big pots
How to grow tomatoes once your seedlings are ready to be transplanted. If your tomatoes outgrow their starter pots before it’s time for them to be planted outdoors, it’s a good idea to replant them into larger containers. New, larger containers are also a good idea when your plant’s true leaves first appear.
The key is always to avoid letting your seedlings become pot-bound. Pot-bound simply means that they’ve got to a point where their roots fill the container. This is something to avoid, as it can stunt your tomato plants’ growth.
Either way, after your seedlings’ first true leaves, grow, transplant them into individual small pots so that the seed leaves are just above the soil level.
As a general rule, a tomato plant should be replanted at the same depth it was growing initially. I also find it helpful to add a little of the seeds’ compost into the mixture when transplanting them into their pots.
Avoid letting your tomato seedlings become pot-bound
When transplanting, use a small utensil like a table knife to help lift the transplants out of their original pots. I’ve found it helpful to hold seedlings by their leaves rather than their stems to avoid crushing the delicate stem tissues. A 4-inch (10 cm) diameter pot that is 3-4 inches (7.5-10 cm) deep is usually adequate. I know it can be tempting to transplant them right into your home garden, but try to avoid moving tomato plants into your vegetable garden until after your area’s average last spring frost date.
Be prepared to protect your seedlings with season-extending garden fabric, row covers, or tomato plant covers if a late frost comes around.
When to fertilize tomato plants (+ not to)
Things to keep in mind when thinking about how to grow tomatoes in regards to fertilizer:
A lesson I learned the hard way at this stage is not to fertilize too much, too soon.
Giving tomato seedlings too much fertilizer too early in the growth cycle can reduce their root growth.
Overfeeding young tomato plants may cause root burn, too.
A half dose of water-soluble fertilizer usually works nicely.
Remember that tomato food is usually not given to soil-grown plants until they typically reach the flowering or fruiting stage—around three months after sowing, depending on the variety.
Thinning tomato seeding
How to grow tomatoes for the strongest, healthiest plants needs to take into consideration that you’ll likely need to pick a favorite. What?! Yes, sorry to break it to you, but this is important since you'll want just one seedling per pot or container.
If you find thinning (removing extra seedlings) emotionally challenging, you’re not alone! After all, you’ve been nurturing these green-leafed cuties for days, but sadly it has to be done.
Removing excess tomato seedlings enables each tomato plant to get sufficient space, full sun, and nutrients that they need to grow.
Select the strongest, healthiest seedlings and use a pair of scissors to snip off the others at the soil line. You could try to transplant the extras into different pots. Still, you risk disturbing the roots of the remaining plant, and realistically, how many tomato plants can your garden accommodate?
Tomato plants are usually ready for thinning about 2-3 weeks after sprouting or when they’re approximately 3-4 inches (7.5-10 cm) high.
When choosing which seedlings to leave, a good rule of thumb is to keep the larger, more developed ones. As in nature, it’s survival of the fittest.
Select the strongest, healthiest seedlings and start thinning!
Transplanting tomato plants outside
How to grow tomatoes once they're ready to move outside to reach their full potential:
When you’re ready to transplant your tomato babies out into the great outdoors, it’s time to complete the process of ‘hardening off’ to give your plants time to adjust to the potentially lower temperatures, increased breeze, and higher light levels.
Tomato plants are easily stressed, so getting them used to outside conditions gradually, over a week or so, helps keep them happy and growing at a consistent rate.
Hardening off is just a matter of leaving your seedlings out longer each day and later in the evening to experience the drop in temperature.
After a week or two of this, they should cope outside overnight if temperatures are favorable. Keep in mind that when you’re hardening off your tomato plants, this isn’t just against the cold. Direct sunlight on seedlings and young plants for several hours can be as harmful as frost.
When growing tomatoes on the patio, it’s important to choose varieties suitable for outdoor growing and mature early.
If you’re growing them in a container, keep stability in mind when growing bush tomatoes in large pots.
On a windy day, pots are easily blown over, so choosing pots with a solid broad base can help.
When using a grow bag as their final destination, I tend to keep the plants in their pots then plant the pots right into the grow bag.
The tomato plant roots will grow through the holes in the bottom of the pots and into the grow bag.
This also helps stop the grow bag from drying out too quickly as less compost is exposed.
It also enables the taproot to go down in search of water, and the more delicate roots around the base of the stem are then able to absorb nutrients.
Tomato plants are heavy feeders. Feeding is done by applying diluted nutrients around the bottom of the stems where the fine roots grow.
