We finally get the memo: Our protracted summer is passing and we have jobs to do. It’s time to bring some plants inside and store others. It’s time to cut back some perennials and improve the vegetable and flower gardens. You can still improve your lawn. And there is lots of time to prepare the landscape for winter.
First things first
1. Tender plants: Take inside now
If you have not done so, get houseplants and tropical plants into their winter quarters before nights hover in the mid-40s. Most survive those temperatures just fine – think about cold nights in Florida – but abrupt changes are stressful for them (moving from the cool outdoors to the heated living room).
Make the move as gradual as possible, and figure out how to increase the lighting and humidity. An exception: Don’t rush the Christmas cactus plant indoors until a frost is threatened, as some cold nights prompt it to set buds; you’ll have a winter flower show.
Plants that are coming inside might include some plants you bought as annuals. All begonias make great houseplants. You can enjoy Plectranthus and geraniums (Pelargonium) with their fragrant leaves. Many gardeners keep Mandevillas and Dipladenias flowering inside for some months. If a plant is pretty, try it – no harm done. If you see disease or a pest infestation, out it goes.
I’m often asked about cleaning up the incoming plants. The books mention soil drenches, and insecticidal soaps, etc. I am much more casual and do none of that. If large plants have a lot of leaf debris around them, I hose them off. I check the pots’ drainage holes for stowaway pillbugs or sowbugs.
Most plants come in from “summer camp” well cleaned up by beneficial insects and rain. If a few beetles or spiders ride along I will spot them and remove them soon enough. It’s never been a problem with my 50-some inside plants. Do trim any plants that are too big or messy – such as spider plants, purple passion plant, the beautiful flowering Streptocarpus, and kangaroo vine. If plants are so root-bound that the soil can’t hold water for a few days, transplant them into the next sized pot in good potting mix.
My dining table and shelves are now crowded with incoming plants, to be matched with cache pots and trays and placed in the most suitable locations – an enjoyable process that goes on for weeks.
2. Tender bulbs and tubers
Cannas, coleus, pineapple lilies and other non-hardy bulbs or tubers must be cut back to a few inches of stem and then lifted. They benefit if you wait until after a frosty night, since that cues them to enter dormancy. If they look dead above ground, they are not; the soil cools down slowly. Use a garden fork, and do not nick or cut them.
• Storage method one: Most collectors just brush off the soil, let them air-dry in a cool place out of the rain, and then store them in boxes using peat moss, sawdust or sand. Some wash them first and dust them with fungicide (labeled for the purpose) or a sulfur-vermiculate mix, but if they are well dried it is not a critical step. Don’t let them touch each other in storage.
• Method two: Some people cut back the plants and leave them in their large containers in a cool basement or attached porch or garage. If the soil separates from the sides of the pot, sprinkle in some water.
Ideal temps for both treatments are the challenge: Aim for between 40 and 50 degrees. Check routinely for rot (destroy those), and for dryness (sprinkle water).
3. In the flower and vegetable beds
Fall may be the most enjoyable and important gardening season of all, although the hype and marketing suggest that spring is the real deal. Cool, sunny days, with just enough rain, let us weed, plant bulbs and woody plants, stir in compost, make new beds, and gather mulch.
• Planting woody plants: Trees and shrubs can be planted successfully, as long as the ground is unfrozen. Two rules: (a) You must plant correctly – generously wide holes with good drainage and good soil (often amended with compost). (b) Ensure that the roots don’t dry out severely before the soil freezes, and then remember to water well in late winter and spring. It is a good time to work with landscape professionals.
• Planting herbaceous plants (perennials): It’s getting late, September being the preferred month. Consider the small root systems, that need some time to anchor the plant in the soil and to prepare to take up moisture. The best choice may be to store the pots-in-waiting in a trench in the soil, in a protected outdoor spot, or in a cold garage. After a freeze, pile mulch around them.
• Planting bulbs: You have time during October and into November, but the sooner the better. Remember the joy of seeing them in April; get some now.
• Clean-up and soil prep: Remove and compost vegetable plants and annual flowers (or turn them directly into the soil). Destroy diseased plants, especially tomatoes, eggplants, potatoes and peppers. Begin your soil improvement process by spreading compost now (on empty beds or around permanent plants).
• Mulch: Gather it now – bags of leaves, pine needles, straw bales, shredded bark – but place it after the soil freezes. (This deters both rodents and fungal growth.)
• Cover the soil: I am always glad I have covered veggie beds with heavy plastic or thick mulch over the winter; so many weeds die under there.
• Cut back finished perennials (generally cutting stems a few inches above the crowns) unless they are attractive (ornamental grasses, sedums), provide seeds for birds (coneflowers), or you want them to self-seed.
• Pruning: It is not the time for pruning projects, except to cut branches that block your path, hit the house, look diseased, or threaten to fall. Save pruning for late winter and spring.
And you thought you were finished for the season. Get out there!
Sally Cunningham is a garden writer, lecturer and consultant.
* Local floral and decorating experts recently shared some ideas for displaying your mums this fall season. Looking for fresh ideas? Here are a few. If you want to share your ideas about decorating with fall mums, you'll find out how to submit photos below: