Planting tomatoes in June is possible, but success requires a strategic approach due to the shortened growing season. While warm air and soil temperatures are ideal for growth, a late start compresses the timeline for fruit production. The key lies in selecting quick-maturing varieties and providing intensive care to help them establish themselves during the hottest part of the year. Your location’s climate and preparation will determine whether you can enjoy a late-summer or early-fall harvest.
Assessing Your Growing Window
The primary factor for June planting success is the length of your remaining growing season. Tomato varieties list a specific “Days to Maturity” (DTM), which indicates the time from transplanting to the first harvest.
To find your cutoff date, identify the average date of the first anticipated fall frost in your region, as this represents the hard stop for production. Once you have this date, calculate the total number of days remaining. The DTM of your chosen variety must be significantly less than this remaining time to allow for establishment and ripening.
For example, if your first frost is in mid-September, you have about 90 to 100 days from a June planting. This means you should select varieties with a DTM of 50 to 70 days after transplanting. A minimum growing window of 60 to 90 days is required for a satisfying harvest. If the window is shorter than 60 days, the risk of the season ending before the fruit ripens is much higher.
Selecting the Right Plants and Varieties
For a June planting, starting tomatoes from seed is impractical, as it adds four to six weeks to the tight schedule. You must rely on purchasing large, healthy transplants that are already well-established.
Look for plants with thick, sturdy stems and a healthy green color. Avoid those that are heavily flowering or setting fruit, as their energy should focus on developing a robust root system after transplanting.
Determinate vs. Indeterminate Varieties
The choice between determinate and indeterminate varieties is a significant decision for late planting. Indeterminate tomatoes are vining plants that continue to grow and produce fruit until frost, often requiring 80 to 100 or more days to reach full maturity.
Determinate varieties, often called “bush” tomatoes, grow to a compact height and set the majority of their fruit over a concentrated period of one to two weeks. Determinate varieties are strongly preferred for a late start because many are bred for faster maturity, often in the 65 to 75-day range, fitting the shortened season better.
Focus on varieties listed as early-season producers, which require 70 days or less from transplant to harvest. Cherry tomatoes, such as ‘Sungold’ or ‘Early Girl,’ are often the fastest to ripen, sometimes taking only 50 to 60 days, making them an excellent choice for planting in June.
Immediate Care for Mid-Summer Planting
Planting into hot June soil presents challenges that require immediate and specific care techniques. The goal is to minimize transplant shock and help the plant quickly adapt to the high temperatures and intense sunlight. Immediately after planting, a deep, thorough watering is necessary to settle the soil around the roots.
Watering and Moisture Management
Maintaining consistent soil moisture is essential to prevent common problems like blossom end rot, which is often caused by irregular watering that limits calcium uptake. Water deeply and regularly, especially during the first few weeks, ensuring the plant receives about one inch of water per week, either through rainfall or irrigation.
Mulching and Temperature Control
Applying a thick layer of organic mulch, such as straw or shredded leaves, is necessary following a June planting. A layer of two to four inches helps regulate the soil temperature, preventing the roots from overheating during summer heat spikes. Mulch also conserves soil moisture and prevents soil-borne pathogens from splashing onto lower leaves.
Managing Extreme Heat
If daytime temperatures consistently climb into the 90°F range, consider providing temporary afternoon shade using a shade cloth for the first week. Extreme heat can cause tomato flowers to drop without setting fruit, stalling your harvest. Providing temporary shade during the hottest part of the day allows the new transplant to focus its energy on root establishment.