Section 1: Tomato (Solanum lycopersicum) History
An Introduction to tomatoes
Tomatoes originated in the Andes Mountains in South America, where wild varieties still thrive today. The fruit — which was originally small and yellow — was cultivated and used throughout South and Central America by at least 500 BCE. The pre-Mayan civilization of Central America and modern-day Mexico called the fruit “xitomatl” and the Aztecs called it “tomatl,” which are both very similar to tomato’s modern day pronunciation.
It’s unknown whether Hernán Cortés (a Spanish conquistador) or Christopher Columbus (the Italian-born explorer/conquistador contracted by Spain) were the first to bring the fruit back to continental Europe in the late 1400s to early 1500s. Regardless of who brought it back first, tomatoes quickly spread from Spain throughout the European continent — especially once people realized the fruit was edible, not poisonous.
Tomatoes soon spread throughout European colonies and trading locations around the world, even as far away as Asia. Each region of the world where tomatoes were introduced soon began breeding their own unique varieties of the fruit that were adapted to the local environments and the specific flavor preferences of the culture and its cuisines.
Today, the USDA says that there may be as many as 25,000 varieties of tomatoes—not bad for 500 years of international breeding! With 93% of all American gardens growing at least one variety of tomato each year, that number might just continue to increase.
We hope you’ll reflect on the remarkable global voyage your tomato seeds have been on before arriving to your garden, and save seeds for future years so their grow journey continues! Read this tomato growing guide to learn how.
Section 2: Seed Germination
You can germinate your tomato seeds one of two ways:
- Germinate indoors: A more time-consuming approach since you have to to keep track of watering your seedlings & making sure they are getting enough light. However, most experienced gardeners start their tomato seeds indoors since that provides earlier harvests and larger yields over the entire growing season.
- Germinate outdoors via direct seeding into your soil: An easier, less time-consuming approach, but you don’t get yields until later in the season since you get a late start. Also, you have a greater risk of plant loss during the seedling stage due to outdoor garden pests.
Use whichever method (starting indoors or outdoors) is ideal for you given the amount of time you have to commit, your level of gardening experience, and the resources available to you.
Option 1: Starting your tomato seeds indoors
Part 1. WHEN TO START YOUR SEEDS
6-8 weeks before your last frost date is the ideal time to start your tomato seedlings indoors if you want to get an early jump on the growing season and get the largest possible yields. (You can find your last frost date here.)
If your last frost-date has already passed, no problem! You can easily direct sow your tomato seeds into your garden as long as you have around 3+ months of warm weather ahead of you. Smaller-fruited tomato varieties need a minimum of 50-60 days to produce fruit, whereas larger varieties require 90+ days to produce.
gPart 2. SOWING YOUR INDOOR TOMATO SEEDS
Sowing depth: Sow your tomato seeds 1/4″ deep in your choice of organic seed starting mix or potting soil (see recommended products below).
Don’t fill your seed cells with soil from your garden, since this tends to harden into an impenetrable brick. Instead, we recommend that you buy a ready-made organic seed starting mix or a light potting mix like Fox Farm potting soil.
Experienced gardeners or gardeners starting large numbers of plants often prefer to mix their own seed starting mix. If you want to make you own DIY seed starting mix, here’s our recipe.
We recommend starting your tomato seeds in one of the following:
No matter which of these three options you use for your tomato seedlings, be sure to put a solid plastic seed tray or an old cookie sheet underneath them to keep water from dripping onto your floor or furniture.
And don’t forget to label your cells with plant markers so you can keep track of which variety is which!
Part 3. GERMINATING CONDITIONS
The ideal temperature range for tomato seed germination is 75° – 85°F.
Place your seed trays in a warm spot in your home (such as a sunny window). For best results, use a seed heat mat (which is also very helpful for starting other summer seeds like eggplants, ground cherries, peppers, etc.). We’ve had significantly better germination with our summer seeds since using a heat mat.
