Annual Flowers for Container Gardening

By the time spring rolls around, many of us are more than ready to jump full swing into the planting season. Just don't be overly anxious and not pay attention to the end frost dates for your zone. Though we have some beautifully warm days, it is the nighttime temperatures you have to worry about. Plants that get nipped by frost may be killed outright or be stunted. If you do want to get a jump start on your plants, at least pay attention to frost warnings and cover your plants at night with a sheet to protect them.

Here in zone 6 the general rule for gardening is to wait till April 15th and for those tender annuals to wait till around Mother's Day.

Yard sales, flea markets and estate sales start up again with warmer weather and offer the perfect opportunities to take advantage of searching out inexpensive "finds" for your planting containers.
You can get creative with the arrangement utilizing various containers for your plants. Keep an eye out at farm sales or flea markets for old galvanized pots and wash tubs. I save those flexible black nursery pots that young trees come in to use inside the larger tubs. You can just fill the tub itself with potting soil and plant directly in them but realize how heavy those tubs will be to move around. Also, come the end of the season it is so much easier to just lift the smaller pots out then to try to empty the tub to store for the winter. To leave the dirt in the tub encourages the bottom to rust and eventually break through. As the plants grow and fill in the plastic pots will be hidden from view.

Though tempting to just go to the nursery and buy a little of everything, it is best to have a plan. Below are photos and a little info about several great annuals for container gardening. When you research your container or window box plantings, keep in mind three things: thrillers, fillers, and spillers.

First shown here is the African Daisy, a tough plant that can tolerate drought and poor soil. It has a profusion of brightly colored flowers all season.  Pinching early in the season encourages a bushy plant and deadheading as the season progresses encourages new growth. Full sun to partial shade. Grows to about 1 foot.

Osteospermum or African Daisy

Ageratum or Floss Flower does well in sun to partial shade. They don't like to dry out so water regularly. Very pretty in mass plantings, these bushy flowers get anywhere from 6 to 24 inches tall, depending on their type. Pinching them back will encourage branching out and remove the spent flowers to keep them producing new flowers.

Ageratum or Floss Flower

Lantana can tolerate neglect. If put right into the ground this butterfly, bird and hummingbird attraction will grow into shrub like proportions. In a pot you'll have to pinch and prune to keep it shapely. Preferring slightly acidic soil, pine needles added to the pot will help.

Lantana

Heliotrope not only smells wonderful, but is loved by hummingbirds and beneficial insects. Deer leave it alone. Prefers sun to partial shade. Will follow the sun like does the sunflower. Heat brings out the fragrance so put where it'll get the hot afternoon sun. Pinch in the spring and deadhead as the season goes along. Gets 1 - 2 ft high and wide. Heliotropes can be brought indoors over the winter.

Heliotrope or Cherry Pie plant

Nicotiana, or Tobacco flower, are wonderful night bloomers to attract Sphinx moths. Shown here is the smaller type not known for its scent. If you want the type with the large white tubal flowers that emit a wonderful sweet fragrance in the evening, plant N. sylvestris directly in the soil, as these are much bigger plants. Tubular flowers attract hummingbirds. Prefers sun to shade and well drained soil. If ingested the plant is toxic. Reseeds easily.

Nicotiana or Tobacco flower

Salvia blooms it spiky flowers all season, attracts butterflies and pollinators, and the deer leave it alone. Grows 1 - 2 feet tall and likes sun to partial shade. If plant looks tired by midsummer prune it back by a third.

Salvia or Sage for some types

Nemesia prefers a cooler climate, so once the heat of summer kicks in, blooming will decrease. Chop them back by one-third and they will bounce back. Available in a wide array of colors, they are one of the fillers. Keep it well watered and cut back to keep the blooms coming.

Nemesia

Actually a tender perennial, Lobelia looks beautiful for a while then will peter out by midsummer. You can cut it back by half and it will rebound, or you can just let the neighboring plants fill in the gaps as they grow. Lobelia prefers more shade if grown in very hot and sunny climates such as the South. Color shades range from blue to purple to pink and white. Pictured here it is blue.

Lobelia

New Guinea Impatiens have beautiful foilage and flowers. They love the sun, unlike the impatiens we select for shady areas. Low maintenance flowers that reach about a foot tall and wide. Great for containers.

New Guinea Impatiens

Calibrachea, trailing 1 inch petunias that bloom profusely until they slowly peter out by late summer. They come in a choice of colors ranging from yellow, peach, pink and purple. Keep them well watered. Like the ever popular annual petunias of which we are so familiar, these beautiful flowers prefer full sun and offer a fabulous array of color.

Calibrachoa

Bidens is a trailing yellow flowered plant that is both heat and drought resistant. Looks great with many container plantings. Loves the sun. Deadheading will encourage continuous bloom. In mild climates Bidens easily reseeds itself.

Bidens

Diamond Frost Euphorbia is a light airy plant with little white flowers great to use to fill in the gaps. Tiny, delicate leaves and flowers adorn this 12 to 18 in. plant which looks a bit like Baby's Breath.

Euphorbia

Trailing Verbena, a trailing perennial often planted as an annual can grow to 12 inches tall and 2 feet wide. The leaves are medium to dark green, ovate in shape with coarse toothed margins and grow to one inch long and half as wide. Beautiful plant as it spills over the edges of its pot, basket or over rocks. Colors options are in the red, pink and purple range.

Trailing Verbena

Bacopa is one of the spillers. It is low growing, reaching no more than 6 - 12 inches. Great for trailing over baskets or rock walls and filling in gaps under larger plants. Likes sun to partial shade.

Bacopa

Sweet Potato Vine is grown for its trailing green or magenta foilage, both of which blend beautifully with other plants for container planting. Does well in sun or some shade. These ornamental types will not produce actual sweet potatoes.

Sweet Potato Vine

Thumbergia or Black-Eyed Susan Vine is such a colorful and well-behaved trailing vine. The yellow to orange flowers with their dark brown tubular centers are interesting to look at. This plant is great when a vine is desired but not one that is overly aggressive. Does best in full sun.

Thumbergia or Black - Eyed Susan Vine

Last we have the accent plants, such as Fountain Grass, Bloodgrass or Dracaena Spikes. Planting either of these in the center of a pot can really add the height and focal point to the arrangement.
Utilizing height, filling in the gaps, and the spilling effect brings it all together.

Bloodgrass

Dracaena Spike

Thumbergia
Bacopa
Calibrachoa
Ageratum
Osteospermum
Nemesia
Heliotrope
Sweet Potato Vine
Fountain Grass
Blodgrass
Dracaena spikes
New Guinea Impatiens
Verbena
Salvia
Petunias
Euphorbia
Bidens
Lantana
Lobelia
Nicotiana