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August 2015
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Get the garden ready for the second season

Sow a mix of lettuces in a container for a colorful, edible display. Photo courtesy Ball Horticulture

Sow a mix of lettuces in a container for a colorful, edible display. Photo courtesy Ball Horticulture

Go for it! A second growing season begins now! Many seeds will sprout very quickly because the ground is warm and well, we’ve had plenty of rain. What are the second season-crops to grow? Here are some suggestions. Read the seed packets for even more information.

Arugula. This leafy lettuce-like plant is pretty and adds a nice bite to salads.

Basil. Sowing seeds now will result in succulent, green leaves until frost kills the plants.

Broccoli. Some garden centers will have transplants of broccoli ready for the garden. Broccoli can take several hits of cold temperatures, which just sweetens the taste.

Carrots. Sow seeds now for late fall and winter harvest. For a harvest well into winter, cover the plants with a thick mulch of straw.

Chard. Rainbow-colored varieties are very pretty. The fact that you can eat the chard is sort of a bonus.

Cilantro. This herb goes to seed very quickly and savvy foodies know to sow cilantro seeds every few weeks for a season-long harvest. Remember the seeds are coriander and can be used in pickling.

The caterpillars of swallowtail butterflies feed on the leaves of fennel (pictured), parsley, fennel and other members of the carrot family © blackboard1965/Dollarphotoclub.com

The caterpillars of swallowtail butterflies feed on the leaves of fennel (pictured), parsley, fennel and other members of the carrot family © blackboard1965/Dollarphotoclub.com

Dill. The swallowtails will thank you for planting more dill or ferny fennel. Late-season caterpillars devour the leaves on these herbs and parsley. By planting more, you’ll have enough for you and enough for the caterpillars.

Greens. Just about any of them: Romaine, mesclun, leaf, mache, baby mixes, mustard, spinach and Asian greens. Harvest until a freeze kills the lettuces. You can extend the harvest by covering most greens with a tent of spun plastic row cover or cotton sheet.

Sow the seeds or plant seedlings in the spaces between plants or the vacancies left when summer-grown, declining vegetables, such as tomatoes, are pulled from the garden. Of course, you can always grow the plants in pots, too.

Plants for the wet areas of your landscape

Cardinal flower thrives in areas that stay moist. Hummingbirds love this late-blooming native perennials. Photo courtesy perennial resource.com

Cardinal flower thrives in areas that stay moist. Hummingbirds love this late-blooming native perennial. Photo courtesy perennial resource.com

What with more than twice our normal rainfall the several weeks, we have probable found places in our landscape where water pools or where the soil stays wet.

I thought about this recently when at Cardno Native Plant Nursery in Walkerton, Indiana, for the annual open house. Among the programs was one on native plants for the landscape, which included those for rain gardens and swales.

We may not have a rain garden or swale, but we may have wetter areas of the landscape where plants struggle. Here are some recommendations from Cardno, along with a few others, for native plants that can handle a moist environment.

For sunny areas:

  • Gayfeather (Liatris spicata) gets 2-4 feet tall and has spikes of purple flowers in mid summer. Butterflies and bees like this plant. Tolerates what’s called dry down, when the area drains the soil dries out. Gayfeather is a lovely addition to cut flower arrangements, too.
  • Cardinal flower (Lobelia cardinalis) has vivid red flowers that hummingbirds love. Gets 1-4 feet tall, and does best in areas that stay moist. Blooms in early summer. Tolerates rabbits and deer.
  • Blue flag iris ( versicolor or I. virginica) has slightly fragrant blooms in late spring and early summer. Gets about 2 feet tall and wide. Prefers rich, organic soil. Tolerates dry down and deer.
  • Swamp milkweed (Asclepias incarnata) has fragrant white, mauve or pink flowers atop 4-5 foot tall stems in mid to late summer. Supports monarch butterfly caterpillars and tolerates deer.

For shady areas:

  • Great blue lobelia (Lobelia siphilitica) tolerates full sun but seems to do better when given a little shade. It gets 2-3 feet tall and has stalks of blue flowers mid summer to fall.
  • False Solomon’s seal (Smilacina racemosa or Maianthemum racemosum) has white or cream colored flower on arched stems in spring. In fall, it sports red berries, which are great for use in flower arrangements. The plant gets about 2 feet tall.

 

 

Our summer of rain stresses garden plants

Too much rain is as stressful for garden plants as is drought or extreme heat and cold. Central Indiana has been undergoing an extended rainy period. © Jo Ellen Meyers Sharp

Too much rain is as stressful for garden plants as is drought or extreme heat and cold. Central Indiana has been undergoing an extended rainy period. © Jo Ellen Meyers Sharp

I don’t know about your garden, but part of mine is thriving and another part is suffering.

