Do Sunflowers Need a Lot of Water? When and How to Water Them

Sunflower Guides /

I watch my sunflowers all the time whilst they’re growing, I do my best to take great care of them when they’re young. An important part of their growth is the level of water they should have. Having watered them too much and too little over the years, I felt it was important to provide the best advice possible for watering your sunflower.

Do Sunflowers Need a Lot of Water? In Comparison with most other plants, yes, sunflowers do need a consistent and plentiful supply of water. Due to their rapid growth, they need a minimum of 2 gallons, (7.57 Litres) a week. More in their early stages of growth. This will prevent weak stems and other issues. Let’s look in more detail.

The equivalent is around a minimum of 1-1.5 inches (2.5 – 4 cm) of rainfall per week. I’d strongly recommend beginning a daily watering routine from the start with sunflowers, certainly during their early stages until they’re around 2 feet (61 cm) in height.

Sunflowers like daily routines! In particular, they like their water routines. This should ideally begin early in the morning before the sun has really started to directly hit them. A good time is before going to school, or work. And if we’ve had a really hot day, then a secondary watering in the evening will do them the world of good during the night.

“Sunflowers like daily routines! In particular, they like their water routines”

With a few simple steps to follow you’ll soon give your sunflower the best start toward a glorious end!

Getting the Soil Conditions Right for Watering

Sunflowers have a deep root system, they need it in order to support a large head and tall, heavy stem during potentially windy conditions – or to even hold the weight of a squirrel hanging off it! Plus the effort it needs to follow the sun

This deep root system can extend up to 1.5 feet below the surface and up to 1.5 feet in diameter around the plant. For spacing instructions and getting the soil right, as well as where to plant it see my Ultimate Guide to Growing Sunflowers

Ensure the soil has good drainage as sunflowers do not grow to their full potential in soil that retains the water.

Right Soil Conditions for Watering Sunflowers

Sunflower Water Requirements

On the plant spectrum, sunflowers are pretty thirsty creatures. They need to be, as one of the few flowers that can grow up to 15 feet (4.5m) or higher. Having a relatively short season means they have a rapid growth rate and this can only be fueled by plenty of water and as much sunlight as possible.

Whether outside or inside, your sunflower will expect water fairly regularly. And whilst watering around the base is important, keep a spray bottle handy and spray a few times over the head of the sunflower too. This helps to keep the head moist, helps wash away gathering dust particles and ensure all areas of the plant gets some direct water.

Watering Sunflowers Outside

As long as there is a sufficient amount of rainwater outside – which is usually a good downpour around 3 times a week, then sunflowers will grow fine. After all, they’re used to mainly just receiving rainwater.

But of course, we want to ensure we get our sunflower to her maximum potential (well usually!). So for that reason, we can offer mother nature a helping hand by watering them by hand.

Apply a good amount of water till it pools, until the sunflower is around 2 feet (61cm) tall then you should consider ensuring it has daily water. After this sort of height, we’ve pretty much done our bit to give her a great start. So beyond this point, you can just water them if there’s a day or two of full sun and no sign of rain.

Water with a sprinkle hose or a watering can rosea as the plant grows, begin to widen the area of watering up to around 6-12 inches around the plant to ensure it reaches the wider root system.

Usually it’s the smaller dwarf varieties of sunflowers that are grown in pots. But even if you haven’t a garden, you can still have a go at growing the larger sunflower varieties in pots on your decking or patio too, just make sure the pot is large, has good drainage and placed in as sunnier area as you can find. Refer to my ultimate guide

carefully water your seedlings and young plants

Watering Sunflowers in Pots

Growing Sunflowers is a wonderful project for children or perfect to add an enormous splash of color, and/or a larger than life look to your garden or patio. If you want to get it completely right, then see my complete guide to growing your sunflower!

Here’s a quick summary guide for you of the above so you can refer back to it if you need to.

Once your seedlings are hardened off and there’s no threat of a winter frost, you can plant them on in their growing site, or your favored pot. Watering daily is very important as pots tend to dry out quicker and need to be kept moist – but not sitting in a puddle, as the plant and roots will be unstable.

Again good drainage is important. And some support as the plant grows bigger might be required. Refer to my complete guide to growing your sunflower.

  1. Ensure you have good, deep soil with adequate drainage
  2. Apply water till it almost pools around the base, daily where possible
  3. Widen the watering area as the plant grows
  4. Use a spray bottle to moisten the head
  5. After it’s 2 feet tall, only water in periods of drought, or if indoors, every other day

How and When Not to Water Your Sunflower

For a quick summary guide on what not to do and things to be aware of, I thought I’d list out a few ‘do’s and dont’s’ and other pointers. I hope it helps as a quick reference tool.

  1. Try to prevent weeds from growing around the base of the sunflower
  2. Do not blast the head directly with the hosepipe, you risk damaging the delicate florets and washing away vital pollen
  3. Do not allow water puddles to sit around the base for too long, this can lead to rotting of the stem base. If this occurs, gently aerate the soil with drainage holes
  4. Do not soak the wider ground so much that it becomes unstable for the roots
  5. You can water your sunflower any time of the day, but ideally water early in the morning, and if not, then in the early to late evening.
  6. Use a rose on your watering can or a sprinkler on your hose, or you risk washing away too much soil, and especially with young plants as it is gentler on them too.
  7. Do not water your sunflower if the ground still appears to be moist from the previous watering
  8. Do not water shortly after it has rained sufficiently
  9. If it forecasts rain, then see if that happens first. It may not rain, but the occasional day without water will not harm your sunflower – whereas overwatering might.
  10. If the base of the stem starts to see signs of browning or rotting, then you’re overwatering, allow it to dry out to try and save it.
  11. Before maturity, if the leaves and other areas begin to wilt, or turn brown, then you’re under watering. Give it a good douse with water, then slowly increase the water quantity gradually to bring it back to life
  12. Once fully grown, avoid watering the head once it has turned brown. At this stage you want the seeds to dry out.
  13. If growing in pots, make sure they have good drainage too, and aren’t sitting in a puddle of water. Don’t let the soil dry out to a cracking stage either, keep the soil moist

If in doubt, or something doesn’t seem right, then refer to my complete Guide to remedy the situation or to get further guidance.

Home Grown Sunflowers


I’m not suggesting watering your sunflower should consume your life, and try not to be paranoid if you don’t follow all the steps to the letter then that’s fine. It’s not a test. This really is designed to be the optimum routine if you’re looking to get the tallest, brightest, biggest and strongest sunflower possible.

It will also impress your friends! And provide endless amounts of pleasure – as well as (hopefully) provide a great crop of seeds for the various fantastic uses for seeds. Happy watering!

Related Questions

How Do You Revive Wilted Sunflowers? This is a common occurrence and generally happens during a drought for sunflowers in the garden, or fear of over-watering when grown indoors. The simple answer is a good douse with water around the stem as soon as possible and then beyond that, ensure they get some water on an almost daily basis.

Sunflowers Wilting in Vase? These tips should add anywhere from 24 to 72 hours to the life of your bouquet.
1. Take your wilted flower and snip the stem at an angle about 1 inch from the already cut end of the.
2. Add three teaspoons of sugar to the lukewarm water in your vase, and place the wilted flower in and let it sit. The sugar will perk them right up!
3. Sprinkle a few drops water on the center of the head of the flower.4. Try this with just one bloom or the whole bouquet, and as the flowers rest in the water, they should drink it up through their newly-snipped stems.
5. If the flowers do not perk up even slightly within 3 hours, add another teaspoon of sugar and a little more water

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