Midsummer Vegetable Gardens

Are you enjoying the “fruits of your labor” from your vegetable garden this summer? With proper care, vegetable gardens provide fresh produce well into the fall.

Watering 3-Sisters Garden with upright sprinkler

Although we had too much rain in June, July began quite dry. It is essential to keep plants watered consistently during the heat of summer. On average, plants need one inch of water per week and this may need to be stepped up to one inch every five days during the heat of summer. Watering is the most important maintenance item, so don't skimp on it. Soak the soil thoroughly to a depth of at least 6 inches rather than sprinkling the garden lightly.

If you did not mulch in spring, consider doing it now. Most vegetables benefit from mulching, including tomatoes, cucumbers, melons, beans, and potatoes. Besides controlling weeds, the mulch will save moisture, keep the soil temperature more even, and keep the fruits clean. The many types of mulch include leaves, grass clippings, straw, cardboard, newspaper, and black plastic.

Straw mulch

Pests are one the biggest frustration for home vegetable gardeners. When possible, use disease-resistant varieties. Crop rotation every 3 to 4 years is also very effective for many insect and diseases problems. This is done by moving vegetable types to other areas of the garden or yard.

New gardeners sometimes wonder when they should begin harvesting their product. This varies from crop to crop, but there are some tips that will help the produce stay fresh and tasty longer. Avoid bruising or damaging them, because injury encourages decay. Most vegetables last longer if they are place in cool storage immediately. In particular, sweet corn loses its sweet flavor quickly if it is not cooled as soon as possible.

Arugula, Swiss card, cucumber, baby carrot, and yellow squash

If you have harvested part of your garden, now is the time to begin your fall garden. A fall garden extends your supply of fresh vegetables. Unfortunately, a successful fall garden demands additional work and planning at a time when you are busiest. Irrigation is usually necessary and weeds grow quickly at this time. But the pleasure you can derive from a fall garden far outweighs the extra effort involved in planning and planting it.

The midsummer planting usually takes place from July 10-20 and could include snap beans, beets, broccoli plants, cabbage plants, carrot, cauliflower plants, and okra. From August 1-10 you could also add many cool-crops such as lettuce, mustard greens, turnips, and winter radishes. Spring radishes, spinach, and more leaf lettuce can go in as late as August 25 to September 5.

How is your garden growing?

Beware of Dangerous Carrots!

Last weekend on a motorcycle ride to Wisconsin, I saw many plants in the carrot family (Apiaceae) growing along roadsides. One of my favorite vegetables is the very edible carrot, but unfortunately the carrot family has a number of dangerous, poisonous plants in it too.

The first two dangerous carrots I’ll cover are stomach poisons, which means they are poisonous if eaten.

Poison hemlock's purple spotted stem

Poison hemlock (Conium maculatum) is not native to Illinois and was added to the Illinois Exotic Weed list in 2015. It grows four to nine feet tall with four to six inch white flowers. It has a purple spotted, waxy stems. This is the plant I saw most on our ride. I could also smell it every time we rode past a good stand of it, which was usually at bridge crossings. Poison hemlock has a disagreeable “mousy” odor. The entire plant is poisonous if ingested.

Water hemlock (Conium maculate) is considered by many to be the most poisonous plant in the northern temperate zone. Only a small amount of the toxic substance in the plant is needed to produce poisoning in animals or in humans. This native plant grows three to six foot tall with 6 inch white flowers and purple-streaked stout stems. All parts of this plant are poisonous, especially the roots.

The next three dangerous carrots cause photo-dermatitis. Cow parsnip, wild parsnip, and giant hogweed contain an allergen that is activated by sunlight to cause rash, blisters, or other skin irritations in susceptible people.

Cow Parsnip (Heracleum lanatum) is a native plant that can reach eight feet tall. Like the hemlocks, its flowers are white, but cow parsnip flowers are larger, growing to 10 inches across. The large flowers were obvious as we rode past them on the motorcycle.