Tomato seed germination time: If the soil is kept damp and temps are maintained between 75° – 85°F, your tomato seedlings will germinate within 7 days.
If the temperatures are cooler than this, your seeds may take an additional 1 – 2 weeks to germinate. Too cold (below 65°F) and your tomato seeds will not germinate at all.
To help with germination, make sure your seed containers stay moist, but not wet. The moisture level should feel like a well wrung-out sponge.
Be sure to also use a gentle watering method such as a misting bottle or a watering can with a very soft pour to prevent the tomato seeds and soil from dislodging. It’s important that your soil mix be thoroughly moistened BEFORE your seeds are added, or you’ll have difficulty getting the soil moist without dislodging the seeds.
The frequency you’ll need to water your tomato seedlings on an ongoing basis varies. Start by watering your seed containers every 24 hours unless they stay really damp. If that happens, hold off and check on them again in a few hours.
Note: Your soil will dry out faster on seedling heat mats or under hotter temperatures.
Again, go for the happy medium of soil with a similar dampness as a wrung-out sponge. Seeds allowed to sit in puddles quickly rot whereas tiny seedlings in crusty, dry soil will soon die due to lack of moisture.
Part 4. ONCE YOUR TOMATOES HAVE SPROUTED
As soon as your tomato seeds have germinated/sprouted above the soil surface, place them in front of a sunny, south-facing window in your home (e.g. the window that gets the most sunlight throughout the day).
Do note that newer, modern windows block a lot of the light spectrum that plants need to grow, so if you have energy-efficient windows, you might want to consider getting grow lights for your seedlings. Here’s how to build your own DIY grow light system.
It’s crucial that your tomato seedlings get adequate light—an absolute minimum of six hours of direct light each day—otherwise they’ll quickly become weak and “leggy” (tall and spindly).
Tip: If growing in front of a window, periodically turn your seed trays so that the same side is not always facing towards the sunny window—this will prevent the side furthest away from the window/sun from getting leggy or stretching sideways towards the light.
When the daytime temperatures begin to get into the 60s, you can start putting your tomato seedlings outside in direct sun. However, if you don’t “harden off” your seedlings before exposing them to direct, unfiltered sun, you risk them becoming sunburned.
You can read more about how to harden off your tomato seedlings in the Transplanting Outdoors section below.
Part 5. FEEDING YOUR TOMATO SEEDLINGS
The first two leaves on your tomato seedlings are called “cotyledon” leaves. The next leaves that develop are the first set of “true leaves.”
About 10-14 days after germination, your tomato seedlings will get their first true leaves. At this point, you’ll need to consider nutrition, depending on whether your seed starting mix did or did not contain nutrition.
When/if your tomato seedlings need nutrition (yellowing leaves or stunted growth are sure signs), you have two options:
- Use Organic Liquid Fertilizer – Start applying a water-diluted organic liquid fertilizer 1-2 times per week. (We like liquid kelp fertilizer.) Dilution ratios vary from product to product, but watering at half-strength (half of what the bottle recommends for feeding mature plants) is a good rule of thumb for seedlings. Be aware that over-fertilizing your plants can make them extra attractive to pest insects like aphids which can proliferate rapidly indoors since no predatory insects are around.
- Transplant Seedlings Into Larger Pots/Cells: This is also called “potting up” in gardening lingo. If your tomato seedlings need nutrition or are running out of space in their smaller cells, you can transplant them into larger, 3-4 inch diameter pots or cells using a seed starting mix that contains worm castings, compost, or slow release organic fertilizer.
Next, keep a close eye on your tomato seedlings to make sure they stay healthy: well-sunned, well-fed and well-watered until your last frost date has arrived. You’re almost ready for transplanting!
Option 2: Starting your tomato seeds outdoors
After your last frost date has passed, directly sow your tomato seeds ¼ inch deep in your garden. Make sure the soil is moist, but not wet, until seed germination/sprouting.
Other than weather, the greatest danger to your young outdoor tomato seedlings is cut worms, which will chew through the stem of your young seedlings, killing them. To stop cutworms from eating our young seedlings, we use the “stick trick.”
The “Stick Trick”: Once your outdoor tomato seed has sprouted, find a stick roughly the diameter of a toothpick and gently insert it into the ground directly next to your tomato seedling’s stem. The cutworms are tricked into thinking the hard stick is the tomato seedling’s stem and move on.
Jump to Sun, Soil, Water section >
Section 3. Transplanting Outdoors
If you started your tomato seeds indoors, follow the instructions below. If you germinated your seeds outside in your garden, you can skip this section and head on over to the Sun, Soil & Water section.
Part 1: “HARDENING OFF” YOUR TOMATO SEEDLINGS
Outdoor direct sunlight is always more intense than either indoor grow lights or light filtered through a window.
Many new gardeners make the mistake of immediately transplanting their tomato seedlings outdoors into direct sunlight before “hardening” them off. This mistake can cause extreme sunburn that severely damages or kills your tomato plants.
To be safe, plan to harden off your tomato seedlings outdoors over the course of a week as follows:
- Days 1-3: Place your tomato seedlings outdoors in a shady spot that will only get 3-5 hours of direct sunlight throughout the day.
- Days 4-5: Place your seedlings in a slightly sunnier spot that will get about 5-6 hours of direct sunlight.
- Days 6-7: Place your seedlings in a full sun spot (6+ hours of direct sunlight).
During this transitional period, be sure to pay attention to these factors:
- Water – If your tomato seedlings’ leaves appear limp, this is likely due to lack of water. Try to keep their soil moist, but not wet.
- Sunburn – If you notice your tomato seedling leaves beginning to look white and papery, they’ve gotten sunburned. Put them in a part-full shade spot for a few days and allow them to recover. Again, if you don’t properly harden off your seedlings, they can get severely sunburned, which will either slow their growth to a crawl while they recover or possibly kill them (if they’re small or weak).
- Cold – Be sure that you bring your tomato seedlings inside any time the temperatures drop into the 40sºF.
Part 2: TRANSPLANTING TOMATO SEEDLINGS OUTDOORS
A. Last Frost Date
Once the last frost date for your area has arrived and your tomato seedlings have hardened off, it’s time to transplant them outdoors.
Before you start planting, make sure to look at your local 10 day weather forecast on www.weather.com. If you see any day or night temperatures below 45°F, hold off on transplanting. This tip has saved us quite a bit of heartache over the past few years as extreme weather and temperature fluctuations have becomes the “new normal.”
B. Tomato Spacing
Plant spacing (distance between plants) and row spacing (distance between rows) is extremely important to consider when planting your tomatoes. There is some spacing variability depending on the growth habit of the specific tomato variety and type you choose – dwarf, determinate, indeterminate, etc. So check for specific spacing recommendations on your seed packets or garden center tag. Planting your tomato plants too close together can lead to poor air circulation, which can cause tomato diseases to proliferate and spread.
As a general rule:
- Plant INDETERMINATE tomato plants about 3′ apart in rows about 4′ apart, and
- Plant DETERMINATE tomato plants about 2.5″ apart apart in rows 4′ apart.
C. Tomato Transplanting Trick
See all those little “hairs” on your tomato seedings’ stems? Those are called “adventitious roots.”
Adventitious roots will become soil roots when they come in contact with soil. Want your tomato plants to require less water and fertilizer while also holding up better against strong wind/storms?
- For any tomato seedlings over 6″ tall, carefully trim off all the side branches below the top growth tip (use clean clippers or scissors and cut each branch back to the stem).
- Next, dig a surface trench in the soil long and deep enough to accommodate the tomato seedling. (Ideally you can also add compost or worm castings to the trench.)
- Lay the tomato seedling on its side in the trench with the growth tip bent slightly up so the top remaining branches and growth tips are a couple inches above the soil surface.
- Bury the tomato seedling’s stem.
