As many gardeners know, there's a common rule of thumb that advises when it's OK to start planting flowers and vegetables: You should hold off on planting until after Mother's Day.
It depends! You can plant trees, shrubs, perennials, and cool-season annuals, vegetables, and herbs now, as long as the ground is not too wet. But you should typically wait to plant warm-season flowers and vegetable plants until May 1st or Mother's day.
When do I know it's safe to bring my plant outside? 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.
Generally speaking, the ideal planting season is between spring and fall. In spring, the weather is usually mild, and it's the time of year when nurseries start filling up with color. Fall is another popular planting period. The soil is typically still warm, which allows roots to grow until the ground freezes.
Time It Right
While it might be tempting to ship indoor plants outside at the first sign of spring, it's best to wait until nighttime temperatures stay at or above 60°F, and after any threat of frost has passed. If you're planning ahead, use the average last frost date for your area as your guide.
Early Spring - As Soon as the Ground is Workable
If it sticks together the ground is too wet to work. Bareroot perennials, as long as they are dormant, can be planted now. Very cold tolerant annuals such as violas, primroses and pansies can be planted, they must be hardened-off in order to survive.
The general answer is around 90 degrees F, with some exceptions to the rule. This means that when temps rise above 90 and remain there for a lengthy spell: Leaves wilt. Water evaporates into the atmosphere more quickly in high heat, draining a plant's reserves.
Depending on your region, March or April can be a good time for planting seeds. Some will still need to be started indoors. A few of the seeds you can start in these two months include: Kale.
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.
There are, of course, many variables that can affect winter hardiness in a plant, but in general, my rule of thumb is as long as the mercury stays in the 20's at night and rises above freezing during the day, our plants should be just fine.
The hardiest of flowers can be planted as soon as the soil in your garden can be worked, even if it's several weeks before the last frost of the season. For half-hardy flowers, hold off until a couple weeks before the final frost, and for tender flowers, plant when there's no chance of frost for the rest of the season.
First, it's good to know which plants are sensitive to temps around 35 or 40 degrees F. These are common tender plants that will need some protection. Hanging baskets: begonias, calibrachoa, gerbera, impatiens, vinca, euphorbia, and scoparia.
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.
With the exception of extremely late in the fall when the ground has either begun to freeze up or is just days away from serious frost, or in winter, gardeners should not worry too much about moving most plants. Now, that's not to say every plant is going to transplant successfully.
An important temperature to remember: tomatoes can be planted in the garden when the soil temperature reaches 60 degrees Fahrenheit. You can buy a soil thermometer to get an accurate reading, or you can guess the soil temperature by placing your finger the soil.
“One of the most underutilized tools in gardening is the soil thermometer,” Olsen said. “Plant your cool-weather crops when the soil warms to 35 or 40 degrees. Go with your warm-weather crops when it gets up to 55 or 60 degrees.”
Most people might think of Spring as the best time to start a new lawn, but the truth is that late Summer and early Fall are far better for starting a new lawn from seed. Any time after August 15th is prime lawn time; the warm soil in combination with cooler air temperatures will encourage far better seed germination.
"Planting A Better Tomorrow" underscores MBAKS' commitment to environmental stewardship and our belief that everyone deserves a place to call home. A healthy environment is fundamental to our region's well-being, and through this initiative, we strive to create sustainable communities for all.
Low Temperatures
Wait until the temperature is consistently above 65 degrees Fahrenheit (18 degrees Celsius) before moving houseplants outside. If temperatures dip below, bring your plants back inside.
Know The Limits
The general rule of thumb is that most plants freeze when temperatures remain at 28°F for five hours. Of course, there are exceptions to this rule. Seedlings, with their tender new leaves, often give up the ghost when temperatures dip to 32-33°F.
Many tropical plants cannot survive temperatures below 40 degrees. If you cannot move your pots (with annual or perennial plants), or you have tender plants in the ground, cover your plants. The idea behind covering plants is to trap the heat from the soil and keep the cold air out.