Archives For How-To

Learn step-by-step how to take on gardening projects at home. Garden staff often teach classes through the Joseph Regenstein, Jr. School of the Chicago Botanic Garden on these topics and others.

Historically, fruit trees, shrubs, and berries were grown at home out of necessity. Colonialists were entirely dependent on what they could produce themselves, and in time, a fruitful garden became a common symbol of independence from foreign imports—highlighting a new American pride in agriculture.

The farm-to-table movement of today epitomizes the fruit-growing traditions of the past by “growing as close to the plate as possible.” Sweet, juicy fruit can be easily grown in gardens of all sizes: on small urban lots, in containers on terraces, or in large suburban gardens. Harvesting homegrown fruit continues to be a gardener’s most satisfying pleasure, and with a bit of advance planning, choosing suitable varieties to plant this spring is possible. Here are a few ideas to get you started creating, and/or caring for, your edible landscape.

PHOTO: A hanging basket growing a mix of strawberry cultivars and lettuces.

Day neutral strawberries are grown in our vertical wall and hanging baskets in the Regenstein Fruit &  Vegetable Garden.

Plan to plant strawberries

No grocery store strawberry ever tastes as good as one grown in your own yard. An easy starter crop, strawberries are self-fertile, so you can start small if you like—plant just one variety or only one plant—and still reap a reward. Choose strawberry varieties carefully, however—they vary greatly in flavor, disease-resistance, tolerance of different climates, and harvest time.

Good choices for Illinois gardens are larger June-bearing strawberries such as ‘Earliglow’ and ‘Allstar’. Day-neutral or everbearing strawberries were developed to produce flowers and fruit continuously throughout summer and fall, ignoring the seasonal effects of day length on fruit production. Of the many day-neutral and everbearing varieties to choose from, ‘Tristar’ is a reliable berry for our zone. At the Garden, we grow everbearing strawberries ‘Mara de Bois’ and ‘Seascape’ in hanging baskets and vertical plantings, because they are among the first to fruit in the spring, but also produce a June crop followed by a final fall crop.

Planting several varieties together in your garden extends your harvest time, ensuring there are plenty of strawberries for eating out of hand and enough fresh berries left over to make strawberry jam.  

Choose healthy plants for a healthy harvest

Start with quality, virus-free, and disease-resistant plants. Mail order nurseries and garden centers have bundles of bare-root plants available. Lesser quality plants are prone to fruit rot, mold, and fungal diseases like Verticillium wilt.

PHOTO: Glass cloche cover strawberry plants in a garden plot in early spring.

Strawberry flowers are susceptible to frost. Here, a transparent plant cover called a cloche (from the French word for bell) is used to protect plants if frost is expected.

Select a planting location in full sun; avoid low-lying spots or crop beds that have grown tomatoes, potatoes, or cane fruit in prior years. These crops can harbor soil pathogens like Verticillium and Phytophthora which can affect new plantings. While strawberries prefer to grow in soil with a bit of acidity, a pH of 6.2 is ideal; the varieties mentioned above perform well in Chicago.

Aim for early spring planting, as soon as the soil can be worked, and its temperature is above 40 degrees Fahrenheit. Mid-April to mid-May is ideal. Space plants 12 inches apart, leaving 3 feet between rows. Fifty plants produce enough fresh home-grown fruit for four people all summer long.

Plant with midpoint of crown at soil level. Roots should be planted straight down. Strawberries are shallow-rooted, and mother plants spread by runners—which can be removed if desired, to develop stronger plants and to promote bigger fruit.

Water your plants well, particularly when they are fruiting. Mulching with straw helps keep fruit clean and dry, and up off the soil.

Spring tasks: Prune Raspberries

Red, yellow, black, or purple raspberries are easy to grow in hedgerows as natural barriers along lot lines or on post-and-wire trellises. Cane fruit is best managed with proper spring pruning, which prevents a tangled mess and makes your late-summer harvest far easier. Regular pruning keeps brambles in line while allowing air flow through the plant—lessening the risk of fungal diseases like Botrytis and rust, and increasing both yield and berry quality. Both types of raspberries—summer-bearing and everbearing (or fall raspberry)—benefit from a good March pruning.

PHOTO: Different kinds of berries in baskets, lined up in a grid.

A bountiful berry harvest on its way to our Farmers’ Market? A bountiful home harvest is also possible with vigilant pruning.

