Preparing your outside plants for the transition to inside growing begins as the days shorten and nights begin to cool. Although the temptation is to leave plants outside until frost threatens, for many the stress of cool nights has already done its damage. Plants may drop leaves and cease to send up new shoots when subjected to extreme temperature changes. Preparing your plants ahead of time eliminates stress and promotes healthy growth.
Move plants inside in late summer before nighttime temperatures begin to cool, and you begin running the furnace. Inside and outside temperatures are similar at this time, reducing the risk of shock to your plants.
Acclimate your plants to their new growing environment by gradually reducing the amount of sun they receive over a week or more. Move sun-loving plants to a partially shaded area for a few days, and gradually increase the amount of shade until they are growing in full shade for a few days.
Inspect plants for any signs of insect infestation. Plants grown outside are subject to a host of summer pests. Examine the undersides of leaves and stems carefully for tiny webs that indicate spider mites. Look for moving insects and remove by hand.
Repot the plant to check for any insects that may have crawled into drainage holes or burrowed into the soil. An occasional earthworm will not hurt your plants, but slugs and other nasty creatures should be removed. Remove old soil, and add fresh potting soil. Water to moisten the soil and to encourage root formation.
Wash the foliage with an insecticide designed for houseplants. A quick bath in a solution of a few drops of dish detergent and warm water will eliminate many plant pests and does not pose a risk to children and pets. Rinse thoroughly to remove soap residue. Insecticide spray can also be used if preferred.
Keep plants separated from houseplants until you are sure they are pest free to avoid an insect infestation. Insects that go unnoticed outside may suddenly cause a serious problem when removed from natural predators and are free to multiply. Repeat insecticide application once a week for the first month, if necessary.
Trim overgrown foliage to encourage new growth and to prevent plants from stretching to reach the light once they are moved inside. Pinching out center leaves forces new growth along stems and from the base of the plant creating a dense compact houseplant. Place in similar light to their outside location.