Tomatoes like warm weather and will not prosper if you plant them when the weather is cold and wet. It pays to wait until soil temperatures are at least 65 degrees Fahrenheit.
Choose early ripening varieties to ensure a good harvest since the Willamette Valley is considered a cool summer region. Ask fellow gardeners or your local garden retailer for favorite varieties that thrive in the region. You can also peruse Oregon State University's list of tried and true tomato varieties for Willamette Valley gardens.
Early summer is a great time to transplant peppers, eggplants and herbs, and to sow lettuce, chard, beans, radish, corn, cucumbers and squash.