Within about a week, the stem will have begun forming roots and your transplanted tomato seedlings’ will begin growing vigorously. To read more about this trick, read our article 5 tomato growing tricks you should start using.
D. Soil Amending
- Castings/compost – Dig a 1′ x 1′ hole and fill it with 50% castings and 50% garden soil before transplanting your tomato seedlings.
- Organic fertilizer – Loosen the soil in a spot about 3-4x larger than the tomato seedling root ball. Mix in slow release fertilizer at the application rate described on the product package, then transplant your seedling into the spot.
When filling the hole back in around the tomato seedling, the soil used should be actual soil. You should not fill the hole with recognizable chunks of mulch, kitchen scraps, leaves, lawn clippings, or other undecomposed organic matter.
E. Top-Dressing Your Beds With Mulch
We can’t overemphasize how important top-dressing your beds with wood chips or mulch is for building and maintaining healthy soil, regulating soil moisture & temperature, and blocking unwanted plants – aka “weeds.” After you plant your tomato seedlings, make sure to put at least a few inches of mulch on top of the soil surface around your plants, if it’s not already there.
Again, mulches should always remain on the surface of the soil (aka “top-dressing”).
If you have ever heard of mulches or compost “stealing” nutrients from garden plants (especially nitrogen), mixing carbon-rich mulches into the soil instead of letting it sit on top of the soil is what causes this problem. You can read more about your plant’s long term soil requirements in the Sun, Soil, and Water section below.
Immediately after planting, give each newly transplanted tomato seedlings a deep watering around the base of the plant. Doing so:
- helps the surrounding garden soil fill in around the root ball;
- allows your tomato seedlings’ roots to fully come into contact with the garden soil;
- expedites plant growth and minimizes transplant shock.
G. The Stick Trick
Newly transplanted seedlings are often “chopped down” by “cutworms,” which come by their name because they chew through the base of young seedlings, killing the plant.
We’ve had 100% success stopping these pests. We simply find a stick roughly the same thickness as a toothpick and stick it in the ground right next to the stem of our seedlings. When the cutworms come along and feel around the seedling, it is tricked into thinking that the plant is too tough to cut down, so it moves along to its next victim.
Part 3: TOMATO CAGING
Our indeterminate tomatoes (varieties that keep growing and producing all season long) will become huge plants by the end of the growing season, often towering to 8′ tall or higher.
Our determinate tomatoes (varieties that produce a single large yield all at once and then get removed from the garden) can reach 5′ tall. To reduce disease, increase air circulation to the leaves, make it easier to maintain the plants and harvest the fruit, we always use some sort of “training” system for our tomato plants. *The exception to this rule: short mounding tomatoes or small cherry tomato varieties, which we let allow to sprawl/crawl on the ground.
There are lots of different options for tomato cages, but we’ve found that most wire trellises from gardening centers are too small and flimsy to help when our tomatoes are fully grown. We’ve tried a lot of tomato training systems over the years, but the one that works best for us is our “homemade” 2.5′ diameter x 6′ tall cages that we make from concrete reinforcing wire (here’s an article showing you exactly how to make your own).
The tomato cages we make from concreted reinforcing wire are tall, strong, and can be reused for many years (ours are a decade old now). We put our tomato cages over our tomato transplants/seedlings as soon as they go in the ground. This helps the plants grow up and through the cages as they mature.
It’s way easier to put tomato cages on small plants than it is to try to force a cage over and around a large plant!
Part 4: “SUCKERING”
As your tomato plants grow, you’ll notice that a new branch will form off the main stem, and between them a new growth will form. This new growth in the “V” between the stem and the new branch is called a “sucker.”
If left unpruned, these suckers will eventually grow into new branches, flowers and fruit. If you’re growing a determinate tomato variety, you do NOT want to prune your suckers since the plant produces all of its fruit at once (you’ll reduce your yield). However, many tomato growers will prune the suckers on their indeterminate varieties as it’s said to help produce larger fruits earlier in the season while also helping improve airflow in and around the plant, thus reducing disease.
