Tips for Your Fall Container Gardens

Are your summer container gardens in need of a fall makeover? Good news! There are many fall-flavored plants that will provide you with texture, form, and long-lasting colors in both flowers and foliage.

I love the combination of purple or blue asters (Symphyotrichum) with ornamental kale as the colors play off each other nicely for a long-lasting fall container. Using other lesser-known plants, such as some of the fall-blooming Salvias or sage can add height and lend to very interesting combinations in your container gardens. Try using cold-hardy vegetables and adding herbs to create interest and texture to any combination. I like using Swiss chard, broccoli, Asian greens, parsley, and onions (Allium) for interesting and colorful effects.

Fall Containers

Here are a few tips for planning your fall containers:

  1. To achieve a fuller effect, use more plants than you would in the spring or summer. As the days begin to get shorter and the nights get cooler, plant growth is slowing down or ceasing. By planting a fuller container, you will see immediate results that can last for the remainder of the fall season.
  2. Try to plant by early September to give your plants a chance to kick in with some growth before the cooler temperatures and shorter days slow things down. Remember, many plants available for fall container gardens can take temperatures in the 20s Fahrenheit without being damaged, while many plants actually begin to show better foliage colors with cooler temperatures. These include ornamental kale and cabbage, Heuchera, and many ornamental grasses as well.
  3. Select plants that have a variety of tones that contrast and set off each other. Think about using colorful cultivars of Heuchera for their many foliage colors, and colorful grasses or grass-like plants, such as Pennisetum, Carex, Juncus, or the black foliage of Ophiopogon. See the list below of other fall plants to consider for your containers.
  4. Remember, a pot of mums looks fresh for three to four weeks at most, and then the show is over. Showy foliage from grasses or kale and cabbage will carry the display much longer.
  5. The fall foliage on evergreen succulents (Sempervivum ‘Hens and chicks’), and many of the stonecrop (Sedum) cultivars changes and develops more dramatic color once the temperatures stay cool.
  6. If you must have flower power, consider long- and late-blooming Salvia, Cuphea, or fall pansies or violas.
  7. When nighttime temperatures drop below freezing, have light blankets, large pots, or even an empty trash barrel handy to cover your container and protect the plantings from frost.
  8. As November passes, the time will come to disassemble your planter. Carefully place your hardy plants in a nursery bed or empty space in your vegetable garden plot to hold them over until next spring, when you can plant them in a permanent home to enjoy for another season.

 

Here are a few fall plants and items that can be added to your fall container gardens:

Brassica varieties - ornamental cabbage

Annuals:

  • Calibrachoa varieties
  • Capsicum, ornamental peppers
  • Dianthus cultivars, ‘Sweet William’ and other Pinks
  • Brassica varieties, ornamental kale and cabbage
  • Tagetes, marigolds
  • Pansies and violas
  • Helianthus, sunflowers
  • Plectranthus
  • Salvia, sages

Chrysanthemums

Perennials, trees, shrubs:

  • Anemone hybrids
  • Aster cultivars
  • Chrysanthemum, hardy fall mums
  • Helianthus and Helianthoides, perennial sunflowers
  • Rudbeckia, black-eyed-Susan
  • Boltonia
  • Sedum and Sempervivum, and other succulents
  • Fall foliage color with trees and shrubs; maples, cornus, viburnum, spirea, and others

Ornamental grasses

Ornamental grasses:

  • Miscanthus cultivars
  • Panicum cultivars
  • Pennisetum cultivars, including ornamental millet
  • Muhlenbergia, Muhly grass
  • Stipa tenuissima, Mexican feather grass
  • Schizachyrium scoparium, little bluestem

Pumpkins

Other fall items:

  • Pumpkins
  • Gourds and squash
  • Corn stalks
  • Straw
  • Branches
  • Fall decorative items; scarecrows, Halloween and Thanksgiving decorations

©2018 Chicago Botanic Garden and my.chicagobotanic.org

Epic Echium

An exotic, tall-dark-and-handsome visitor has returned to the Chicago Botanic Garden this spring. Its bold blooms draw pollinators in as well as Garden visitors. What is it, you ask?

Some of the most unusual plants our Production Greenhouse team grow for our display gardens are six species of Echium, a biennial plant that produces giant spikes of flowers—but not right away. Echium take two years of growth to become the epic plants you see throughout the Garden. You won’t find these Dr. Seussian plants in many other gardens in the Midwest (if you do, please let us know).

