With a rainbow of colors and explosive flavors cherished for fresh eating and sauces, tomatoes rank among gardeners' favorite produce to grow. The trick to a successful and lengthy harvest is knowing when to plant tomatoes.
Tomatoes thrive in summer's warmth and shrivel from frost, so they're one of the last and most tender plants or seeds you'll put in your garden. That also can mean a short season for growing.
To stretch your harvest season, start your seeds indoors or buy garden-ready plants. You can also target varieties that ripen earlier than others. This can speed your progress to just-picked tomatoes on your dinner plate.
Here's a look at when to plant tomato seeds or seedlings.
Starting Tomato Seeds Indoors
The best bet for most gardeners dreaming of a bumper crop and wide variety of tomatoes is to get a head start by starting seeds indoors. Choosing seeds gives you the widest range of choices, especially if you like to try new varieties each season and blend a rainbow of colors.
Most seeds can be started about six weeks before your last frost. To calculate the best date for when to plant tomato seeds, read your seed packet. It will tell you how long until seeds germinate and offer general guidelines for when tomatoes can safely be planted outdoors depending on your growing region. You can also find your growing zone on the United States Department of Agriculture's website and research your zone to find your last frost date.
Before you plant your seedlings outdoors, you need to harden them off for about a week. This is a way to incrementally accustom tender tomato seedlings to bright sun and breezes after leaving the climate-controlled indoors. Set seedlings into a shaded, sheltered area for the first day or two, gradually increasing the exposure to light and breezes each day, making sure they're watered as needed.
You can plant them once your garden or container soil is well drained and has warmed for a few weeks after the last frost. That can be mid- to late May in most parts of the country.
Purchasing Garden-Ready Plants
If you're new to gardening (or you missed the timeframe to start seeds indoors), you can still fast-track your tomato harvest by ordering garden-ready tomato plants. These plants are professionally started in greenhouses, which have ideal light and temperatures for producing healthy, sturdy seedlings. Burpee's garden-ready plants can be preordered and are shipped to arrive as soon as it's safe to plant in your growing zone, based on your ZIP code.
If you're planting in containers rather than in a garden, choose compact bush varieties for your tomatoes, such as 'Veranda Red Hybrid' and 'Sweetheart of the Patio Hybrid.' If you're growing heftier tomatoes, such as heirlooms and beefsteaks, invest in tomato cages and other supports you can use in your garden every summer. Tomato cages and supports hold up the plant as heavy fruits ripen and weigh down the stems. If plants tip and ripening tomatoes touch the soil, they're vulnerable to rot or pests.
Water new seedlings thoroughly with at least an inch of water a week. Gently water near the base of the plant to keep leaves dry and minimize the spread of soilborne disease. Mulch around your seedlings to help regulate soil temperature, retain moisture and prevent weeds.
Consider Early Ripening Tomatoes
Most tomatoes need two to four months to produce fruit. Large slicing tomatoes such as beefsteaks and colorful heirlooms tend to take the longest to reach full ripeness. Northern gardeners or those at higher elevations might have only two or three weeks for larger tomatoes to ripen before fall's first frost may wipe out their plants.
If you're in northern areas of the country, it can help to choose shorter-season varieties such as grape and cherry tomatoes that ripen more quickly. Look for varieties such as 'Napa Grape Hybrid,' 'Sunchocola Hybrid,' golden orange 'Honeycomb Hybrid' or pinkish 'Maglia Rosa.'
For larger tomatoes, choose seeds or garden-ready plants for early varieties such as 'Summer Girl Hybrid' or 'Bush Early Girl Hybrid.' These should produce their first harvestable fruit about two months after plants start growing in the garden.
When it comes to planting tomatoes, timing is important. Now that you know when to plant tomatoes, you can rest assured that you'll have a summer crop before the fall frost hits.
For a full rainbow of tomatoes, from heirlooms to cutting-edge hybrids and novelties, check out Burpee's garden-ready plants.