Wild parsnips

Wild Parsnip flower

       Wild Parsnip (Pastinaca sativa) has large yellow flowers that are about five inches across. It is a stout plant that grows to five feet tall with grooves along its stem. I know a few people, including my sister, whom are very allergic to this plant.

Giant hogweed (Heracleum mantegazzianum) is the worst of the three that cause blisters in the sun. This plant lives up to its name as a giant. It grows 15 feet tall with five foot leaves and 2 ½ foot white umbel flowers. Its massive size makes it desirable to some home gardeners, but it is a public hazard that causes severe skin irritation in susceptible people. A USDA pamphlet says this plant’s sap produces painful, burning blisters that later develop dark scars that may persist for years. Fortunately, it has only been found in an isolated location in northwest Illinois, and those plants have been eradicated. Giant hogweed is a federal noxious weed, making it unlawful to propagate, sell or transport this plant in the United States.

Queen Anne's Lace flower

Finally, not all carrots are dangerous. Queen Anne’s Lace (Daucus carota) is also called wild carrot due to its large, edible taproot. It grows four foot tall with lacy four inch flowers. This plant is the ancestor of our cultivated carrot, though its roots are white instead of orange.

Other edible plants in this family grown for their roots are parsnips and bulb fennel. Anise, caraway, celery, chervil, cicely, coriander (cilantro), cumin, dill, fennel, and parsley are grown for their edible leaves and seeds.

Think I’ll eat a salad with lots of carrots for lunch!

Ferns Add Texture to the Shade Garden

I love ferns. Ferns make areas greener and provide interesting texture. The past few years I’ve been working on my fern identification skills. I’ve found many different types of ferns growing in Illinois natural areas (watch for a future blog on this!). For now, Let’s look at a few that are commonly grown in home shade gardens.

Hardy, outdoor ferns are easy to grow and are essential in the woodland garden. Ferns come in all shapes and sizes, but most require similar growing conditions. Nearly all ferns do best in dappled shade. Most ferns require a soil rich in organic matter, with good drainage, and slightly on the acid side. Although most ferns also prefer moisture, there are several that will tolerate dry situations.

The most commonly grown hardy ferns are the lady fern, cinnamon fern, Christmas fern, ostrich fern, and Japanese painted fern.  The lady fern  (Athyrium filix-femina) is easily grown and often found as foundation plantings. It has very lacy leaves, grows 1 to 3 feet tall, and spreads well. It prefers shade but will tolerate some sun as long as the soil is moist.

The cinnamon fern (Osmunda cinnamonmea) is named for its bright cinnamon-colored fertile fronds. This is a member of a majestic group of quite large ferns called flowering ferns. This fern will grow in the sun or shade but needs moisture and acidic soil. It grows 3-4 feet tall and has attractive fiddleheads in the spring.

The Christmas fern (Polystichum acrostichoides) resembles a Boston fern but has much darker leaves and cascades less. It withstands sun or deep shade and grows up to 2 to 3 feet high. This one also doubles as a houseplant. It gets its common name from the fact that the early settlers used it for Christmas decoration.

The ostrich fern (Matteuccia struthiopteris) has a vase-shaped form and grows 2 to 6 feet tall. Also easy to grow, the ostrich fern tolerates sun to full shade, with moist soil. This is one of the most widely used ferns in temperate gardens.

The Japanese painted fern (Athyrium niponicum ‘Pictum’) is unique due to its exceptional coloring. An interesting addition to any garden, it boasts dark green fronds with silvery centers and red stems. It grows 10-15 inches high. The best color develops on plants in light shade. Too much sun washes out the color. With moist, loose soil it will send up fronds all summer and into the fall.

These are just a few of the hardy ferns available to us. Lush ferns create a cool, calming effect. They are useful in any shady area, along a pond, or in a woodland garden. Also, many tropical ferns are used as annual outdoor plants, but also make beautiful houseplants. Include ferns in your garden: indoors and out.

