July 28, 2015, Kim’s Weekly Garden Newsletter © Kim Willis
Well we can safely say summer weather has arrived. I don’t like hot humid weather one bit. Some plants thrive in it though, but some plant diseases also love this weather and can become a problem. I write about two of them below. Make sure to keep hanging baskets and container plants well-watered in the heat. You may have to water twice a day, I know I sometimes do.
It’s almost August- can you believe that- and gardens are at their color peak. I have some huge volunteer sunflowers in bloom, zinnias and dahlias are blooming and the wild Jewelweed is now providing lots of tiny flowers for the hummingbirds and bees. My larger tomatoes are ripening and the sweet corn has ears. I have harvested several cabbages and some carrots. Blackberries and raspberries are ripe.
I was enthusiastic about my solar fountain pumps earlier in the season but I am not so happy now that both have quit working. One quit after two weeks, the other quit yesterday after maybe 6 weeks of work. These were inexpensive but if you have to replace them several times a season you might as well buy something more expensive.
Milkweed is blooming in my fields but I have yet to see more than the one Monarch butterfly I saw early in the summer. The swallowtail butterflies are fewer this year too. Toads and frogs are abundant this year but at my house we have only seen one turtle this summer and no snakes. I think the last 2 winters have been very hard on them.
Late Blight in Michigan ( tomatoes and potatoes)
According to the MSU Late Blight monitoring site there has been confirmed cases of late blight in potato fields in Montcalm County which is on the west side of the state. When late blight is found on potato fields, there is a good chance tomatoes will soon be affected. The conditions will be excellent- warm and humid – for late blight for at least the next week. The site predicts most of the state will have an elevated risk of late blight development during the next few days.
|USDA Blight Leaf and stem images courtesy of Meg McGrath, Cornell University |
and tomato fruit image courtesy of Jean Ristaino, NC State University.
Symptoms of late blight include a blackened, water soaked or greasy look to leaves, stems and tomato fruit or potato tubers, with rapid wilting and death of the plant within a few days. The blackened areas may look brown at first, and often have white fuzzy looking growth (fungus) on them. Check the backs of darkened leaves to look for white fungal growth. Tomato fruits that are green or ripe can be affected with hardened brownish black spots. Most other tomato diseases take a long time to kill a plant and the plants keep putting out new growth. Late blight spreads from plant to plant very quickly so in warm, wet weather home gardeners should check their plants daily for symptoms.
Many other tomato diseases have similar symptoms and home gardeners may have a hard time deciding if their plants have late blight or a somewhat less serious fungal disease. It is hard for home gardeners to find somewhere to get a good diagnostic report done on a sample of your plants. If your county still has an Extension office with a horticulture department you can try there or you can take a sample to MSU’s plant and soil diagnostic clinic in East Lansing. There is a fee for diagnostic work there. For accurate diagnoses the sample must be picked fresh, with symptoms showing on foliage and or fruit and brought to the lab within a few hours.
Here’s the contact information:
578 Wilson Rd., Room. 107 East Lansing, MI 48824-6469
Phone: (517) 355-4536 Fax: (517) 432-0899
There is little home gardeners can do to prevent late blight other than to begin spraying your potatoes and tomatoes with fungicides before the plants are affected. After symptoms begin spraying won’t help that plant and it should be pulled and put in a plastic trash bag including all fruit and leaves that fall off. Tie the bag tightly and send it to the landfill or let it sit in the sun for several weeks and then burn the residue. The only preventative sprays effective that homeowners can easily get are those with Chorothalonil and some copper based fungicides. Look for a garden fungicide, check the ingredients and make sure it lists late blight as being controlled. Follow the label directions exactly. Also water early in the day so foliage dries before nightfall. Don’t eat tomatoes or potatoes with late blight lesions or can them.
This hot humid weather is sure to bring on Black Spot in roses if you aren’t protecting them with sprays or growing resistant varieties – Here’s an article on Black Spot.
Black Spot on roses
One of the most common diseases of roses is Black Spot. Black spot is a disease caused by the fungus, Diplocarpon rosa. It is extremely common in older varieties of tea roses but when conditions are right even roses marked as resistant to Black Spot can develop a mild case of the disease. Warm humid conditions, especially when there are heavy dews or the foliage stays wet overnight are the prime times for Black Spot to develop.