All this rain has pushed lush growth on hosta, hydrangea, coneflower and a lot of other plants, including weeds. Other plants are suffering with too much water, such as the dogwoods, even though they generally tend to prefer it more wet than dry.

The National Weather Services says June 2015 was the 7th rainiest on record in Central Indiana, with Indianapolis receiving 8.36 inches, 4.11 inches more than normal. Bloomington received 10.57 inches in June, more than twice its normal amount. July hasn’t been any drier. Before mid July, Indianapolis received 4.43 inches, which is very close to the 4.55 inches we normally receive for the full month.

Plants, including trees, shrubs, perennials and annuals, can be as stressed by too much rain as they can by drought. Stressed plants are more susceptible to insects and diseases.

One of the telltale trouble signs of too much water is reddish-streaks on the leaves of trees and shrubs. My native flowering dogwood (Cornus florida) shows the early signs of mildew, a leaf fungus. This has never happened before on these trees. Other symptoms include bleached, yellow or discolored leaves and wilting.

Too much rain can cause red streaks in dogwood (shown) and other shrubs and trees. © Jo Ellen Meyers Sharp

Too much rain can cause red streaks in plants, including dogwoods, such as ‘Cayenne’ (Cornus amomum) and other shrubs and trees. © Jo Ellen Meyers Sharp

It may be difficult to image, but plants suffocate as heavy rains force oxygen out of the soil. The rain also flushes nitrogen and other elements quickly from the soil. Don’t do any supplemental watering, including the lawn when we’re in rainy periods.

Replenish lost nutrients with fertilizers, especially for vegetable plants. Read and follow label directions. And, as we discussed a few weeks ago amid the June deluge, keep an eye open for fungus disease. Pick off any yellow or splotchy leaves from tomato plants, peppers, herbs and other edibles as soon as you see them. Dispose of the diseased leaves in the trash, not in the compost pile. If watering becomes necessary, avoid overhead sprinklers.

Avoid walking on wet soil. Doing so, compacts the soil, which makes it harder for roots to grow and develop. It undoes all the hard work of working adding organic matter to improve the soil quality.

There’s a new Sweet Summer Love in my life

‘Sweet Summer Love’ clematis blooms throughout most of the summer and into fall. © Jo Ellen Meyers Sharp

‘Sweet Summer Love’ clematis blooms throughout most of the summer and into fall. © Jo Ellen Meyers Sharp

A new clematis has stolen my heart.

It’s hard not to be amorous over ‘Sweet Summer Love’, which has been blooming since late June and will continue into September, or maybe October.

This is a new version of the fragrant, sweet autumn clematis (C. terniflora or C. paniculata) without all of its bad habits, such as smothering nearby trees and shrubs and self-slowing, as if there’s no tomorrow. Originally from Asia, this clematis’ overabundance of seedlings and smothering habit landed this white-flowering vine on Indiana’s invasive species list.

‘Sweet Summer Love’ is a fragrant, vigorous vine, and that’s about where the similarities end. It does not self-sow and being true to its name, blooms most of the summer.

'Sweet Summer Love' clematis flowers are about 2-inches wide and fragrant.

‘Sweet Summer Love’ clematis flowers are about 2-inches wide and fragrant.

The flowers are very different, too. Instead of the numerous, but small, 1-inch wide blooms of sweet autumn clematis, ‘Sweet Summer Love’ is flush with 2-inch wide cranberry-maroon flowers. It was introduced by Proven Winners.

This clematis gets 6-10 feet tall and wide, but what I’ve been doing is weaving it back and forth among the arrowwood viburnum branches (V. dentatum) I’m using as a trellis. I removed the viburnum last fall, but saved the nice straight-as-an-arrow branches for reuse in just this manner.

‘Sweet Summer Love’ does not get clematis wilt, a soil-borne fungus disease that affects the larger-flowering clematises, such as ‘Jackmanii’, just as they burst into bloom. (Unfortunately, there’s nothing we can do about the wilt, except cut the plant back. It will regrow and may possibly rebloom.)

Grow ‘Sweet Summer Love’ in full to part sun with average soil. Give it a good drink of water periodically, especially during dry spells. If needed, cut back in late winter, leaving at least two buds on stems coming out of the ground.

As you can see, there’s a lot to love about this clematis.