Summer-bearing raspberries produce a single crop in the summer on canes which have overwintered. It is important to confine them to a 1- to 2-foot-wide hedgerow to encourage air flow and sunlight. Begin your pruning by removing dead, diseased, or damaged canes first. Then, head back (prune) the spindly top 6 inches of cane tips. Removing the thinnest wood which produces the smallest berries forces the growth into the more vigorous lower part of the plant.  Finally, remove less vigorous canes—in an established plant, those canes with less than a pencil’s diameter thickness—leaving 6 inches between canes (enough room to easily pass your hand between canes).

Fall-bearing red and yellow raspberries can produce fruit on both the current season canes (called primocanes) and second-season growth (floricanes). Thus, they can be pruned to bear one or two crops with a method called, “double cropping.” (We demonstrated both methods last year on our brambles in the Regenstein Fruit &  Vegetable Garden.)

  1. To produce one heavy fall crop, cut all autumn raspberry canes back to ground level in the spring. Canes should be cut as close to the ground as possible to encourage new buds to break just below the surface. All new canes will grow from this radical pruning and produce a single crop of berries.
  2. A second method of pruning produces a small crop on the previous year’s growth and later, a second crop on the current season’s canes. When a double crop is desired, remove dead, diseased, or damaged canes in March, leaving the vigorous canes to fruit. Tip-prune those back by one-third of the total length of the cane, or to trellis height. The new shoots or primacies will produce the second larger crop. After the second fruiting, the canes will die and should be removed.

Pruning for blackberries is similar to raspberries. They are also pruned in March by heading back the “leaders”—the main canes—by one-third (or about 36 inches). This tip-pruning helps to stimulate the growth of lateral branches, which is where blackberry sets fruit. The lateral branches should be pruned back to 12 inches, or where the branches’ thickness is about the diameter of a pencil. 

Want to learn more about cultivating berries? Join us for Growing Fruit Trees and Berries, May 29 to July 10, or check out other fruit cultivation classes at the Garden this spring.

©2014 Chicago Botanic Garden and my.chicagobotanic.org

How to Select a Good Orchid

Anne Nies —  February 18, 2014 — Leave a comment

After visiting the Orchid Show (purchase tickets here), you may be inspired to try growing an orchid in your home, but for the new orchid grower, selecting an orchid may seem overwhelming. Here are a few tips to get you started. 

(Can’t play the movie above? Watch here on YouTube.)

A healthy orchid.

A healthy orchid. Notice the plump pseudobulbs (stems), smooth green leaves, and beautiful flowers. If you look closely, you’ll even see new buds forming.

1. Know yourself, your growing environment, and what you’re buying.

Orchids live in a wide variety of habitats and come in a wide variety of sizes, so you’ll want to make sure that you choose one that’s well suited to your home and to your schedule. For example: if you have lots of bright, direct sun in your home, a Cattleya will do very well, but a Phalaenopsis may struggle. If you have questions about an orchid’s growing conditions, you can always ask the grower you’re buying from, or check out the American Orchid Society’s Culture Sheets. Also, make sure that your plant has a tag identifying it, or that you get its name and put a tag in the pot right away. There are thousands of orchid species and hybrids, and often it’s difficult to identify a plant on the flower alone. Having a tag will help you to always remember what species or hybrid your orchid is.

2. Choose a plant you really like.

This may sound obvious, but orchids aren’t like other house plants. Most only flower once a year  so you will probably need some good motivation to keep caring for it when it’s not in flower. Also, sometimes the shock of moving from the greenhouse to your house will cause orchids to skip a year in flowering. Don’t lose all hope though! There are some orchids that flower continuously for most of the year, and others from which you can get multiple flowerings in a year.

3. Only buy a healthy plant.

PHOTO: Closeup of an adult soft brown scale with offspring (tiny pollen-sized dots).

Soft brown scale (Coccus hesperidum) and offspring on Phalaenopsis.

The easiest way to tell if a plant is healthy is to look at it. It should have smooth green leaves, fleshy, plump pseudobulbs (if present), and no bugs. Discoloration and spotting of the leaves may be due to cultural conditions, but it may also be a sign that the plant has a virus. Unlike people, orchids don’t recover from viruses. Like people, however, they can spread the virus to other plants in and around your home.