Echium are native to the Canary Islands, regions of the west coast of Africa, and southern Spain/Portugal. They are not hardy plants in Chicago, meaning they cannot withstand our winters outdoors. Growing them requires strict cultural practices to ensure their successful flowering.

Echium fastuosum (Pride of Madeira)
Echium fastuosum, or Pride of Madeira
Echium pininana 'Blue Steeple'
Echium pininana ‘Blue Steeple’

The team starts the plants from seed in November, transplanting seedlings into smaller pots to establish healthy root systems, before placing them in a cool greenhouse for the winter.

The following spring, they are transplanted into their final growing container and moved outside. They are grown in a semi-shaded location and fertilized regularly all summer.

Echium 'Red Rocket'
Echium ‘Red Rocket’

In fall, they are moved into a protected nursery quonset, with temperatures of 42-45 degrees Fahrenheit all winter long. (It is called vernalization, and it is a process by which keeping a plant in colder winter temperatures induces a bloom cycle.) The Echium‘s second spring—about 20 months after sowing the seed—is usually mid-to-late March; they begin to set flower buds and elongate their flower spikes.

An assortment of colors of Echium fastuosum, or Pride of Madeira, is a focal point of the Heritage Garden this spring.
An assortment of colors of Echium fastuosum, or Pride of Madeira, is a focal point of the Heritage Garden this spring.

You will find Echium growing in beds and containers outside the Visitor Center, in the Heritage Garden, and the English Walled Garden. These stars of the show are hard to miss! As you come across them, we hope you, like us, think of the team of skilled horticulturists who cultivate these “wows” each year—as well as nearly 70,000 spring annuals and vegetables.

Learn more about these Echium on display in our Plantfinder.


©2017 Chicago Botanic Garden and my.chicagobotanic.org

Keep holiday plants beautiful beyond the season

Holiday plants and flowers make great gifts for everyone on your shopping lists. They are perfect gifts for family members, the host and hostess of the holiday parties you attend, and of course, are beautiful for decorating your own home. Plus, they can be enjoyed long after the holiday season is over, adding color and life to your home on chilly winter days.

But getting your plants to last longer will require a little special care. Here’s how to take care of the most popular gift plants, both during the holiday season and long after.

Jubilee Red poinsettia
Euphorbia pulcherrima ‘Jubilee Red’

Poinsettias (Euphorbia pulcherrima) appreciate bright light away from heating vents, fireplaces, and drafty windows or doors. Maintain even moisture (but avoid soggy soil); plants will wilt dramatically if allowed to dry out. The plants should never be allowed to stand in water for more than 20 minutes if possible.

Poinsettia plants can be a challenge to keep year-round, and most gardeners discard the plant after the holidays. However, those trying to force a rebloom the following season can follow these guidelines:

  • As long as the plant looks healthy, continue to provide it with even moisture and warm temperatures in a bright location, out of direct sun. In six to eight weeks, it will begin to lose its leaves and turn slightly off-color. At that point, cut the entire plant back to 6 inches and repot in a larger pot, adding enough extra soilless mix or potting soil to fill the pot. Water thoroughly and place the plant in a south-facing window.
  • Begin to fertilize the plant twice a month with a dilute 20-20-20 or 10-10-10 mix. New growth should begin. Begin pinching new stems back once a month to encourage bushy growth. Continue this pinching until the end of summer.
  • In mid-May, after all danger of frost has passed, gradually introduce the plant to the outdoors, bringing it back in at night until the nighttime temperature remains above 60 degrees Fahrenheit. Then place the pot in a sunny spot where it is protected from strong afternoon summer sun. Water and fertilize regularly.
  • When night temperatures approach 60 degrees, it’s time to bring the poinsettia back inside to a sunny windowsill. By the end of September, the plant must be placed in a completely dark closet or covered with a box every night from 5 p.m. to 7 a.m.—with no exceptions. After 7 a.m., it can be placed back in a sunny window but returned to the closet at 5 p.m. This dark treatment is necessary for the plant to set its flower buds. Provide normal water during the day and fertilize monthly.
  • Poinsettia plants thrive in warm rooms with bright light and will suffer if exposed to drafts, sudden temperature changes, or excess dryness from heating vents. Continue this treatment until the middle of December, when the plant should be fully colored up for display again for the holidays.

Cocktail amaryllis
Hippeastrum ‘Cocktail’

Amaryllis (Hippeastrumbulbs should be potted up in wide, squat containers using a soilless mix. Allow the “shoulders” of the bulb to remain above soil level; water well once and then allow soil to dry out before watering again. Keep the pot away from direct sunlight, drafts, and heating vents.

