fall gardening – My Chicago Botanic Garden

Are your summer container gardens in need of a fall makeover? Good news! There are many fall-flavored plants that will provide you with texture, form, and long-lasting colors in both flowers and foliage.

I love the combination of purple or blue asters (Symphyotrichum) with ornamental kale as the colors play off each other nicely for a long-lasting fall container. Using other lesser-known plants, such as some of the fall-blooming Salvias or sage can add height and lend to very interesting combinations in your container gardens. Try using cold-hardy vegetables and adding herbs to create interest and texture to any combination. I like using Swiss chard, broccoli, Asian greens, parsley, and onions (Allium) for interesting and colorful effects.

Here are a few tips for planning your fall containers:

To achieve a fuller effect, use more plants than you would in the spring or summer. As the days begin to get shorter and the nights get cooler, plant growth is slowing down or ceasing. By planting a fuller container, you will see immediate results that can last for the remainder of the fall season.
Try to plant by early September to give your plants a chance to kick in with some growth before the cooler temperatures and shorter days slow things down. Remember, many plants available for fall container gardens can take temperatures in the 20s Fahrenheit without being damaged, while many plants actually begin to show better foliage colors with cooler temperatures. These include ornamental kale and cabbage, Heuchera, and many ornamental grasses as well.
Select plants that have a variety of tones that contrast and set off each other. Think about using colorful cultivars of Heuchera for their many foliage colors, and colorful grasses or grass-like plants, such as Pennisetum, Carex, Juncus, or the black foliage of Ophiopogon. See the list below of other fall plants to consider for your containers.
Remember, a pot of mums looks fresh for three to four weeks at most, and then the show is over. Showy foliage from grasses or kale and cabbage will carry the display much longer.
The fall foliage on evergreen succulents (Sempervivum ‘Hens and chicks’), and many of the stonecrop (Sedum) cultivars changes and develops more dramatic color once the temperatures stay cool.
If you must have flower power, consider long- and late-blooming Salvia, Cuphea, or fall pansies or violas.
When nighttime temperatures drop below freezing, have light blankets, large pots, or even an empty trash barrel handy to cover your container and protect the plantings from frost.
As November passes, the time will come to disassemble your planter. Carefully place your hardy plants in a nursery bed or empty space in your vegetable garden plot to hold them over until next spring, when you can plant them in a permanent home to enjoy for another season.

Here are a few fall plants and items that can be added to your fall container gardens:

Brassica varieties - ornamental cabbage

Annuals:

Calibrachoa varieties
Capsicum, ornamental peppers
Dianthus cultivars, ‘Sweet William’ and other Pinks
Brassica varieties, ornamental kale and cabbage
Tagetes, marigolds
Pansies and violas
Helianthus, sunflowers
Plectranthus
Salvia, sages

Chrysanthemums

Perennials, trees, shrubs:

Anemone hybrids
Aster cultivars
Chrysanthemum, hardy fall mums
Helianthus and Helianthoides, perennial sunflowers
Rudbeckia, black-eyed-Susan
Boltonia
Sedum and Sempervivum, and other succulents
Fall foliage color with trees and shrubs; maples, cornus, viburnum, spirea, and others

Ornamental grasses

Ornamental grasses:

Miscanthus cultivars
Panicum cultivars
Pennisetum cultivars, including ornamental millet
Muhlenbergia, Muhly grass
Stipa tenuissima, Mexican feather grass
Schizachyrium scoparium, little bluestem

Pumpkins

Other fall items:

Pumpkins
Gourds and squash
Corn stalks
Straw
Branches
Fall decorative items; scarecrows, Halloween and Thanksgiving decorations

Now that the leaves are turning and the days are growing shorter, if you’re tempted to pack away your gardening gloves…don’t!

PHOTO: Baby brussels sprouts budding at the end of September. — Brussels sprouts (*Brassica oleracea*) enjoy the cooler weather of fall for producing their delicious edible buds.

