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Why Start Tomatoes from Seed?

This is a great question and one I ask myself every time I plan to do it. Honestly, there is something to be said for walking or driving to a good quality nursery, picking out their healthiest tomato plants, bringing them home, digging a hole in the ground, and just dropping them in. Easy peasy…But then, where is the fun in that?

For a few years I started my own tomatoes, then last year I decided to push the easy button and go the plant nursery route. But here I am again, planning to start my own tomatoes this year. Am I a glutton for punishment? Do I like to make extra work for myself? Do I like the look of my living room with the window sills full of dozens of messy, dirty little plants…some of which have attracted fruit flies? I can definitively say, “No”, to all of those questions.

With a rose colored glasses perspective, I like to think it’s actually my quest for small victories. I know it seems like a small thing, but the experience of planting all those tiny seeds, nourishing the little plants with light, water, and touch, (Yes, touch…I’ll get to that later), and then watching them grow into these behemoth tomato plants full of fruit, is one of the greatest accomplishments of my life.

Also, ego. You can walk your amateur gardener ass into a room of diehard expert gardeners, have no idea what you are talking about, and the minute you drop the bomb…”I start my own tomatoes”…you now garner mad respect. You have joined the gardening VIP club and you are now sitting at the winner’s table. It doesn’t matter if you picked only a single tomato off those plants of yours. You just have to say the words, “I start my own tomatoes”, and then strategically drop your favorite salsa recipes into the conversation, because it’s the only way you could ever use all the bushels of tomatoes sitting on your kitchen counters, and “Boom!”, you’re an expert.

You’re welcome.

But Seriously, What is the Advantage of Starting Tomatoes Indoors?

What is the Advantage of starting tomatoes indoors from seed? Starting tomatoes indoors, when its still too cold to plant outside, gives you a head start on the growing season. If you plant tomato seeds in the ground at the point the outdoor temperatures won’t kill them, you are probably already too late. The tomato plants will never grow fast enough to produce a decent harvest in the time you have before the first winter frost sets in. Tomatoes can be finicky, and they have a very specific window of time where temperatures are ideal for them to set and grow fruit.

Another reason to start your own tomatoes is that healthy, flourishing seedlings do better at being transplanted into the ground, and they yield a better crop. You have no idea how store-bought plants have been treated. Were they exposed to chemicals? Or did they endure other stress which can affect their productivity? Store bought plants are also commonly root bound, which also impacts their ability to thrive. (You can usually tell a plant is root bound if the roots are growing out of the bottom of their container.)

When to Plant Tomato Seeds Indoors

Admittedly I am running behind this year. The last time I started tomatoes indoors, I planted the seeds indoors, in starter trays, on March 14th, and I transplanted them into my garden boxes on May 16th. I am still going for it though. If I get seeds into dirt this week, that gives me until the end of May to get them into my planter boxes. That’s plenty of time, right?

When to Start Tomatoes in Oregon

There is conflicting information out there, but my experience is that in Oregon you should seed your tomatoes indoors in mid-March, and you should transplant them outdoors at the end of May or perhaps the very beginning of June.

Where to Buy Tomato Seeds Online

Once of the other reasons I love to start tomatoes from seed is that it opens a vast number of options for tomato varieties that are not available as starts in your local home improvement or garden store. My “go-to” seed company to buy tomato seeds online is Park Seed. They have a gorgeous palette of conventional and heirloom tomato seeds in all shapes and colors, and perusing their catalog to place my order every year can be likened to a six year in 1985 perusing the toy section of the massive Christmas edition of the Sears Catalog. It brings me pure joy and childlike anticipation. 

For optimal results, I recommend trying a combination of early producers and conventional producers, determinate and indeterminate, heirloom and non-heirloom, and a variety of sizes and colors.

Planting Tomato Seeds in Trays

When planting your seeds, a smaller container is better, so you can concentrate water and nutrients.

I have used containers from the dollar store, bio degradable starting trays from Amazon, and this year I am using a self-watering plastic tray from Target. I chose the self-watering tray because a past challenge I had was mold on my biodegradable trays and plant roots because they retain so much moisture. On the other extreme, I have also lost a bunch of my starts to dehydration after a long weekend away at the Coast or at Mt. Hood. With the self-watering tray, I can get some of my freedom back and shouldn’t have a mold problem.

Plant two seeds per cell. This doubles your chances of success. Once the seedlings start to grow, identify which one appears to be the healthiest, with the sturdiest stem, and then gently remove the other seedling, to leave only one.

As you plant your seeds in your starter trays or containers, don’t forget to label them. I can guarantee in a few weeks, when you go to transplant them, they all look the same and you will not remember what you planted where.

Soil for Tomato Seedlings

I prefer to grow my seeds in coconut coir concentrated seed starting mixes, made from coconut husks. It comes in brick size blocks, and you add water to expand it into a soil like growing medium. It supposedly holds the perfect amount of moisture and aids in nutrient absorption for your baby plants. It’s also easy to find on Amazon. There are also a number of soil mixes made specifically for starting seeds that you can find in stores and online.

The point to remember is that your starts need to stay moist at all times, so using a growing medium that retains moisture is key to keeping your baby plants from drying out.