  • Most amaryllis plants will send up stalks and flower first (leaves will emerge after a bloom cycle). As the stalk grows, rotate the pot for even growth. After flowering, allow the stalks to yellow and wither before removing them from the bulb.
  • Continue to water the plant after leaves emerge. After May 15, take the plant outside and place it in a location where it receives morning sunlight. Fertilize regularly with a dilute 10-10-10 or 15-15-15 mix.
  • Around October 15, bring the plant inside for its resting period. If the leaves have yellowed, remove them from the bulb. If they are still green, allow them to yellow before removing them from the bulb. Take the bulb out of its container; shake off the dirt and place it in a cool, dark room (40 to 50 degrees). At that time, cut off any dried roots from the bulb and re-pot. Signs of new green growth can occur from six to 10 weeks later.

Cyclamen 'Salmon with Eye'
Cyclamen ‘Salmon with Eye’

Cyclamen plants prefer quite cool indoor conditions. Water only when the soil dries out, and avoid splashing water on foliage.

  • Water these plants below the foliage, or set them in a shallow saucer to soak up water. Discard any unused water after 20 to 30 minutes. (To prevent root rot, make sure the plants don’t sit in water for long periods of time.)
  • Cyclamen will continue to bloom for a few weeks if they are kept in a north- or east-facing window. Remove the faded flowers and their stems at the base of the plant as soon as possible to keep the plants blooming in a tidy fashion. Most gardeners find it too difficult to force the plant to bloom again the following season.
Azalea 'Big Joe'
Azalea ‘Big Joe’

Azaleas require moist soil, bright light, and occasional misting. They perform best if kept in cool locations. Flowers will remain for months if old blossoms are quickly removed, the plant receives adequate moisture, and it is kept in cool conditions.

  • In May, once all danger of frost has passed, the plant can be taken outside to a shaded or partially shaded spot where it only receives morning light in the garden. At that time, begin to fertilize twice a month with a dilute liquid fertilizer formulated especially for acid-loving plants.
  • Bring the plant back indoors before October 15.

Phalaenopsis orchid
Phalaenopsis orchid

Phalaenopsis or moth orchids prefer warm rooms in bright, but not direct sun. Moth orchids will bloom for months, but sudden temperature changes can cause the plant to drop buds. Remove drying buds to maintain the beauty of the plant. Orchids potted in fir bark generally require once-a-week watering. Those in potting soil can be watered less often.

  • After flowering, allow the stem to yellow before cutting it off at the base of the plant. Begin fertilizing plant twice a month with a dilute orchid fertilizer. This will encourage the growth of a new stem and more flowers the following year.
  • Wash the foliage monthly. It’s not necessary to take this plant outdoors for the summer; but it will tolerate being moved outside if kept in shady location, and not allowed to dry out.
  • Continue normal watering and fertilizing until a new stem appears, approximately 10 to 12 months later. When the plant initiates flower buds, discontinue fertilizing.
  • Continue to provide bright light—but keep out of direct sunlight—in a warm room. During winter, try to provide extra humidity from pebble trays, or by misting daily if possible. 

 


Ivy topiary
Ivy topiary

Ivy topiaries are popular holiday plants that can last for years if given proper care.

  • Like cyclamen and azaleas, ivy also prefers quite cool conditions and bright light far away from heating vents or fireplaces.
  • Mist the plant regularly, or rinse the plants in a sink to keep the foliage clean and free of spider mites. As new growth emerges, train the new growth to the desired form.
  • Take the plants outside after May 15. Maintain growth during the summer by keeping the plants watered often, and fertilize them at least once a month, keeping the plants in a semi-shaded location. Continue training and pruning the plants periodically to keep their desired form.
Paperwhites
Narcissus papyraceus

Paperwhites (Narcissus papyraceus) may require a cage or a ring of raffia tied around them to keep them from flopping as they grow. If purchased as bulbs, grow them in a shallow dish filled with pebbles rather than soil. Arrange the bulbs close together and cover them with pebbles, with just their tips exposed. (The weight of the pebbles helps to keep them from falling to the side as they grow.) Water just enough to encourage root growth, not soaking the bulbs.

Paperwhites can be discarded after blooming, as they are not hardy to be planted outside in your garden.


©2016 Chicago Botanic Garden and my.chicagobotanic.org

Repotting Alice the Amorphophallus

I have an update on Alice the Amorphophallus: Alice has been repotted and has a leaf sprout. Yes, Alice is alive and well, happily growing in the production greenhouses here at the Chicago Botanic Garden.

