Seed-starting: when to plant vegetables

The following table is Susan's personal guide and shows suggested vegetable seed-starting guidelines for USDA zones 5 and 6. If you live in a warmer climate, check the seed packets for the timing of your plantings. The "Indoors" column refers to the date you would start seeds indoors. If a crop is only listed under "Outdoors," that means it should be sown directly into the garden.
CropIndoorsOutdoors
Arugulasow directly Apr. 15 and/or Aug. 15
ArtichokeMarch 1transplant May 15
BasilApr. 15transplant May 30 OR sow directly outdoors May 30
Bean (pole or bush)Maytransplant May 15 OR sow directly outdoors May 15
BeetApr. 7 and/or Aug. 15
BroccoliMar. 1 to Mar. 15transplant Apr. 21 to May 1
Carrotsow directly Apr. 15
CeleryMar. 15transplant May 15
CilantroApr. 1 OR the first week of August so leaves are plentiful during tomato harvest
CornMay 1transplant May 15-20 OR sow directly outdoors May 15-20
CucumberMay 1transplant May 15 (with protection) to June 1
EggplantMar. 1transplant May 15 (with protection) to June 1
KaleMar. 1 or July 1 (winter crop)transplant Apr. 15 or Aug. 15 (for winter crop)
LeekFeb. 1 to Mar. 1transplant May 1
Lettucesow directly Apr. 15
MelonMay 1-15transplant May 15 (with protection) to June 1
ParsleyMar. 1transplant Apr. 15-May 1
Parsnipsow directly Apr. 15
PeaApr. 10transplant Apr. 15 OR sow directly outdoors Apr. 15
PepperMar. 15transplant May 15 (with protection) to June 1
PumpkinMay 1-15transplant May 15 (with protection) to June 1
Spinachsow directly Apr. 15 and/or Aug. 15
Squash (summer or winter varieties)May 1-15transplant May 15 (with protection) to June 1
Swiss chardsow directly Apr. 15
TomatilloMar. 15-30transplant May 15 (with protection) to June 1
TomatoApr. 1transplant May 15 (with protection)