In our opinion, if you’re only growing a few indeterminate tomato plants, then it might be worth “suckering” them. However, you’re more likely to spread disease if you’re constantly touching your tomato plants.
If you do choose to sucker your plants, be sure to use sanitized tools and carefully clean your tools before moving on to the next plant so you don’t accidentally spread any tomato diseases (especially problematic in warm wet climates like where we live in the southeast US).
We stopped suckering our indeterminate tomatoes a few years ago because we typically grow 50+ tomato plants each summer, and we just didn’t want to spend all day suckering them. If it’s made our fruit size or yields smaller, we haven’t noticed. It has certainly reduced the time we’ve had to spend suckering, which leaves more time for fun and food!
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Section 4: Sun, Soil, and Water
Tomato plants thrive in full-sun spots (6+ hours direct sunlight per day). However, tomato varieties that produce smaller fruit (such as cherry and currant tomatoes) can produce good yields in lower light environments, even part shade.
Planting tomatoes against a light-colored wall or fence can also increase yields since they reflect light and heat.
Tomato plants perform best in rich soil with lots of organic matter.
Five techniques that you can use to drastically improve your soil health & biological fertility are:
- “hugelkultur” (click here to read about this technique);
- polyculture plant guilds (see “Guild Plants,” the next section in this guide);
- top-dressing your soil with 3-6 inches of wood chips/mulch twice per year in the fall and spring;
- using living cover crop mixes rather than leaving your soil fallow;
- using compost from hot composting methods (Berkeley method) or worm castings. Either: a) Apply the compost/castings on top of your beds, or b) Make actively aerated compost tea (AACT) to use as a soil drench or foliar spray. (Option b gives you the most bang for your buck.) Both methods of application drastically increase the quantity and diversity of beneficial microbes in your soil and on your plants.
All five of these soil building techniques can improve your soil fertility to the point that your tomato plants may not require any additional fertilizer and virtually no additional water throughout the growing season once their root systems get established.
If you have poor soil or you do decide to use fertilizer, we recommend that you NOT use non-organic/synthetic fertilizers as these will have a compounding harmful effect on your soil over time. Instead, use a slow-release organic OMRI-listed fertilizer.
Tomatoes need approximately 1″ of water per week in normal summer conditions.
As your tomato plants mature, their root systems will develop and will be able to get more water from the surrounding soil and mycelial web (the symbiotic fungi in the soil). If your soil is healthy, your plants have established their root systems, and rain is regular, you may not need to provide any additional water to your tomato plants.
If you do need to water, be sure to:
- Water the base of the plants (not the leaves) in the morning (not in the evening). Wet leaves, especially overnight, can increase the risk of fungal diseases.
- Water deeply (shallow watering can lead to shallower root systems).
Section 5. Helpful Guild Plants/Companion Plants for Tomatoes
Definition: A plant “guild” is a polyculture plant system (multiple plant species planted together) purposefully designed to create symbiotic relationships between species, increase plant productivity and generate higher survival rates amongst the individual plants in the guild system.
If you’ve ever visited a “wild” ecosystem (mature forest or prairie), you’ve unknowingly seen plant guilds. Like people, plants tend to perform better in companion communities than they do as isolated individuals.
Some Common Plants to Consider in Your Tomato Guild:
- peppers (especially hot pepper varieties)
- bee balm
- lemon balm
- marigolds (French and Mexican)
Section 6. Edible Landscape & Containers
Part 1. Planting Tomatoes in your Edible Landscape
Oddly enough, some people don’t think tomato plants are good landscaping material. We can’t really relate since there is nothing that draws us into a garden like a lush tomato plant loaded with sun-warmed fruits.
For people with warm summers who can expect indeterminate tomato varieties to reach 10’ or longer, consider flaunting its kudzu-like proportions by growing it like a climbing rose on a trellis or garden arch. Your garden visitors will gasp in surprise when they realize they are looking at tomato vines instead of a more traditional ornamental.
For extra oomph (and as backup if tomatoes in your area succumb to blights later in the season), you can grow a “cypress” vine (Ipomoea quamoclit) at the base of the arbor. Allow the cypress vine to weave in and out of the tomatoes while attracting hummingbirds with red, pink, or white trumpet-shaped blooms. Also, the leaves of this plant are made up of feathery, needle-thin filaments that don’t shade out a fast-growing tomato!
In cloudy, cold, or shorter-season climates where even indeterminate tomatoes stay relatively short, we recommend purchasing a topiary frame (or building a DIY version) that you can train your tomato on in order to mimic a pillar or standard rose.
If you’re someone who questions a tomato plant’s ability to look great in the landscape or your local cooperative extension office says your region is prone to difficult tomato diseases like late blight, you can use the strategy of camouflage.
This involves using hardscaping elements like benches or vigorous crops as plant partners to hide or soften the effects of tomatoes in the ornamental garden. Just make sure your tomato has plenty of room, air flow, and sunlight in spite of how you blend it into its surroundings so that you still get a delicious harvest.
Using “shoes and socks” in edible landscaping with tomato plants
Some good options are using 2-3 foot tall “shoes and socks” plants in front of your tomato. Since the lowest tomato leaves tend to look the worst as the season wears on, covering the with other plants (like shoes to hide your ugly socks with holes) is a good strategy to consider. See the photo above where marigolds serve as “socks.”
You can also place more eye-catching features like a sculpture, pots, or a brightly painted bench in front of the base of the tomato plant to hide any “ugly” lower foliage.
Using odd tomato variations
Some tomato varieties are bred to be extremely dwarf and are best used as front-of-the-border accents or for dangling over prominent garden walls or stair edging. Determinate tomatoes are bred to put on all their growth and fruit at once and then die back after they are harvested (popular with market growers and with people who enjoy canning in big batches).
Determinate and semi-determinate tomatoes can work with the above design ideas but you should plan for them to be shorter (and thus use shorter garden supports for them to climb on). You’ll need to factor in what plants you plan to replace them with to fill the bare space after they are harvested and begin to decline.
Part 2. Planting Tomatoes in a Container
A. Tomato container/pot size and pacing for maximum harvest
Recommended minimum container size – min. 9-15 gallons (per 1 plants), approx. 12-20 in. diameter, 8-16 in. deep.
We’ve grown tomatoes on our patio in pots for a few years now and we’ve found that Sub-Irrigated Planters (SIPs) are really the best & easiest way to grow larger, healthier (i.e. no blossom end rot & good fruit set) tomatoes.
The first consideration when growing a tomato variety in a container is: how top-heavy is it going to get by the end of the season? Be sure to check the packet description to get an idea of what type of tomato you are working with.
- If it’s a large indeterminate tomato variety, we recommend anchoring the pot and/or using a particularly heavy container (clay, not plastic).
- Determinate and semi-determinate varieties could get big, but likely won’t need quite as much preparation.
- Dwarf tomato varieties can be treated like an ornamental pepper plant (usually 8 inches up to 3 feet tall) and will do well in smaller containers than their giant counterparts.
B. Tomato support, caging, staking
Once you’ve decided what size container to use, you’ll need to decide if your tomato will spill out of the pot like a steadily-enlarging octopus or if you plan to cage or stake it for vertical growth. Your method of support should either: a) fit in the pot with the tomato plant, or b) mount over or behind the pot.
Planning out these fine details in advance will go a long way in how aesthetic your tomato looks later in the season (an unhappy tomato is not an attractive tomato!). Well-designed tomato planters should stay where you put them and be able to provide the plant with enough moisture and nutrients in between reasonably frequent waterings and feedings.
C. Choosing tomato pot/container color
Now to the fun part! As long as your container is at least the minimum recommended volume (more is better), you can choose any color or pattern you like. We advise against multiple plants in the same container unless it is a very large raised growing bed (instead, just surround your tomato pot with other potted plants).
When choosing a color, consider that a pink-fruited tomato in a neon orange container should probably be surrounded by other over-the-top, tropical-looking plants to create a lively theme. You can choose any color scheme you like, though—the sky’s the limit… in fact, sky blue isn’t a bad idea for your container since it would nicely contrast with the dark green leaves and any tomato variety’s ripe fruit color.
Additional Reference: How and why to use SIPs (sub-irrigate planters)
Section 7. Common Pests & Diseases
A. During (Indoor) Seedling Stage
Indoor plants and seedlings (including tomatoes) are more susceptible to certain pests and diseases than outdoor plants, since there aren’t predators around to manage their populations.
Common problems you might encounter during the germination and seedling stage of your tomato plants:
- Description: Small sap-sucking insects that proliferate on young plant stems and the underside of young leaves.
- Symptoms: Sticky leaves; curled leaves; weakened, limp or dying plants despite adequate water and nutrition.
- Organic Treatment: insecticidal soaps, horticultural oil sprays, organic insecticides (neem oil works great.). The more time you can get your seedlings outdoors, the less problems you’ll have from aphids. Aphids are a favorite snack for ladybugs, parasitoid wasps, and other predatory insects that you probably don’t have in abundance inside your home.
- White Flies
- Description: Small, white flies that proliferate underneath leaves.
- Symptoms and Organic Treatment: Same as aphids (above).
- Fungus Gnats
- Description: Small dark-colored gnats; the small, white-colored larvae live in soil and eat the roots of young seedlings.
- Symptoms: Seedling growth rate slows and seedlings eventually die if untreated.
- Organic Treatment: For prevention or treatment of fungus gnats, add beneficial/predatory nematodes to your soil.
- Damping Off
- Description: Death of young seedlings caused by fungal disease.
- Symptoms: Young seedlings wither and die, sometimes suddenly.
- Organic Treatment: Prevention is the best cure for damping off. Two most important methods of prevention: 1) don’t overwater, and 2) try to keep your seedlings in an area with good air flow. Additional prevention methods: Use a sterile potting mix. Sterilize your reused seed trays before using them. If a seedling or seedling tray gets damping off, immediately remove it from your seedling area.
B. After Transplanting Outdoors: Identifying & Treating Tomato Pests & Diseases
Listing the full range of possible outdoor pests and diseases that can affect tomato plants would require a full book to cover! Do you have a tomato disease that you’re trying to identify and treat? Clemson University Extension has a great tomato disease identification (with pictures) and treatment guide.
Organic Pest & Disease Management Products
If you need to buy trustworthy, organic pest and disease control products that work, be sure to check out the curated Pest & Disease Management products in our online store.
If we had to pick one store-bought product to recommend to help prevent and treat a wide range of tomato diseases, it would be Serenade, a foliar spray and/or root drench containing beneficial microbes that fend off pathogenic, disease-causing microbes.
A healthy garden needs pest insects. Pest species provide food for beneficial species. A garden ecosystem that’s teeming with life will tend to hold the population of any one species in check.
We’ve found that by focusing on improving our soil health and using polyculture plant systems that attract and nurture a wide variety of insects, we’ve virtually eliminated all pest and disease problems from our garden.
We’d like to encourage you to be thoughtful in your approach to these potential problems. Is your soil healthy and teeming with microbial life? Have you planted other beneficial plants throughout your garden system that might help with the problem? If you wait a few days, will the “pest” become the food of a predator?
Observe your garden system and think holistically before taking any action that could disrupt the web of life. Pesticides kill beneficial insects too, not just pest insects; fungicides kill beneficial funguses too, not just “bad” funguses; etc.
Personally, we’d rather lose a plant than accidentally harm or kill wildlife.
Section 8: Harvesting
One of the many benefits of growing your own tomatoes, is you get to pick them at the absolute peak of ripeness! This doesn’t just mean better flavor, it means better nutrition.