Leaf pitting, scaring, and holes also may be cultural, but more likely are an indication of bugs. Bugs are small and can be difficult to spot. Some examples are soft brown scale and the longtailed mealybug. These bugs are quite common and quite difficult to get rid of once you have them. They survive by feeding on the sap of the plant, sucking away its life and leaving behind ugly marks. Although the adult bugs are usually easy to spot, the juveniles are easy to miss because they’re tiny and hard to see.

PHOTO: An otherwise healthy orchid shows a yellowing leaf with pale scale spots.

Yellowing and pitted leaves are signs of the stress this orchid is suffering because of a scale infection.

PHOTO: Closeup of an adult longtailed mealybug with young.

Close-up of an adult longtailed mealybug with offspring.

4. Consider the flower.

You have basically two choices when buying an orchid: buy one that’s flowering or about to flower, or buy one that’s not in flower. Especially for the beginning grower, buying orchids in flower is often the better choice. The biggest reason is that you get to see your orchid flower at least once. People who grow orchids will readily tell you about how many they’ve killed—it’s just part of the learning process. If you buy your plants in flower and they die, it’s not really any worse than buying a bouquet of cut flowers. (Orchids are about the same price, and the flowers last much longer.) Another reason to buy when the plant is flowering is so that you can be sure that you like the flower, and that it has no abnormalities that you find unattractive. 

5. Look for new growth.

This is an indication that the plant is doing well and will continue to do well. Often, next year’s flowers come from this year’s growth, so if there’s no growth, there may also be no blooms. You can find new growth in two ways: new leaves or green tips on the roots. Roots sticking out of the pot are no problem and are the easiest to check.

Find an orchid at the Orchid Marketplace, open weekends throughout the Orchid Show.


©2014 Chicago Botanic Garden and my.chicagobotanic.org

While you are inside wondering if winter will bring another chilling polar vortex, or six feet of snow, or 40 degrees Fahrenheit and rain, join me in contemplating the sweetness of plants.

PHOTO: Burgundy leaves of the Bull's Blood sugar beet.

The common sugar beet, Beta vulgaris (this one is cultivar ‘Bull’s Blood’), is the source of our refined white sugar—not sugar cane!

All sugar comes from plants. All of it. Plants are the only thing on earth that can make sugar, and plants are made of sugars. Even plant cell walls are composed of a substance called cellulose, which is a compound sugar. Sugars from plants are the basis of our food chain.

Our favorite dietary sugar, sucrose, comes from the juices of sugar cane or sugar beets, which are boiled until the water evaporates, leaving the sugar crystals we all know and love as table sugar. Now that you know where your candy comes from, let’s use some sucrose to make a treat.

How to Make Rock (Sugar) Candy

Rock candy is pure, crystallized sucrose, and you can make it at home. This will take one to two weeks, so get started now if you want to give it to someone special for Valentine’s Day.

You will need

  • 1 cup water
  • 3 cups sugar, plus about a spoonful extra to coat the skewers
  • Food coloring (optional)
  • Flavoring (optional)
  • Bamboo skewers
  • Very clean, heat-resistant drinking glasses or glass jars (like Ball or Mason jars)
  • 2 clothespins
PHOTO: Tools and ingredients for making rock sugar candy laid out on the kitchen counter.

All the ingredients for the solution are assembled and ready to go. Note: the flavoring pictured here is not the best to use, because it contains alcohol. Use an essential oil for better results.

Directions

First, assemble the hardware. Cut the bamboo skewer to 6–8 inches, depending how long you want it. Attach two clothespins to one end. They will rest on the edges of your glass, suspending the skewer straight down in the glass without allowing it to touch the sides.

Cut a piece of paper towel with a hole in the center. This will go over the top of your glass to prevent dust from settling on the surface of the solution. Remove the paper towel and skewers; you’ll reassemble this after you’ve poured the solution in the glasses.

PHOTO: Glasses and skewers set up for making rock sugar candy.

Suspend the skewers using one or two clothespins as pictured here, and be ready to cover loosely with a piece of paper towel like the glass shown in the middle.

Important tip: The directions I followed (from a reputable source) instructed me to moisten the end of the skewer with water and roll it in some sugar to “seed” the formation of new crystals. When I tried this, the sugar crystals all fell off the skewer the minute I put them into the solution. Crystals will not grow on a bare skewer. What did work was dipping the skewer into the sugar solution (which you are about to make) and then rolling it in sugar. This kept the tiny sugar crystals stuck on the skewer and allowed larger crystals to grow.

