That doesn't mean warm... growth will not start until the soil reaches about 70 degrees. Window sills can be quite chilly at night, when the sun isn't shining. Also the seeds may have been cooked if the sun shines in really hot in that place... Moderation in all things is best
I think I'll need to get the temperature up a bit I don't tend to use the central heating in the winter unless it's exceptionally cold
In my part of Arizona, I start my pepper seedlings in February in the warmest south-facing window in my house.
Starting tomato seeds. that is only seeds I've ever started. Plan to try broccoli, this year as it is easy to freeze. I have a small garden, but with skyrocketing prices, I plan to expand.
My pepper seedlings have emerged, inside my house. I wait to start the tomato seedlings, because they grow faster after emergence, and nothing can get transplanted from my tiny greenhouse to the garden until after the last frost in April. Meanwhile, out in the garden, preparation of the planting beds continues.
I would start off small, then get bigger... In March I will start seedlings inside with a warming mat, in a sunny place. April will bring some warmer weather, but their could still be frost. But then it is time to prepare larger pots with good soil or creating some raised beds for the seedlings to go into. From Wikipedia: Raised-bed gardening is a form of gardening in which the soil is raised above ground level and usually enclosed in some way. Raised bed structures can be made of wood, rock, concrete or other materials, and can be of any size or shape.[1] The soil is usually enriched with compost.[2] In many places it is wise to line the bottoms of the beds with wire screening to keep out voles, moles and other creatures that like to dig underground and eat the roots of plants. This year I may just stick with a garden on my large front deck. I can easily block the stairs so that deer and larger varmints will stay off the deck. I use a variety of pots in different sizes, depending on what I am growing! I have used 20 gallon bins for growing potatoes, and small pots for herbs of all sorts. Carrots like a deeper soil, as do many larger vegetables. I have great luck with cherry tomatoes, peppers of sweet and hot varieties, and chard. I have not tried kale yet, as I am not too fond of it... I know there are lots of gardening books out there, but George Van Patten's is really helpful! Amazon.com It covers all types of gardening, not just hydroponics!