Helianthus annuus and other species.
I have heard many people complain about warm-season growing: the challenges, the heat… However it is the warm season crops that transform the garden. In particular plants like sunflowers add height, altering the whole look of your gardening space.
When you look for seed of sunflowers, keep in mind that they are often separated from vegetable garden seed, and put into the flowering plants section of catalogs. This transgression is aimed at the sunflower because of it’s beauty. Often when something is beautiful, it’s usefulness is overlooked.
Native to the new world, sunflowers are wonderfully old-fashioned and quintessentially American. They are also wonderfully gorgeous and diverse. Their cheery nature is poetic fact. But more than all this, sunflowers are useful too. They produce copious amounts of edible seed for both humans and birds. They also provide pollen for bees. Since bees have had such a hard time in recent years, I will do almost anything to help out bees.
Though most sunflowers are annuals (which means they die at the end of the season), some species of sunflowers are perennial and produce rhizomes. They will come back year after year. Helianthus maximiliani is one such species of sunflower. Another perennial sunflower, and one that I have written about before is Helianthus tuberosus or Jerusalem artichoke, source of the delicious tubers.
Begin planting seed of sunflowers after threat of frost is over, or protect early planted seed when frost does occur. Make sure you space plants out well, being aware the ultimate height of each plant. If they are happy, they will spread out and take up some space. Keep this in mind when planning out your garden plot. They will shade out everything if put in the wrong spot. Perennial types can be planted from containers, or tubers.
Plant in full sun, in average garden soil. Their nutritional needs are not great, but make sure the soil texture is such that allows them to have consistent moisture. As I say with almost everything, mulch plants well. If sunflowers start to get aphids, this is probably due to inconsistent watering.
Feed fish emulsion, kelp or compost tea to encourage vigorous plants. But you will find sunflowers don’t really beg for a lot of attention.
To harvest seeds, watch as the flowers become seed heads. The backs of the seeds will harden, and in most cases turn dark (though there are some white-seeded varieties). You can also leave seed heads for the birds. They love them. However, if you want them for yourself, you might invest in some netting to omit feathered pillagers.
Territorial Seed and Baker’s Creek have good selections of sunflowers. Arizona native heirlooms can be found at Native Seed/SEARCH. One seed company I love that I haven’t had much of a chance to give a plug is Plants For The Southwest. They are a good source of the perennial sunflower Helianthus maximiliani. Oikos Tree Farm is my source for interesting varieties of Jerusalem artichoke, but if you see them in the grocery store, you can plant those tubers straight into the ground.
Time Lapse of a sunflower growing.