Making the sugar solution. Pour 1 cup of water in a saucepan and heat to boiling. Then turn the heat to low. You do not want to boil the water after you have added sugar, or you will make a syrup that is stable and will not yield crystals. Add the 3 cups of sugar gradually, and stir to dissolve. Push down any crystals that form on the sides of the saucepan during heating to dissolve in the water. This takes some time! Your final solution should be clear—not cloudy at all—and you should not see any crystals.

PHOTO: Green-dyed rock sugar candy solution in a Mason jar.

You can choose to pour the liquid into two small glasses or one larger jar.

If you want to color or flavor your candy, now is the time. Add 2 to 3 drops of food color and/or 1/2 tsp of food-grade essential oils (like peppermint), and stir in thoroughly. Avoid using alcohol-based extracts like the bottle you see pictured in the blog. I’m not sure if this caused a failure during one of my trials, but I can say with certainty that I had better results when I used a flavoring oil.

Dip the end of the skewer a few inches into the solution and remove. Let the excess sugar water drain into the pot, and then roll the sticky end in dry granulated sugar to coat evenly. Set aside.

Pour the warm solution into the glass container(s), and fill to the top. With this recipe, you will get about 3 and 1/2 cups of solution, which will fill one jar or two glasses. You can scale the recipe up if you want more.

PHOTO: Rock sugar candy skewers.

After about eight days, you can see the cube-shaped sugar crystals on these skewers. The longer you leave them in the solution, the larger the crystals will grow.

Carefully lower the sugar-coated skewer into the solution, holding it in place with the clothespins. Cover lightly with the paper towel and place it in a safe location where nothing will bump it or land in it for at least one week—two weeks if you want larger crystals. Do not totally seal your glass or jar. The water needs to evaporate for the sugar to come out of solution and crystalize on the skewer. If all goes well, then over the next week you will see large crystals forming only on the skewer.

Got candy? Remove the skewer and drain the syrup. Eat immediately, or allow to dry, wrap in plastic, and save for later. Now that is what I call cultivating the power the plants!

One more thing: You can use string instead of a stick. Tie a small weight on the bottom and tie the top to the a pencil balanced on top of the glass so that the string hangs in the liquid.

PHOTO: A weighted string coated in rock sugar crystals.

The string was weighted with a metal nut so it would sink into the solution.

While you are waiting for your sucrose to crystalize, let’s contemplate where it came from.

Sugar from Plants

You probably know that plants harness energy from the sun to convert water and carbon dioxide into sugar and oxygen in a process we call photosynthesis.

PHOTO: diagram of a plant showing carbon dioxide and light energy entering the plant leaf andwater entering through the roots, while glucose is formed in the leaf and oxygen is released into the air.

This basic diagram shows photosynthesis in action.

The product of the reaction is a sugar called glucose, which is chemical energy that a plant can use to build plant cells and grow. The formula looks like this:

6CO2 + 6H2O (+ light energy) C6H12O6 + 6O2.

Translated, it means that inside plant cells, six carbon dioxide molecules and six water molecules combined with energy from the sun are converted into one sugar molecule and six oxygen molecules.

Glucose molecules are combined to form more complex sugars. Sucrose, or table sugar, has a molecular formula C12H22O11.  It looks like two glucose molecules stuck together, but missing one oxygen and two hydrogen atoms (or one water molecule).  

ILLUSTRATION: Sucrose molecule.

This sucrose molecule looks good enough to eat!

PHOTO: Sugar cubes.

Just kidding. It looks better in normal scale.

As I mentioned earlier in this post, plants are the only thing on earth that can make sugar. Through modern chemistry, food scientists have figured out how to extract and modify plant sugars more efficiently. They have also developed different kinds of sweeteners, because the food industry is always striving to develop less expensive ways to satisfy our craving for sweets, as well as supply alternative sweeteners for different dietary needs. Some sugars you may see on food labels include dextrose (which is another name for glucose), sucrose, fructose, high fructose corn syrup, maltose, and sucralose. All of these “natural” sweeteners were processed from plants, even though they do not exist without help from a laboratory.

Have you noticed that all of these sugars, including the sugars in plant cell wall structures, have names that end in “ose”? That is no accident. The suffix “ose” is the conventional way chemists identify a substance is a sugar. Go ahead, share that information at your next party as you consume goodies made from plant sugars. Having some chemistry facts at your sticky fingertips makes you sound smart while you’re nibbling on sweet treats.

