Not long after January 1 comes and goes each year, gardeners all across the country find themselves eagerly awaiting the onset of spring, their anticipation heightened by the arrival of seed catalogs. Others consider starting a garden for the first time, their reasons varying from taking charge of their food supply to getting outside and exercising more.
All of this not-so-patient waiting presents a common question: When is the right time to start a garden?
As you might expect, the answer to this question depends on where you live. But rather than refer you to average frost dates, as is typical, let’s try a different approach and take a cue from nature.
- Midwinter. Soil and air temperatures often below freezing. No plant growth.
- Late winter. Soil temperatures below 40°F. Daytime air temperatures often above freezing. Earliest native plants emerge.
- Early spring. Soil temperature at least 40°F. Cool-season grass growth begins.
- Mid-spring. Soil temperature at least 50°F.
- Late spring. Soil temperature at least 60°F. Cool-season grass grows aggressively.
- Early summer. Average last frost date is past. Soil temperature at least 70°F.
- Midsummer. Cool-season grass growth slows and warm-season grass growth speeds up.
- Late summer. Daytime air temperatures start to cool off. Cool-season grass growth resumes. Warm-season grass growth slows.
- Early fall. Soil temperatures below 70°F. Warm-season grass growth stops.
- Mid-fall. First hard frost hits. Soil and air temperatures below 60°F. Trees drop leaves. Cool-season grass growth stops.
- Late fall. Soil temperature below 50°F. Nighttime air temperatures often below freezing.
- Early winter. Soil temperature below 40°F. All plant growth stops.
(This is a very abbreviated version of Hansen’s information for evaluating seasonal changes. If you plan to grow by the seasons, you will definitely want a copy of her book on your shelf.)
These indicators are important because weather does not precisely track with calendar seasons. Weather patterns are influenced by a number of other factors, ranging from solar cycles to ocean temperatures to circulating air currents.
While gardeners do have a number of tools at their disposal for ensuring favorable growing conditions for plants, including irrigation, greenhouses, and shade cloth, the amount of effort required to reap a harvest can be considerably reduced by staying in sync with nature. For example, germination rates will increase noticeably when seeds are planted at their preferred soil temperatures. Likewise, awareness of a sluggish spring can help you avoid putting sensitive plants at risk of frost, even if the calendar says it is time to plant.
Each season, in turn, has its own set of gardening tasks. Those specifically related to sowing and starting plants include:
- Late winter. Start cold-tolerant seedlings indoors. Sow cold-tolerant seeds in cold frames.
- Early spring. Start heat-loving seedlings indoors. Sow cold-tolerant seeds outdoors.
- Mid-spring. Sow the bulk of the seeds outdoors.
- Late spring. Sow the most tender seeds outdoors. Sow succession crops. Transplant most seedlings outdoors.
- Early summer. Sow succession crops.
- Midsummer. Sow fall crops.
- Late summer. Sow the latest fall crops.
- Early fall. Sow crops to be overwintered in cold frames.
The Best Time to Start
With this information in mind, the best season for starting a garden actually depends on your level of interest. The bulk of the planting is typically done in mid-spring, although peas, lettuce, and other cold-loving vegetables can be started in early spring. For those who are dedicated to raising their own seedlings or using season extension methods, however, the need to grow can be fulfilled starting in late winter.
But it is by no means too late to start a garden once spring ends. For those who missed the primary gardening season, another excellent window of opportunity begins in midsummer, with the chance to start a fall garden.
So don’t overlook any chance—most of the year is suitable for gardening!
“Soil Temperature Conditions for Vegetable Seed Germination”
This fact sheet is helpful both for knowing what to sow when and for maintaining proper temperatures indoors.