How to Grow Calendula: Everything You Need to Know

Calendula is one my favorite flowers.  It is one of those plants you want to add to your garden.  Not only do the bees and butterflies love it, it makes a wonderful salve and tea.  So,  let me show you how to grow calendula.  I got you covered from A to Z about this plant.

Tell Me More About Calendula:

Calendula (calendula officinalis) is an annual that is easy to grow and subsequently, re-seeds itself.  It can grow from 8 to 24 inches.  If you have a small garden area or want to grow it in pots, you might like Botanical Interest’s Daisy Oops variety which grows to 8 inches in height.

Its other name is pot marigold although it isn’t related to marigolds.  Calendula is part of the Asteraceae family.  Ragweed, daisies, and asters are also part of this family.   So if you are sensitive to ragweed, you might want to avoid using or growing calendula.

Its flowers are generally yellow or orange.  There are several varieties of this plant such as Pacific Beauty, Touch of Red, and Greenheart Orange.

Generally, calendula blooms when temperatures are less than 85 degrees.  However, Cornet and Pacific Beauty varieties are heat tolerant.

It isn’t invasive; however, if you don’t deadhead the flowers you will most likely have calendula next year in places you might not want.  However, deadheading won’t guarantee random seedlings.  I do deadhead the flowers since I collect them for my herb shop but I find that they still re-seed themselves all along the dirt around my raised beds.

I deal with the seedlings by either moving them in the spring or getting rid of them.  They really don’t like to be transplanted when they are really small so I lose many that I move.

(Note, you can pot the errant seedling and let them get big and strong in pots before planting them in your beds.)

If you are looking to create a butterfly and bee haven, make sure you add this plant to your garden.  Both love this plant.

How to Grow Calendula

Sow your seeds indoors about 6 to 8 weeks before your frost date.  I use indoor lights so my plants don’t become leggy.  (This is what I use.)

Botanical Interest is my go to source for seeds,  but many heirloom and organic seed companies carry the seeds.  (Here are some of my favorite seed companies.)

Some people sow them directly into their beds but I am too impatient and like to grow them inside.

If you do like to grow them inside, don’t use a heat mat.  They like to germinate at 55 to 60 degrees.  It will take 7 to 14 days for the seeds to germinate, so be patient.

However, if you want to sow seeds into the beds, sow them 1/4 inch deep and 8 inches apart when the soil temperatures reach 60 degrees. (I use this soil thermometer.)  Wait until your last spring frost has passed.

Utah State Cooperative Extension suggests adding 2 to 4 inches of compost to your soil along with 1 to 2 teaspoons per square feet of all purpose fertilizer.  I can’t stress enough that you should obtain a soil test to see if you are missing nutrients.  Don’t waste money adding any old fertilizer if you don’t know what nutrients you do and don’t have in your soil.

Obtain a soil kit at most county cooperatives or universities.  It takes a few weeks for results.

By the way, my go to fertilizer is Dr. Earth. (It is OMRI approved for organic gardening.)  I use Dr. Earth’s products for almost all my vegetables and fruit trees and bushes.

Plant your seedling in full sun to part shade.

During the Season:

Periodically side dress the plants with soluble fertilizer to insure growth.  Provide 1 inch to 1 1/2 inches per week of water during the summer.

Pick often so that the flowers keep producing.  They may stop producing when the weather turns warm but will resume in the Fall.

I find by the time Fall comes around, they start to look pretty straggly and don’t produce as many  flowers.  If you live in a warmer climate than mine, you can sow seeds again in late summer for a fall/winter harvest.

According to Utah State Cooperative, the plants are cold hardy up to 25 degrees.  Mine seem to die around the time temperature dips into the thirties.  Snow is not their friend.

This year, I might experiment with planting some in a shadier area in late summer.  For some odd reason, calendula sprung up in another one of my beds in late summer.  It continued to produce until a hard frost and didn’t look like my other worn out spring sown calendula.

Pests and Disease:

Calendula pests are whitefiles, aphids, slugs, snails, and cabbage moths.   I didn’t have a problem with white flies or aphids  but I did have a problem with little green worms in the flowers.  Washing them in vinegar did not kill those little buggers.  I had to hand pick them out of the flowers.  They tend to live in the center of the plant.

So word to the wise, check the flowers when you bring them in!  I always had a soapy glass of water nearby to drown the worms.

If you have a problem with white flies and aphids, first knock off most of them with a hard spray of water in the morning.

Washing the petals in a vinegar water solution will kill them.  Make sure you wash them well.  Dry them in a dark warm area far away from your houseplants.  No one wants whiteflies or aphids to be friends with your houseplants.

I always have a problem with whiteflies and aphids with my kale, broccoli and Brussel sprouts.  Vinegar has become my best friend.

In addition, powdery mildew can affect calendula plants.  White fungal spots will appear on the leaves.  Overhead watering and cool weather can exacerbate this problem.  Make sure you don’t crowd your plants which reduces air circulation.

I am often guilty of plant crowding since  I don’t like to thin my plants.  Take it from me–thin your plants.

Love Calendula But Don’t Want to Grow It.

If growing isn’t your thing, but you want to make salve or teas with these wonderful flowers, then you have come to the right place.  Order the flowers intact HERE or just flower petals HERE from my herbs shop.  All herbs are handpicked by me and air dried, then vacuum sealed to keep them fresh.  Start enjoying this flower now!

Next up–the wonderful uses of calendula!

Join the Conversation:

How do  you grow calendula? Have any tips?

Disclaimer:  There may be affiliate links in this article.  Thank you for supporting Green Talk.  For each purchase, Green Talk receives pennies but it helps with my plant obsession.

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