Planting Hot Crops: Timing and Tips for a Bountiful Harvest

Hot crops are the cornerstone of a summer vegetable garden, but success hinges on precise timing. These plants, often referred to as ‘tender crops,’ thrive in heat and cannot tolerate sustained cool temperatures. On the other hand, cool crops (a.k.a. hardy crops) will often suffer in the summer heat.

In the Toronto area, our relatively shorter growing season and the unpredictable nature of spring and early-fall temperatures mean we need to watch the weather forecasts in May and September. In May, wait until nighttime temperatures consistently remain above 10°C before moving hot crops outdoors. In September, if the nighttime lows go consistently below 10°C, then pull any remaining hot crops and plant your cool crops.

This isn’t just a restriction, it’s an opportunity! Knowing the difference between hot crops and cool crops, and timing your plantings accordingly, will enable you to get 3 full harvests each year from every place in your garden. Plant cool crops in April-May, hot crops in June-September, and cool crops again in October-November. For more information, see our guide on Cool Crops.

Key Hot Crops

So which vegetables are considered hot crops? These popular vegetables require warm temperatures and full sun (at least eight hours) to thrive.

  • Squash (both summer and winter varieties)
  • Melons
  • Cucumbers
  • Beans
  • Corn
  • Tomatoes (start seedlings indoors and transplant)
  • Peppers (start seedlings indoors and transplant)
  • Eggplants (start seedlings indoors and transplant)
  • Sweet Potatoes (start seedlings indoors and transplant)
  • Okra

Maximizing Your Harvest in a Short Growing Season

Due to the limited number of frost-free days in the Ontario growing season, crops that require a long maturity period must be started indoors. Starting seeds indoors speeds up the growth process and is key to a successful harvest.

  • Start Seeds Indoors: tomatoes, peppers, eggplants and sweet potatoes typically need 90–110 days to begin to produce fully ripened harvests. To maximize your garden’s productivity and get several flushes of harvest, start these seeds indoors six or more weeks before the expected outdoor planting date. For a full guide on this process, visit Seed Starting.
  • Direct Seeding Outdoors: Most other hot crops, like beans, corn, squash, and cucumbers, are best seeded directly into the garden once the soil is sufficiently warm. Visit our Direct Seeding Vegetables guide for best practices.

Practical Tips for Success in the Ontario Growing Season

Planting is only the first step. Protecting your tender crops is vital for a strong season, especially when dealing with unpredictable weather patterns in the Toronto region.

Cold and Frost Protection

Always monitor the long-term forecast after planting. A sudden drop in temperature can severely damage or kill tender young plants.

  • Warm the Soil: Laying dark mulch over your garden beds helps the soil absorb and retain heat from the sun, keeping the roots warm on cool nights.
  • Use Row Covers: Keep row covers or frost blankets on hand. If a cold night is forecasted, cover your hot crops to retain ground heat and prevent frost from settling on the foliage. For more on this technique, see Using Row Cover.
  • Strategic Placement: If planting early or in a garden microclimate prone to frost pockets, choose plant varieties that are more frost-tolerant and plant them in the higher, best-ventilated areas of your garden.
Water and Heat Management

Once the summer heat arrives, keeping your hot crops adequately watered is critical, as they can quickly wilt in temperatures above 30°C.

  • Maintain Hydration: Keep your plants well-watered during periods of extreme heat. Plants use water for cooling, and insufficient water will cause them to shut down growth. It’s just a myth that you should not water plants in the afternoon on hot days.
  • Wind Protection: Tender, broadleaf crops like cucumbers and eggplants are susceptible to damage from strong winds and should be planted in a location that offers some shelter.
  • Pair Wisely: Consider planting hot crops alongside mutually beneficial partners. For instance, peppers thrive when planted near tomatoes, basil, zucchini, and parsley. Learn more about helpful garden pairings in our guide on Companion Plants.

Ready to Grow More?

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  • In the Greater Toronto Area (GTA)? Join Our Program at Downsview Park: Enroll in our full-season Grow Veggies program for hands-on learning and a share of the harvest.
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