Master_gardeners_09-37

Jeff Green | Sep 17, 2009

Tender plants add a beautiful dimension with their bold array of colors, shapes and forms within our gardens, however tender plants which have bulbs, tubers and corms, do require storage over the winter, so that we can enjoy their beauty next year and for many years to come.

Most tender materials should be dug after the foliage dries up or is killed by the first strong frost and before the ground starts to freeze. Dig carefully so as to minimize damage, which can cause disease or rotting.

For larger roots such as dahlias, cannas, Caladium the roots can be gently washed with a hose to get rid of soil, then left in open air away from direct sun or winds to dry for 1-3 days.

Smaller corms such as gladiolus, Crocosmia, tigridia, tuberous begonias, Acidanthera are best left unwashed and allowed to dry for three weeks, then the soil may be gently removed by hand. Be sure to label each batch so you know the plant names and colors for next year.

Once dried, do an inspection to check for insects and disease. Old corms should be removed, and keep only those that are healthy, then dust with an insecticide-fungicide mixture following the labeled instructions for various plants.

For winter storage, the ideal location is one that stays constantly just above freezing around 4c/40f. Many older homes have cold storage areas, which are ideal. If not, find the coolest dark location in your basement. Perhaps an unheated room up against an outer wall or directly on a cooler floor, as long as the area is dry and not prone to flooding. Larger bulbs can be packed in boxes with dry sphagnum peat moss or vermiculite under and all around them. The smaller tubers such as those of tuberous begonias can be stored in perforated plastic bag filled with peat moss or vermiculite in a cool dark place (40-50f). Check on your tubers periodically in areas with low humidity, which may cause drying (shriveling). If this is the case you may need to add a very small amount of moisture with a spray bottle to present drying.