Top Garden Flowers to Start from Seed in March

The bane of winter is one that gardeners are well acquainted with, with its starving, icy fingers and pale ascent. But eventually, the spring months jostle into place. 

When summer comes like a jolt, announcing its arrival with a bright ambush of flowers, those blooms are already there on the ground. Classic garden flowers are known for their reliability – they frolic and play, splashing the ground with multitudes of color. They abound in confetti-like layers, and while lacking the pomp and splendor of more expensive specimens, are reliable plants that quickly fill your yard with color. 

Here is a list of the top garden flowers that will stay with you from summer to fall. 

 

Getting Started with Seed-Starting Essentials

Before you start throwing seeds into random dirt patches, it is important that you follow the growing instructions on each packet. Here are a few essential tools: 

• Seed trays or small pots: Choose containers that are sturdy and well-made, with drainage holes.

• Seed-starting mix: A light, well-draining mix encourages healthy root development.

• Light source: Plants need to receive plenty of sunlight, which can be accomplished with sunny, south-facing windows – or in the cases of shadowy apartments, grow lights.

• Plant Labels: As you transplant your plants outside, it can be confusing to keep track of multiple plant varieties. These plant tags are reusable, built to withstand heavy rainfall and scorching sun. 

1. Marigolds  

Marigolds are a gardener’s favorite because of their pompom-like blooms and their resistance to the many obstacles nature throws at them. They are cheerful and jaunty, parading around as if in a medieval caper, playing the part of a bard. French and signet marigolds anytime from spring through midsummer, while tall African marigolds should be planted immediately in the spring after danger of frost has passed. Start them indoors 4 to 6 weeks before your last frost date. 

2. Zinnias  

Prized for their ability to catch the eye and flower all summer long, zinnias are another springtime favorite. There is no doubt that dahlias are outrageously beautiful, but they are not the easiest to grow. Zinnias (especially, double-flowering, 'Dahlia Flowered' types, or varieties like 'Queen Lime' and 'Oklahoma' series) are the best low-maintenance substitutes for dahlias, mimicking their architectural, spherical look. As they have sensitive taproots, it is recommended that you directly sow them onto the ground, directly in the sun. 

3. Delphiniums

While most mass-blooming flowers are deemed fillers, delphiniums are the exception, bringing unrivaled color and height to the garden. Their tall, dramatic spikes suit the elevated structure of raised beds, which provide excellent drainage and, if tall enough, help prevent waterlogging. They are most common in shades of indigo and blue, but some varieties debut in lighter whorls of color, including the poetically named Delphinium ‘Guinevere’. 

4. Cosmos  

Even those with a constant litter of cats (or children) to take care of can grow cosmos. Like zinnias, they flourish in abundance with little maintenance. Deadheading cosmos with a hori hori knife is a fun and rewarding task. Direct sow once threat of colder nights has passed. 

5. Sweet Peas  

There is much to love about sweet peas: they look and smell like a cotton candy dream. Some varieties produce a dreamy array of colors, including purple, mottled pastels, pink, blue, and cream. Because sweet peas produce long taproots, small containers can constrain their growth – deep containers, at least 6 inches, are recommended. Despite advice to soak sweet pea seeds overnight, some experts say soaking will actually reduce germination. If the seed is of high quality, soaking is not needed. Once seedlings are established, they avidly climb on trellises or fences. 

6. Foxgloves 

Foxgloves are beautiful flowers that make everything in the garden seem as if it were sprinkled with magic. Digitalis purpurea 'Camelot Lavender' blushes a lovely lavender in the setting sun. Foxgloves don’t transplant well, so it is recommended that you start them outdoors in March, in warmer zones only. Prolific self-seeders, foxgloves will come back if you grow them in an undisturbed area. 

7. Calendula  

Famed for its exceptional healing properties, calendula are brilliant flowers that bless your beds with sprightly patches of color. Though often confused with marigolds, they are not one and the same. In ancient times, calendula was used by the Romans in religious ceremonies and for medicinal purposes. To protect your plants during periods of intense heat, wheel them inside in raised rolling beds. 

8. Poppies   

The classic flowers dotting California hillsides, poppies are both bittersweet and nostalgic. Folklore tells of poppies symbolizing grief and conflict, used to commemorate those who died in wars. The red poppy is ubiquitous, but there are also varieties that subvert expectations: the Flemish Antique Peony Poppy, a flouncy flower with speckled petals; and the gossamer oriental varieties, which feature splotches of color. Poppies allow you to get lazy and scatter the seeds without burying them into the soil.