Rabbit, Rabbit, Rabbit!

Taken at  Frederik Meijer Gardens & Sculpture Park 
in Grand Rapids, MI in 2007

Elmer Fudd from The Looney Tunes said it right, “Bugs Bunny?! You’re a pesky wabbit!” I am at war with rabbits in my gardens. So far, they’ve eaten a tomato; all my cabbage, cauliflower, and broccoli; basil; calendula; parsley; celery leaf; and purple coneflower. I’ve seen many rabbits in our yard, but I think the “cute” little rabbit I saw hop down my walk is the culprit!

My first line of defense was to learn more about rabbits from the Wildlife Illinois website at wildlifeillinois.org/. Here is what I learned.

As you know, our Eastern cottontail rabbits produce many offspring and grow quickly. One female cottontail rabbit may have 20-25 young per year, which reach full size in six months.  

My efforts to naturalize many parts of my property likely increase my rabbit population. They are found in open spaces near woody cover and are abundant where grass fields adjoin bushy areas. I have many locations with that exact description.

You might ask how I know a rabbit ate my plants. Rabbits clip off flower heads, buds, or small stems (my tomatoes!) at a clean 45^o angle. Deer, on the other hand, do not have sharp teeth like a rabbit and instead twist and pull plants when browsing. Cutworms don’t eat the entire plant, although I have also seen rabbits clip off plants and leave part of them on the ground.

Unfortunately, there is no easy fix for managing rabbits and other wildlife in our yards. Control options include habitat modification, exclusion, repellents, and removal.

I first chose to try the exclusion method. I fenced in my new terraced vegetable garden with chicken wire and trellises. The mesh was small enough (¼” x ¼”) to prevent small and large rabbits from slipping through. However, because the area sloped, parts of the fence were only a foot tall and thus they jumped right over. I have since extended the height.

I used milk crates and wire cages over herbs in my herb garden. However, the baby rabbits were able to get through the holes. They also burrowed under the lighter weight cages. I finally gave up and moved most of the annual herbs to containers placed on a cart out of the rabbit’s reach (I hope).  

The rabbits have also eaten some of my purple coneflowers. I don’t plan to eat the coneflowers, so repellents are an option, since they are not safe for human consumption. These products are taste repellents and are applied directly to the plants. Unfortunately, it must be reapplied after heavy rains or watering and as the plant develops new growth. These haven’t worked very well for me at all.

A better repellent for me is garlic oil in a little green dispenser (by Luster Leaf) that can be clipped on the plant or another structure. These last a long time and seem to keep the rabbits away.

I recently learned about another option I want to try. Bunny-Be-Gone Coleus (Coleus canina) is marketed as a natural repellent. Also called Scaredy Cat Plant, this mint family herb is sticky with a foul odor like dog urine. No research currently exists to support these claims, but it’ll be fun to try it anyway.

You might ask why I don’t use Elmer Fudd’s method for controlling Bugs Bunny – a gun. Yes, I do have a 4-10 shot gun and know how to shoot it. However, I’ll have to wait since rabbit hunting season in Illinois is from November through early January. We also have a live trap; but in Illinois, an animal removal permit from an Illinois Department of Natural Resources District wildlife biologist is required to trap rabbits.

In the meantime, I’ll try to find joy in watching the rabbits play in my yard. They just better stay away from my landscape plants!

Help, my Oak tree has weird bumps and growths!

While sitting in our hot tub this morning I noticed that the black oaks around us have several walnut-sized green masses on their stems. 

During my 30 year horticulture career, I had many calls and questions about abnormal growths on oak and other trees. These abnormal growths, called galls, can be very disturbing to the people whose plants are affected. Fortunately, most galls affect only the appearance of the trees and are not detrimental to plant health.

Galls are a plant's response to insects, mites, bacteria, fungi, or nematodes. Galls are actually created by the plants themselves in response to some stimulus from the invading organism. The plant may create the gall in response to the invaders feeding or the critter might "trick" the plant into forming a home for it to live in.

