How to grow sunflowers
Are sunflowers difficult to grow?
Everyone loves sunflowers and growing them is generally simple.
The majority of annual sunflowers (Helianthus annuus) ask for nothing more than lots of sun and water combined with average soil. Generally speaking, the more sun they get the larger the flower will be and the stronger the stems will grow to hold up the large flowers. Fertilizer is unnecessary – maybe some added compost – but mulching will help to hold moisture in the soil. Sunflowers have a very deep tap root that is more than capable of finding water several feet (up to four feet) below ground.
Woodland gardeners, however, may find that their gardens’ lack of sun requires a little more effort and planning to ensure success. Adding to a lack of sunny areas, if deer are regular guests in your garden, there’s a good chance you will also have to take extra steps to get the plants to adulthood.
The rewards of planting sunflowers are many: Fun cheery flowers from summer into the fall and even longer if planted in succession; a tap root that helps to bring nourishment from deep in the soil to the surface; and, especially a natural food source for birds and other backyard wildlife that put sunflower seeds very high on their nutritional needs. (Check out my complete story on providing birds with natural food sources.)
Growing your own sunflowers is great for the birds, bees and butterflies, but don’t overlook the fun you will have photographing them as they brighten up your garden when they begin to bloom. For my comprehensive post on taking a creative approach to photographing sunflowers and ten tips to capture them go here.
In this article, I’ll take readers step by step – over the course of a spring and summer – through the process of growing sunflowers and bringing them to maturity both in containers and in the landscape. I’ll be starting some early under lights in our Click and Grow (link to my article) complete with its automatically timed grow lights and self watering system.
We will also be growing sunflowers in small peat containers that will later be transplanted into the landscape. Other seeds will get their start later in spring in our outdoor raised planters away from hungry deer and still others will be directly sown in our large outdoor planters. Finally, I’ll plant a number of seeds directly into our garden and do my best to get them to maturity despite an abundance of deer and other fauna that visit the garden.
For more on the value of sunflowers in our gardens, check out Fields of Gold: Sunflowers and Goldfinches.
Do deer eat sunflowers?
Let’s start with our number one question: Do deer like to eat sunflowers? Anyone with a bird feeder knows that deer love sunflower seeds, but we are more concerned with them eating the plants rather than the flower head and seeds when it matures.
Deer love the tender shoots of sunflower when they first emerge and will nip them off until the stems begin to get more robust and they thicken and grow too tough to be appetizing. If we can get the plants to this stage, the deer tend to leave them alone for the remainder of the growing season.
I’m sad to say that I did not have much luck getting the plants to this stage before squirrels, deer and rabbits decided to dine on them. (I think part of the reason for this is that I started to grow the plants inside too early and the green plants stood out in the otherwise brown landscape just a little too much. This spring I’ll wait another couple of weeks to put them out into the garden when there is more for the wildlife to dine on.)
(Early June Edit) It’s early June and so far we have had mixed success. The dwarf sunflowers that were grown in the Click and Grow lighting system did well. They grew fast and I was able to get them into several containers by mid May where they continued to grow. Three of these dwarf varieties have bloomed, but it wasn’t long before chipmunks and squirrels went in for the kill and decided the flowers were there for their lunch.
Two small sunflowers (dwarf varieties) growing in a new large container were attacked by squirrels and decapitated but luckily I was able to get a flower from it. (See second and third images above.)
• I planted a multi-flowered variety in a large container in the front garden that was doing very well until a squirrel or chipmunk decided to use it as a swing. The plant was healthy and about 3-4 feet tall with a large bud forming getting ready to flower before it was broken off. I thought growing it up through a trellis should provide a little protection and give it support. But in the end it was broken off before flowering.
If a sunflower bud is broken off will it regrow a new one?
Unfortunately it is unlikely that a sunflower will regrow a bud once the main one has been broken off. Even if the stem is alive and appears to be doing well, once the bud has been broken off or removed, the chance of flowering is unlikely. If it is a clean break, and you get it early, or if the bud is broken but still hanging on, you may be able to save it by taping it up with a gardener’s tape.
July Edit: Forget everything I wrote directly above about regrowth after the stem has been broken. Our multi-flowering sunflower suffered several bud-stem breaks from squirrels or chipmunks, but it now has 7-10 sunflower buds on it. So, to answer the question “If a sunflower bud is broken off will it regrow a new one?” the answer is YES they can. Sunflowers, especially multi-flowering varieties, can regrow buds after the main leader has been broken off. The image above is an example of the plant in flower.
