The growing season in USDA hardiness zone 3 is short. There is frost into late spring and again in early autumn. Additionally, many parts of Zone 3 are at high altitudes. These factors make Zone 3 more challenging when you want to grow a vegetable garden. By choosing the best seeds for your zone and by caring for those seeds with consideration to your short season, you can have a successful harvest.
Root crops do well in Zone 3. The seeds of radishes, beets, kohlrabi and turnips all grow quickly and can be planted more than once in a Zone 3 growing season. These seeds, as well as those of carrots and rutabaga, will still be thriving in the cool fall weather. Leeks grown from seed can be harvested in a short period of time if you do not mind a smaller size. Parsnips are slow to germinate and usually take 100 to 120 days before harvest, but parsnips still do well in Zone 3.
There are some fast-growing green vegetable seeds as well as cool weather loving green vegetable seeds that perform well in Zone 3. The seeds of snap peas and pole beans germinate quickly and produce well in Zone 3. The seeds of garden cress produce in 12 short days. The seeds of spinach, chard, parsley, cilantro and basil also are quick to produce a crop. The seeds of radicchio, collards, kale and escarole grow well in cool fall weather.
Some seeds do best in Zone 3 if they are started indoors several weeks before planting time. Keep the seeds in a warm (70 degrees F) room with plenty of southern sun exposure. Plant the seeds of cabbage, endive, chives, Brussels sprouts and broccoli six weeks before the recommended planting time for Zone 3. Plant the seeds of lettuces (black seeded Simpson, romaine, bibb, arugula, mesclun mix, salad bowl) five weeks before the recommended planting time. Plant the seeds of squash four weeks before the recommended planting time.