Timing for all planting is based on first and last frost dates. For example, if planting in hardiness zone 5, the last frost date is generally between April 1st – April 15th, and the first frost date typically falls between October 16th – October 31st. These dates will in part dictate when the best time to plant is.
The best time to plant any plant is during the dormant season – in North America, this is usually late fall through early spring. While it's okay to plant during the rest of the year, it will require more maintenance from you in the form of watering, fertilizers, etc.
Fall is Good for Root Growth
Warm soil temperatures encourage root growth – more so than in the spring when the soil is still warming up. Plus, with the shorter days and cooler air temperatures, plants spend less energy on growing foliage and flowers and more on building a strong root system in preparation for winter.
Most flowers should be planted after your region's last frost date. Planting flowers in spring is the most popular time, but perennials do fine if planted in early fall in the North and late fall in the South.
You can continue (or start) planting any early-season crops, plus tomatoes, squash, melons, eggplant, peppers, sweet corn, cucumbers, potatoes, and herbs. Water and mulch any new transplants with care. If choosing to sow directly in the garden, start your carrots, beets, and radishes.
The latest time to plant for most vegetables would be the second week in June with a short harvest time. If planting crops that mature within 50 days, you could plant those as late as the last week in June, but keep in mind the weather will be turning cooler, especially at night. Cool crops are best for late plantings.
It's never too late. It just matters what you put into that garden. It's too late to grow tomatoes in your Chicago garden in September because you'll be getting cold weather soon, but you could still grow carrots, radishes, and lettuce plants.
April is a great time to plant many types of flowers. Some of the best choices include pansies, petunias, snapdragons, and lilies. Pansies are ideal for cooler climates as they can tolerate light frost and bloom in bright colors like yellow, purple, or white.
The best time to start seeds is usually late March to late May. Only the southern zones are suitable for starting plants from seed in the earlier months. Give the plant enough time to germinate and grow to an appropriate transplant size.
Technically, you can plant perennials any time your soil is workable. Practically, the best times to plant perennials are spring or fall. These seasons allow plants to get settled and grow new roots before summer's hot, dry weather arrives. Planting in summer is okay, but you'll need to water frequently.
Autumn's cooler temperatures and wetter weather mean a better start for trees, shrubs, bulbs and perennials. Vegetables and herbs grow well in fall, too, especially greens and root vegetables. When you plant in fall, you take advantage of milder weather. More rain and moderate temperatures equals less watering.
Fall is a great time to plant perennial herbs, which come back year after year and thrive in either pots or planting beds. Plant herbs such as thyme, oregano, mint, and sage any time from summer to mid fall, and you'll be able to harvest now and up until a hard freeze.
The most vigorous growth of plants will be in the summer when the sun is up and out the longest. During winter, the sun is neither as high in the sky, nor in the sky for as long as it is in the summer. For your plants, that means less light. For some plants, this may trigger dormancy.
It's safe to move your plants outside when the outdoor temperatures stay consistently above 50°F. Pay attention to the weather report. If nighttime temperatures are set to fall below 50°F, bring your plants in for the night. Bring them back outside when temperatures rise.
Planting too early in cooler temperatures can cause stunted growth, wilting, surface pitting, foliage necrosis and increased susceptibility to disease. Low soil temperatures can stunt plant growth and prevent root development. Most summer vegetables like soil temperatures of between 55 and 65 degrees.
Once the snow is gone and the ground is no longer frozen, you can plant as soon as the soil can be worked. This phrase can confuse new gardeners. It means the soil can not be too wet. Working wet soil destroys the soil structure and causes compaction.
In general, wait until the temperatures range from 60 to 70 degrees Fahrenheit to plant tender vegetables like corn, tomatoes, peppers, eggplants, okra, summer squash and beans. Use a soil thermometer to make sure the soil is warm enough to plant.
April is the best time to plant most of your vegetable seeds after your last frost for all zones. It's still not too late to plant tomatoes and peppers from seeds as well! Check out the below vegetables that can be started in April. Be sure to check your gardening zone for last frost dates.
March may be a good time to plant perennials, depending on when your last frost date is. You can safely plant frost-tolerant perennials 2-3 weeks before your last spring frost. Growing spring-blooming perennials is a great way to add a splash of color and beauty to your garden.
I did some research and found out that houseplants need to be taken indoors before overnight temperatures dip below 45 degrees. Most tropical plants suffer harm from temperatures below 40 degrees.
The general advice for gardeners is to get their crops in the ground by the end of June at the latest, but that doesn't mean you should give up hope now that it's July. There's some wiggle room for planting late in the season, depending on your hardiness zone and how strategic you are about what goes in the ground.
Light freeze - 29° to 32° Fahrenheit will kill tender plants. Moderate freeze - 25° to 28° Fahrenheit is widely destructive to most vegetation. Severe or hard freeze - 25° Fahrenheit and colder causes heavy damage to most plants.