How to Grow Hollyhocks

Learn how to grow hollyhocks and enjoy a cottage-garden favorite that has been around for a century. Hollyhock’s flowers begin blooming from the bottom of the stalk and move up to the top, producing a long display of color and an almost endless supply of blossoms. Learn how to grow hollyhocks, and you will often have reseeded beds that endure for years. 

Hollyhock flowers can be single or double and come in colors ranging from pink and white to yellow, red and even nearly black. Some old-fashioned types can reach 12 feet tall, while hybrids grow 2 to 8 feet tall. 

Follow these six tips to learn how to grow hollyhocks, and check the end of the post to learn how to grow hollyhocks in Arizona.

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6 Tips for How to Grow Hollyhocks

1. Understand how hollyhocks grow

Don’t despair when your seedlings emerge but don’t bloom the first spring. At the end of summer they may seem brown and dead, but don’t pull them out. Trim off dead leaves and stems, and then wait. The plant will overwinter and emerge into spring bloom. Many hollyhocks are considered a biennial, producing clumps of leaves the first year and tall flower stalks the next year. 

Although many hollyhocks are biennial, they often seem to be perennials as fallen seeds germinate and grow each year, producing year after year of flowers. 

Allow seeds to fall around plants to encourage new plants. Self-sown seedlings often make hollyhocks a permanent addition to the garden. Learn how to grow hollyhocks, and you will often have reseeded beds that endure for years. 

What is a biennial? Biennials live for only two years. Normally, biennials germinate from seed and grow strong root systems and foliage the first year. The following growing season, they send up flowering shoots that produce seed and then die.

2. Choose the right location to plant hollyhocks

Hollyhocks flourish in sunny locations and prefer moist, fertile, well-drained soil. Plant seeds no more than ¼ inch deep. Allow about 2 feet between and all around plants for good air circulation. 

Use hollyhocks to attract hummingbirds to your garden. Hollyhocks also attract butterflies and serve as host plants for caterpillars.

The flowering stalks of hollyhocks get tall (up to 10 feet) so plant at the back of a border garden or up against a wall. Hollyhock blooms are beautiful as a backdrop for roses, larkspur, dianthus, and bachelor’s button. 

3. Plant hollyhocks at the correct time

• Start annual seeds in tall individual pots (hollyhocks have long taproots) about 9 weeks before the last frost date for summer bloom.
• Plant seedlings outside 2-3 weeks after the last frost.
• Keep in mind that many hollyhocks are biennials and will not bloom until the following year.  

In the low desert of Arizona:

Start seeds indoors:
August – September
December – January
Plant seeds or transplants outside:
October – November
February – March

4. How to grow healthy hollyhocks and have more blooms

• Amend the planting area with compost each spring. 
• Water deeply to penetrate the root zone. 
• Pinch or trim off faded blooms before seed pods form. Regular deadheading will encourage more flowers because it encourages energy to shift from seed production to flower production. 
• Remove damaged and dead leaves to keep the plant healthy and looking better. 

5. How to prevent and treat rust on hollyhocks

• Water plants at ground-level (not overhead) to keep water off leaves.
• Allow about 2 feet between plants to allow for good air circulation; planting plants too close together can encourage rust.
• Remove and discard (not in compost) affected leaves.
• Clean up debris around plants, and remove weeds.
• Remove heavily infested plants.
• Fungicides such as sulfur or copper are organic options if you decide to treat. I like this copper fungicide from Amazon. 

6. What to do after hollyhocks flower

• If you want seeds in place for next spring, let a few stalks produce and drop seeds in place. 
• Cut stalks back to about 6 inches above the ground. 
• To harvest extra seeds for sharing or adding to other areas of the garden, simply gather seeds when the seed pods are completely dry and brown. 
• Divide and transplant smaller plants from around the base of plant. Self-sown plants may or may not resemble the parent plant. 

How to grow hollyhocks in Arizona

Start seeds indoors:

August – September

December – January

Plant seeds or transplants outside:

October – November

February – March

Prune spent hollyhock stalks back to about 6 inches tall in the fall, and remove all spent plant material from around plants to discourage pests and diseases.

Hollyhocks do best with morning or filtered afternoon sun. The heat of a west-facing wall would probably be too intense for hollyhocks to survive the summer after blooming. In my yard, the hollyhocks that do best are on a north-facing wall. 

Hollyhocks bloom from April through June or July. 

Divide and replant hollyhocks in the late fall when temperatures cool off.

Want to add more color to your garden with flowers?

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