Even though August often brings heat and dryness, you can still grow different crops and flowers. It’s an ideal month to stay ahead of the game in decorative garden beds and start preparing for the upcoming year. Seeds worth sowing in August include tough annuals. Planting them now means you’ll enjoy an early flush of blooms in spring. Similarly, biennial varieties planted this month will be ready to flower by next summer.
You can plant perennials during any season, but fall and spring remain the most favorable times. These seasons give the plants a better chance to establish sturdy roots before the winter chill or intense summer heat sets in. Fall, in particular, is often the preferred time because the soil retains warmth, encouraging steady growth. While summer planting is possible, it demands consistent watering to help plants cope with the heat.
August is also an excellent time to add autumn-blooming bulbs like colchicums to your garden. These bulbs, along with other vibrant flowering plants, can instantly brighten up tired-looking borders. You can also place colorful choices such as marigolds or low-maintenance shrubs like caryopteris in containers. Remember to water them regularly to prevent the soil from drying out.
Flowers to Plant in August
August may signal the end of summer, but it’s still a perfect time to refresh your garden with vibrant blooms, especially if you’re looking for flowers to plant in August that thrive in warm, sunny conditions.
Zinnias
Zinnias are bold, colorful annuals that bring instant cheer to gardens and make excellent cutting flowers. With a short growing period of just 60 to 70 days, they’re among the easiest flowers to plant in August if you’re hoping for late-season blooms. Even when planted in the last weeks of summer, many zinnia varieties will reward you with vibrant fall flowers.
These sun-loving plants thrive in warm weather. To grow zinnias successfully this month, choose a sunny spot with well-drained soil and keep the soil evenly moist, especially while the seedlings are establishing. Opt for fast-maturing varieties and sow the seeds as soon as possible with a bit of care, and you’ll enjoy bright blooms until the first frosts arrive.
Cosmos
Cosmos are delicate, charming annuals that may not withstand frost, but they grow quickly from seed, making them ideal for late-summer planting. These fast-maturing flowers typically begin blooming just 50 to 60 days after sowing. If you’re in a region where the first frost arrives later in the season, cosmos are a top choice to add to your list of flowers to plant in August. They don’t need nutrient-rich soil, just good drainage and plenty of sunlight. With proper care, you can expect a lovely display of August blooms by late September or even October, depending on your local climate and the variety you choose.
Marigolds
It’s easy to associate these vibrant annuals with the hottest days of summer, and for good reason, marigolds thrive in full sun and high temperatures as long as they’re kept well-watered. Surprisingly, though, they also show impressive resilience to the cold. In many areas, marigolds continue to bloom right through the first frosts and won’t truly fade until temperatures regularly drop below 40°F (4°C).
If you choose fast-maturing marigold varieties and sow them in early August, you could be rewarded with cheerful blooms by late September. Most types of flowers take just 50 days after planting, making them one of the quickest options for late-season color. As an added bonus, marigolds give off a distinct scent that naturally repels pests, making them an excellent companion for your fall vegetable garden.
Rudbeckia
Rudbeckia hirta is a classic native perennial that has earned a permanent place in many gardens. With sturdy stems and bright golden, daisy-like petals surrounding a dark, cone-shaped center, they bring timeless charm and reliable structure to flower beds. Each bloom stands tall on 1- to 2-foot stems, appearing individually and adding a bold splash of late-summer color.
While most varieties are known to flower toward the end of summer, there are exceptions worth noting. ‘Early Bird Gold,’ for instance, is a day-length neutral selection of the well-known ‘Goldsturm.’ It shares the same vibrant appearance but begins blooming much earlier — sometimes as soon as late May — and continues well into the colder months. In warmer zones, this could mean a flowering season that lasts until December, while northern gardeners can expect blooms from late June through October.
Cornflowers
Cornflowers (Centaurea cyanus) are a charming addition to any garden, and they’re one of the easiest flowers to plant in August if you’re planning for spring color. Sowing them now can reward you with beautiful May blooms. Popular cultivars to consider include ‘Black Ball,’ known for its rich, chocolate-toned petals, and the classic ‘Blue Boy’ with its vivid blue flowers.
Sow cornflower seeds directly into well-drained soil in a sunny location, or start them in trays or pots under cover for transplanting later. Be sure to thin out the seedlings once they sprout to give each plant enough space to grow strong and healthy.
Pansies
Bright and cheerful pansies are one of the best flowers to plant in August, especially in regions with mild autumns and cool winters. Starting seeds this month gives you a head start on fall blooms. Sow them in a partly shaded area where they’re protected from intense summer heat, and keep both the seeds and young plants consistently moist during early growth.
By mid to late fall, you’ll enjoy vibrant blooms that thrive in cooler temperatures. Since pansies grow low to the ground, they’re perfect for edging garden beds, filling containers on the patio, or adding color to hanging baskets. To ensure healthy growth, plant them in well-drained soil enriched with organic matter, and deadhead spent flowers regularly to encourage continuous blooming.
