When you think of sprucing up your landscaping for fall, don't forget about planting fall flowers. Fall foliage trees or shrubs with colorful autumn leaves may be most prized, but perennials can add a boost of color, while annuals are an inexpensive alternative. These flowers are a great addition to other autumn decorations in your yard, such as carved pumpkins and scarecrows.
Buying and Planting Timeline
Don't wait until autumn to buy flowers—unless you live in a warm climate—because planting them too late shortens the length of the time you have to enjoy the blossoms. However, even in the north, it's usually too hot to plant through the first part of August. Therefore, the window of opportunity for planting can be quite short, and there is usually no set date for planting, even for particular regions. You must play it by ear.
During some summers, a rainy period arrives in mid to late August, giving you the perfect opportunity for planting. In other summers, a late August planting would still subject your transplants to too much heat-stress, so it would be better to wait until early September.
There is also the question of what plants are available during this time (as the summer wears on, few garden centers will be carrying your favorite annuals). Buy the plants no later than early August.
Hardy and Tender Choices
Plants that will survive the first frost, such as chrysanthemums, flowering kale, and flowering cabbage, are great choices for fall plantings. All provide the landscape with color well after the first frost. However, don't be afraid to mix in annuals, too, including:
- Marigolds (Tagetes)
- Red salvia
- White alyssum (Lobularia maritima)
- Nasturtium (Tropaeolum majus)
- Pansies (Viola; treated as annuals in the North)
- Snapdragons (Antirrhinum)
- Celosia argentea var. cristata
The contribution of annuals will be brief but spectacular. Marigolds are one of the best picks because they bloom in the classic autumn colors of orange, yellow, and gold.
How to Buy Inexpensive Flowers
If you're on a budget, you may question the wisdom of planting such tender plants as marigolds in autumn, as they will be dead in a few weeks. It would be a waste of money if you were getting them at springtime prices; however, you can find flowers that will not break the bank in July and August when garden centers slash prices after prime time for annual sales has passed. Ideally, they want to move these bargain-basement flowers by July and may even continue to carry an inventory of cheap flowers in August.
Go ahead and purchase the annuals, but do not plant them in the ground yet. Instead, transplant them into containers, which can be moved in and out of the sun, based on how your annual is holding up to the summer heat. When temperatures cool later in the month or in September, transplant them out of their containers and into the ground for an eye-catching display of fall flowers.
Check the undersides of the leaves before buying to make sure the plants are bug-free.
When you knock the annuals out of their flats, check the root ball. If you have wall-to-wall roots forming such a dense mat that soil is not dislodged even when you squeeze it, then you have a root-bound plant. Break up that dense mat by scoring all around the root-ball with scissors. It seems harsh, but this is a case where a little corrective surgery can do wonders.
Also, many annuals respond well to a good trim. You can revitalize everything from alyssum to petunias by cutting off the top half of the current growth (stems, leaves, and flowers).
There's another way to get seedlings for fall planting. Some retail outlets call in fresh recruits (seedlings started in summer) to put on sale as the dog days of August are coming to a close. These plants are just starting to grow, so their foliage will still be fresh by the time they bloom in fall. You may pay a bit more for them than for the older, leggy plants, but they are still often sold at a discount, due to lack of consumer interest in annuals so late in the season.
Form, Texture, and Designing Visual Interest
"Form" refers to the rough shape of a plant. Visual interest can be achieved by using contrasting shapes. A mound-shaped plant such as Silver Mound (Artemisia schmidtiana), a perennial as far north as planting zone 4, gives you a good counterpoint to a spiky plant such as Dracaena indivisa. Both artemisia and dracaena are grown for foliage, not blooms, so add some fall flowers to such a planting to give it more color.
Landscape designers also take the form of individual parts of a plant into account. For instance, the leaves of one plant can have a form different from those of another plant. Leaf form and bloom form are central to "texture."
Form cannot be completely separated from the texture. The texture is mainly a visual matter in landscape design, and it's dependent upon the form of the plant's blooms or its leaves. For example, the texture of the leaves of Senecio cineraria 'Silver Dust', for example, with its toothed edges, contrasts with a neighboring plant that has leaves with smoother edges, such as Salvia splendens 'Red Hussar'. The former is perceived as having a more delicate texture.
Likewise, visual interest is provided by putting a relatively small-leafed, delicate plant such as chrysanthemum (the hardiest will overwinter in planting zone 5) next to a plant bearing larger leaves, such as the coarse-looking flowering kales and cabbages.
The element of color plays a large role, too. Most people have specific colors in mind when planning a fall color scheme. Red, yellow, and orange is a classic combination for the harvest season. Orange and yellow nasturtiums, lemon yellow French marigolds (Tagetes patula "Lemon Drop"), and reddish-purple plumed Celosia will set your fall gardens ablaze.
A metallic color scheme—golds, silvers, and bronzes—is also popular for fall. Golden African marigolds (Tagetes erecta "F1 Gold Galore"), Artemisia ludoviciana "Silver King" (perennial to zone 5), and a bronze coleus (Coleus x hybridus) work well together.
Other perennial choices include:
- Montauk daisies (Nipponanthemum nipponicum)
- Goldenrod (Solidago)
- Joe Pye weed (Eupatorium maculatum)
- Bluebeard (Caryopteris; a sub-shrub often treated as a perennial)
- Autumn Joy stonecrop (Sedum 'Autumn Joy')