Forcing amaryllis: Were we doing it wrong?

White and pink amaryllis in bloom by Stofko
Amaryllis. Photo by Connie Oswald Stofko

by Connie Oswald Stofko

A few years ago, David Clark, nationally and internationally known gardening educator, shared tips with us on potting and caring for an amaryllis.

Now he has changed his methods.

“It’s always good to learn new ways,” Clark said. “What a huge difference it made in the way my flowers grew.”

Clark also gives us advice on what to do if the amaryllis gets red streaks on its leaves.

You can learn more from Clark in the series of horticulture classes he teaches at the Buffalo and Erie County Botanical Gardens. He can also speak to your group. Find out more here.

How to force your amaryllis to bloom indoors

healthy amaryllis plant
This is what a healthy amaryllis plant looks like. Notice that about one-third of the bulb sticks up out of the soil. Photo courtesy David Clark

Many people want to force their amaryllis to bloom indoors over the winter. They get the plants around the holidays and enjoy the bloom, then want to have the plant rebloom again inside the next year.

It’s not difficult to do.

First, don’t cut off the leaves. That advice hasn’t changed.

In fact, Clark has added another suggestion: Don’t cut off the flower stem, either.

Instead, as the flowers fade, cut off each flower at the top, but leave the stalk. If you have cut an amaryllis flower stalk in the past, you probably noticed the slimy liquid that runs out of it. That liquid has nutrients that the bulb can use, Clark said. Leave the flower stalk in place and the bulb can absorb the nutrients and store them for the following year.

In the spring, when the danger of frost has passed and night temperatures are at 55 degrees Fahrenheit, put the plant outside. The plant needs to build up energy in the bulb so it can bloom again inside the next winter.

In the past, Clark recommended leaving the bulb in the pot when you place it outside, but he notes that some people think it’s better to take the bulb out of the pot and place it directly into the ground.

During late summer or fall, depending on when you want your amaryllis to bloom, you will bring your pot or bulbs inside and stop watering.

Timing to get amaryllis to bloom for holidays & next steps

To have your amaryllis bulbs bloom around Dec. 20, you need to start the process around the middle of August. You need about 8 to 10 weeks of dormancy before the bulb blooms.

Bring the bulbs inside. If they are in a pot, you can leave them in the pot. Stop watering them. The leaves will turn yellow and brown in about a month. (That would take you to the middle of September.)

Take the bulb out of the soil.

Store the bulbs in sawdust inside a paper bag or cardboard box. You can also use foam packing peanuts — they promote air circulation around the bulb. Make sure to include a plant tag or write the container so you know what kind of amaryllis you have, Clark added.

Set the prepared bulbs in a place where the temperature is 40 to 50 degrees Fahrenheit for six weeks. (This would take you to the end of October or beginning of November.)

Then it’s time to repot your bulbs. That should be about six weeks before you want your plants to bloom. Clark potted his up last year on Nov. 11 and they bloomed on Dec. 20.

Repotting your amaryllis

Clean your pots. Clark uses hot tap water, a splash of white vinegar and a splash of inexpensive mouthwash. Not only will this sterilize the pot, he said, it will remove those white, powdery salt deposits. Submerge the pot in the cleaning solution and let it soak overnight. Scrub the pot with a brush to remove any discolorations.

Use fresh soil. For your potting mixture, start with 75 percent soilless potting mix (peat moss, perlite, vermiculite,) 10 percent garden soil or bagged topsoil (this supplies nutrients), 10 percent compost and 5 percent pumice or perlite.

If you can, repot the bulb into same pot because the bulbs like being rootbound. There should be only one-half inch or one inch on each side of the bulb. You should have about one-third of the bulb sticking out of the soil.

Place the pot in the living area of your home. Water the soil, then don’t water again until you see some sign of growth. When you see growth, sprinkle just a quarter cup water around perimeter of bulb. If you water sparingly during this period, you’ll encourage the growth of the flower rather than leaves, he said.

Don’t fertilize until the flower is done.

Red streaks on amaryllis leaves

red blotch on amaryllis leaves
This is what red blotch looks like on amaryllis leaves. Photo courtesy David Clark

Red streaks on the leaves of your amaryllis can be red blotch, Clark explained. A mite chewing on the bulb injures the emerging leaf structure, then a fungus takes the opportunity to make a home in the damaged leaf.

