Cabin fever, frost, rain and worn-out pages of seed catalogs are the complete picture of the winter gardener.
All the articles tell us to get prepared and be ready for planting. Our instincts are telling us to plant, get spring going and food on the way. In reality, we might be curing manure, building raised beds and doing yard clean up. Or perhaps we are sitting next to the fire, waiting for several days of consistent warmth outside. How do you know when to step out the door with seedlings in hand to plant?
Gardeners must work backward. When is it safe to plant in your area? Luckily there is a calculator to give you your area’s frost date. What are frost dates? A frost date is the average date of the first light freeze in fall and the last light freeze in spring. There is a possibility of 50 percent that there will be a frost after the calculated date. Also, topography and local weather may affect the calculation.
Frost dates are a great guideline to help gardeners from jumping out too soon with tender plants. There are three classifications of freeze temperatures and they are based on how that temperature affects plants. A light freeze is 29 degrees to 32 degrees Fahrenheit, and those temperatures will kill tender plants. A moderate freeze is 25 degrees to 28 degrees, and is widely destructive to most vegetation. A severe freeze is 24 degrees and colder. A severe freeze creates heavy damage to most plants. Knowing the light freeze date will give your plants a better chance of surviving, and the gardener a quick way out of the gate.
By using The Old Farmer’s Almanac we can calculate the last spring frost date for Sonora. The Old Farmer’s Almanac shows Sonora with an elevation of 1,676 feet. The last spring frost date is April 18 this year. The first fall frost date is Nov. 6. That makes a growing season of 201 days.*
Knowing the length of the growing season is important in order to plan. Yes, we do need to know a date to plant, but there are other uses. If your growing season is short, you might want to skip the monster pumpkin if you are starting late. If you want to plant a second planting of tomatoes to enjoy tomatoes in January, then you need to back up from the fall frost date. Most seed and plant labels will give a time element to maturity and harvest.
If the potential first frost date in the fall is Nov. 6 and you want a second crop of celebrity tomatoes with a 70 to 80 day harvest schedule, then put the seedlings in at the halfway point of your growing season. Celebrity tomatoes are determinate, with smaller, bushier plants. They are the opposite of vining tomatoes that keep producing tomatoes on ever growing stems. So, the second crop will have strong, new growth and determination to fruit way into fall
If you are wondering how to have green tomatoes in January, this is how to do it. First realize that Mother Nature and the weather must cooperate. Second, purchase heavy-duty frost cloth. Help your plants get a strong root system with proper soil and fertilizer TLC.
During the regular growing season, pick tomatoes off the top of the plant and any others that ripen underneath. When the weather changes, cover the entire plant with frost cloth; keep the frost cloth elevated inches above the plant. If the cloth touches the plant directly it will conduct the cold and not be as useful.
Keep the plant watered if rain is not present or the ground dries out. When picking the green tomatoes, choose the largest ones then bring them in to ripen on your counter. Watch for the ones that are turning colors and pick those first.
To be prepared for a successful spring, keep the following tasks in mind: Clean up in preparation for planting, prepare your tools, give your soil some TLC, create a plan, and next spring maintain your hard work. Always know your region, but be prepared to be pleasantly surprised. Water wisely, and try to be patient.
While you are planning that spring garden, remember there are really never too many tomatoes, zucchini or cucumbers. Relatives, neighbors, fellow workers and the food bank will joyfully enjoy your bounty and hard work. Always plant an extra row for those who can’t.
*This information applies to only a small area in Sonora due to microclimates and changing elevations. Cedar Ridge is a “Sonora” address but has an elevation of 4,000 feet in places and has frost in June.
Julie Silva is a University of California Cooperative Extension Master Gardener of Tuolumne County.