Is It Too Late to Plant Sunflower Seeds? Tips for Late Season Planting

The sunflower is the typical flower of late summer and fall. Late summer sunflowers have round, happy flowers that can’t be beat. But what if you didn’t plant them in the spring or early summer? Is it too late to enjoy them?

It depends on where you live, but for many gardeners, planting sunflowers in late summer is a good idea.

Sunflowers are one of the most iconic and beloved flowers across the world. Their bright, sunny faces can instantly lift your mood. As a gardener, you likely look forward to planting sunflower seeds each spring. But what if you missed the ideal planting window? Is it too late to plant sunflower seeds?

The answer depends on several factors, including your planting zone, weather, and sunflower variety. With some planning and preparation, it is possible to successfully plant sunflowers later in the season. Here is what you need to know.

When is the Ideal Time to Plant Sunflowers?

Sunflowers thrive when planted in the late spring or early summer when soil temperatures reach at least 55-60°F, This timing gives the seeds time to sprout and establish before hot summer weather arrives It also allows the plants to mature and bloom before the first frost in fall,

The ideal planting window is generally April to early June. However, this can vary by growing zone. The further north you live, the shorter your growing season is likely to be.

In southern climates, planting can occur as late as August. But in northern regions with cold falls, early to mid summer may be the cut-off.

How Long Do Sunflowers Take to Bloom?

Sunflower maturity times depend on the variety. In general, most take 70-100 days from seed to bloom. So when planting late in the season, choose quick maturing varieties under 90 days.

Some fast-growing sunflower options include

  • Sundance Kid (75 days)
  • Sunburst (85 days)
  • Sunspot (85 days)
  • Soraya (75-90 days)

With careful timing, you can still enjoy sunflowers even if planting later than usual. Just ensure your season is long enough for the variety you choose.

Can You Plant Sunflowers in Summer?

Planting sunflower seeds in early summer can work well, granting you get started by early July at the latest. Just keep in mind that germination may suffer if soil temperatures are very high. Ensure the seedlings get ample moisture as well.

Look for heat tolerant varieties like ProCut Orange, Ring of Fire, and Hot Spots. Stagger planting a few weeks apart for an extended bloom time. Also, give plants plenty of space and prune lower leaves to encourage airflow.

Avoid planting new sunflower seeds mid to late summer. It is likely too late for them to mature and bloom before frost.

Tips for Successfully Planting Sunflowers Late

While not ideal, determined gardeners can still find success planting sunflowers past prime season. Here are some tips:

Get a head start indoors: Start seeds indoors 4-6 weeks before your last expected frost date. Transplant them outdoors once the weather warms up. This gives sunflowers a development jumpstart.

Provide frost protection: Use cloches, cold frames, or fabric row covers to protect tender seedlings if cold snaps or frost threatens after planting.

Choose short season varieties: Opt for quick maturing sunflowers under 90 days to bloom. They will have the best chance of flowering before frost.

Boost nutrients: Enrich soil with aged compost or manure before planting. This provides nutrients to aid growth during the short season.

Water diligently: Don’t let plants dry out. Consistent moisture is key since the root system has less time to establish.

Pay close attention: Monitor plants daily for pest or disease issues since they will be more vulnerable when planted off-season. Act quickly if any problems arise.

Harvest promptly: Once blooms appear, don’t delay harvest. Get seed heads cut for drying as soon as possible.

What Happens if You Plant Sunflowers Too Late?

Attempting to plant sunflowers in mid to late summer when growing seasons are waning never goes well. Here are some issues that arise:

  • Poor germination due to hot soil temperatures
  • Drastically reduced time to mature and flower
  • Weak, underdeveloped root systems
  • Increased pest and disease pressure
  • Frost damage before blooms fully form
  • Inadequate pollination for seed production
  • Lower seed yield and viability

While you may get lucky and still get some blooms before frost, the quality and quantity of flowers will be severely reduced when planting too late.

Should I Just Wait Until Next Year?

If you missed planting sunflowers during the ideal window this season, it may be best to simply wait until next year.

Sunflowers thrive when conditions are right and all their needs are met. Trying to push the limits by planting too late usually leads to disappointment.

Be patient, and look forward to next season. In the meantime, collect ideas on new varieties to try and ways to tweak your approach for maximum success.

The takeaway? While possible to plant sunflowers late under the right conditions, the ideal timing is key for robust, vibrant blooms. Know your climate, choose quick varieties, and prep your soil. With care and luck, you can still enjoy these classic beauties before summer’s end.

Can You Plant Sunflowers in Late Summer?

Sunflowers are generally planted in spring or early summer for late summer and fall blooming. If you live in a warmer area, though, you can plant a second time for flowers in the middle to late fall.

Sunflowers that bloom late in the season may get a little shorter or have fewer flowers because there will be less daylight. You can still get a second blossoming of sunflowers as long as it isn’t too cold though.

You should be able to plant a second crop of sunflowers in USDA zones 8 and up, but watch out for early frosts. Start sowing the seeds in mid or late August for the best results.

Growing Sunflowers in Late Summer

If you do decide to grow a new crop in late summer, make sure you give the seeds 55 to 70 days to grow before you see flowers. Use this to time your planting based on your areas first frost. Sunflowers can tolerate some light frost.

Like when you plant things in the spring, make sure you plant sunflower seeds in a sunny spot with good drainage. It depends on the type of sunflower you have, but in general, the seeds should go about half an inch (1 cm) deep. ) deep in the soil.

How late can you plant sunflower seeds?

FAQ

What is the best month to plant sunflower seeds?

The best time to plant sunflower seeds is between April and May. Sow seeds individually in 10cm pots of peat-free, multi-purpose compost. Cover the pots with a clear plastic bag and place them in a warm spot for the best chances of germination. Remove the plastic cover once the seedlings have emerged.

Is it OK to plant sunflower seeds now?

When to Plant Sunflowers. Plant seeds after the danger of spring frost has passed and the soil temperature is at least 60 degrees. This will be between March and May, depending on where you live.

Can I plant sunflowers in June?

You can still plant flowers, too! Planting later crops in June also applies to flowers! Plant more marigolds, sunflowers, cosmos, zinnias, four o’clocks, nasturtiums, etc.

How long does it take for sunflower seeds to germinate?

Soil temperature and moisture influence how long it takes for sunflower seeds to germinate, but in most cases you should see sprouts in 7 to 10 days. When seedlings have the second set of leaves, thin them 2 to 3 feet apart if your goal is seed production.

When to plant sunflower seeds?

Planting sunflowers in August in warmer growing zones, especially the fast growing varieties, is definitely an option. Sunflowers are a choice cut flower in our garden. We grow lots of them in a very short growing season. It is therefore very important for us to know how late we can plant our sunflower seeds.

Can you plant sunflower seeds late?

To increase your chances of success when planting sunflower seeds late, there are several precautions you can take. First, plant in an area with plenty of sunlight throughout the day. This will help offset the shorter days and colder temperatures.

When do sunflower seeds bloom?

Consider the time frame to maturity for your seeds. If you plant the seeds at the beginning of June, it will be several weeks or so before they germinate. Then it can take another sixty days to bloom ( if they are the fast growing sunflowers ). You will likely have blooms in mid to late August.

Can you plant sunflower seeds outside if it frosts?

Other years we have later frosts, as was the case just last year when we still had dahlia plants blooming in early November. If you have unpredictable frosts in your growing zone, just be aware that your late planted sunflowers may be at risk to frost damage by an earlier than expected frost. When Can I Plant Sunflower Seeds Outside?

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