Zone 4

USDA Hardiness Zone 4 encompasses regions with average minimum winter temperatures ranging from -30°F to -20°F (-34°C to -29°C). This zone includes parts of the northern United States and southern Canada. Gardeners in Zone 4 enjoy a slightly longer growing season compared to Zones 2 and 3, but still face significant cold challenges. Ideal plants for this zone include cold-hardy trees like maple and fir, shrubs such as hydrangea and dogwood, and perennials like hostas and coneflowers. Successful gardening in Zone 4 involves selecting plants that can thrive in these cooler temperatures and making the most of the growing season​.

What is the climate like in Zone 4?

Zone 4 experiences average minimum winter temperatures between -30°F and -20°F (-34°C to -29°C). These temperatures can cause damage to plants that are not adequately cold-hardy. Gardeners must select plants capable of withstanding these frigid conditions and take measures to protect more delicate plants during the harsh winter months.

Frost can occur late into the spring and return early in the fall, which shortens the effective growing season. The average last frost date in Zone 4 typically falls between late April and early May, while the first frost date can be as early as late September or early October. This necessitates careful planning to ensure plants have enough time to mature and produce a harvest before the first frost​.

Zone 4 often experiences significant snowfall, which can provide a natural insulation for plants and soil during winter. However, heavy snow can delay the start of the gardening season as it takes time for the snow to melt and the soil to warm up and become workable. This can impact early spring planting and soil preparation.

The growing season in Zone 4 is relatively short, typically lasting around 120 to 150 days. This limited timeframe requires gardeners to choose plant varieties that can mature quickly and to use techniques such as starting seeds indoors to maximize the growing season​.

Freeze-thaw cycles common in Zone 4 can cause soil heaving, which can damage plant roots. Proper soil preparation and the use of organic matter can help improve soil structure and drainage. Mulching is also crucial to protect plant roots from extreme temperature fluctuations and to retain soil moisture during dry periods​.

What is the recommended planting schedule?

Below, you can see the recommended planting schedule for vegetables and herbs.

Vegetables

Plant Sow seeds indoor Transplanting to outdoor Harvesting Month Last date
Cucumber N/A N/A N/A N/A
Brussels Sprouts N/A N/A N/A N/A
Tomato N/A N/A N/A N/A
Spinach May 12 May 22 June 26 August 20
Beets June 10th June 15th August 4th July 14th
Zucchini N/A N/A N/A N/A
Cabbages N/A N/A N/A N/A
Potato June 9 June 19 August 18 July 5
Radish May 31 June 5 July 3 August 14
Broccoli May 27 June 6 July 31 July 22
Carrot May 12 May 26 August 18 June 15
Cauliflower May 24 May 31 July 20 July 28
Onion April 16 April 25 August 23 June 8

Herbs

Plant Sow seeds indoor Transplanting to outdoor Harvesting Month Last date
Marjoram N/A N/A N/A N/A
Parsley April 27 May 17 July 6 July 23
Dill N/A N/A N/A N/A
Fennel May 16 May 30 August 14 July 7
Sage N/A N/A N/A N/A
Thyme March 22 April 11 June 10 August 2
Oregano May 29 June 5 July 20 July 28
Mustard May 29 June 5 July 5 August 12
Mint N/A N/A N/A N/A
Lavender May 22 June 5 July 15 August 2
Rosemary May 7 May 22 August 10 July 6
Ginger N/A N/A N/A N/A
Basil N/A N/A N/A N/A
Cilantro N/A N/A N/A N/A