How Seasonal Planting Windows Work, From Spring Through Late Summer
Most planting calendars break the growing season into overlapping windows rather than single dates: an early spring window for cold-hardy crops, a window around the last frost for warm-season crops, a mid-summer window for succession planting and heat-tolerant crops, and a late-summer window for fall-harvest crops that need to mature before the first fall frost. Because frost dates shift by region, the specific calendar dates in any guide — including this one — should be treated as a general guide rather than an exact rule for your garden. For a broader look at how much regional variation matters, see the planting season guide by region.
What to Plant in May
In much of the US, May falls around or after the average last spring frost in many regions, which makes it a common month for both finishing cool-season plantings and starting warm-season crops. Based on zone-specific planting calendars (such as the Almanac’s regional charts), May is frequently a transplanting and direct-sowing window for crops like beans, cucumbers, melons, squash, and tomatoes, depending on your local frost timing — in colder zones these may not go out until late May or early June.
Vegetables and Herbs Commonly Planted in May
Herbs that are commonly planted in May include thyme, dill, lavender, sage, basil, mint, oregano, catnip, and rosemary, based on commonly cited planting guidance for this period. Many of these tolerate a range of soil conditions and are often started outdoors once the risk of frost has passed in a given region.
Should You Soak Seeds Before Planting?
For some seeds — particularly larger or harder-coated ones like beans, peas, and beets — a brief soak (often a few hours, sometimes overnight) can help speed up germination by softening the seed coat. Not all seeds benefit from soaking, and oversoaking can sometimes cause rot, so it’s worth checking guidance for your specific crop rather than soaking everything by default. This is the same underlying idea behind soaking garlic cloves before fall planting, which is covered in more detail in this guide to planting garlic in October.
Mid-Summer Planting (June-July)
By mid-summer, spring crops are often finishing up, and attention shifts to two things: keeping heat-sensitive crops productive, and starting the next round of plantings, including fall crops.
Is 90 Degrees Too Hot to Plant?
Ninety-degree heat can stress many seedlings and newly planted transplants, particularly cool-season crops, but it doesn’t automatically rule out planting. General guidance from summer planting resources suggests checking soil temperature directly (rather than just air temperature), choosing heat-tolerant varieties for summer successions, and timing transplants for cooler, cloudy periods when possible, with extra attention to watering and shade during establishment. If you’re planting heat-sensitive crops, it’s generally more cautious to wait for a cooler stretch than to push through a 90-plus-degree week.
What Can You Still Plant in July?
This varies a lot by region and climate, so treat any specific list cautiously. Anecdotal reports from warmer-climate gardeners (for example, in Gulf Coast states) mention crops like cowpeas and okra as realistic July plantings in their area, with cool-season greens such as collards, cabbage, and onion seed started indoors in partial shade to avoid cooking the seed in summer heat. In cooler regions, July is more often used to start fall brassicas (broccoli, cabbage, cauliflower) indoors so they can be transplanted once the weather cools. Because of how much this depends on local climate, it’s worth checking your local frost date and the crop’s days-to-maturity before committing to a July planting.
Late-Season and “Is It Too Late” Planting
Is August Too Late to Start a Garden?
Not necessarily, but it depends heavily on what you’re planting and your region’s first fall frost date. Fast-maturing, cold-tolerant crops — lettuce, radishes, spinach, turnips, and similar greens — can often still be started in August in many regions, since they mature quickly and tolerate light frost. Long-season, heat-loving crops like tomatoes or winter squash are generally not realistic August starts in most climates, since they wouldn’t have time to mature before frost.
Working Backward From Your First Frost Date
A more reliable approach than asking “is it too late” in the abstract is to work backward from your expected first fall frost date:
- Find your crop’s average days-to-maturity (seed packets and extension guides usually list this).
- Add roughly 10-14 extra days to account for slower growth as days shorten in fall — a buffer suggested by seasonal planting guidance from several extension-linked sources.
- Count backward from your first fall frost date by that total number of days to find your latest reasonable planting date.
- Check the crop’s frost tolerance — some fall crops (kale, spinach, turnips) tolerate light frost and can be pushed a bit later than this calculation suggests, while tender crops cannot.
Vegetables and Flowers That Tolerate a Late Start
Crops commonly cited as reasonable late-season or fall options include kale, peas, winter radishes, bok choy, cabbage, lettuce, turnips, beets, and garlic (planted in fall for next year’s harvest — see the guide to planting garlic in October). For flowers, late-summer sowing options tend to lean toward quick-maturing annuals and self-seeding types, though exact choices vary enough by region that it’s worth checking a local source before committing to a specific flower list. For a zone-by-zone breakdown of this same fall list, including a days-to-maturity table, see this guide to fall crops by hardiness zone.
A Simple Framework for Finding Your Own Cutoff Dates
Rather than memorizing fixed dates, it can help to keep three numbers in mind for any crop you’re considering late in the season: your area’s average first fall frost date, the crop’s days-to-maturity, and its frost tolerance. Combining those three gives a reasonably reliable personal cutoff, and it travels well across regions — unlike a single calendar date, which, as the planting season guide by region explains, can be off by weeks or months depending on where you garden. For perennials specifically, timing logic differs somewhat from annual vegetables; see planting perennials in Colorado for an example of how that plays out in a specific region.
FAQ
What flower seeds can I plant in late summer? This varies by region and climate, but quick-maturing annuals are generally the safer late-summer choice over slow-to-bloom perennials or flowers with long maturity windows. Check a regional source for specific variety recommendations.
Should I soak my vegetable seeds in water before planting? For some larger or hard-coated seeds (beans, peas, beets), a short soak can help speed germination. Not every seed benefits from soaking, and it’s worth checking guidance specific to the crop rather than applying this to all seeds.
What plants should be planted in May? This depends on your region’s frost timing, but commonly cited May plantings include warm-season vegetables after the last frost and herbs such as basil, thyme, dill, sage, and rosemary.
Is August too late to plant a garden? Not necessarily — fast-maturing, frost-tolerant crops like lettuce, radishes, and spinach can often still be started in August in many regions. Long-season or heat-loving crops are generally too late by then in most climates.
What vegetables can you plant late in the season? Commonly cited options include kale, peas, winter radishes, bok choy, cabbage, lettuce, turnips, and beets, though exact timing depends on your first fall frost date and each crop’s days-to-maturity.