September 15, 2002

September brings us the last days of summer and the onset of a new season. Autumn will have shorter days and chilly nights. It's time to bring in any houseplants that have spent the summer outside. Even though the days are still warm, by bringing the plants in now there will be less shock from differences in temperature and humidity. Even so, expect some of the plants to drop some of their leaves while adjusting to the indoor.
Check the plants carefully for insects before bringing them indoors. A good wash with the hose should dislodge any hitchhikers. Insecticidal soap can also be sprayed on the foliage to eliminate pests. Houseplants can put on quite a bit of growth during their vacation outdoors. It may be necessary to repot the plants into the next size pot. If there are roots growing out of the drainage holes or you can see more roots than potting soil, re-pot the plant.
One of the plants that are often put outside for the summer is the amaryllis. After enjoying the spectacular blooms indoors during the winter, you can use the amaryllis as a patio or garden foliage plant. And you can keep the bulb growing for many years. Whether you have kept the amaryllis outdoors or indoors, it needs to be put through a rest period before blooming again.
During the last week of September lift the bulb from the garden or pot. Shake off the soil and cut the foliage off to about 2 inches above the top of the bulb. Place in a dry, airy place out of the sun. I usually use the garage. The bulb must rest for a minimum of five weeks. About the middle of November, you can pot up the bulb for indoor blooming.
Cut the roots back to about 2 inches and then soak the bulb in a shallow dish of water. The bottom of the bulb should be sitting in the water. Let it soak this way for 24 hours. Then plant the bulb in a pot large enough so that there is an inch of space all around. Use a good commercial potting mix. Set the bulb in the pot so that at least half the bulb is above the soil line. Two or more bulbs can be potted together in the same pot as long as the pot is large enough. This will create a much better display of flowers.
Water just enough to moisten the soil and place the pot in a warm location out of drafts. Keep the soil moist, watering from the bottom until the bulb begins to sprout. Never let the pot sit in standing water for more than three hours. Once the bulb has sprouted, water as needed and fertilize lightly each week to produce good growth and large flowers.
The amaryllis will bloom in 6-10 weeks from the time it is potted. With careful timing you can plan the blooming to coincide with holidays or stagger plantings for a sequence of blooms indoors during the winter months.
Another plant that needs to be lifted from the ground before frost is the gladiola. After the gladiola flowers the foliage feeds the corms. The corms mature about 6 weeks after bloom. The best time to dig them up is when the foliage begins to yellow and before a hard frost. If you wait until the foliage is completely brown it may be difficult to find all the corms underground.
Loosen the soil carefully with a spading fork and lift up the yellowing stalks with the corms attached. Shake off the soil and twist off the stalks from the corms. Any mud can be washed off with a hose. Discard any corms that have lesions or look diseased. Lay them out to dry in a warm, airy location. After 2 weeks they should be dry enough to store. Separate the old original corm from the new and discard it. Be careful to keep the tunic or husk on the corm to protect it from drying out during storage. The corms can be stored in single layers using shallow trays, grocery bags or cardboard boxes. Just don't use plastic bags, they hold in too much moisture, which can cause rotting.
Store the trays in a cool, dry place such as an unheated garage or basement. The ideal temperature is around 40 degrees. Make sure you label the different color varieties. Inspect the corms periodically throughout the winter months, discarding any that succumb to rot.
Beth Nardone, botanist, is a resident of Hillsborough and is the Nursery Manager at the Belle Mead Co-Op. Questions and comments can be sent to bethtanical@rcn.com