Stay safe: Use caution when mowing the lawn

Be sure to dress for the job when moving the lawn. Wear substantial shoes and protect your sight and hearing. ©mBaba760/canstockphoto.com

Be sure to dress for the job when moving the lawn. Wear substantial shoes and protect your sight and hearing. ©mBaba760/canstockphoto.com

The other day, I saw a what appeared to be a father and son mowing the lawn. The dad pushed a gasoline-powered mower. The little boy pushed a toy mower and walked right behind his dad.

There’s a lot wrong with this cute image and I’m not even mentioning that the dad was wearing flip-flops.

About 250,000 people are treated annually for lawn mower related injuries, including about 17,000 children, according to the Consumer Products Safety Commission and the American Academy of Pediatrics.

Injuries include cuts, maiming or amputations from mower blades and burns from the engine. People are injured by projectiles, such as rocks and sticks, thrown from the mower. About 90 deaths are attributed to riding mowers that overturn. A 17-year-old Kosciusko County boy was killed in April when his clothing got caught up in the mower he was working on.

AAP recommends that children be at least 12 years old before operating a walk-behind mower and 16 years old to operate riding equipment. Of course, the kids (and adults) need to be trained on how to use the equipment. Here are some other tips for lawn mower safety from the Outdoor Power Equipment Institute:

  • Don’t mow when the lawn is wet.
  • Make sure children and pets are out of the area. It’s best if they are indoors.
  • Clear the area of any objects that could be thrown by the mower or caught in the blades, such as branches, stones and toys.
  • Make sure the mower is operating properly and that guards and safety devices have not been tampered with.
  • Dress properly. Wear substantial shoes, hearing protection and safety glasses.
  • Allow the engine to cool before refueling.
  • Use caution when mowing hills and slopes. It’s easy to lose your footing, which can cause people to slip and fall into the mower blades or engine. Most deaths from riding mowers are caused when the equipment falls over and crushes or runs over its operator.

 

For more information about operating power equipment safely and tips visit opei.org.

When mowing, remember not to remove more than one-third of the lawn blade at a time. If the grass is 4 inches tall, mow to 3 inches. Keep the lawn at 3 to 4 inches to shade the soil, keeping it cool and reducing opportunities for weeds to take hold. Cutting the lawn too short opens it up for sunscald, drought damage and overall weakened condition.

Mid-season tasks for more flowers and veggies

Annabelle and White Dome hydrangeas, blue larkspur and the seed heads of allium form a July Fourth bouquet of flowers cut fresh from the garden. © Jo Ellen Meyers Sharp

Annabelle and White Dome hydrangeas, blue larkspur and the painted seed heads of allium form a July Fourth bouquet of flowers cut fresh from the garden. © Jo Ellen Meyers Sharp

Even though the season of summer just arrived last weekend, the growing season has been upon us for three months.

And with all of the rain the last several days, plants have been on steroids, seeming to be ahead of their usual performance.

Weeds, in particular, seem to be thriving in my yard, and with the heat and humidity, the task of getting them under control is not pleasant. Hostas, too, seem to have emerged bigger and more lush this year. Some of us think this may have more to do with the past winter rather than the current season.

Some plants, especially those in pots, have just rotted off because of the humidity and rain. My sweet alyssum has all but disappeared because of the heat and rain.

What to do:

  • Apply a water-soluble fertilizer to pots, window boxes and other containers. Fertilize vegetables, too. For this, I prefer a granular product. Read and follow the label directions.
  • Give annuals a haircut, especially if they’ve grown leggy. Cut back to tidy up and shape the plant. With the dose of fertilizer, the annuals will snap back in no time.
  • Deadhead perennials. Not only does this tidy up the plant, it encourages the development of more blooms from side shoots.
  • Try to keep weeds under control. Weeds rob desirable plants of the nutrients they need to thrive. Fortunately, weeds are easier to pull after a rain.
  • Monitor for fungus diseases on plants. Fungus causes mildew, fuzzy growth and spotted leaves, as well as root and stem rot. Once a fungus is on a plant, there’s not much to do. Most fungus is opportunistic, which means the right conditions have to be in place for it to occur. If you chose to use a fungicide, always read and follow the label directions. Fungicides, even organic ones, are deadly to bees.
  • Be on the look out for aphids and other bugs. With all the rain, aphids may come calling for their favorite meal –bursts of tender plant growth. Also earwigs and millipedes seem to be abundant this year.
  • If your pots can be viewed from all sides, rotate them periodically to ensure good light exposure for the plants.

Lastly, pick a bouquet of red, white and blue flowers for your Fourth of July celebration and enjoy the holiday.