PHOTO: Fresh produce in a wicker basket.

Yum!

Please enjoy sucrose crystals responsibly, as part of a balanced diet that includes forms of sugars closer to their origins. (In other words, eat fruits and vegetables, too.) And remember to brush your teeth!


©2014 Chicago Botanic Garden and my.chicagobotanic.org

Do you remember the orchid spheres that were featured in the Tropical Greenhouse during Wonderland Express in 2012? I always wondered, “How did they do that?” and tried to examine them after they were already created.

Orchid Sphere

Orchid Sphere in Wonderland Express

When I heard they were making ten of them for the Orchid Show, I asked horticulturist Elizabeth Rex to show me (and you) exactly how they do it. She and the other talented horticulturists constructed them from up to 150 light and dark purple Phalaenopsis orchids, spending six to eight hours per sphere. I’m not sure any of you will be creating your own orchid spheres at home, but if you do, Rex tells me they will last up to six weeks with proper care. That’s good, because the Orchid Show will be open from February 15 to March 16.

Keep a look out for other fantastic orchid creations including arches, chandeliers, and trees. I wonder how those were made…

Visit and discover the Orchid Show for yourself! Click here to purchase advance tickets.


©2014 Chicago Botanic Garden and my.chicagobotanic.org

My daughters love fresh grapefruit, and winter is the season when this fruit is at its best. Instead of throwing away the rind, we decided to make a bird feeder. This is a great winter project for the family.

PHOTO: The supplies needed for the project.

The grapefruit sections have been cut and eaten; the rind is ready to become our bird feeder.

To make a grapefruit bird feeder you will need:

  • Half a grapefruit rind (you can also use an orange)
  • Three pieces of yarn, each cut about 18 inches long
  • A knife, skewer, pointed scissors, or other sharp tool
  • Birdseed

First, eat the grapefruit and drain the remaining liquid. Then, use the skewer or knife to poke three holes in the grapefruit. They should be about half an inch from the top edge and spaced evenly around the circumference. (Some people do this with four strings, but I find that using three strings makes it easier to balance the fruit.)

Push a piece of yarn through each hole and tie it off.

PHOTO: Skewering the grapefruit rind.

Hold the grapefruit firmly with one hand while you poke the skewer through the rind. Be careful not to poke your finger!

PHOTO: Tying yarn to the grapefruit to hang it.

Pull 2-3 inches through the rind and tie the short end to the longer strand.

Hold the grapefruit up by all three strings and adjust the length of the strands so the fruit is not tipping. When it is balanced, knot the strings together about 4 or 5 inches from the top. (The ends will probably be uneven, and that is all right.) Make a loop knot with those top ends, so you will be able to hang it from a branch. 

PHOTO: The final product.

Our grapefruit bird feeder is balanced, full of seed, and ready to hang outside.

Finally, fill the fruit with birdseed and hang it outside for your feathered friends to enjoy. If you like, you can add a little suet, but you may find it doesn’t stick well to the wet fruit. Here in the Chicago area, you’ll probably find that most of your winter guests are black-capped chickadees, nuthatches, dark-eyed juncos, common redpolls, and downy or hoary woodpeckers, who balance their primary diet of insects and grubs with bit of suet and sunflower seeds.

One more thing: Make sure it’s tied to the branch firmly so that your local (determined) squirrels — who will also find this bird feeder appealing — don’t knock it down.

Don’t worry if you don’t have any visitors the first few days after you’ve placed your feeder. It can take up to two weeks for birds to discover their new food source, but once they do, they tell all their friends in the neighborhood.

PHOTO: Grapefruit birdfeeder hung from a snow-covered fir.

The final product is ready for visitors.

What is birdseed?

You probably know that if you plant birdseed, you won’t grow a bird. And there is no such thing as a birdseed plant. So what plants make birdseed? What we call “birdseed” most commonly comes from two sources: millet, which is a grass, and sunflower. Other seeds used to feed birds include thistle, safflower, cracked corn, and sorghum seed, which is also called milo. Some birds have a preference for certain kinds of seeds, so bird lovers stock their feeders with seeds to attract their favorite birds and keep them visiting the feeder.

After you hang your bird feeder, take some of the seed and plant it to see what grows. Maybe you can grow your own food for the birds this year!


©2014 Chicago Botanic Garden and my.chicagobotanic.org