Fall Care for Perennials
By fall, most perennials are through blooming, and by then you might be ready to throw in the towel, but there are still a few things you need to do to ensure that your perennials survive the winter. After a season of enjoying the blooms from your perennial flower garden, late fall is a time in cold-winter regions to prepare the beds for winter. Taking good care of beds in fall will help them thrive next spring and summer.
Water less. Plants need to naturally get ready for winter by hardening off (becoming accustomed to colder temperatures). You can help by cutting back on the amount of water you give them, but do not let them completely dry out.
But water more. In dry-winter areas that do not freeze or have much snow, water perennials once a month on a sunny, warm day to keep them alive and healthy.
Dig them. After the first frost has filled back the foliage, dig and store tender perennial bulbs such as dahlias and gladiolus that can not survive the winter in the ground in a cold climate.
Cut them back. On perennials that have finished for the season, cut back stems to 6 to 8 inches from the ground. Compost the foliage as long as it's not diseased.
Feed them. Fall is a good time to feed perennials by working in a 4- to 6-inch-thick layer of compost around the beds.
Mulch them. After the ground freezes, remove old mulch and replace it with hay, evergreen boughs, or floating row covers. This extra layer protects tender perennials and helps catch and hold snow, which will also insulate the bed.
In cold-winter areas, stop fertilizing perennials by midsummer to encourage them to slow their growth and harden off for winter. In warm-winter areas, fall is a good time to plant perennials. However, in winter check for signs of disease, especially during wet periods, since the plants are growing slowly and conditions are right for rotting to occur.
And no – you do not have to find space indoors for all these gigantic plants. You can; of course, over winter cannas that have been grown in pots by simply bringing them inside and letting them continue the show. It's easy. All you need is some peat moss and a few paper bags, plus a cool, dry place to store the bulbs. Do not use plastic bags, as moisture can build up in them leading to rot. Some people save the string bags that onions and potatoes come in and use those to encourage a good airflow around the plants. You must, of course, be willing to do a bit of digging – but it's a small price to pay for saving and increasing these beautiful plants.
Cannas, Calla lilies and Caladium, Dahlias and many other tender perennials that grow from bulbs, corms or rhizomes are quite easy to over winter. Just enjoy them until that first big frost hits. You will emerge the morning after to find a shriveled and blackened looking mess – but take heart. Cut off that sad-looking foliage leaving only an inch of stem above ground.
Then dig up the rhizomes that they are attached to. Use a digging fork and work your way carefully below the bulb being careful not to nick it – nicks and scrapes provide a possible entry for rot and infection. If you do happen to scrape something, make sure you leave that particular corm or tuber out to dry and form a protective scab. Some growers recommend dusting the wound with a cleanser.
You can leave the dirt right on them without you being an excessively tidy soul. In that case, at least wait until it has discharged and can be easily shaken off. Then you can simply toss them into a paper bag at this point and stow them away in the cool but frost-free basement until spring. If using old grocery bags, it is perhaps more prudent to add some very slightly damp peat moss to the bag so that the plants will not dry out. This is obviously not practical with string bags and other perforated containers.
Now put them in a frost free, cool but not too damp place to spend their winter. An ideal storage place is one that contains temperatures of between 50 and 60 degrees F.
Check them every month to make sure that they are not drying out too much. If so, moisten the peat moss just the tiniest bit or transfer those in string bags to a container with slightly dampened peat moss. You should not be able to wring the peat moss out and see anything drip from it – only to be able to sense that there is a trace of moisture there.
If you see that any of them have begun to rot or decay in any way, discard those so that they do not infect the remaining plants.
In spring all you have to do is open the bags, shake out the plants-to-be, wash away the excess soil and plant. Cut back most perennials to about 3 inches from the ground. Any closer may damage crowns. Remove debris from the garden to help prevent diseases. Wait until spring to cut back some species, including European ginger, bishop's hat, ferns, Lenten rose, ornamental grasses, and upright sedums. In addition to adding winter interest, some perennials over winter better if left uncut. If the growing season has been dry, water deeply in fall before the ground freezes.
Basic upkeep and care of your perennials will promote healthiness and produce better results. With some basic upkeep and care, your perennials will produce beautiful blooms and keep your garden looking beautiful over many seasons and many years.