Tender tubers and bulbs require some attention
Last week I shared several essential gardening tasks you’ll need to perform before the arrival of cold autumn temperatures in a few short weeks. Today, I’d like to tell you about one more.
If you grow tender bulbs and tubers, over the coming weeks you’ll need to dig them out of the garden and store them for the winter.
Elephant ears, dahlias, caladiums, tuberose, tuberous begonias, cannas, calla lilies, freesias and many other tender tropical bulbs will not survive the winter if left in the ground here in Pennsylvania. If you want to see them return to your garden next year, proper autumn removal and storage of the bulbs and tubers is a must.
All of the tender plants mentioned above, along with many others, can be stored in a similar manner. The trick is to dig them out at the proper time, cure them appropriately, and then put them into storage so they don’t desiccate during the winter months.
You can dig any tropical bulb or tuber out of the ground any time between when the nighttime temperatures start to dip close to freezing and just after the arrival of the first frost. Some gardeners prefer to wait until a killing frost has blackened the plants, which does make removing the green top-growth a bit easier, but it isn’t an absolute must. If you want to get a jump on this important job, you can get started as soon as nighttime temps regularly dip into the 40s.
No matter which tender bulbs and tubers you grow, cut all the green leaves and shoots off when you dig them out of the garden. Then, use your hands to gently brush off any excess soil. Do not rinse or hose off the tubers or bulbs.
Lay the bulbs and tubers out in nursery flats or newspaper in a garage, shed or other dry, protected site. Let them cure for about 10-14 days. During this time, any remaining soil will fully dry, making it easy to brush it off when the time arrives. This is also when the “skin” of the bulb or tuber cures and hardens, forming a protective barrier and preventing future moisture loss. This curing period is essential for good winter storage and low rates of bulb rot.
Once the bulbs and tubers are cured, use a soft paintbrush to remove any remaining dried soil, then pack the bulbs and tubers into cardboard boxes filled with peat moss or vermiculite.
To prevent the spread of rot, should any happen to develop, pack the bulbs in single layers and do not allow them to touch each other inside of the box. Each bulb should be fully surrounded by peat moss or vermiculite. Do not wet the peat moss or vermiculite prior to use. Simply scoop it out of the bag and put it straight into the box.
Once the box is full of bulbs, tubers and peat moss or vermiculite, fold the flaps closed but do not tape them shut. There should be a small ventilation hole at the top of the box to allow for an exchange of air.
Store your box of bulbs and tubers in a dry, cool site. A cold cellar, attached garage or basement is ideal. Temperatures between 35 and 50 are best. Check your tubers and bulbs for signs of rot every few weeks throughout the winter months by sifting gently through the box. Remove and discard any that have developed soft, mushy spots.
Come spring, after the threat of frost has passed, it’s time to head back out to the garden to plant your overwintered tender bulbs and tubers and enjoy another year’s worth of blooms.
Horticulturist Jessica Walliser co-hosts “The Organic Gardeners” at 7 a.m. Sundays on KDKA Radio with Doug Oster. She is the author of several gardening books, including “Attracting Beneficial Bugs to Your Garden,” “Good Bug, Bad Bug,” and her newest title, “Container Gardening Complete.” Her website is jessicawalliser.com. Send your gardening or landscaping questions to firstname.lastname@example.org or The Good Earth, 622 Cabin Hill Drive, Greensburg, PA 15601.