It's time to bring in houseplants as temperatures drop into the fifties at night. Plants left out much longer will respond to the cooler air and a noticeable decrease in growth, that combined with leaf drop will be hard to reverse once inside. Act now to maintain the vigor your indoor plants have established as they benefited from fresh air and higher light levels. It is unwise to repot them now, a top dressing of fresh potting soil will do more in the long run. If houseplants or tropicals have been planted in the garden, gently sink your shovel in the soil, a bit further out than the original root ball and lift the plant with only a tad more soil and repot it into a pot only slightly larger than it was before. Many indoor plants suffer from over potting this late in the year when light levels drop and excessive soil remains too wet, causing roots to rot. The ideal time to replant houseplants is in the summer, allowing time for fresh and vigorous new roots to penetrate new soil.

Tropical water plants must be dealt with also, the water temperatures drop fast in fall and most tropicals need a water temperature of sixty degrees or more to maintain a healthy root system. The black leafed colocasia comes to mind first as a tender tropical that should be lifted now and either kept alive in warm water or allowed to dry out as a method of forcing dormancy. The oversized tuber or root that forms the wealth of its strength is very prone to rotting if left in cold water. As each potted water plant is allowed to dry, soil can be removed and the tuber stored in a bag of dry peat in a warm location. You may also leave the root and tuber in the pot and grow it as a houseplant in a semi-sunny window. I have found that east or west facing works best.

The tender Papyrus can be saved, store it in a shallow water container for winter, you may or may not want to remove tall stalks as you bring Papyrus indoors for winter, they can be very large and have a tendency to snap from their own weight. A south or west window will provide enough sun to keep your Papyrus alive and reasonably happy through winter.

Now is also the time to consider purchasing bulbs. Availability may be low on a few choice varieties such as double snowdrops, sternbergias and winter aconites. Both the snowdrops and aconites should be planted as soon as possible, their viability sinks as they remain in boxes on shelves, waiting for gardeners to purchase and plant them. I soak winter aconites or eranthis in water for 24 hours before planting, this way they plump up considerably, regaining moisture after dry storage. A savvy gardener plants in drifts rather than in lines. A cluster of bulbs placed in pockets will do if drifts are too expensive.

Now is the time to plant paperwhites with your pansies. The show is beautiful in November as the paperwhites rise above the pansies and provide a final salute, a gardeners witty last hurrah! The preferred strain of paperwhites for this application is 'Ziva', a hybrid of considerable strength, it's reliable and pretty darn cold tolerant.

Karen Rexrode is owner of Windy Hill Plant Farm (703) 327-4211