All over the internet you will see gardeners swear by heat mats for getting their starters going in the spring. Given their ubiquity we wanted to ask if they really were necessary or if they’re just another gardening fad going around.
Long story short, no, heat mats for seed are not necessary.
In the rest of this article we’ll take a look at why, where they can help, and if you should use them.
What Are Heat Mats?
A heat mat is what it sounds like, a mat that when plugged in generates heat at a specific temperature. When used with starter cell trays, heat mats purportedly help the soil stay at optimal growing temperatures and can aid in germination by lightly heating the starter environment.
Now, is that true? Sure heat mats can help when used properly with seeds that need warmer temperatures to start, but let’s explore that.
Why Would You Use a Heat Mat?
Heat mats help heat your soil so that your seeds can germinate better. So what temperature does your soil need to be? If you’re starting your plants inside we would hope that your room temperature is somewhere near 70F. The soil will be some degree cooler than that, but not my too much.
So for a lot of seeds starting them with a heat mat will be wholly unnecessary. It can help keep the temperature up, but you don’t want to push the temperature up too much as that can be counter productive and kill your seeds!
Heat mats are most useful when your indoor temperatures are low or inconsistent and your seeds require higher temperatures to germinate. If your indoor temperatures are high, consistent, and you cover your seed trays, heat mats are unnecessary and potentially harmful.
Benefits of Using a Heat Mat
When a heat mat is appropriate you will end up with seeds that germinate faster, a more even rate of germination, and better overall set of starters. That sounds promising, and it is, but the key point here is that this is when it is appropriate. If you start cool weather plants indoors with a heat mat the seeds might grow poorly or not at all.
To get the most benefits you need to understand when the heat mat will be a useful tool to use.
Heat Mats Aren’t All They’re Cracked up to Be
If you can start your plants in early spring outside, as many people do, heat mats are obviously not a requirement. They can be helpful and in some cases are an appropriate tool to use, but like most things, they have a right time and a right place to be applied and shouldn’t just be used across the board in all situations.