Before you start your seeds indoors, you need to know your last frost date. My last frost date is April 24th. It is generally recommended that you should start tomato seeds 6-8 weeks before your last frost.
Go to Farmer’s Almanac and put in your zip code to find your last frost date.
Then I look at a calendar and count back 8-6 weeks. This is how I decide when I need to plant my tomatoes.
After you figure out your last frost, it is time to plant your seeds. For seed starting you should plant your seeds into a seed starting soil. Seeds do not need any fertilizer to germinate. The seed has all of the nutrients and energy it needs to germinate inside. Your seedling doesn’t need any fertilizer until it has developed its 1st set of true leaves. The leaves that emerge from the soil are cotyledons, they are not true tomato leaves. They will eventually fall off.
I choose to start my seeds in small seed starting cells/pods to start off and will pot them into bigger containers once they need it.
You can start your seeds in larger containers to start, but you run the risk of dampening off (when seedling stops growing and falls over at the base of the stem). The bigger the container you start with, the more water the container will hold. Seedlings start by shooting out 1 root from the seed (called a radical). That one root can’t absorb all of the water that a solo cup can hold. Excess moisture can eventually lead to problems in your seedling. This is why I choose to start in smaller pods.
I used a 72 cell tray to start both my peppers and my tomatoes. 36 tomatoes and 36 peppers.
Pre-moisten your seed starting mix before you plant your seeds. This will prevent your seeds from moving around after you put them in the hole.
Poke a hole into your soil about 1/4 in deep. Depending on how good your seed’s germination rate is you may need to plant more or less seeds per hole. Generally, I plant 2 seeds per hole. For seeds that are older and have lower germination rates I plant 3 to guarantee one comes up.
After you’ve planted all of your seeds, put your plants in a warm place. Tomatoes need at least 70 degrees Fahrenheit to germinate. I use a heat mat to keep mine warm.
If you do not have a green house you will need to put plastic wrap or a humidity dome over top of your plants in order to keep moisture in. I keep mine in a little 5 shelf green house in doors, so I do not put a dome on mine.
It is important that the soil stay moist. The plants need moisture in order to germinate.
It takes around 5 -12 days for tomatoes to germinate. If you use a heat mat and keep the soil moist, the faster they will germinate.
Once the tomato seeds have emerged from the soil, they need light right away to avoid getting leggy. A sunny south or west facing window is best. If it is in your budget, look online for a $20-$40 grow light on Amazon. Honestly, the ones in that price range will work perfectly for a small set up. Do not leave the light on 24 hrs., plants need “rest” just like we do. 16 hrs is recommended for strong healthy plants.
After the seedlings are completely out of the soil I start putting a fan on them. This mimics wind and will make them stronger. I use a small clip fan that I clip to my shelf. You can also brush your hands over top of the seedlings if you do not have a fan.
After my tomatoes have formed their first set of true leaves I will pot them into a bigger container using a fluffy potting mix. (I like to use Pro-Mix).
I hope this helps you start your tomato seedlings! Best of luck!
If you have any question leave a comment below.
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Eager Gardener 