Green Daily

When the first sunny warmer days of the late winter season arrive, it is tempting to get outside immediately to begin planting this year's garden. However, the first early warm days can be deceptive. To guarantee seeds planted will sprout into new growth and young plants thrive into optimum fullness, it is best to determine when the last frost in your area is likely and refer to the hardiness zone map to match up plants to the climate most supportive to the life of the plants you want to grow.

Based on a 10 degree Fahrenheit difference in the average annual minimum temperature between each zone, the US Department of Agriculture's has created hardiness zone maps designating 11 different North America climate zones. The hardiness zone maps include Canada, the US and Mexico.

Finding your zone will help in choosing plants that will grow best based on your zone. Not all plants grow well in all climates. We have published the maps in the gallery Gardening Guide: Hardiness Zone, First Frost, Last Frost Reference Maps.

To determine the last frost and first frost for your area, we have created an easy to use Last Frost First Frost Reference Chart. In addition to the chart, you can use a soil probe thermometer to obtain the most accurate reading of soil temperature. Normally, instructions on how to use the soil probe will be included in the soil probe kit, but if you find one without instructions, it is fairly easy to use.

Over the course of a week to 14 days, insert soil probe two inches into soil each day around noon in an area that does not get direct sunlight to get an overall average of the soil temperature. For early cool season seed germination and planting, the soil temperature needs to be 40 degrees. For late warm season seed germination and planting, insert soil probe four inches into the soil. The soil needs to be at least 50 degrees. This will let you know when it is safe to start planting.