Everyone loves a planter overflowing with petunias, geraniums, or begonias, and containers planted with a single type of plant can be spectacular. But don't be afraid to combine different types of plants, too. You can create dramatic, professional-looking displays by following a few simple rules.
Choose Compatible Plants
Make sure plants have similar growing requirements. The most important considerations are light and moisture preferences. Some plants, including portulaca and lavender, prefer full sun and very well-drained soil. Dahlia and diascia needs full sun and moist soil. And impatiens and torenia prefer shade and moist soil. Mixing plants with different needs in a single container is a recipe for disaster.
Select Plants with Different Growth Habits
Tall, spiky plants, like grasses or snapdragons, provide a vertical element for the center or back of the planter. Smaller, mounding or shrubby plants provide substance at mid-height. And cascading plants soften the edges of the planter.
Plant for the Seasons
Some plants thrive in the cool temperatures of spring and fall but fade in midsummer heat. Others thrive in the hottest weather. In warm parts of the country there are three distinct growing seasons. Choose cool-season plants for your spring containers. When they begin to flag in the heat, replace them with heat-lovers. In fall, switch back to the cool-season plants.
Here is a chart with some common container plants and their preferences.
| Plant | Sun | Part Sun | Shade | Drought tolerance | Cool- season | Warm- season | Notes |
|---|---|---|---|---|---|---|---|
| Alyssum | x | x | low | x | Low-growing, cascading; can withstand light frost | ||
| Angelonia | x | medium | x | Upright; sometimes called summer snapdragon | |||
| Begonia | x | x | x | low | x | Mounding; different types have different needs | |
| Coleus | x | x | low | x | Mounding; some cultivars are tolerant of full sun | ||
| Dahlia | x | low | x | Form and height varies | |||
| Dianthus | x | x | low | x | Mounding; can withstand frost | ||
| Diascia | x | moderate | x | Nice filler plant; can withstand light frost | |||
| Dichondra | x | x | moderate | x | Cascading | ||
| Gaillardia | x | high | x | Mounding | |||
| Geranium | x | medium | x | x | May begin to flag in summer heat | ||
| Helichrysum | x | x | high | x | Cascading; nice filler plant | ||
| Impatiens | x | x | low | x | Mounding | ||
| Lantana | x | medium | x | Mounding to cascading | |||
| Lobelia | x | x | medium | x | x | May flag in midsummer heat | |
| Millet | x | medium | x | Upright | |||
| Nemesia | x | medium | x | x | Upright | ||
| Pansy | x | x | medium | x | Low-growing; can take frost | ||
| Penta | x | high | x | Mounding; loves heat | |||
| Perilla | x | medium | x | Likes heat | |||
| Petunia | x | x | medium | x | May begin to flag in heat but pick up in fall. | ||
| Plectranthus | x | high | x | Mounding, cascading | |||
| Portulaca | x | high | x | Cascading | |||
| Snapdragon | x | x | low | x | Upright | ||
| Torenia | x | x | low | x | Mounding | ||
| Verbena | x | x | high | x | Mounding, cascading | ||
| Vinca | x | high | x | Likes heat | |||
| Zinnia | x | moderate | x | Mounding |
The sky -- or rather, the rainbow -- is the limit when it comes to choosing a color scheme for your planters. When you see a color combination that suits you -- whether it's from upholstery, your wardrobe, or a garden -- make a note of it and plan to replicate it in your container plants.
Pastels. Soft pink, lavender, pale yellow -- these gentle colors set a mood of tranquility. Pastel colors look best when viewed from relatively close up, and they can looked washed out in the harsh mid-day sun.
Brights. Racy reds, vibrant oranges, and sunny yellow -- these colors invigorate and energize. Bright colors hold up well to brilliant sunshine, and attract the eye even from a distance.
You can liven up a pastel planter with a splash of vibrant color and tone down a too-bright one with silvery foliage plants.
If you are concerned about your ability to choose colors, a harmonious color scheme might be a good starting point. Harmonious colors are next to each other on the color wheel; examples include blue and violet, orange and red, and orange and yellow. As you gain confidence in your design eye, you can always add splashes of another color to liven things up.
Think Outside the Pot
How about including an ornamental pepper or culinary herbs like rosemary or sage to your container planting? Edible flowers, such as nasturtium, combine well with herbs, such as purple basil, for an attractive and tasty combo. Don't spray edibles with pesticides, however.
Containers are perfect for experimenting with color and texture combinations. Try some new plant and container combos this season, and light up your landscape with color and style.