Black Spot causes black spots on the upper surfaces of rose leaves, surrounded by a yellow area. If the fungus is heavy the leaves may look almost totally yellow, sprinkled with black spots. Rose flower petals may show streaking, red spots or distorted areas. Infected leaves soon drop off the plant. The plant struggles to put out new foliage and this weakens the plant and reduces blooming. Infected plants may not survive the winter as well as those with mild or no infection. And half bare, yellow leaved plants just aren’t very attractive.
Black spot overwinters on rose leaves on the soil or on the rose canes. Rain and wind move the spores to new foliage on the roses in the spring. When conditions are right, (warmth and humidity), usually about June, the fungus germinates and infects the rose.
How to control Black Spot
|Black Spot on roses|
If you have had problems with Black Spot in the past or your area experiences lots of humid, hot weather you’ll want to plant roses with resistance to Black Spot. Some modern shrub roses have pretty good resistance to Black Spot and rarely require treatment. Even some tea roses have recently been bred that have some resistance. Older roses with resistance are the gallicas, rugosa’s and albas. If you don’t like chemical spraying choose resistant varieties and hope for the best.
Resistant varieties are not immune to Black Spot. In really heavily infested areas and ideal conditions even resistant roses may get Black Spot. Some resistant varieties perform better in some geographical areas than others. If one variety of rose always seems to get infected in your garden try another rose or at least another location in the garden.
Other ways to control black spot are to remove all rose leaves from under the plant in the fall or early spring before the plant leafs out. During growing season pick off any yellowed or spotted leaves and remove those that fall on the ground as soon as you see them. Don’t crowd the roses, they need good air circulation and roses against buildings or with hedges behind them may have more problems with black spot.
Water your roses at the base, trying not to wet the foliage and do so early in the day so the foliage dries before evening. Keep roses healthy by planting them in full sun and regularly fertilizing them as roses are heavy feeders. You’ll also want to control rose insects such as rose chafers and Japanese beetles as these weaken the plant and make them more susceptible to damage from black spot.
There are many chemical controls for Black Spot and other fungal diseases of roses. If you are going to use fungicides begin spraying in June or as soon as you see even one infected leaf. If you want nice looking tea roses you will probably want to start a spray schedule soon after the plants leaf out. Follow label directions and keep up the schedule for best results. The sprays don’t help already infected leaves but they do help new foliage stay healthy to make food for the plant.
The Consumers’ Association Magazine put eight fungicides to the test between April and October last year to combat black spot on roses. The products they found did the best job were Bayer Garden Systhane Fungus Fighter Concentrate, Scotts Fungus Clear Ultra, and Bayer Garden Multirose 2 Ready-to-use.
The test was conducted on a variety of modern rose called ‘Silver Jubilee’ which has some resistance to black spot. Black spot was noticed in June on the roses and treatment according to label directions was begun. Some roses were left untreated as a control. The researchers found that any chemical product was better than no treatment. There are organic treatments on the market but many of these do little or nothing to control fungal disease.
Beware of so called “home remedies” for Black Spot on roses. Soap solutions do not work on fungal disease. Alcohol, peroxide and other odd substances may actually harm roses, and you won’t see the experiences of the people who have had that happen in the advertisements for books and magazines listing these miraculous cures.
With the many disease resistant varieties of roses on the market and a little tolerance for less than perfect foliage almost everyone can grow roses, even without chemical sprays. Don’t let the fear of Black Spot or other rose diseases keep you from enjoying them in your garden.
Another reason to avoid soybean oil
New research done at the University of California, Riverside, found that when animals were fed soybean oil as their source of fat, they had a 25% higher increase in weight, more insulin resistance and liver damage and developed fatty liver and diabetes more often than animals fed coconut oil as a source of fat. The amount of soy oil added to animal diets was calculated so that it was the dietary equivalent of the amount of soybean oil consumed by the average American. Both diets had the same percentage of fat and calories.
When fructose was added to both diets the animals with soybean oil and fructose were the least healthy, adding kidney and bowel diseases and cancer to the other health problems. When fructose was added to the coconut oil groups diet it did increase weight gain by 9% but effects like diabetes and liver problems still remained lower than the soy and fructose group.
Researchers point out that the rise in obesity and diabetes in the US correlates strongly with the rise in consumption of soybean oil in the US and that the rise in use of high fructose corn syrup may have exacerbated certain disease problems. Certainly the combination of soybean oil and fructose is not healthy. Research is going to continue, comparing other fats like lard and olive oil to see their effects on health. My bet is that olive oil will be found to be healthy- no surprise there, but that lard will also be found to be healthier for you than soybean oil.
