Ever wondered how fast do sunflowers grow? Gardening is all about timing. You have to plant at just the right time of year, and if you’re planting fall crops in the same beds as your summer crops, you almost have to time it down to the day.
Since many sunflower varieties are annuals and will die at the end of summer or early autumn, knowing how fast they grow will help you plan your garden accordingly. It will also make planning out your cut flower arrangements easier too.
So, how fast do sunflowers grow? Let’s find out!
Sunflower Growth Rate – How Fast Do Sunflowers Grow?
The variety of sunflowers you’re growing will greatly affect how fast it can grow. Dwarf varieties will only grow several inches each month, medium varieties may grow a few feet, and giant varieties will grow several feet in one month.
You can determine your sunflowers’ growth rate by looking at the information on the seed packet.
If the packet says it will take about 75 days to bloom and grow to be 12 feet (3 meters) tall, you can assume it will grow almost 5 feet (1.5 meters) each month. (That’s the mature height divided by the number of months it takes to grow.)
How Much Does A Sunflower Grow In A Week?
Expect your sunflowers to grow anywhere from 2 inches to 2 feet per week. That wide range doesn’t help much, but it depends on what kind you’re growing!
Generally speaking, the smaller your sunflower is, the less growth you’ll see each week. Be sure to check how long it takes to bloom because that will also be a factor.
The fewer days it takes to bloom, the faster the weekly growth will be.
What Makes A Sunflower Grow Tall
Not all sunflowers will grow at the same rate. Two varieties grown next to each other may not grow at the same speed, and two of the same varieties grown in different locations won’t have the same outcome, either.
Why is that? There are four main factors to consider.
Cultivars and Varieties
As was mentioned earlier, the variety of sunflowers has a lot to do with growth speed. Dwarf sunflowers don’t have to exert a lot of energy to create giant stalks that will reach taller than your roof, so they only grow a few inches per month.
Giant varieties of sunflowers, however, have a lot of growing to do before their growing season is over, so you can expect them to grow several feet in just one month. Medium varieties will be somewhere in the middle of the two extremes.
If you’re looking for something that will grow fast and tall, consider the Russian Mammoth, American Giant, or Cyclops varieties. Their quick growth rates will surprise you, and you’ll have giant sunflowers in just a few months!
As far as sunflower care is concerned, sunlight might be the most important factor that affects growth rates if you take varieties out of the equation. Sunflowers require at least six hours of direct light every day to grow to their full size.
If sunflowers are grown in partial shade, you can expect their growth to be much slower and likely won’t reach their full size.
If you have limited direct sunlight access in your yard, consider growing dwarf varieties in pots so you can move them around to get the most amount of sun each day.
Or, you can give your sunflowers partial sun and settle for what it’s able to do.
Sunflowers can adapt to be drought-tolerant, but they grow their best when they receive sufficient water. They typically need 1-2 inches of water per week, which typically comes out to two gallons (7.5 liters) per week.
Not receiving enough water may result in wilting or stunted growth. Well-draining soil is equally as important as watering enough.
If your soil can’t drain and holds water, your sunflowers won’t grow as well as they could. They don’t like wet feet, so make sure containers have drainage holes, and flower beds don’t hold standing water.
Sunflowers don’t require fertilizer, especially if the soil you’re using is healthy and full of nutrients. If your soil lacks nutrients or you’re trying to get your sunflowers to grow even taller, use a slow-release all-purpose fertilizer with an NPK ratio of 15-30-15 or 4-8-4.
You don’t want the nitrogen level to be too high. While it’s responsible for foliage growth and will allow your flowers to get even taller, too much will cause the plant to focus on leaves and not grow stunning blooms.