If You're Starting Plants Indoors, How Do You Know When It's Time to Move Them Outside?
Many people like to start their seeds indoors to get a jump start on the growing season. This is especially true in areas where springtime still means snow and cold weather. But it can be difficult to know when it's time to take those plants outside and get them into the ground or potted on the patio. To help you craft the best timeline, we spoke with two garden experts who shared exactly what you need to know about moving your seedlings outside.
There is no rule of thumb.
Because there are so many different varieties of plants to start inside, the indoor-to-outdoor timeline will depend on the type of plant you're growing, explains Christina Stembel, the founder and CEO of Farmgirl Flowers. "Do the research for your specific varieties to know when is the best time to plant, check the weather in your neck of the woods diligently, and move your seedlings outside as soon as you're confident the conditions will ensure your hard work is rewarded, not decimated, once you get the little guys into the ground!" she says.
Prepare your plants for the great outdoors.
When it's time to start moving your plants outside for the first time, you should do so slowly. "In general, anything that happens quickly to a plant can be shocking, but a rapid introduction of direct sunlight tops this list and can burn or kill young plants," Stembel says. "Keep your plants in their containers and take them for quick daily 'visits' outside." Most gardeners refer to this process as hardening. "Gradually increase the time they spend outdoors every day," she adds. As for light exposure? Even if your variety is sun-loving, start off by placing plants in bright, but indirect light during this phase. "As they get acclimated to being outside, you can move them into the light conditions they'll eventually spend their growing lives in," Stembel explains.
From start to finish, this should take about a week, notes Adrienne R. Roethling, the Director of Curation & Mission Delivery at Paul J. Ciener Botanical Garden, who says to "get to know your last frost date" before you attempt hardening. She explains that timing can vary from year to year: "Even tender plants can become vulnerable to temperatures just above freezing," she says, adding that anything below 40 degrees could be tough on your plants.
Do your research.
Because you're starting your plants from seed, you may have access to varieties that don't normally grow in your area, unlike when you buy plants from your local nursery. "Research twice—buy once! The USDA Hardiness Zones are one of the most important things you can research before buying plants," explains Stembel. "As much as you may love a particular plant, it may not be appropriate for your region. Find out what zone you're in and then buy plants accordingly."