Currently 60% of the edible oil used in products or for cooking in the US is soybean oil. If you look at food labels of processed foods you’ll find soybean oil in a large percentage of them. Salad dressings are almost always made with soybean oil so you are dousing a healthy food with something very bad for you. If you are concerned about weight gain, diabetes, and liver disease you should be avoiding all sources of soybean oil.
Pot for pain
A new research trial at the University of California San Diego found the inhalation of cannabis (marihuana) helped ease diabetic nerve pain in patients that weren’t getting relief from prescription pain killers. The side effects were that patients got happy and sleepy.
Cosmos- light and lively summer charmer
No, we aren’t talking about the ladies magazine or the vast universe but rather a delightful annual flower that can light up the summer garden. Cosmos are unusual because the common name and scientific name are the same, although Cosmos is the genus name and there are several species. Cosmos bipinnatus is a common garden species, but many cosmos species have been hybridized to make some garden varieties. Cosmos atrosanguineus, often sold in catalogs as chocolate cosmos or chocolate daisy is thought to be extinct in the wild.
Cosmos are native to Mexico, South America and the southern United States. It is thought that Spanish priests growing them in Mexican named them because of the orderly spacing of the petals – cosmos refers to “orderly universe” in Greek or Latin. Most garden species are annuals but some perennial species exist. In many places around the world Cosmos have naturalized or gone wild. Cosmos will grow in poor, dry soil and are easy to grow. They are excellent for children’s gardens, cottage style and informal beds and also attract butterflies and bees. Cosmos are good cutting flowers too.
The Cosmos bipinnatus plant and related cultivars has fine, narrow leaves that occur in pairs along the stem, giving them a lacy or ferny look. Their flowers generally occur in pastel colors, rose, lavender and white. Cosmos sulphureus or the yellow cosmos has broader, lobed leaves. The colors of this cosmos and its cultivars are hot colors, red, orange and yellow. Cosmos range from about 2 feet to 4 feet or so tall, depending on the variety and growing conditions.
All cosmos flowers are daisy like, with a yellow center and colored petals surrounding the disk. Some ornamental cosmos have the petals rolled into a quill or “shell” shape. There are now cosmos flowers that are bi-color or streaked. Cosmos begin blooming in mid-summer, as the days begin to shorten and with a little deadheading will bloom until frost.
Some varieties of cosmos are ‘Seashells’ – a mixture of pastel flowers with rolled or quilled petals, 'Candy Stripe' which is white with red streaks, 'Day Dream' is white with a red center, 'Picotee' has white petals with red edges, ‘Antiquity’ comes in shades of dusky pinks and mauves, ‘Double Take’ is a lovely double flowered form white , with red or pink stripes, ‘Double Click’ has double flowers in soft pinks, ‘Bright Lights’ is a mixture of hot colors, ‘Sensation’ is a mix of pastel colors. A cultivar of the chocolate cosmos, Cosmos atrosanguineus is ‘Choca Mocha’ which is a deep chocolate color.
Cultivation of cosmos
You can sometimes find started plants in the spring but cosmos are very easy to grow from seed sown directly in the garden. Simply sprinkle the seeds on bare moistened soil where you want them to grow after danger of frost has passed and lightly cover them with soil. Plants grown from seed will often bloom at the same time as plants set out as transplants because cosmos don’t bloom until the days are getting shorter. Thin seedlings to about a foot apart.
Cosmos will thrive in almost any soil and can tolerate some drought, although they appreciate some watering when it’s really dry. They need full sun. Moderate fertilization, such as a timed release flower food mixed into the soil at planting, may increase the number and size of flowers but it may also cause the cosmos to “flop” which they are somewhat prone to anyway. They are best mixed in among sturdier plants that help support them or planted in a dense group to help them support each other. Cosmos have few insect pests or diseases and will generally flower reliably for you.
Deadheading- removing the flowers as they fade- keeps the cosmos plant blooming longer and encourages it to produce flowering side branches. As frost approaches you may want to let some flowers alone and collect the seeds that form. Or you can let the seeds fall in the garden, which some seem to do anyway, and they will usually sprout when the weather warms. Be watching the area for the tiny seedlings next spring and don’t pull them thinking they are weeds.
If you need a tough, easy flower to add late summer color to the garden try some cosmos.
Eastern Michigan State Fair
If it’s not too hot this week I may visit the Eastern Michigan State Fair, Imlay City, Michigan. It starts today, July 28 and runs through Saturday, August 1st.. The Lapeer Master Gardeners have a building there you might want to visit. There won’t be any poultry there this year because of avian flu but there will be other farm animals, fair food, rides, grandstand events, a circus and so on all for one low admission price, free parking. Admission is $15 except for Tuesday and Wednesday when its $10 until 2 pm.