Tomato plants are also easily stressed, so get them used to outside conditions gradually.
Supporting Tomato Plant Growth
How to grow tomatoes with the support they need to grow a large harvest
TOMATO SUPPORT STRUCTURES
Just like any good athlete, plants need support, training and proper nutrition. Think of your tomato plants as the Olympians of your garden, and they need you, their coach, to help them reach their full potential.
If left to their own devices, they tend to be more prone to disease, and the fruit quality and quantity can suffer. So, using a support system that lifts plants off the ground and allows for air circulation can help you grow a more significant and tastier haul.
In this section, we have included a list of the four primary solutions for taming those unruly tomato plants, however, there are a few things that you should consider before choosing the best solution for you and your garden.
For example, how much room do you have? For small garden spaces, it will be better to choose a compact solution like a cage and ladder. These provide a narrower footprint than other support options and are stackable when it’s time to store them.
Another consideration is which type of tomato plants are you growing—determinate or indeterminate?
Indeterminate varieties need taller support.
Determinate varieties can often get by with something smaller.
Will you be pruning the ‘suckers’ off your tomato plants to reduce foliage?
If so, give ladders, weaves, or tripods a try.
If you’re letting your plants grow wild and free, you might prefer cage-style support.
TOMATO CAGES AND LADDERS
Cylindrical or square wire cages are the most common way to keep tomatoes upright if you want to avoid tying stems. Instead, the cage walls are used to support your leaves and stems. However, something to keep in mind is that although they are easy, they’re often not big enough for indeterminate varieties.
A quick fix is to:
Make larger cages using 10-gauge concrete reinforcement wire with 6-inch openings—available at almost any home improvement store.
Then cut a four 1/4-foot (130 cm) length of the wire, and coil it to make a circular cage that’s about 18 inches (45 cm) wide in diameter.
Snipping off the bottom two levels of horizontal wires will help you create ‘legs’ that can be pushed into the ground to hold the cage in place.
Plant one tomato inside the cell and then simply pull the stems through the wire for support as they grow,
FLORIDA WEAVE AND TRELLIS
Often used commercially for determinate varieties, this training technique supports tomatoes with twine woven horizontally between rows of stakes. This makes cleanup a dream at the end of the season, as you can just snip the string at the end and compost the tomato plants.
For this technique:
Tomato transplants (at the seedling stage) get planted about two feet apart in single rows within raised beds.
I’ve also done this successfully between two large planters on my patio—don’t worry about how the farmers do it; it’s excellent in any growing space!
Drive a stake into the soil at each end of the row and between each tomato plant in the row!
When the transplants are roughly about a foot (30 cm) high, tie twine to the first stake at about 6 inches (15 cm) high and loop it around the next stake at the same height.
Make a double loop around the last stake for strength, and loop your way down the opposite side of the bed, keeping tension on the line all the way down.
When you get back to the first stake, tie off, and cut the twine.
Depending on how fast your tomato plants grow and how heavy they get, you’ll need to run another line of twine about six inches higher every week or so to keep supporting your tomato plants.
This support system works exactly as it sounds: grab stakes, hammer them into the ground, and grow! Okay, maybe it’s not quite that simple, but pretty darn close.
For starters, you’ll want to make sure that your stake is at least 6 feet (182 cm) tall when measured from the ground for indeterminate tomato plant varieties.
As your tomato plant grows, tie the stems loosely to the stakes with fabric strips, twine, or zip ties.
Personally, I prefer using metal rebar stakes as wooden stakes can shatter, splinter, or rot if stored outdoors.
Rebar won’t give you those challenges, and its smaller diameter (3/8ths of an inch/just under 1 cm) is easier to get into the ground, especially if you moisten the soil.
These take a little longer to build, but they are pretty once up and incredibly durable. Fastening three stakes into a tripod provides extra stability for tomato plants located in a windy region. This is especially true once you’ve trained your tomato plant to wind up the stake, as the weight of the plant helps further anchor the tripod to the ground.
Do your tomatoes and yourself a favor, and wrap a nice long string of twine loosely around the outside of the tripod to act as a trellis. Just tie it at the top and then spiral it down approximately every 6-inches (15 cm), and then connect the other end of your string to the base. It makes training your tomato plant vine SO much easier!
