Moving Plants Outdoors for Summer

Moving Plants Outdoors for Summer

Brian Jervis: Master Gardener

Tuesday, May 16

Q: Is it a good idea to move my houseplants outside for the summer? Should they be repotted? K.S., Tulsa

A: Yes, it is a good idea to move most houseplants outside for summer, but you must respect their individual requirements for temperature and sunlight.

Most houseplants are tolerant of reduced lighting indoors, but they usually originated as outdoor plants. Your plant would like to be outdoors again if the conditions are favorable.

Do not move houseplants outdoors until all danger of frost has cleared and the outdoor temperature is about the same as indoors. When moving plants, they should be placed in shade for a couple of weeks, then gradually moved to full sun or sun/shade, depending on their requirements.

Some plants, such as one of the Chinese evergreen cultivars, cannot tolerate sunshine. They get sunburned and should be located in dappled or full shade. Other plants such as the cacti, bougainvillea, hibiscus, plumeria and others do best in full sun.

Because houseplants usually grow much more rapidly outdoors in summer, they need more water and fertilizer. Depending on the plant, a balanced liquid fertilizer every 2-3 weeks or so should be a good plan. Water requirements during the hot summer may mean watering every day or even twice daily, depending on the plant, the weather and the type of potting soil.

Inspect the plant’s roots when moving outside. If the plant has filled the pot with roots (called being “root-bound”), it grows more slowly and may eventually die. Hints that the plant has this problem are if the plant needs frequent watering or if large numbers of roots come out of the container’s drainage holes. Remove the plant from the pot, and if you see mostly dense roots growing in circles, it probably should be repotted. An exception to this is if the plant looks healthy, and you do not wish for it to grow any faster or taller, keep the plant as is.

Another indication for repotting is if a white crust has formed on the soil. This is an undesirable accumulation of salt residue from fertilizers.

Select a new pot an inch or two larger than the old one. The soil for the new pot should be a commercial potting soil, which will ensure good drainage. Never use soil from your garden; it drains poorly and may carry disease. Before planting, consider making three to four vertical slits in the root-ball of root-bound plants, which have large numbers of circling roots.

Place a coffee filter or fine screen at the bottom of the pot to keep soil from leaking out. It is not recommended that a pile of potting shards or gravel be used on the bottom. Rather than improving drainage, these materials placed over the pot’s drainage holes may actually prevent drainage by producing a “perched water table” zone just above the gravel. This has to do with the physics of water drainage and can be unhealthy for the lower roots.

Garden tips

• Clean out water garden and divide and repot water garden plants. Begin feeding fish when water temperatures are higher than 50 degrees.
• Plant warm-season vegetable crops such as watermelon, cantaloupe, cucumber, eggplant, okra, sweet potatoes and other warm-season crops now.
• Fruit trees, especially apples and peaches, must have their fruit thinned for best production. Prune apples 4-6 inches apart and peaches 6-8 inches. This will ensure larger fruit and less damage to limbs. If not thinned, the tree's resources will be used to such an extent that next year’s crop will suffer.
• Late May is the best time to control borers in the orchard. Contact OSU Tulsa Master Gardeners for fruit tree spray recommendations.