7 Easy-to-Grow Perennials and Biennials to Plant in July – Your 2027 Garden Will Thank You
Our expert pick of the best flowers to sow this month
Depending on where you live, July is often considered the height of summer. With almost everything already planted out for this year’s season, you may be wondering if there is any point in sowing any flowers in July?
Among the deadheading, fertilizing, weeding, and watering, if you can find time for some sowing, you could be looking forward to some stunning blooms next season.
Having grown ornamentals and cut flowers both commercially on a flower farm and at home in my gardens over the years, here are seven of the easiest flowers to sow in July for your beds and borders, or to cut and enjoy in a vase.
Foxgloves
A stalwart of wild and cottage gardens, foxgloves (Digitalis) are adored for their tall flowering spires. Generally flowering from late spring to early summer, foxglove varieties are available as biennials, perennials, and shrubs.
An easy-to-grow biennial, Digitalis purpurea is a prolific self-seeder and can often leave you with more plants for the following year than you need. However, if you would like to grow them for the first time, July is the perfect time to sow them so you can enjoy them the following year.
To sow, simply scatter thinly onto moist seed compost, but do not cover as they require light to germinate. You can purchase mixed-color foxglove seeds from Amazon. However, being toxic, gloves must be worn when handling all foxglove parts, including the seeds.
Coneflowers
Also known as Echinacea, coneflowers are a stunning addition to your container or borders.
A native plant, coneflowers adore full sun and are a magnet for bees and butterflies. They are available in an array of colors and sizes, and there is a wealth of coneflower varieties to choose from.
Ideal for sowing at this time of year, you can sow coneflower seeds either in a seed tray or in a small pot. Keeping the soil moist, pot on the young plants as they mature and plant out in the fall or the following spring.
With its striking pale petals, you can purchase Echinacea ‘Wild Swan’ from True Leaf Market.
Columbine
Another easy-to-grow cottage garden favorite is columbine, or Aquilegia as it is botanically known. An elegant and stunning perennial with dainty-looking flowers, it is available in calming pastels to vibrant hues.
Considered cold-hardy in zone 3 and above, Columbine is tough and a plant I have consistently grown over the years. Nevertheless, it is also a poisonous plant for which care must be taken.
A natural self-seeder, you can sow Aquilegia seeds at various times throughout the year, including July. To sow outdoors, prepare an area by weeding and raking to a fine tilth, then scatter the seed thinly and water in. Keep the soil moist and the seeds should germinate within 3 weeks.
Producing purple and white delicate flowers Aquilegia vulgaris 'Winky Purple & White' is available to purchase from Nature Hills.
Honesty
Prized for its vivid-purple or classical white flowers and stunning seed pods that stand over the winter, honesty (Lunaria) is an ideal border biennial plant. Growing to around 2-3 feet tall, it is perfect for the middle of a bed and self-seeds when given the chance.
Thriving in both full sun and partial shade, it prefers a fertile and moist, yet free-draining soil.
To sow honesty in July, prepare a seedbed and sow the seeds, covering with a light dusting of soil. Keeping the soil moist, the seeds should germinate within 1-2 weeks and form young plants that will bloom the following year.
Cold hardy in USDA zones 7 and above, you can purchase honesty seeds from True Leaf Market.
Sweet Rocket
Perfectly suited to a backyard or a cut-flower patch, Sweet Rocket (Hesperis matronalis) is a scented biennial, or short-lived perennial, that produces sweet-smelling flowers in its second year.
Available with purple or white flowers that are irresistible to pollinators, it grows to around 2-3 feet tall and 1-2 feet wide. To grow from seed, sow indoors in modules or direct outdoors from late spring through to July. If started undercover, plant out early in the fall to establish before winter sets in.
Suitable for growing in zones 3-9, you can purchase Dame’s Rocket Seeds from Amazon.
Delphinium
Grown for their tall flowering spikes that add height and impact to a border, delphiniums are ideal for cottage gardens. Flowering in early summer, delphinium varieties are commonly available in blue and purple, or in paler pastel hues such as pink and white.
Commonly sown undercover in the spring, you can also sow delphinium seed outdoors this month. To sow in July, sow the seeds where they are to grow and cover them thinly with a layer of soil. Keep the soil moist until germination, which generally takes 2-3 weeks.
Preferring full sun to partial shade, delphiniums grow best in a fertile, well-drained soil. However, to protect their delicate blooms from any harsh winds, a sheltered site is recommended.
As it is a highly toxic plant, gloves must be worn when handling any part of the plant, and care must be taken if children or pets are present.
Available in an array of colors, you can purchase Delphinium ‘Magic Fountain Series’ seeds from True Leaf Market.
Wallflowers
Generally, a biennial plant, wallflowers (Erysimum) can also be perennial, though short-lived.
Considered hardy in USDA zones 4-9, wallflowers come in a range of vivid shades from red and orange to yellow and purple and are perfect for a garden border and equally at home in a container.
Sown from spring until the summer, you can sow wallflowers in July either in a greenhouse or where they are to grow outside. However, germination is most successful at temperatures below 70°F, so a cooler spot is preferable.
If sowing outside, sow sparingly in rows spaced 12-18 inches apart and water in gently to avoid dispersing the seed. With the soil kept moist but not overly wet, seedlings should appear in 10-14 days. As it is a poisonous plant, gloves should be worn when handling any plant material, and caution should be exercised if children or pets are present.
For mixed colors, English Aegean Wallflower Seeds are available to purchase from Walmart.
What to Shop
Along with flowers, there are also vegetables you can sow now to ensure a bounty of produce to pick later this summer or in the fall. From French beans to Florence fennel, discover which vegetables our expert recommends planting in July.
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