Annual flowers are like the few bright toss pillows on a beige or gray sofa. They accent. They cheer. They are easily removed or replaced.
Mass planting is not the only key to success in landscaping with annuals.
Sometimes the attractive planting contains very few annual plants. Even carefully worked out color combinations may disappoint.
The proper placement of plants and the concern with proportion are, of course, important.
You may feel as I do those tiny sweet alyssums are lost when placed in front of yews or junipers.
You may have also found that zinnias and snapdragons are far better companions than zinnias and asters.
All these things considered, go two steps farther. Pay careful attention to spacing and staking.
The Space Gardener
Whether you buy annuals in flats, start them early indoors, or grow them outdoors for transplanting to a particular site.
Also, give some thought to your plants’ height, the habit of growth, and spacing.
The chart below gives spacing information for 20 favorite annual flowers.
| Plant | Type – Height | Inches Apart |
|---|---|---|
| Ageratum | Dwarfs, 3-8” Tall, 18-24” | 8” 12” |
| Asters | Dwarfs, 8-12” Pompons, 15-20” Bouquets, 24-30 Super Giants, 36″ | 6-8” 10-12” 12-15” 15” |
| Centaurea | Dwarfs, 12” Medium & Super Giants, 30” | 8” 10” |
| Celosia | Dwarfs, feather, crested, 6-12” Giants, feather, crested, 24-36” | 8” 12” |
| Cleome | Giants, 42-48” | 12” |
| Cosmos | Medium kinds, 30” Single, double-flowered, Giants, 42-48” | 12” 18” |
| Dahlias | Dwarfs, 20” Pompons, 36” | 12” 18” |
| Dimorphotheca | Hybrids, 8-12” | 10-12” |
| Gloriosa Daisies | Singles and doubles, 36” | 15” |
| Larkspur | Giant Imperials, 36-48” | 6” |
| Lobelia | Annual types, 4-6” | 6” |
| Marigolds | Petites, 6-8” Dwarf doubles and singles, 6-12” Large-flowered hybrids, 48” | 8” 10” 15” |
| Nasturtiums | Dwarf singles and doubles, 12-15” Semi-tall singles, doubles, 18” | 10” 18” |
| Petunias | Miniatures, 6-8” Dwarf types, 10-12” Multifloras, grandifloras, others, 12-18” | 10” 10” 15” |
| Phlox drummondii | Dwarfs, 6-8” Tall kinds, 15” | 6” 10” |
| Salvia | Dwarfs, 6” Medium kinds, 12-18” Tall kinds, 36” | 8” 10” 12” |
| Snapdragons | Dwarfs, 6” Semi-dwarfs, 10-18” Doubles, Giants, 24-30” Double hybrids, and others, 36” | 6” 8” 8” 10” |
| Sweet Alyssum | Named annual kinds, 4-10” | 6-12” |
| Verbenas | Dwarfs, 6-9” Bush kinds, 8-10” Hybrid Giants, 12” | 12” 15” 18” |
| Zinnias | Miniatures, 6-8” Dwarfs, 12-18” Giants, other large flower types 18-36” | 8” 10” 20” |
I have described the kinds of plants usually available from local nurseries.
For example, each type of petunia has a special use, hence a different spacing problem.
Multiflora petunias seldom grow more than 12” inches tall, and they are perfect on a low border.
Space them a foot apart, and the result is a continuous line of color.
Planted any closer, they soon become entangled and ragged-looking. Planted farther apart, there is a spotty, weedy look.
On the other hand, Grandiflora petunias have larger and possibly fewer flowers.
They need more room to stretch out. So give Grandiflora petunias a spacing of at least 14 inches.
Take Courage, Space Properly
Picture yourself down on your knees, trowel in hand, setting out petunias.
Beside you is a flat of plants. They may or may not be in flower yet.
The plants seem small, especially after you have spaced them appropriately. Do not feel disappointed.
Within 10 days, you will be amazed at how the gaps have begun to disappear!
Catalogs often suggest that snapdragons be spaced 1’ to 2’ feet apart.
I have found, however, that snaps, larkspurs, and other plants of the spike form look better placed as close together as possible.
Snaps 2 or 2 ½’ feet tall can be set 8” inches apart.
When this is done, staking is often unnecessary. The snaps lean on each other and give a neater appearance than you can get with any stake.
Avoid The Stake Issue
If you dislike as much as I do stake plants, choose to branch rather than columnar types.
The base-branching varieties of snapdragons, pompon asters, and bushy salvias do well unstaked.
New today are shorter, stockier plants that need no staking.
In an annual border 3’ feet wide, or wider, it is almost impossible to eliminate tall plants and, therefore, plants that may prove floppy.
Examples are:
- Tall cosmos
- Marigolds
- Asters
In this case, I stake only a few of the tall plants —particularly those on either end of the border and the center plants.
Staking should be done early so that the stake will not cut into the root systems of the tall plants.
In front of these, I plant the middle growers—those with near 15-inch height.
I like for these to be erect and bushy. Taller kinds of ageratum are good in this position.
Some of the salvias, also. The bushier, the better, for they help support the unstaked taller plants.