Four words to live by Pruning. Is. Your. Friend. Oh, how your tomatoes will thank you! Let me count the ways! How to grow tomatoes more effectively with pruning:
1. Helps keep your tomato plants compact
2. Makes it easy to use supporting methods like ladders
3. Maximizes tomato production by helping your plant focus on fruit development
4. Minimizes disease problems by improving air circulation
But moderation is essential, as too much pruning can remove leaves that would otherwise feed your tomato plant. The reduction of foliage can also expose fruit to full sun, which may result in the equivalent of a sunburn, and you don’t want that.
Pruning consists of pinching off ‘suckers’—the tiny stems that pop out where side branches meet the main stem.
A good way of maintaining moderation in your pruning is to remove suckers that grow below the first flower cluster.
This keeps the main stem strong while retaining upper suckers that will eventually produce flowers and fruit.
Leaving plenty of foliage on also helps to reduce the risk of sun scalding if you live in a place with the intense summer sun.
Important Note: some gardeners who live in regions with short growing seasons prefer to start pruning off suckers in late summer to encourage the plant to direct its energy towards existing fruit.
Those gardeners using cages or towers to support their plants often pinch suckers from the lower stems, allowing the ones higher up to grow.
If space is at a premium, or if you’re using ladders, stakes, or other tall, narrow supports, try pruning your tomatoes to one or two main stems by pinching off all suckers. Otherwise, they will grow into additional branches and create a comprehensive, bushy plant.
If you prune all the suckers, the stems left standing will grow strong and will be easier to tie to your supports.
Removing lower leaves can help with air circulation around the base of your plants, as can eliminating old decaying leaves to discourage bugs and diseases.
As lower leaves (below the first truss) start yellowing, remove them as side shoots.
The truss on a tomato plant is a group or cluster of smaller stems where flowers and fruit develop.
In general, leaves can usually be removed gradually up to the first truss, then above the first truss after producing ripe tomatoes.
Usually emerging at or near the point where a primary stem meets a secondary or a leaf stem, trusses create yellow flowers from whose centers small green tomatoes eventually appear.
Keep in mind that de-leafing a plant too quickly and removing too many leaves can result in a poorer harvest, so slow and respectful is key.
The best way of maintaining moderation in your pruning is to remove suckers that grow below the first flower cluster.
Feeding and fertilizing tomatoes
How to grow tomatoes with the food they need to produce healthy plants and mature crops.
Let's go back to our analogy of tomatoes being the Olympians of your garden for a moment. We can agree that just like any other athlete, your toms need a steady and moderate diet of water and nutrients.
I like to avoid high-nitrogen fertilizers like ammonium sulfate or fresh manure because it can be easy to overuse them.
Over-fertilizing can result in tall plants with few tomatoes, which isn’t the point, after all.
Before fertilizing, it’s beneficial first to test your soil.
If your soil is balanced or high in nitrogen, you should use a fertilizer that is slightly lower in nitrogen and higher in phosphorus, such as a 5-10-5 or a 5-10-10 mixed fertilizer.
Although organic matter such as bone meal, dried manure, or cottonseed meal are excellent, it’s good to remember that most organic fertilizers don’t naturally offer a balance of the essential three significant nutrients—nitrogen, phosphorus, and potassium.
For example, if we look at dried manure, we see that it tends to be low in phosphorus, so you should consider adding some bone meal at the same time to give it a healthier balance. Mixing things up to create a perfect balance is the way to go.
Next, you’ll want to think about when to fertilize, as this is just as important as what you use and how much you add.
A typical time to start feeding your tomato plants is when the first tomatoes have just formed, and after this point, you should continue to add fertilizer approximately every 3-4 weeks.
I tend to use about 1.5 tablespoons of a 5-10-10 solution per plant.
Draw about a 1 inch (2.5 cm) deep trench around the plant, making sure that the track’s circumference is about 5-6 inches (12- 15 cm) away from the stem all the way around for the fertilizer to go into.
(Try not to get any of this fertilizer on the leaves or stem as it can burn the plant.)
Then cover the fertilizer with fertile soil. Rain and your watering routine will help carry those nutrients down to your plant’s roots.
What you’re ultimately trying to achieve is healthy soil, as this will result in you growing healthy plants and tasty fruit. Sounds simple right?
Aim for slow-release formulas that gradually break down in the ground to provide a continuous source of nutrition. As most experienced gardeners tell you, the better your soil, the better your plants will grow.
Building the soil up nutritionally, rather than simply adding a quick chemical fix, is the best plan for the long run.
Mulch is just a fun way of saying organic layer of leaves, hay, coconut husk, wood pieces, or pine cone pieces. There are plenty of mulch forms you can choose from.
Being organic, it will decay over time and provide a continuous source of additional nourishment for your tomato plants.
Also, placing mulch on the soil around your plant also aids water retention and increases room for aeration if you lightly mix it with the topsoil.
The most significant and immediate impact of using mulch relates to watering, as mulching can significantly reduce the rate of water that evaporates from the soil.
When you mulch, then, you may find that if you were previously watering your tomatoes twice a day (or more), you may now only have to water once daily—that sounds like a win to me.
Common tomato challenges (+ solutions)
How to grow tomatoes without the common vegetable pests chomping away at them:
SLUGS AND SNAILS
Those little rascals! One big problem caused by heavy rainfall is that it brings out the slugs and snails who love to eat tomato plants.
Solution: My favorite way of dealing with this issue is to place French marigolds in pots between the tomato plants, as slugs and snails tend to go for the marigolds first.
These ‘Marigold Hotels’ provide a double service. In addition to marigolds being top of the menu for hungry snails, thus diverting them from your toms, the bright color of the marigolds also attracts bees other flying insects who help pollinate the tomato flowers.
PLANTS HAVE A LOT OF LEAVES BUT NO TOMATO FRUITS
There’s a good chance that your plant is getting too much nitrogen and not enough phosphorus.
Solution: Choose a fertilizer with a balanced ratio of the three major elements, such as 10-10-10, or try a fertilizer where the first number (nitrogen) is smaller than the second number (phosphorus).
BLOSSOMS FALL OFF BEFORE ANY TOMATO FRUIT FORMED
This is often caused by cool weather that prevents fruit from forming.
Solution: This changes typically naturally as the weather warms up during the summer, but if you can provide a greenhouse cover for your plants, these cooler periods are an excellent time to do so.
TOMATOES ARE CRACKED
Inconsistent watering is likely the culprit. Irregular watering—missing a week and trying to make up for it—leads to blossom end rot and cracking. A sudden rush of water can pop the skin of a ripening tomato, much like an overfilled water balloon.
Solution: Instead of a quick sprinkle every day, try watering deeply once or twice a week (depending on rainfall). Mulching is also a big help because it keeps moisture from evaporating. That being said, this issue is just cosmetic. Cracked tomatoes are still very much edible.
TOMATOES HAVE A SOFT OR ROTTEN SPOT
This is usually a sign of a calcium deficiency and is often caused by uneven watering. Frequently going between wet and dry soil can interfere with your tomato plants’ abilities to use calcium. Luckily, most fertilizers made for tomatoes do include calcium. However, a handy little extra trick I like to do is to add eggshells to the soil.
Solution: About once a month, after using eggs in the kitchen, I’ll wash and dry the shells and then toss them into a coffee grinder to make a powder out of them. Then I mix that powder into the soil. Eggshells provide an excellent (and seemingly appreciated) calcium boost for my tomatoes.
LEAVES HAVE SPOTS
Spider mites or tiny pale aphids often cause those little spots.
Solution: A good spray down from a watering hose of both sides of the leaves usually often takes care of these infestations.
However, if that doesn’t work, try spraying the leaves with a dish soap solution. In some cases, those brown spots could indicate a minor fungus infection caused by overwatering and poor air circulation.
If this is the case, try staking and pruning your tomato plants as described earlier in the book.
BROWN SPOTS ON PLANTS’ STEMS
These brown spots, especially at the joints, can be the early signs of a fungus disease called late blight. This has been especially prevalent in the Northeast region in recent years. Solutions are hit or miss, especially if keeping your garden organic is essential to you. For this reason, I say prevention is king. There are many resistant variations of tomato seeds available to choose from, for starters.
Solution: If your area is prone to blight, select a variation that’s up to the job. It’s worth keeping in mind that late blight can stay in the soil, so next year, it’s advisable to plant your tomatoes (and potatoes) in a different location to avoid any new contamination.
Lastly, try to prevent overwatering and do what you can to improve circulation.
BITES ON THE EDGES OF LEAVES
If so, then look for a two-inch (5 cm) long green fellow called a hornworms caterpillar.
Solution: Pluck him off and drown him in soapy water. Do look carefully, though, because if the caterpillar has white knobbly growths on it, you should leave it be. Those little white growths are eggs laid in the caterpillar’s flesh by a parasitic wasp.
It sounds gross, but those eggs are beneficial for you. As the eggs hatch, those baby wasps will eventually eat the caterpillar and possibly a few others to boot, keeping your tomatoes naturally free of pests.