The question that most vegetable gardeners field this time of year is “when will you put your tomatoes in the ground?” While it’s true that folks in the warmest climates can plant seedlings and even direct sow outdoors throughout the year, most gardeners will need to be cautious about setting out plants. Too little light or heat, too much rain, or a cold snap could set you back by weeks.
Gardeners in the very warmest zones (think 10 and 11) can plant spring vegetables in late fall to harvest in late winter. Summer vegetables can be placed outside in winter for spring harvest. (This shift in the calendar means that the very hottest months, July and August, are too hot to grow, effectively becoming the gardener’s winter break.)
For gardeners in the rest of the country, the back of the seed packet is the best place to start when determining how early you can plant your garden.
Begin by checking the “days to germinate” and add the “days to maturity.” Working with your area’s last frost date, use this sum and count backward to get the ideal date to begin planting.
Use this handy chart from Bonnie Plants to find your area’s average date of last frost.
To get the most out of your vegetable garden, do your research, follow the signs, and pull out a few tried and true gardener tricks to be the first in the neighborhood with red, ripe tomatoes, green beans and fresh herbs.
4 Steps to an Early Vegetable Harvest:
- Begin by choosing early maturing varieties. Bonnie Plants tomato varieties mature in as few as 50 days for Early Girl. Cherry tomatoes like Super Sweet 100 mature in 65 days.
- Use a cold frame. Either store-bought or DIY, cold frames are mini-greenhouses, kept at ground level. The cold frame has a glass or polycarbonate window that can be vented during the day to allow air to circulate and to keep plants from overheating on warm days. Learn how to build a cold frame.
- Row covers keep frost off of tender greens and seedlings. The Season Starter protects plants from frost damage. The vertical tubes, when filled with water, create an insulation barrier inside. A benefit of these protective covers is that they prevent pesky critters from gobbling up the tender green seedling shoots.
- Elegant, bell-shaped glass cloches have been taken from the garden and used for home décor for decades, but their gardening purpose is still vital. The cloche is a terrarium, retaining heat and moisture for each plant as it matures.
An affordable, although less stylish alternative is a cloche made from a gallon milk jug. Just cut out the bottom and cover the tender seedling. Be sure to keep the cap off for ventilation. When temperatures are consistently above freezing, remove the milk carton.
Additionally, you can rely on charts and apps, or get outside with a soil thermometer. Warm-weather vegetables like tomatoes, eggplants, peppers, cukes, squash, corn and melons like soil about 70 degrees for germination. Cooler temperatures are needed once leaves appear.
If setting out transplants, look for daytime soil temperatures of 60 degrees and at nighttime above 50 degrees.
At the same time that you start your seeds indoors, warm soils outside with plastic sheeting. Once the seedlings are transplanted, cover the sheeting with mulch for moisture and warmth, and to keep weeds down. Learn more about starting edibles from seed.
Still keep an eye on weather forecasts and cover plants if there is talk of frost. You’ve worked hard to bring up these seedlings — don’t let the frost bite them.