If I need proof that fall is about to gallop into view, all I have to do is look at my garden. The peas are gone, the vines fed to the chickens weeks ago. The herbs keep trying to go to seed. The broccoli stems have no main heads, although the stems left behind continue to valiantly push out miniature side spears. The vibrant colors of my flower baskets have noticeably dimmed. And, in case I miss the obvious in the backyard, my inbox has lots of questions related to end of season preparations.
This week alone I received three emails asking if it is too late to plant perennials. As I was about to pen an answer, the Plant Kingdom newsletter appeared like magic, dedicated to that very question. I thank Cyndie Warbelow-Tack and The Plant Kingdom Greenhouse for letting me reprint a portion of the advice they gave. Their generosity saved me the effort to compose an answer, and they gave more information than I would have thought to offer.
“One of the great advantages of containerized perennials, both herbaceous and woody, is that it is not too late or too early to plant them as long as the soil where they are being planted is thawed and workable. By containerized I mean a plant that is growing in some sort of container so that the roots are well-established in that container resulting in minimal disturbance to the plant as it transfers from that growing situation to its new home in the landscape. In most years this means that you can plant a perennial from mid-April to early October assuming that it is a hardened off plant ...
If you are bringing a perennial out from a heated space such as a greenhouse or your garage or if you are bringing it from a warmer climate such as an out of state nursery, you must harden it off before subjecting it to the cool temperatures of the early or late season. If you are digging and moving a perennial rather than planting one that is growing in a container, the best time to do this is early in the spring while the plant is still dormant or later in the fall when it is going dormant for the winter ...
One might question whether you really gain much growing time by planting late in the fall. The answer is yes! The fall-planted perennial may begin some root growth before winter sets in, and even if it is planted too late in the season for this to happen, it will still begin growing in the spring long before a gardener is likely to plant it in the spring.”
My garden does not have a lot of perennials but that does not mean I don’t have plants I save from year to year. Begonias are among my favorites, so some years I turn them into houseplants for the winter. I trim them back and then put them in our dining area, which is our sunniest room. Until about November, they can sit on the windowsill, but after that they are moved to the table so the leaves don’t suffer when we have our lowest temperatures. (You can do the same with geraniums and fuchsias. I grow neither of those because the former, no matter what the variety, really have an unpleasant odor to me. And the charms of fuchsias totally escape me; I think each blossom looks like it has a monkey butt hanging out of it.)
But, in truth, by the time September comes, I often am ready to be plant free for a few months. Those years I dig up the begonia bulbs, and then when the leaves and stems have died back, I snap off the tubers and over-winter them in buckets of sawdust, peat moss, cat litter or vermiculite. I make sure they are not touching each other. You can preserve geraniums in somewhat the same way: trim back the foliage and stems, dig the plant up, and brush off the excess soil. However, instead of burying them in a box of sawdust, put each one in a paper sack or a plastic bag that has had some air holes punched out of it. Hang them in a cool place where they won’t freeze, like a garage wall, and they should be good until the spring.
There is another way to preserve fuchsias and geraniums. Trim them back to only a few inches tall and put the pots someplace like a garage, where it stays about 40 degrees or so. No lighting required or wanted. Water them just enough to keep the stems from dying, and you’ll be able to revive them in the fall.
Despite the depredations of my dog earlier this season, my dahlias kept hanging in there. After we have a gentle frost, I will cut back the huge leaves and stems and dig up the tubers. I’ll spread them out on a table until the soil dries and can be brushed off, and then they will go into boxes lined with newsprint and filled with sawdust. Each clump of a mother tuber and attached babies will have its own box. I will top the sawdust with more newspaper and find yet more room in the garage to store them.
Not too many people seem to have gladiolas, and they often don’t survive a winter’s storage. However, if you want to give it a try, dig up the plant and pull off the new corm you will see growing off the bottom of the old one. Let it dry for a few hours, no longer, before storing it in sawdust or the like, and setting the box in a cool area.
And, finally, roses. You can wait until after a light frost to cut them down to about 6 inches tall. Cover the stems with paper sacks — heavy duty ones like the ones grocery stores hand out. Water lightly every few weeks, just before the dry soil is about to turn into dust.
Most of the tender crops that lived outside my greenhouse have been harvested. However, I do have boxes and old sheets ready to throw over the remaining few fragile vegetables on those nights when the temperatures are predicted to hit 35 degrees or colder. If you have potatoes, leeks, Brussels sprouts or pumpkins, they can be left to their own devices until an actual frost comes along.
Linden Staciokas has gardened in the Interior for more than two decades. Send gardening questions to her at firstname.lastname@example.org.