At the Regenstein Fruit & Vegetable Garden, we’re as busy as ever. Our cool-weather crops include brussels sprouts, spinach, and toscano kale. Fall is a great time to grow vegetables—insects die off, weeds wither, and moisture is plentiful. If you don’t have much space, remember that you can grow vegetables in containers, window boxes, and hanging baskets.

Don’t say good-bye to your summer garden yet

Document the good, the bad, and the ugly. Walk around your garden making notes, drawing pictures, and taking photographs; document challenges and successes, problems, tasks, and ideas for next year. Make a list of the plants that worked and should be planted again.
Bring in twigs, nuts, berries, and seedheads to dry for fall decorations or winter wreath making. Gather the stems into bunches, and secure them with a rubber band. Hang the bunches for several weeks to dry in a warm spot (but out of direct sun).
Harvest herbs to dry, freeze, or use fresh.
Lift tender perennial herb plants like rosemary and lavender to replant in pots. Annual basil lasts for several additional weeks in a sunny kitchen window.

PHOTO: Dried plants and seedheads. — Now is the best time to gather plants at the end of the season for beautiful arrangements for the fall table.

Other prep work

Remove debris such as leaves, clippings, and bits of fruits and vegetables. Garden sanitation is important to remove the overwintering habitat for many insects. Cucumber beetle and squash bugs overwinter on leaf litter and create problems in the spring.
Perform bed prep and broad forking—break up densely packed soil now to avoid working heavy soils in the spring (when you do so, you further compact the soil and destroy soil structure). Fall prep ensures that the bed will be ready for early peas around St. Patrick’s Day.
Add organic matter to feed the soil rather than using fertilizers to feed the plant.
Add mulch, thumb deep, to help maintain soil temperature and moisture.
Everbearing raspberry bushes produce their fall crop on the top half of the canes. After harvesting, prune out the top half of the plants. The lower half of the canes will produce fruit early next summer.
As you harvest, remember to save seeds for next season! Got extra? Join us for our annual Seed Swap.

PHOTO: Butternut squash. — Harvest warm-season vegetables, including winter squash and pumpkins, before the first frost.

PHOTO: Tropaeolum majus 'Kaleidoscope Mix' nasturtium. — The edible flowers of nasturtium last well into fall and make a wonderful planting in the garden or containers.

Plant cool season crops

PHOTO: Spotted cucumber beetle. — Thorough fall cleanup is important to avoid pests like spotted cucumber beetle, whose larvae overwinter in leaf litter. Photo by Pollinator at en.wikipedia [GFDL, CC-BY-SA-3.0 or CC-BY-2.5], from Wikimedia Commons

Short-season crops and salad plants—radish, spinach,  arugula, lettuce, mustard, mizuna, and tatsoi—should be sown 30 to 40 days before the first frost (roughly October 15 in Chicago-area suburbs and a bit later downtown).
Plant cool-season herbs like parsley (flat or curly), chervil, cilantro, and edible flowers such as calendula and nasturtium.
Get edible bulbs—such as garlic bulbs, shallot, and onion sets (small onions for planting)—into the ground by Halloween; they’ll be ready for harvest in July.
Harvest hardy vegetables after the first frost, when they become sweeter—kale, brussels sprouts (remove the tops of the plants in early September), cabbage, broccoli, collard greens, and cauliflower.
Harvest warm-season vegetables, including winter squash and pumpkins, before the first frost. Don’t let the first frost touch your peppers and tomatoes; if they’re still green, they’ll ripen a bit indoors.
Think about ways to extend the growing season—with row covers, garden blankets over raised beds, cold frames, etc.

For more ideas or inspiration, drop by the Fruit & Vegetable Garden (in October, come see the giant pumpkins on display). Did I mention that fall is a good time to plant fruit trees for spring blooms and fruit? Plant the trees in cooler weather, under less stress—and they’ll be ready to soar in the spring.

For more seasonal gardening tips, tune into my weekly Saturday morning audio podcast on news radio WBBM. Get past tips online at chicago.cbslocal.com/audio/gardening-tips.

Tag: fall gardening

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