Downy mildew attacks basil

Downy mildew has taken a toll on basil the last few years. One symptom is fuzzy spores on the undersides of leaves. Photo courtesy Purdue Plant and Pest Diagnostic Lab

Downy mildew has taken a toll on basil the last few years. One symptom: fuzzy spores on the undersides of leaves. Photo courtesy Purdue Plant and Pest Diagnostic Lab

Basil has taken a huge hit over the last few years from a downy mildew, which can quickly decimate a crop in the farmers’ fields, growers’ greenhouses and our gardens.

Downy mildew is the common name for this disease, even though the fungus that causes it may be different, depending on the plant. It gets the name from the symptoms, downy-like fuzz on the leaves.

On basil, the culprit is Peronospora balbahrii. Initially, the leaves turn yellow, and then black spots appear. That’s followed by fuzzy spores on the undersides of leaves. The problem starts at the base of the plant and moves up. The fungus is air borne or can be splashed on plants from infested soil. Plants and seeds can be infected, according to the University of Minnesota Extension, which got its first reports of the disease in 2012.

Here in Indiana, Purdue University has seen only a handful of samples since 2009. “A couple each year,” said Tom Creswell, director of Purdue’s Plant and Pest Diagnostic Lab.

“Most of our reports from the home garden have been from the home garden of Tom Creswell,” he joked. “It seems that if this is showing up extensively in the home garden, then either no one is paying attention or it comes on so late in the season that they’ve already made pesto, or they don’t know they can send samples to the lab for help.”

What can we do?

  • Remove any infested leaves. It’s all right to eat healthy leaves from infested plants.
  • Plant resistant varieties. Sweet basil (Ocimum basilicum) is the most susceptible, which includes Genovese, Nufar, Italian Large Leaf, Queenette, Superbo, Poppy Joe’s and others, according to Minnesota extension. Red Rubin and Red Leaf (O. basilicum purpurescens) and lemon basils (O. citriodorum) are considered moderately susceptible. Blue Spice, Spice, and Blue Spice F1 (O. americanum) are less susceptible.
  • Don’t plant basil in the same spot year after year. If you grow basil in a pot, dump the soil each year and scrub the pot with a solution of one part bleach and nine parts water. Use fresh potting mix each year.
  • Give plants plenty of air circulation.
  • Closely examine basil plants at garden centers to make sure they are symptom free.
  • Consider growing basil from seed. It’s easy and plants comes up quickly.

Lilac trees extend the fragrant season

Lilac tree flowers are as fragrant as their shrub cousins. (C) Jo Ellen Meyers Sharp

Lilac tree flowers are as fragrant as their shrub cousins. (C) Jo Ellen Meyers Sharp

At garden centers, on garden tours, over dinner and in emails, people are asking about a tree with fragrant white flowers.

It’s a Japanese lilac tree (Syringa reticulata), a gorgeous beauty that blooms later than lilac shrubs. The ornamental tree has a rounded to pyramid form and reaches 30 feet or more tall and 20 feet wide. It is considered one of the easiest lilacs to grow.

The 12-inch long, creamy white flowers bloom in June, attracting butterflies, hummingbirds, pollinating insects and human attention. Cardinals, chickadees and finches like the seeds. The tree tolerates clay soil, deer browsing and salt spray.

Japanese lilac tree does best in full sun but tolerates light shade, which may reduce blooms. It needs decent drainage and is considered a good urban tree. You’ll see it planted as a street tree in several Indianapolis neighborhoods, along the Indiana Central Canal, the city of Carmel and other communities. It also makes a lovely hedge, windbreak or seasonal screen.

Good air circulation is recommended, even though the tree is considered resistant to powdery mildew, the plague of many shrub lilacs. It also is resistant to scale and borers, other pests of lilacs. If the lilac tree needs to be pruned, do so within a month after it is done blooming.

There are a couple of cultivars, but ‘Ivory Silk’ is the most widely available. More compact, ‘Ivory Snow’ gets up to 25 feet tall and is a profuse bloomer, usually a little earlier than the straight species of Syringa reticulata.

The seed capsules dry and are abundant enough to provide a bit of fall interest. The smooth, attractive, reddish-brown bark resembles a cherry tree.

For more information about the lilac trees and shrubs, download Lilacs for Cold Climates, a very helpful, free publication by Laura Jull, a horticulture professor at the University of Wisconsin.

