Planting Fall Flowers for Autumn Colors

Annuals as Inexpensive Options, Plus Some of the Best Perennials

Tagetes patula (marigold) in bloom.
Many marigolds have flowers with classic fall colors. Taco Witte/ Flickr/ CC BY 2.0

When you think of having autumn colors in your landscaping, don't forget about planting fall flowers. Fall-foliage trees or shrubs with colorful autumn leaves are king, but perennials can add much color, and annuals are an inexpensive alternative. You may associate annuals with late spring (everyone gets the planting bug then), but fall planting with tender annuals is the mark of the true lover of great landscaping. For success in enjoying them in the autumn landscape, though, you need to plan ahead (no later than August).

Growing fall flowers in the garden will improve a landscape that's already graced by fall-foliage trees. But if your landscaping lacks such trees altogether, planting fall flowers takes on even greater importance. The color display put on by these annuals and perennials is a great addition to the non-living autumn decorations in your yard, be they carved pumpkinsscarecrows, or scary ghouls. Learn about some of the best choices, plus tips on timing and on saving money.

When Should You Buy and Plant Fall Flowers?

Don't wait till autumn to buy flowers unless you live in a warm climate. Planting them too late shortens the time you have to enjoy them. Yet, even in the North, it's usually too hot to plant through the first part of August.

Thus the window of opportunity for planting can be quite small, and there's no set date for planting, even for particular regions: You must play it by ear. Some summers, a rainy period arrives in mid-to-late August, giving you the perfect opportunity for planting. Other summers, a late August planting would still subject your transplants to too much heat-stress, and it would be better to wait until early September.

There's also the question of what plants are available at this time (as the summer wears on, few garden centers will be carrying your favorite annuals); buy them no later than early August.

Hardy and Tender Choices

Plants that will survive the first frost, like chrysanthemums, flowering kale, and flowering cabbage, are great choices for fall plantings. All provide the landscape with color well after the first frost. But don't be afraid to mix in annuals, too, including:

The contribution of annuals will be brief but spectacular. Marigolds are one of the best picks, because they bloom in the classic autumn colors: orange, yellow, gold, etc. The two most common groups of marigolds are the French marigolds (Tagetes patula) and the African (Tagetes erecta). In each case, the common names are misnomers, as the marigolds are New-World plants.

From the point of view of saving money, you may be questioning the wisdom of planting such tender plants as marigolds for fall, since they'll be dead in a few weeks. It would be a waste of money if you were getting them at springtime prices. But here's a way of avoiding paying top dollar for them.

Take Advantage of Bargain-Basement Flowers

Cheap flowers can be found in July and August. By slashing prices after prime time for annual sales has passed, garden centers can unload leggy annuals that they couldn't sell in spring. Ideally, they want to move these bargain-basement flowers by July. But others grow or buy in fresh recruits and continue to carry an inventory of cheap flowers during August.

The cheap flowers in the "leggy group" may not look like much when you buy them, because they've been sitting in nursery flats for too long. But they're still a great bargain, because they can be revived if you follow a few simple tips. Check the undersides of the leaves first, though, to make sure they're bug-free. It's too hot to plant these flowers in July, but that shouldn't stop you from buying them. Go ahead and purchase the annuals, but do not plant them in the ground yet. Instead, transplant them into containers. Containers can be moved in and out of the sun, based on how your annual is holding up to the summer heat. You simply don't have this flexibility with annuals planted in the ground.

So resurrect those poinsettia pots you've been throwing behind the garage after every Christmas, disinfect them, and use them as "sick bay" to nurse your bargain-basement plants back to health. To disinfect, soak them for several minutes in a solution of one part bleach to nine parts water, then wash them as you would kitchen pots (with sponge, hot water, and dishwashing liquid).

When you knock the annuals out of their flats, check the root-ball. If it's wall-to-wall roots, forming such a dense mat that soil isn't dislodged even when you squeeze it, then you have a root-bound plant. All is not lost, though. Before transplanting 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 "haircut." You can revitalize everything from alyssum to petunias by cutting off the top 1/2 of the current growth (stems, leaves, and flowers). In fact, you almost must do this if your annuals are leggy.

During August you can nurse along your bargain-basement annuals, getting them ready for fall planting. 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.

Fall Flowers for Brown Thumbs

Brown thumbs will be glad to hear that 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 out in life, so their foliage will still be fresh by the time they bloom in fall. This means that you won't have to nurse them back to health. You may pay a bit more for them than for the older, leggy plants, but they're still often sold at a discount, due to lack of consumer interest in annuals so late in the season.

Landscape Design Tips for Arranging Fall Flowers

While color comes to mind immediately, color is but one of the five basic parts of landscape design. Texture and form, for example, can also be used to improve your landscaping. And if, when buying your fall flowers, you make your choices with an eye to achieving contrast (either in form, texture, or both), your landscaping will have neighbors convinced that you're a real pro.

"Form" roughly means the shape of a plant. Visual interest can be achieved by using contrasting shapes. A mound-shaped plant like Artemisia schmidtiana Silver Mound, 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."

For form cannot be completely separated from texture. Texture is mainly a visual matter in landscape design (rather than having to do with touch). It's dependent upon the form of the plant's blooms or, especially, of its leaves. But speaking of plant texture in isolation makes little sense. Some context must be provided. We draw conclusions about plant texture based on how it compares or contrasts with the plants around it, either in terms of size or form.

The texture of the leaves of Senecio cineraria Silver Dust, for example, with its toothed edges, contrasts greatly with a neighboring plant whose leaves have 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, more 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. 

Let There Be Color!

The element of color does, of course, play a large role, too. Most people have specific colors in mind when planning a fall color scheme. Red-yellow-orange is a classic 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 is also popular for fall: golds, silvers, and bronzes. 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.

Alternative Fall Color Schemes, More Perennial Choices 

Some prefer the pinkish-purple chrysanthemums and another perennial, the purple Aster novae-angliae, to traditional fall color schemes. A taller specimen is the reddish Amaranthus caudatus.

Other perennial choices include: