How Long Does It Take Tomato Seeds To Germinate? How To Speed It Up

By Paul Smart •  Updated: 05/06/22 •  6 min read

How Long Does It Take Tomato Seeds To Germinate? How To Speed It Up Tomatoes are incredibly popular fruit to grow at home because the homegrown tomato tastes so much better than what you can purchase from the local grocery store however one of the most common questions that is asked is how long does it take for tomato seeds to germinate?

Tomato seeds will take approximately 5 to 10 days to germinate at temperatures roundabout 68-86°F (20-30°C) according to a study published by the University of California. However, the rate of germination is significantly affected when the temperature falls below a temperature of 59°F (15°C). The table below shows the impact of temperature on the rate of germination;

Days To GerminateTemperature (°F)Temperature (°C)

Additionally, it is interesting to note that once the temperature gets above 100°F the seeds will also not germinate which is an indication that seeds are designed to only germinate when the conditions are sufficiently favorable for successful production of fruit.

Why Are My Tomato Seeds Not germinating?

In some cases, you will note that seeds do not germinate which can occur for a number of reasons, the most obvious being that the temperature is not in the ideal range for germination.  

The other reason why you may also see seeds not germinating is that they are either no longer viable or have been inhabited by the gel around the outside of the seeds which needs to disintegrate before germination can occur.

If you need to test whether your seeds are dead or not you can place them on a damp towel in a sealed Tupperware container and leave them for a few days. If they are viable they will begin to sprout over 7 to 10 days in most cases, if not the seeds are most likely dead.

Aside from these sorts of issues, the other obvious cause is having insufficient water for the plants to grow is also a critical factor in the successful growing of seeds.

How Do I Make Tomato Seeds Germinate Faster?

To optimize the rate of seed germination it is important to maintain a warm moist environment that has plenty of light. If you are trying to get tomato seeds off to it an early start to accelerate your harvest in the growing season the best way is to start the plants indoors around 4 to 6 weeks prior to the last frost.

It is generally recommended that you plant two seats per cell to ensure that all cells are occupied with at least one tomato plant. If both plants germinate then thin seedlings leaving the strongest one in the cell.

However, to optimize the growth rate the most effective way is to use a heated propagation tray as this will enable the temperatures to be controlled accurately and consistently throughout the germination period. If you live in an area that is relatively cold in winter and you also have a relatively short growing season it is a really good idea to buy a heated propagation tray.

The product that we would recommend is the ipower germination kit which features a removable seed tray and humidity dome. The removable seed tray is advantageous for these types of products because that is a component for deteriorates first so being able to replace it will extend the life of the unit significantly.

The humidity dome is also an important feature particularly if you live in a really cold area because it helps to maintain the heat that is being supplied to the seeds. To see the latest price for this item click on the link below.

Get Off To An Early Start With A Heated Propagation Tray

Optimizing The Rate Of Growth Of Tomato Plants In The Garden

Once you have got the seeds off to a rapid start the next important step is to optimize the rate of growth when the plants go into the garden. In a similar manner to germinating the seeds temperature is the key factor that will maximize growth. 

When plants are placed out into the garden you can provide them with significant amounts of protection earlier on which will allow them to develop in size and structure relatively quickly.

The easiest way to do this is to use either a cloche or a row cover. Cloches can easily be made from old milk cartons with the bottoms cut off and the lid removed however, I personally recommend that you use row covers as they will allow you to protect the plant for a longer period of time because they are generally much larger in size.

There are many different types of row covers available on the market if you need to purchase one the one we recommend is the growsun row cover because it is relatively tall which will allow the tomato plants to be protected for longer during the season maximizing the rate of growth. To see the latest price on Amazon click on the link below.

Extend Your Season With Growsun Row Covers

Additional measures that are also very important to speed up the harvest is to ensure that you pinch out side shoots which are the shoots that grow on a 45-degree angle between the main stem and the side limbs.

If these are not removed what happens is the plant will produce huge amounts of stems and foliage. This means that it is focusing it is time on the production of foliage rather than flowers and fruit.

The other thing that we also recommend is that you grow at least a few cherry tomatoes in your garden.  The reason for this is that cherry tomatoes will produce ripe fruit earlier than larger varieties in most cases because the size of the fruit does not get as large. This means that it takes less time to create the crop.

I hope you found this article useful and have great success growing tomato plants in your garden at home. If you have any additional questions or comments please leave in the section below.

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Paul Smart