What are the best sunflowers to grow?
There are many different sunflowers we can grow including a perennial native wildflower and an assortment of annuals. When it comes to annuals, there are basically two types – single and multi-flowering. The single-flowering sunflower sports a large (sometimes greater than 12 inches) flower on a tall, stout stem that can easily reach 8-16 feet tall.
The multi-flowering form combine several flowers usually consisting of a main flower with smaller secondary ones on a stem that can reach 6-8 feet high but is more often 4-6 ft.
One annual cultivar that is popular is the everblooming sunflower from Proven Winners called Suncredible Yellow that flowers on a heavily-branched plant with blooms that are about 4 inches across and do not need deadheading to continue blooming. The plant grows to about 3 feet tall and blooms longer than similar sunflowers lasting well into the fall.
The native perennial (zones 3-7), Woodland Sunflower (Helianthus divaricatus) is a lovely multi-flowering wildflower that will attract bees and many butterfly species including Checkerspot and Painted Lady. The flower is much smaller than the traditional annual variety. It can be planted along woodland edges in full sun or partial shade along side Black-Eyed Susan for example and, unlike the annual plants, is deer resistant. (Check out my post on why we should be using native plants in our garden and how they help birds and other predators.
Our woodland sunflowers are beginning to show buds and I expect flowers to begin emerging in the near future. This will be the second year the woodland sunflowers will be in the garden, so I am hoping for a good show this year.
Last spring, I planted the native perennial woodland sunflowers in a back part of our garden and am looking forward to seeing how they perform this year.
But, we are here to talk about the wide assortment of annual flowers ranging from the massive flowering types, to the medium ones good for both containers and in the landscape, as well as smaller dwarf varieties that are ideal for containers.
All are excellent choices, but consider how best to use them in your landscape.
What are the best sunflowers for containers
If you are planning to use the sunflowers in containers, use a dwarf variety for best results, unless the container is quite large. Remember that the root systems of sunflowers are extensive and include a large and aggressive tap root. (There is a list below of some of the better multi-stem and dwarf varieties.)
The dwarf variety that I started in the Click and Grow have done well and made it into the garden containers in mid May. Most flowered quickly before the beginning of June and are now providing our chipmunks and squirrels with early snacks.
The big boys are probably best at the back of the garden or used as a large windbreak or privacy screen in a long line of plants. If you are planting them in this way, it’s always a good idea to stagger the plants to give them room to grow and air around them to circulate to prevent mildew and fungus problems. Leave at least six inches between plants (more is probably better) and make sure they get all-day sun or close to all-day sun.
The mid-size sunflowers are an excellent choice providing the sunny cheerfulness that only sunflowers can provide, but in a more manageable size coming in at 5-6 feet in height.
Here is a short list of some of the better sunflowers.
Tall single-flower sunflowers
Skyscraper: Sunflowers can reach heights of up to 12 feet and produce 14-inch petals.
Sunforest Mix: Rises from 10-15 feet.
American Giant: This sunflower can reach up to 15 feet and a flower face that grows up to a foot tall
Russian Mammoth: Expect heights of 9 to 12 feet with a huge flower face.
Smaller, dwarf sunflowers include:
Sundance Kid: This bicolour red and yellow flower grows from between one to two feet tall.
Little Becka: Is a pollenless sunflower that sports red and yellow petals and grows between one to two feet tall
Pacino: This muti-flowered plant has a bright yellow face and grows to between 12-16 inches.
Sunny Smile: Another plant in the 12-15 inch range with bright yellow petals and a dark-brown centre.
Coloured sunflowers include such show stoppers as Moulin Rouge with its solid red petals, Terracotta sporting cream and orange petals, and Chianti: dark purple petals and dark centre.
If you are on the lookout for high quality, non-GMO seed for the Pacific North West consider West Coast Seeds. The company, based in Vancouver BC says that “part of our mission to help repair the world, we place a high priority on education and community outreach. Our intent is to encourage sustainable, organic growing practices through knowledge and support. We believe in the principles of eating locally produced food whenever possible, sharing gardening wisdom, and teaching people how to grow from seed.”