Each gall-inducing insect or mite chooses a specific plant to associate with. Identification of the gall maker is based on the gall it produces. Insects on trees produce over 2,000 types of galls. The majority of these insect galls are produced by wasps, and over 700 of these wasp-produced galls occur on oak trees.

Wool Sower Galls on burr oak

Over the years, I've seen several types of galls on oaks in my yard. One year the burr oak tree in my yard had these very interesting wool sower galls, which are tan, spongy, and pong-pong ball sized. It was fun to pull the gall apart to look for the ant-sized adult wasp inside. Don't worry, they don't sting.

Oak apple gall is also caused by several species of gall wasps. It consists of large, dry galls attached to the midrib or petiole of a leaf. As the galls mature they become papery. The single larva in each "apple" is inside a small and very hard seedlike cell. No, they are not edible!

Leaf gall on oak

Although leaf galls may be unsightly, most do little or no damage to the host plant. However, the horned and gouty oak stem galls can be debilitating, even killing younger trees. It too is caused by a wasp, but this one causes woody masses on stems that reach two inches or more. Over it's one to three year life cycle, this wasp's gall can choke off and kill the ends branches and twigs. The pin oak is a primary host for the horned oak gall.

There is no effective chemical control for galls. The gouty and horned oak galls can be removed by pruning, and the debris should be destroyed. The other galls mentioned do not remain on the tree from year to year so don't have to be pruned away. They may or may not return the following year.

Enjoy your oak trees!

I really like this factsheet on Oak Problems, including galls, from the University of Illinois Plant Clinic (found under Publications: Reports on Plant Disease). 

Grow Vegetables in Containers

ICC Master Gardener display garden
in 2018 

This year I added a terraced raised bed garden where I am growing most of my vegetable crops. It is allows me to grow a lot of food in a smaller space, while also looking good. If you don’t have space for a large row garden or just want to try something different, here are some other options to try.  

Container herbs on 5-13-2020

One trend right now is growing vegetables in raised beds and containers. Container vegetable gardens are particularly popular with gardeners who have little or no ground space. Containers may be located almost anywhere and can be both decorative and harvestable. Popular choices for container gardens include attractive pots of kitchen herbs, hanging baskets of ripe red tomatoes, and window boxes of bright leaf lettuce or fresh radishes.

'Mighty Mini' aerogarden tomatoes

Dwarf vegetable varieties work particularly well in containers. For example, there are many different types of dwarf tomatoes that produce fruit in small spaces. Most dwarf tomatoes have determinate growth habits (see definitions at bottom of page). I have had success in the past growing ‘Bush Goliath’ tomato in a container. It is a two to three-foot-tall plant with 3 to 4-inch, sweet tomatoes. I have also grown ‘Mighty Mini’ cherry tomatoes in my indoor aerogarden. Considered by many to be the smallest tomato plant, it grows only five to six inches tall, producing sweet salad tomatoes. By the way, the trick to growing tomatoes indoors is good light and pollinating flowers by hand.

  

If you don’t have a container you can actually garden right in the potting mix bags. Purchase potting soil bags at your local nursery or garden center, and cut a few drainage holes in the back side of each bag. Lay the bags flat on the ground, and then cut holes in the top of the bags to make room for the plants. Use a hose to moisten the potting mix, and then add plants. This makes a quick and easy vegetable garden.

Watermelon in 2013 at
Washington Community Garden

For those with extremely limited space, a vertical garden might be the way to go. Vining crops work especially well when trellised up a wall. Other options include bean poles, teepees covered in vines, may poles, or even tomato cages. Vegetables to try include peas, pole beans, squash, melons, cucumbers, pumpkins, and some tomatoes. When choosing the structure, make sure that it is strong enough to support whatever will be grown upon it. Plants loaded down with fruit can become quite heavy. In some situations, dwarf varieties might work better.