(Many of you might remember we successfully pollinated Alice with pollen from Stinky, donated to us from the Denver Botanic Gardens’ own Amorphophallus titanum.)

Alice followed a normal growth cycle—as it would have in its native habitat on the island of Sumatra, Indonesia—producing fruit and seeds. This past summer, the flower stalk with the remaining fruit began to wither and collapse as Alice went into dormancy. (We successfully sowed and germinated the seeds, and were rewarded with several dozen seedlings.) On Tuesday, September 13, we removed Alice from the wooden crate she had been living in for the past 24 months, pleased to observe a healthy corm—and a new leaf shoot emerging from the top! We loosened the corm below the soil surface in order to repot it and record its current measurements, and got a few pretty interesting photos. 

First, we washed the corm thoroughly so we could examine it better and get accurate measurements of the corm’s weight and size. We looked for areas of rot, if any, and pulled off any new bulblets that may have developed. (We removed and potted up two new small bulblets—mini-corms—from Alice at this repotting.)

PHOTO: Amorphophallus corm before repotting.
Here is Alice the Amorphophallus as removed from the crate, before washing.
PHOTO: The freshly washed titan arum corm awaits weighing.
The freshly washed titan arum corm awaits weighing.

One big observation was that the corm had actually decreased in size and weight. The big cracks seen in the images below are from the corm rapidly shrinking in size. This is from the large amount of energy (starch and sugars) used for Alice to bloom, and in the production of fruit and seeds. Rather than losing mass and becoming spongy, the post-bloom and fruiting corm is the same density, but smaller in size—both diameter and height—by several inches.

PHOTO: Titan arum corm with emerging leaf sprout and roots.
Splits in the titan arum’s corm are from its rapid decrease in size as energy was used up.
PHOTO: Closeup of a large split in the titan arum corm.
Close-up of a large split in the corm

Now Alice is getting ready to begin the life cycle all over again as a leaf. A ring of new roots at the top of the corm is to support the growth of the emerging leaf bud. The roots do not form or add to a new corm—new corms come from the main corm as bulblets on the side and bottom of the original corm.

The corm has been repotted in a mixture of peat, coir (coconut fiber), composted bark, and perlite, back in its original crate, which still has room to grow in it. 

PHOTO: Alice the Amorphophallus gets ready to leaf out, almost exactly a year after blooming.
Alice the Amorphophallus gets ready to leaf out, almost exactly a year after blooming.

Here are some interesting details on the corm: 

  • Corm size: 13 inches in diameter and 7.5 inches in height
  • Corm weight: 17.5 pounds (weight at last repotting in 2014 was 28.2 pounds)
  • Base of old stem (top growth plate): 4.75 inches in diameter
  • Bottom growth plate: 3.5 inches in diameter
  • New growth/leaf shoot: 2 inches tall (still underground) with a healthy rosette of new roots
  • Surface of the corm: very lumpy and warty looking

I can’t believe it has been a year since we all gathered in the Semitropical Greenhouse at the Chicago Botanic Garden to celebrate Alice’s bloom and stink. What an event that was! Alice will bloom another day, maybe three to five years from now; we will just have to wait and see. But in the meantime, it’s likely another one of the titan arums in our collection will bloom before then. 


©2016 Chicago Botanic Garden and my.chicagobotanic.org

The Fruits of our Labor—Alice is Fruiting!

Alice the Amorphophallus, our titan arum (or corpse flower) is fruiting! Alice is on display at a new location in the Tropical Greenhouse here at the Chicago Botanic Garden so that all of our visitors may come see the beautiful, dark orange fruit that is developing.

As many of you know, we manually pollinated Alice’s flowers on the morning of September 29, 2015, after the plant began blooming late the previous evening. We used the pollen we had collected from Alice’s “brother” Spike a month earlier, plus pollen from the Denver Botanic Gardens’ bloom, Stinky (in the same bloom cycle as Spike). About half of the developing fruits are from Spike’s pollen and the other half are from Stinky’s pollen.

PHOTO: The remains of the spadix have been removed—showing its fibrous interior—as the titan arum's fruit continues to mature.
The remains of the spadix have been removed—showing its fibrous interior—as the titan arum’s fruit continues to mature.

