Saturday, April 12, 2014
Different vegetables require different ideal soil temperatures for germination. An early start is not necessarily the best way to get excellent germination and strong, healthy plants.
Summer veggies like tomatoes, eggplant, peppers, cucumbers, squash, and beans love a little extra heat. Tomatoes, eggplant and peppers need temps at least 60 F to germinate in a timely manner. If you try and start the summer lovers in cold soil, many times the seed will rot before it sprouts.
A good rule of thumb is at least 70 F soil temps for starting summer veggies indoors. You can buy a simple, cheap heat map at any big box store.
For cold crops, hotter is not better. Lettuce will not germinate if the soil is above 80 F. This is the reason you may need to start lettuce indoors during the dog days of summer unless you have a cool, shady spot to start the seeds.
Here is a link to a table on % germination rate and days for seedlings emergence for different daytime soil temperatures: http://tomclothier.hort.net/page11.html
If you want to go high tech, I found that using an Aerogarden with the seed starting insert gave an almost 100% germination rate for any type of seed.
Here is a link to their web page: http://www.aerogarden.com
Look for the "Garden Starter System" accessory for the seed starting insert.
It can be tempting to start all your seeds as soon as you get them. If you are starting them outdoors, be sure they are sown when the temps are right for the type of crop; follow the seed packet instructions.
If growing indoors, you can modify the conditions to what suits the type of veggie you are sprouting.