Regardless of your gardening style or technique, have fun. Home gardening is quite rewarding and very tasty.

25-foot indeterminate tomato
at Dixon Springs Ag 

Definitions

Determinate and Indeterminate tomato growth habits. Determinate varieties set fruit at the ends of their branches on terminal buds. Once buds are set they stop growing in height, so these plants need little or no staking and generally have a short harvest period. Indeterminate varieties continue to grow and produce leaves and flowers until the first frost and require staking and pruning.

Tomato label terminology. Look for label terms that indicate a tomato plant’s resistance to various diseases: A for alternaria disease resistance, F-fusarium, N-nematodes, T-tobacco mosaic virus, and V-verticillium. This does not mean they are immune to the disease, but rather that they are less likely to get that disease. Also, be sure to rotate your crop for better disease management.

Rhubarb...delicious though sometimes poisonous

We have a freeze warning tonight so it seems like a good time to discuss rhubarb. 

I love rhubarb, but it can be toxic. The leaves of rhubarb are extremely poisonous. They contain large amounts of oxalic acid and should not be eaten. Also, do not feed rhubarb leaves to animals. Rhubarb stalks (stems) are safe to eat, unless the plants are severely frozen. If rhubarb leaves freeze and leafstalks are “mushy” the oxalic acid may have migrated from the leaf blades to the stems. Additionally, frozen leafstalks have poor texture and flavor and should not be eaten.

Also known as the pie plant, rhubarb is a very hardy perennial garden vegetable that grows extremely well here. Rhubarb is available in either red or green stalk varieties. A popular green stalk one is Victoria. More types are available in red including Canada Red with long, thick, extra sweet stalks, Cherry Red with red inside and out, Crimson Red that is tall and plump, and MacDonald with tender skin and brilliant red color.

If you want to start rhubarb, here are some tips. Plant enough for your family. A half-dozen plants should provide enough rhubarb for most families. Plant or divide rhubarb roots in early spring when the plants are still dormant for best results. You can move small plants now, but don’t wait much longer.

Place roots with the crown bud 2 inches below the surface of the soil. Space the roots 36 to 48 inches apart in rows 3 to 4 feet apart. Good drainage is essential. Water new plants properly and keep weeded. Rhubarb doesn’t need much additional care once established. If you want to fertilize, use a complete garden fertilizer such as 12-12-12 granules before growth begins in the spring.

Harvest requires a few rules of thumb. Never harvest rhubarb during the first year of planting or too late in the fall. The plants need upper growth to build up healthy and vigorous to make it through the winter. Stalks may be harvested for 1 or 2 weeks during the second year. By the third year, you should get a full harvest of 8 to 10 weeks.

If seedstalks and flowers develop during the spring and summer, cut them from the base of the plant. This will assure the plants put energy into more stalks and not flowers. Leafstalks are the highest quality in early spring, but can be harvested through mid-summer.

Although considered a vegetable, rhubarb is used as a fruit in pies, tarts, cakes, and sauces. Here are two of my favorite rhubarb dessert recipes. 

Rhubarb Cobbler Dessert

Crust

Blend the following, then press into a square (9x9) pan and bake 15 minutes at 350 degrees. 

- 1 cup flour 

- 5 Tablespoons powdered sugar

- 1/2 cup melted butter

Filling,

Mix the following well. Spread on crust. Bake at 350 degrees for 30-35 minutes. 

- 1 1/2 cup sugar

- 1/4 cup flour

- 3/4 teaspoon salt

- 2 beaten eggs

- 2 cups chopped rhubarb

Easy Rhubarb Cobbler

Fill a 9 x 13 baking dish 1/2 - 3/4 full with chopped rhubarb, add sugar if you prefer sweeter cobbler 

Sprinkle dry white cake mix over the top

Dot with butter every 1-2" across top of dry cake mix

Bake at 350 degrees until butter melts, cake mix is brown, and rhubarb is bubbly (~30 minutes)