If you see red streaking during the growing season, use a neem oil spray on the leaves, bulb and soil.

Neem oil breaks down quickly, so it’s safer for the environment than some other pesticides, he noted. You still have to be careful when applying it. Wear safety gear and don’t spray on a windy day. Don’t spray it during the day when beneficial insects are most active. Instead, spray very early in the morning or late at night.

When it’s time to bring your bulbs indoors to force the bloom, do this next step. However, this step should be done outdoors, not in the house, Clark said.

Put on protective gear: safety goggles, a dust mask that you would wear for sanding and nitrile safety gloves. Make a solution with water and a powder called Bordeaux mixture or Bordo Mix or a copper-based fungicide. Drop the bulb in the solution and let it sit for 30 minutes. Make sure you wear gloves when you take the bulb out. 

red blotch on amaryllis bulb
This is red blotch on an amaryllis bulb. Photo courtesy David Clark

Another method recommended by Hadeco, an amaryllis exporter, is to soak the bulbs in a water bath at 104-115 degrees Fahrenheit for 30 minutes. 

Take the bulb out of the solution or water bath and let it dry in the sun for a couple of days. If you’re doing this late in the season and the outdoor temperatures are freezing, dry the bulb indoors, Clark said. However, we want to do this procedure before we get freezing temperatures.

10 Comments on “Forcing amaryllis: Were we doing it wrong?

  1. Hello Connie!

    Thank you for the interview and for posting the great article on “rethinking” Forcing Amaryllis!

    I like to think of gardening (both indoors and outdoors) as an art … practice makes perfect. We are always leaning new ways to perfect our art, and hopefully take it to the next level. If one technique doesn’t give you the results you expected, don’t be afraid to explore other options…that is one of the teaching points in my classes and presentations.

    I hope your readers find this article to be timely, and most helpful on their “gardening journey”.

    Kind Regards,
    David Clark, CNLP

  2. I’ve been given an Amaryllis for Christmas two years ago. Since then it has produced two long leaves and no flower, twice. It’s now In the process of growing leaves , again. Why don’t I get a bloom? Will I ever get a bloom?

  3. Leslie, did you put it outside for the summer? Did you bring it inside and let it go dormant? Is the pot the right size– not too big? My best suggestion is to follow the steps in this current article, or to go back to the previous article and follow those steps.

  4. Nice educational section on the red streak fungus. And, I’m a bit surprised at the advice to leave the flower stalk intact but I’m definitely gonna try that technique. Thanks, David and Connie! Happy New year!!

  5. Hello Brett!
    Thank you for finding the red streak fungus information interesting. I have found out that many growers, as I do, now recommend that the flower stalk be left on the bulb.
    I did perform the hot water treatment on two of my bulbs, ‘Red Pearl’ and ‘Santiago” that were affected by fungal issues at the end of last season.
    I did also use a Mancozeb systemic fungicide soak to control the Stagnospora curtissii Red blotch infection on those two bulbs. So far at this time, they are only showing leaf growth, but I am hoping for flower stalks to become evident…
    Best wishes for a superb 2020!
    Regards,
    David Clark, CNLP

  6. I have a large number of Amaryllis and have shared many of them, but now hesitate to do so as they all have the Red Bloch infection. I’ve used Mancozeb to spray on all sides of the leaves & ground around the plants, but have started earlier this year in hopes of having better results. I live in Zone 7 and always keep them planted in the ground….they multiply like crazy! I usually cut the bloom stalk close to the ground because when I don’t, the fall rains fill the hollow stem with water & the bulb rots & turns to mush. Please advise. Thanks for your informative article.

  7. Hello Nicki!
    Happy to hear that you are able to grow them directly in the soil!
    Mancozeb is a powerful fungicide (good to use on Red Blotch). Be aware that using it too often may compromise the nitrifying bacteria population in the soil. When dealing with the bloom stalk, I just snip off the individual flowers, leaving the stalk top on. It will slowly go limp on its own and you won’t have the issue of rain filling the stalk and rotting the bulb.

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