It can take five to six months for the fruit to ripen, and the fruiting process is quite beautiful to observe, as the fruits change from a gold color to orange, and finally to a dark red color once ripened. After the 400+ fruits are ripe, we will harvest the fruits, and extract the two seeds that are produced by each fruit. We hope to germinate a few of these seeds in order to grow more titan arums to add to our collection—and increase the age diversity of the collection as well. (As many of our current plants have the same seed or corm source, they are all roughly the same age.) Some of the seeds will be shared and distributed to other botanical gardens, universities, and educational institutions as requested. The rest of the seeds harvested will be stored in our seed bank freezer in the Daniel F. and Ada L. Rice Plant Conservation Science Center. This will help with increasing the genetic diversity of the species and continue to aid with plant conservation efforts. 

I realize there are many questions that you may have regarding Alice’s fruit, many of which were asked during the time that Alice (and Spike) were on display last year.

DIAGRAM: Life Cycle of the Titan Arum (Amorphophallus titanum).The titan arum is the largest non-branched inflorescence in the world, and it is found in the dense jungles of Sumatra. An inflorescence is a cluster of flowers—like a bouquet. The inflorescence of the titan arum is composed of two parts: The outer, purple, vase-like sheath (a single leaf) is called the spathe. It protects the inner tube-like spike called the spadix, which attracts pollinators. The flowers are small and are located on the base of the spadix. There are hundreds of them.

What does it mean that Alice is producing fruit?

The fruiting process of a titan arum is just like that of other flowering plants. After a flower is pollinated, the fleshy fruit develops (think of a cherry or apricot). The fruits of the titan arum grow from a yellow-gold to a more orange-red tone. When the fruit is fully ripened, about six months after pollination, it will have a soft outer flesh that is dark red in color. After fruiting, the plant will return to dormancy, and send up a leaf in its next growth cycle.

Does Alice still smell? 

No. Alice is not producing any odor and it is not blooming. Odor is only produced within the first 24–48 hours during the initial bloom. After flowering, Alice’s spathe shriveled and dried out, and was removed one week after the initial bloom. The spadix began to collapse five days after pollination; it was removed two months later after it was completely dried up. 

PHOTO: Titan arum (Amorphophallus titanum) leaf bud emerging from the soil.
A young leaf sprout displayed next to Alice’s fruit emerges from a small, young corm. A leaf stalk from a mature (older) corm would dwarf visitors, and would be heavy enough to be immovable during its growth cycle.

Will Alice bloom again?

Yes, but not in the near future. After the fruits mature, the plant will go dormant for a period of time, then produce a new leaf every year for a number of years. Once the corm’s energy has been replenished, Alice will bloom again. However, we now have 13 titan arums in the Garden’s collection, and we expect that another will bloom within the next year or two. We do not know when, as it is hard to predict—even in nature. The plant needs to recover and build up energy before it can flower again.  

What did you do with pollen from Alice?

Garden conservation scientists collected pollen from Alice during her bloom. Several small holes were cut in the spathe for manual pollination to take place. The same access holes were used to collect pollen later in the day. The pollen is now in cold storage to use in pollinating the next titan arum bloom at the Garden. We also share pollen with other botanic gardens, universities, and educational institutions.

Today, the Garden has 13 titan arums in its collection. But the increase in number is not the result of pollination. Just like many of our spring bulbs (such as narcissus, canna, and dahlias), the tuber, or bulb, that produces the flower for the titan arum grew additional bulbs that we hope will produce fully-grown plants.

PHOTO: Rhinoceros hornbill (Buceros rhinoceros).
Rhinoceros hornbill (Buceros rhinoceros) ©2007 Derek Ramsey (Ram-Man) (Self-photographed) [GFDL 1.2 or CC BY-SA 2.5], via Wikimedia Commons.

Is the fruit edible?

In nature, the fruit is eaten by the rhinoceros hornbill (Buceros rhinoceros). Attracted by the brightly colored covering, the birds eat the fleshy fruits and excrete the hard, resistant inner seeds. The fruit is not suitable for human consumption.

What does the titan arum look like before it blooms?

This plant produces one leaf at a time for several years. The leaves start out small and get progressively larger each year. We have several in our production area now. The leaves photosynthesize and allow the plant to store energy in a large (sometimes weighing up to 40 pounds) underground tuber called a corm. Each leaf lasts about a year before it dyes back and goes dormant. Because flowering takes so much energy, it takes several years before the plant has enough energy stored to produce a flower. Alice took 12 years to come to flower!

Come out and see Alice and her fruit now through April 8, 2016. To learn more about Alice and Spike, read our previous blog posts!


©2016 Chicago Botanic Garden and my.chicagobotanic.org