“One of the pleasures of being a gardener comes from the enjoyment you get looking at other people's yards.”
― Thalassa Cruso, To Everything There Is a Season: The Gardening Year
“He who has a garden and a library wants for nothing” ― Cicero
Events, classes and other offerings
Please let me know if there is any event or class that you would like to share with other gardeners. These events are primarily in Michigan but if you are a reader from outside of Michigan and want to post an event I’ll be glad to do it.
Master Gardeners if you belong to an association that approves your hours please check with that association before assuming a class or work day will count as credit.
Do you have plants or seeds you would like to swap or share? Post them here by emailing me.
An interesting Plant Id page you can join on Facebook
Here’s a seed/plant sharing group you can join on Facebook
Here’s a facebook page link for gardeners in the Lapeer area
Here’s a link to classes being offered at Campbell’s Greenhouse, 4077 Burnside Road, North Branch. Now open.
Here’s a link to classes and events at Nichols Arboretum, Ann Arbor
Here’s a link to programs being offered at English Gardens, several locations in Michigan.
Here’s a link to classes at Telly’s Greenhouse in Troy and Shelby Twsp. MI, and now combined with Goldner Walsh in Pontiac MI.
Here’s a link to classes and events at Bordines, Rochester Hills, Grand Blanc, Clarkston and Brighton locations
Here’s a link to events at the Leslie Science and Nature Center, 1831 Traver Road Ann Arbor, Michigan | Phone 734-997-1553 |
Here’s a link to events at Hidden Lake Gardens, 6214 Monroe Rd, Tipton, MI
Here’s a link to all the spring programs being offered at Seven Ponds Nature center in Dryden, Michigan. http://www.sevenponds.org/education/progs/springprograms/
Here’s a link to events and classes at Fredrick Meijer Gardens, Grand Rapids Mi
http://www.meijergardens.org/learn/ (888) 957-1580, (616) 957-1580
Garden Day 2015, August 1, 2015, 8 a.m. - 4:15 p.m. Veterinary Medical Center / Plant & Soil Sciences Bldg., MSU campus, East Lansing, MI
This is MSU’s horticulture departments annual garden seminar. The public is welcome. Key note speaker is Rick Darke, a widely published author, photographer, lecturer and consultant focused on regional landscape design, planning, conservation, and enhancement. You get a choice of 2 other classes and a closing speaker also.
Cost is $85.60 for non-2015 Garden members prior to July 24, $95.60 on and after July 25th this includes lunch but not the evening reception.
Please visit www.hrt.msu.edu/garden-day-2015/ for a full schedule, workshop descriptions and more. Contact: Jennifer Sweet, CMP, CTA, at 517-355-5191 ext. 1339 or email@example.com.
MSU Plant Trial Field Day, August 4, 2015, 8:30 a.m. - 2 p.m. 1066 Bogue Street, Plant & Soil Sciences Bldg. (1st floor), East Lansing, MI 48824
Commercial growers, landscapers and advanced gardeners are invited to this annual event to learn about some of the superior new plants and how they perform in mid-Michigan in the MSU Trial Gardens. Plant performance, ornamental characters, and special needs of plants will be covered. We will also host presentations on the most recent research on the development and spread of impatiens downy mildew and up-to-date discussions on the evolving ethics of American gardeners. For this important and timely topic, Entomologists and Horticultural Extension Specialists will bring us up-to-date on the latest news in pollinators, native insects, and pesticides such as neonicotinoids.
The $42/person registration fee (by July 30) includes morning refreshments, lunch, parking, trial booklet, and the program.
For more, please visit http://planttour.hrt.msu.edu/fieldday.
Contact: Jennifer Sweet, firstname.lastname@example.org
If you would like to pass along a notice about an educational event or a volunteer opportunity please send me an email before Tuesday of each week and I will print it. Also if you have a comment or opinion you’d like to share, send it to me. Please state that you want to have the item published in my weekly notes. You must give your full name and what you say must be polite and not attack any individual. I am very open to ideas and opinions that don’t match mine but I do reserve the right to publish what I want.
I write this because I love to share with other gardeners some of the things I come across in my research each week. It keeps me engaged with local people and horticulture. It’s a hobby, basically. I hope you enjoy it. If at any time you don’t wish to receive these emails just let me know. If you know anyone who would like to receive these emails have them send their email address to me. KimWillis151@gmail.com