How to Move Indoor Plants Outside for Spring and Summer—Without Killing Them

Like humans, plants enjoy spending time outdoors after a long, dreary winter. The increased light from the warm summer sun and the fresh air encourage plants to produce new, healthy growth. Additionally, a refreshing rain shower washes away the dust that may have accumulated indoors, helping your plants photosynthesize more effectively.

While transitioning your plants outdoors during the warmer months can be beneficial, it requires work and dedication. A sudden shift to outdoor conditions without gradual acclimation can cause plants to become stressed and may even kill them.

Below, our gardening experts offer tips on the best time to move your plants outside and how to ensure a safe transition to their spring and summer home.

When to Move Plants Outside

Transition plants outdoors once temperatures are consistently above 50 to 60 degrees Fahrenheit during the day, says Joanne Dietz, owner of Mad River Garlic Growers. Although moving your plants outside in early spring is tempting, doing so too early can harm most houseplants, especially in colder climates with late frosts.

"Most foliage plants that we cultivate in containers are tropical to semi-tropical in nature and can be harmed by temperatures in the mid-40s," says Bill Miller, a horticulture professor at Cornell University. Moving plants outside too soon can lead to a chilling injury, which is similar to the damage bananas experience when stored in the refrigerator.

How to Transition Your Plants Outside

Transitioning your plants outdoors requires a process known as hardening off. Hardening off is the gradual acclimatization of indoor plants to outdoor conditions, including temperature fluctuations, wind, and changes in sunlight. Sudden exposure to bright sun can degrade the chlorophyll and damage the leaves, so hardening off is essential. 

Ahead, Dietz shares her expert tips to help your plants gently and successfully acclimate to the outside world.

1. Start the hardening-off process about one to two weeks before relocating your plants outside for spring and summer.
2. Place the plants in a shaded, protected area, such as a covered porch, for a few hours each day.
3. Gradually increase the time the plants spend outside by an hour or two each day.
4. After that, slowly increase their exposure to sunlight by introducing them to morning sun, eventually building up to full sun exposure.
5. Water the plants daily, but be cautious not to overwater them. The growing medium should feel damp but not overly wet.
6. When temperatures remain 50 degrees or above, the plants can remain outside overnight. (Bring plants indoors if temperatures drop below 45 degrees Fahrenheit.)

Tips for Moving Plants Outdoors by Type

While the hardening-off process for seedlings, fruit trees, flowering plants, and houseplants is relatively similar, there are some differences.

• Flowering plants: Certain flowering plants, such as fuchsia, enter a dormant phase during the colder months and are often stored in locations like a basement or garage for the winter. To successfully wake them from dormancy in the spring, place them on a windowsill and let them acclimate to the light. Once the risk of frost has passed, proceed with the regular hardening-off process.
• Houseplants: Many houseplants come from tropical climates with high humidity levels. If you live in a dry region or experience a dry summer, misting your plants during their transition is advisable.
• Fruit trees: Transporting your potted fruit tree from indoors to outside while acclimating it can be challenging. To make this transition easier, consider placing your fruit tree on a wheeled cart. This way, you can move it more easily until it’s ready to permanently go outside for spring and summer.
• Seedlings: Seedlings are very delicate and should be protected from harsh elements such as strong winds and intense sunlight. Place them next to your home to provide shelter from the sun, wind, and rain.

Key Considerations for Moving Plants Outdoors

Transitioning plants from indoors to outside and vice versa is a relatively straightforward process, but there are some things to keep in mind.

Repot If Needed

During the summer, your potted plants are likely to experience a growth spurt, which may require you to repot them into larger containers. You can tell that a plant has outgrown its pot when you see the roots growing out of the drainage holes or circling tightly around the pot's edges. When choosing a larger pot, select one that is 1 to 3 inches larger in diameter than the current pot.

Expect Leaf Drop

When plants are moved back inside in the fall, some varieties drop their leaves, says Miller. This is a response to a sudden decrease in light. "The remaining leaves and new ones to be formed will then be tolerant of lower inside light," he says.

Increase Water and Fertilizer

Plants moved from indoors to outside will require more water and fertilizer. “Keep in mind that increased sunlight and stronger winds can lead to a significant increase in water loss from the plants," Miller says. So keep a steady eye on your newly transitioned plants and feed them according to their specific needs.