This information came from HomeTownSeeds.com. At one point they sent me a box of seeds (a “survival pack,” or enough seeds to plant an acre) and these instructions were included. I can’t find it on their website, and I can’t find any mention of this anywhere else! It kind of makes sense, because when the conditions are right for an apple tree to get going, it would make sense that conditions are right for other seeds regardless of the date. We are lucky enough to have a neighbor’s apple tree near our garden, I will keep an eye out this year to see how it behaves!
Hardy Group- Pea, Radish, Onion, Spinach, Cabbage. Plant when soil is dry enough to work, or when apple buds swell, or about March 15-May 15.
Semi-Hardy Group- Swiss Chard, Beet, Carrot, Lettuce. Plants a week or two after Hardy group, or when apple buds are in a tight cluster or about March 20-July 1.
Tender Group- Bean, sweet corn, cucumber, zucchini. Plant on the average date of last spring frost, or when apple blossoms are open, or about May 5 to July 1.
Very Tender Group- Pepper, winter squash, tomato. Plant about two weeks after tender group, or when there are little green apples on the tree or about May 20 to June 10.