By late June, many gardens start to fade. Early blooms slow down, and warm soil dries faster. But your growing season isn’t over. Some flowers thrive in heat and still bloom before summer ends.
With the right choices, you can fill bare spots and bring fresh color to your yard through August and beyond. These flowers grow quickly in warm conditions and keep blooming when many spring plants shut down.
Here’s what to plant now for a strong finish to the season.
1. Sunflowers
Sunflowers love direct sunlight and warm soil. Most varieties bloom in 60 to 75 days. Short-season types like ‘Dwarf Sunspot’ or ‘Teddy Bear’ are ideal for late planting.
To plant sunflowers: direct sow seeds into loose, well-drained soil; space seeds 8 to 12 inches apart; and water deeply once or twice a week.
For late-season pollinators, choose single-headed varieties. Open centers provide easier access to pollen and nectar. For more information, follow this guide on growing sunflowers by University of Illinois Extension.
2. Zinnias
Zinnias bloom quickly and tolerate full sun. Most varieties flower within 45 to 65 days. These annuals thrive in dry heat and require minimal care.
Sow seeds directly into warm soil and space them about 6 inches apart. Once the plants reach 6 inches tall, pinch the growing tips to encourage branching. Deadhead spent blooms to keep flowers coming. Zinnias also attract butterflies and hoverflies, which help support pollination in vegetable gardens.
3. Cosmos
Cosmos bloom within 50 to 70 days and grow well in lean soil. These flowers need full sun and warm nights to reach their full height and color.
Sow seeds where you want them to grow. Water until established, then reduce watering to prevent weak stems. Cut flowers weekly to extend the bloom period into fall.
Cosmos reseed naturally. Leave a few flowers on the plant at the end of the season if you want them to return next year.
4. Marigolds
Marigolds sprout quickly and bloom within 45 to 55 days. French and dwarf varieties work well for borders, pots, and vegetable garden edges.
Plant seeds in full sun and thin them to avoid overcrowding. Marigolds deter aphids and nematodes, making them a popular companion plant. Water consistently during hot spells. In containers, water more often to prevent root stress.
5. Celosia
Celosia adds height, texture, and bold color to summer gardens. These flowers bloom in 60 to 80 days and thrive in dry, hot conditions. Direct sow seeds in full sun. Thin plants to at least 8 inches apart. Celosia holds its color after cutting and works well in dried arrangements. Avoid soggy soil. Water only when the top inch of soil feels dry.
Seeds or Starts: What to Use in Late June
In warm soil, most annuals grow well from seed. Zinnias, sunflowers, marigolds, and cosmos germinate quickly and bloom before frost. If you want faster blooms or are starting late, transplants can help.
Use transplants for celosia or longer-maturity flowers. Seeds offer more variety and are budget-friendly. Starters reduce wait time but may cost more. Choose based on how much growing time remains in your zone.
Late-Season Bloom Chart
Use this chart to compare flower maturity timelines and plan accordingly.
| Flower | Days to Bloom | Notes |
| Zinnias | 45–65 | Pinch for fuller plants |
| Marigolds | 45–55 | Compact and heat-tolerant |
| Cosmos | 50–70 | Light feeders, tolerate poor soil |
| Sunflowers | 60–75 | Choose dwarf types for faster growth |
| Celosia | 60–80 | Great for cut or dried bouquets |
Start shorter-timeline varieties if planting in early July.
How Late Can You Plant and Still Get Flowers?
To get blooms before frost, count backward from your average first frost date. Most summer flowers need 45 to 60 frost-free days to mature.
In zones with late frost dates (October or later), planting through mid-July still works. In cooler zones, stick with fast-maturing flowers and plant no later than the first week of July.
Late-Summer Flower Tips
Keep flowers blooming longer by adjusting your care for summer conditions.
- Water early in the day and target the base of plants
- Mulch to protect roots from heat and slow moisture loss
- Fertilize once with compost or low-nitrogen feed
- Deadhead weekly to trigger more blooms
- Watch for mildew in zinnias and thin plants if needed
Even heat-tolerant plants benefit from consistent care.
Late-Summer Flowers: There’s Still Time to Grow
Late June is not the end of the season. It’s a chance to restart your garden with fast-growing, sun-loving flowers. Direct seed where possible, use transplants when needed, and keep plants watered until established. With a little care, you’ll enjoy fresh color through August and beyond.
What flowers are you planting in this heat? Share your favorites, how they’re doing, or what’s already starting to bloom. We’d love to hear what’s growing in your zone.
FAQ: Late-Summer Flowers
Is June too late to plant flowers?
No. Many warm-season annuals grow fast and bloom within 60 days.
Do I need to start these flowers indoors?
No. All recommended flowers grow well from seed when soil is warm.
How can I extend blooms into fall?
Water deeply, deadhead often, and use mulch to protect roots during hot spells.
Will these attract pollinators?
Yes. Sunflowers, zinnias, and cosmos support bees and butterflies in late summer.
What if I’m planting in early July?
Choose fast-maturing types like marigolds or zinnias and check your local frost date first.
