Tomatoes, peppers, squash, basil, cucumbers and beans are all warm season vegetables so do not plant seedlings out until the night temps are above 50 degrees. This means mid to late May in the Pacific Northwest. There are also cool season edibles such as lettuce, cabbage, radish, peas, kale and cole crops that can be planted earlier in the spring such as late March or April depending on your type of soil and location of the garden. A local gardening expert or Master Gardener would be the best source of information for exact dates in your micro climate. Another easy answer is to just wait until June to plant. Then the soil is warm and you have a better chance of success with all heat loving plants. Keep growing, Marianne Binetti