Trees and shrubs to consider for your landscape

Native Virginia bluebell form a carpet of blue beneath the yellow Japanese Kerria. (C) Jo Ellen Meyers Sharp

Native Virginia bluebell form a carpet of blue beneath the yellow Japanese Kerria. (C) Jo Ellen Meyers Sharp

If I could only have one perennial for certain situations, such as shade or sun…that’s what we talked about in last week’s column. This week, we’ll look at a few shrubs and trees.

First up is viburnum, a species that has a shrub for about any location. There are several native viburnums that are garden worthy, including arrowwood (V. dentatum) and the American cranberry bush (V. opulus var. americana), sometimes listed as V. trilobum).

But my favorite is burkwood viburnum (V. x burkwoodii), a large, semi-evergreen shrub with fragrant, pinkish-white, waxy flowers in April and respectable leaf color in fall. Although burkwood does best in full sun, mine has been in part sun for years and does just fine. It gets about 8 feet tall and 6 feet wide. The size and the fact that it holds onto its leaves well into winter, make it a good choice for a three-season screen. It is drought tolerant and attracts butterflies and birds. The latter likes the showy fruit, which is not messy.

For deep shade, consider a kerria, sometimes called Japanese yellow rose (K. japonica). My preference is the single flowering kerria, called ‘Simplex’, but there’s a double flowering yellow (‘Pleniflora’) and single white one, too (‘Alba’). In my yard, the kerria gets early morning sun and blooms the same time as my Virginia bluebells (Mertensia virginica) to make a beautiful spring scene.

Kerria does not do well in full sun, which bleaches out the flowers. Arched chartreuse branches brighten the winter landscape. At maturity, it will get 3-6 feet tall and wide, suckering a bit to develop a colony. The suckers can be removed to keep kerria the right size for your space. It tolerates clay soil, dry and wet sites and deer. The flowers are about the size of a quarter and it’s not uncommon for kerria to rebloom in late summer. ‘Golden Guinea’ is slightly smaller than the species.

For a shade tree, I select a thornless honey locust (Gleditsia triacanthos var. inermis) for lots of reasons. The native tree provides dappled shade, which allows grass to grow underneath. The small ferny leaves also blow away in fall, reducing raking duties. This tree can become a problem if the roots are cut or removed, which can promote the growth of sprouts. There are several honeylocust cultivars available. At maturity, the tree will be 30 to 70 feet tall and wide.

If I could only have one perennial for these spots

Epimedium. (C) Jo Ellen Meyers Sharp

Epimedium. (C) Jo Ellen Meyers Sharp

I get asked a lot of the time what my favorite flower is and my response is “whatever is blooming.”

But what if you could only have one of something, what would your choices be? Here are some of my picks:

Hydrangea – the oakleaf (H. quercifolia) would be my choice, but most are very large shrubs, usually in the 6-8 foot tall and wide range. That size is fine for larger properties. Because I have a small yard, I prefer Sike’s Dwarf, Pee Wee or Ruby Slippers, which are closer to 3-5 feet tall and wide.

Native in the southeast United States, oakleaf does best in part shade or dapple shade, but tolerates full sun if given adequate water. It begins blooming in June with white cone-shaped flowers that turn red as they age through the season. The leaves turn a deep, wine red in fall and persist through winter.

Sike's Dwarf oakleaf hydrangea. (C) Jo Ellen Meyers Sharp

Sike’s Dwarf oakleaf hydrangea. (C) Jo Ellen Meyers Sharp

Bishop’s cap (Epimedium), commonly called barrenwort or bishop’s cap, is my choice for a shade-loving perennial. This is nearly a four-season plant, beginning with delicate, wiry flowers in early spring, followed by reddish-tinged, leaves. The leaves are dark green in summer, and in fall, become leathery, deep maroon. I cut this plant back to the ground in February. Epimedium thrives when given adequate moisture, but is tolerant of dryer sites. Start with two vigorous (but not invasive) cultivars: the yellow-blooming (E. x versicolor ‘Sulphureum’) and red (E. x rubrum).

'Magnus' purple coneflower (Echinacea purpurea). Photo courtesy perennialresource.com

‘Magnus’ purple coneflower (Echinacea purpurea). Photo courtesy perennialresource.com

Purple coneflower (Echinacea purpurea) would earn space in a sunny spot. Another eastern United States native species, this long-blooming perennial is favored by bees, butterflies and hummingbirds in summer and in winter, the finches devour the seed heads. There are a lot of garden-worthy cultivars available, but to me, the best performers are the straight species or ‘Magnus’. Somewhat drought tolerant, purple coneflower appreciates a good soaking of water during dry periods. Coneflowers are usually 24-30 inches tall and form a clump about 12-inches wide. They can self-sow a bit, but are not invasive.