For those of us that have huge gardens of perennial flowers, adding colorful annuals is a must! However, there’s a lot of money put into those containers so some direction may be helpful.
Annuals for Small Spaces
- Sunny Spaces: Window boxes, curbside planters, and the small areas of open soil next to mailboxes and light poles are often in direct sunshine for six or more hours a day, but they don’t have room for exuberant growers like cosmos and four-o’clocks. Small annuals that should thrive in these situations include ornamental peppers, alyssum, dwarf dahlias, heliotrope, lantana, love-in-a-mist, ageratum, verbena, creeping zinnia, signet and other small marigolds, petunias, cockscomb, and geranium.
- Shady Places: Small planting areas that get only three hours or so of direct sunlight are often ideal for houseplants enjoying a summer outdoors, as well as nursery staples such as begonias, impatiens, lobelias, and torenia. Browallia, caladium, coleus, cigar plant, shrimp plant, purple passion vine, rabbit’s-foot fern, and maidenhair fern are also choices to consider.
Annuals for Fragrance
Annuals offer some of the sweetest perfumes in the flower kingdom, so if you are a fan of good scents, be sure your strolling and cutting gardens include as many of these as possible: sweet alyssum, hesperis, the annual lupine called ‘Sunrise’ (Lupinus hartwegii ssp. cruickshankii), nicotiana (Nicotiana alata and N. sylvestris, but not N. Langsdorffii), stock (Matthiola incana), night-scented stock (M. longipetala), mignonette, and sweet peas.
Petunias should be on the list, too, but be sure to read seed catalogs carefully or smell plants before buying. Some, like old-fashioned trailing singles, are powerfully fragrant, while others, including many large-flowered hybrids, are very faint in the perfume department.
Annuals That Beat the Heat
Most flowering annuals are happiest when night temperatures stay below 80ºF, but not everything gets cooked when the weather is baking hot. The following plants are extreme-summer stalwarts, providing colors when lesser plants fade (as long as you keep them well-watered):
Gaillardia, globe amaranth, four-o’clocks, lantana, Madagascar periwinkle, ornamental peppers, portulaca, salvia, sunflower, torenia, narrow-leaf zinnia (Z. haageana).
Note: Most plants, like most people, can take heat more easily if humidity is low. Even when temperatures are moderate, long runs of muggy weather are usually synonymous with fungus invasions.
The ads on television would have us believing that you should be out fertilizing your plants once a week for good growth during the summer. However, you can get fairly good results by feeding everything once a month with a bloom-boosting fertilizer. Bloom boosters are high in phosphorus, which supports the formation of flowers and seeds.
Usually. Like all rules, this one has exceptions: nasturtiums, nigella, morning glories, and poppies, among others, will flower most abundantly if they are given no extra fertilizer at all. Just plant them in good, well-drained garden soil.
At the other extreme, hybrid petunias, million bells, and the sunflowers that are bred for cutting are heavy feeders. They need rich soil and biweekly doses of bloom booster if they are to live up to their full potential as flowering machines.
But you will have stronger plants and more flowers if you do just a bit of fine-tuning. Plants that are cut back repeatedly are being asked to put out more growth than those that simply sit and bloom, and they need more food to do it. This is especially true of cutting flowers, which lose substantial amounts of stem and leaf as well as blossoms. The more you take, the more important it will be to give the plant something to eat.