When watering delicate, fragile baby plants, use a spray bottle, (on the “mist” setting, as opposed to the “stream” setting). Pouring water over the little starts can drown them or crush them, so be gentle and spray them frequently enough to prevent the soil from drying out. When not using a self-watering tray, I spray my starts two to three times a day.

Tomato Starts Need Light

Spindly or leggy plants is one of my greatest “lessons learned” from the first time I started my own tomatoes. Within a couple of weeks my tiny baby tomato plants looked like a floppy piece of yarn. They were “spindly”. What was the problem? Not enough light. Turns out setting my start trays in a sunny window didn’t cut the mustard. Tomato starts need LOTS of light, so invest in a little grow light. I got mine on Amazon for about $30 and it made all the difference. Position the light as close to the plants as possible…like, I know people who place them as low as an inch from the plants. Leave it on all day and turn it off at night. Tomatoes are living things. Just like your kids won’t grow faster if you leave the lights on in their room all night, so it goes that your tomato plants need to experience the cycles of night and day to thrive. So, at night, turn off the grow lights and give them a break.

Speaking of Spindly tomato starts…remember before when I mentioned “touch” as I was describing how I take care of my tomato plants? It turns out your tomato starts need exercise to create a strong stem. So, a few times a day, gently run your hand over their tops and move them gently. If you are less “Helicopter” and more of a “Tough Love” kind of plant parent, then you can simply rotate the starter tray a few times a day. The baby plants will respond to the change in the direction of sunlight by moving themselves towards the sun, thus getting the exercise they need to strengthen and thicken their stem. If you want the most well-adjusted tomato starts possible, do both.

When to Fertilize Tomato Starts

I don’t add fertilizer when I plant my tomato seeds, but I add a very small amount of tomato fertilizer after the first true leaves have formed and I move them to a larger container, and then again when I transplant them into my planter boxes. Fertilizer is a whole other conversation, but suffice it to say, you can begin with a fertilizer specially formulated for tomatoes and be very careful about how much you add. Too much of the wrong nutrient can result in huge leafy tomato plants with little to no fruits.

Have you ever noticed the stem of a tomato plant is furry? A fun fact to know and tell is that the stem of your tomato plant will grow roots, if it’s in the ground. So, every time you transplant your tomato plant, do the following: Pick off the bottom leaves and then plant your tomato start in the dirt up to the bottom of the next set of leaves.

Transplanting Tomato Starts

Because I like to make work for myself, I transplant my tomato starts two times. My first transplant is from the starter tray into a larger container similar in size to the ones you buy plant starts in at your local garden store. This gives the plant a little more space to grow and avoids them becoming root bound as they grow.

The first leaved that appear on your starts are called Cotyledons. They are not actually leaves, as they are part of the seed or embryo of the plant. Your tomato starts are ready for their first transplant when the first set of “true leaves” have grown in.

When you tomato seedling has formed its first set of true leaves, it is time for the first transplant. I just keep and reuse the little plastic pots from other plants I have purchased at local nurseries. They are free and the perfect size.

Fill the pot about halfway with potting soil. Remove the cotyledons from your seedling and place the seedling on top of the soil, then fill the pot with soil up to the bottom of your seedling’s true leaves. It seems like you are planting the seedling too deep, but this will allow the stem below to grow roots and will create a sturdier plant. You can add a small amount of tomato fertilizer to the soil in the new container before transplanting.

Make sure you continue to label each container so you don’t forget what plant is in which container.

Continue to keep your starts in good light, indoors, (use your grow light!). Keep the soil moist and continue to rotate them and “pet” them…(and talk to them, or sing to them, or whatever floats your boat.)

Hardening Tomato Starts

About two weeks before you are ready to plant your tomatoes outside, you should harden them. The goal of hardening your starts is so they adapt to the weather and elements, such as temperature changes, wind, direct sunlight, and rain.

Start by placing your starts outside for about an hour a day. After three or four days, if your plants seem to be tolerating the elements, increase the time to two or three hours a day. Over the course of the next couple of week, systematically increase the length of time you leave your starts outside until they have been outside at least one entire day and night.

Once your tomato starts are tolerating the outdoor elements, they are ready for their second transplant…this time into the ground or garden box. Follow the same process as before. Dig an appropriately sized hole, add a small amount of fertilizer to the bottom of the hole, mix it around a bit, remove the lowest pair of leaves from your plant, and bury the starts up to the bottom of the next set of leaves. Water the plants when you are done.

I have one last tip before we wrap up. My hope for you is that, come the height of summer, your tomato plants are thriving and producing more fruit than you can eat. Some tomato varieties, especially heirloom, can grow to be over four feet tall and the fruit can be very heavy. I advise you avoid the lightweight tomato cages that you find in the garden department of your local home improvement store. Instead, invest in sturdy, heavy duty cages. When you are first planting your starts in the ground it is hard to imagine you need this kind of support, but if you have ever had a beautiful, thriving heirloom tomato plant completely topple over its supporting cage, at the height of its fruit production, you know it’s best to plan ahead and spend the extra cash on quality tomato cages.  

Good luck and happy planting!