There’s no wrong way to enjoy sun-ripened tomatoes:
- fresh-sliced with a sprinkling of sea salt, cracked pepper, garlic powder and fresh basil;
- fresh garden-veggie salsa;
- with fresh basil pesto, sliced on a nice crunchy ciabatta
- sun dried (our recipe).
Experiment and enjoy eating your fresh, ripe tomatoes as many ways as you can dream up!
Harvesting green tomatoes?
Yes, you can also pick unripe, green tomatoes to make into some wonderful foods. Large green tomatoes are ideal for the southern classic: fried green tomatoes. You can use virtually any size green tomato to make one of our favorite treats: green tomato jelly.
Need Gardening & Harvesting Tools?
Need some quality pruners or other garden tools? Be sure to check out the curated Tools & Supplies section of our online Amazon affiliate store.
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Section 9: Saving Seeds
Saving seeds is an important part of being a full-circle organic gardener. This critical step ensures that seeds are passed down from generation to generation.
Please give tomato seed saving (and even tomato breeding) a try. Also be sure to share your seeds with other people! Another benefit: seeds you’ve properly saved from your own garden will be better adapted to your specific growing environment via natural epigenetic processes.
You can save your new, open-pollinated tomato seeds (don’t bother trying to save hybrid seeds) as follows:
1. Avoid Cross-Pollination
Even though tomato flowers are “perfect” (e.g. possess both male and female parts) and are able to pollinate themselves from a shake caused by breeze/wind, different varieties of tomatoes can cross-pollinate. The most common cause of cross-pollination is bees, although tomato flowers aren’t particularly attractive to pollinators if other sources of pollen and nectar are abundant.
To avoid cross-pollination in your tomato plants, provide an isolation distance of 25 feet between tomato varieties for your heirloom tomatoes. Another option is to cover the tomato flowers of the fruit you intend to save for seed with a cloth covering, removing the cover once the fruit has set. Just be sure to shake the flowers or hand-pollinate them if you cover them to ensure that you get fruit set.
2. Select the Best
Choose the best, fully ripe tomatoes from your healthiest plants. Don’t worry: you can eat most of the tomato and still manage to extract a bunch of seeds!
3. Ferment & Label
Scoop or pour out the tomato seeds and the gel-like substance surrounding them into a small glass or jar. Immediately label the jar so you know the variety of seed you’re saving.
4. Add Water and Wait
Add a small amount of water (half cup or less depending on the size of your container). Then set your labeled container aside for 3-5 days in an indoor spot out of direct sun.
We typically put a piece of plastic wrap with small holes punched in it over the top of our container, but you can also just leave the container open if you prefer. A layer of mold will form on the top.
5. Separate the Seeds
After 3-5 days, your tomato seed “goop” will have begun to ferment. First, remove the film of mold on the top. Then add a bit more water to the container and stir.
The bad seeds will float, and the good seeds will sink. Carefully skim or pour off the bad seeds and gunk from the top of the water. Pour the good seeds through a fine mesh screen (a metal pasta strainer works well).
6. Dry & Store
Place the seeds on a drying surface that they won’t stick to. A ceramic plate or cookie sheet works well (paper towels dry the seeds well, but tend to stick).
Label the drying plates if you have multiple seed varieties. Give your seeds a couple of weeks to fully dry, especially if you live in a humid environment like we do. Once your seeds are fully dry, store them in an airtight container (add rice or silica packages to hold any moisture). You can also store the seeds in envelopes, although this will make them more susceptible to moisture damage over the course of several years in storage.
How long will your newly saved tomato seeds last?
Your new tomato seeds can remain viable (e.g. able to be grown) for 4-8 years or longer under ideal conditions.
Plant and share your tomato seeds so their grow journey continues!
10. Additional Resources
- 5 tomato growing tricks you should start using
- How to make your own incredibly strong, long-lasting tomato cages
- How to make sun-dried tomatoes
- How to make your own DIY indoor grow light system
- Complete guide to seed starting (with video classes)
- Top 5 ways to prevent or stop plant diseases in your organic garden
- Top 5 reasons you keep killing your potted tomato plants