Extension Educator, Local Food Systems and Small Farms
Extension Educator, Horticulture
May 27, 2010
We are now in the middle of the correct planting time for the warm loving vegetables for our gardens. This would include lima beans, cucumber, eggplant, melons, peppers, summer squash, winter squash, and pumpkins. Pumpkins for use as fall ornamentals should be planted around Father's Day so they have less chance of rotting before fall display. Believe it or not, we're at the proper timing for fall garden plantings as of this coming weekend. That means potatoes, kale, and some others. Some of the planting dates overlap this time of year. That basically means plant it, but you can expect harvest to be closer to fall.
Keep pruning flowering shrubs after they complete bloom. That will allow for more flower buds for next year. Coming up the end of June will be the pruning time for evergreens.
Bagworm spray time will be coming up mid-June. We'll try and fine tune the date as we get closer. The cool spring has delayed things to this point, but warm weather could catch us back up to the book timing of June 15.
May 27, 2010
West Nile Virus (WNV) has, unfortunately, become a household phrase. WNV was first isolated in Uganda, Africa. It can harm humans, birds, and other animals. It is transmitted by infected mosquitoes, primarily the northern house mosquito. The mosquito becomes infected after biting wild birds that are the primary host of the virus. The mosquito is actually able to transmit the virus after 10-14 days after biting the infected bird.
The mosquito life cycle has four life stages (egg, larvae, pupa, and adult). The female mosquito lays eggs on water or moist soil. Most of the larvae hatch after 48 hours and the larvae and pupae live in the water. The females need a blood meal before they can lay eggs, so only the females bite. They bite every few days during their adult lives, which may last several weeks.
Preventing mosquitoes is a first step. Homeowners can best accomplish this by eliminating standing water. Tires and old containers are obvious places to start, drill holes in the bottom of recycling containers, clean clogged gutters, don't allow stagnant water in anything such as birdbaths, change landscape slopes to eliminate standing water, and use larvacides in standing water that can't be eliminated. B.t. Israeli is the strain that is effective against mosquito larvae – not the B.t. variety commonly used on trees and gardens! The mosquitoes have already begun hatching, so treatment time is at hand.
Also protect yourself from bites. Mosquitoes can travel up to three miles from their breeding sites! Make sure that screens and doors are tight, use proper outside lighting such as fluorescent lights, stay indoors at dawn and dusk when mosquitoes are most active, wear long-sleeved shirt and long pants when you must go outside, and use insect repellents properly applied. Exposed skin should be sparingly treated with a repellent containing up to 30% DEET (up to 10% for children), and make sure to treat thin clothing as well (since mosquitoes can bite through the thin clothing).
May 27, 2010
After viewing some of the maples trees with poor looking leaves, it appears many started with wind damage from the hard blows of a few weeks ago. There is some diseases starting in them, but the predominant damage was from drying out and tender leaf material being torn. There are new leaves starting to appear on some of those trees now. Cross your fingers and hope they escape the anthracnose.
May 19, 2010
With the widely fluctuating amounts of rainfall, blossom end rot is definitely a possibility. The best solution is to mulch tomato plants to help even out the moisture supply, and help keep the roots cooler. This problem is caused by uneven calcium amounts in the plant. Addition of lime when you see the problem usually isn't as effective as evening out the moisture flow for the plant by mulching. Any material will do (grass clippings, straw, commercial mulch, etc.) with two inches being adequate and four inches being better. You may have to compensate with a small amount (emphasis on small) if you use items which decompose quickly – such as grass clippings.
May 19, 2010
As mentioned last week, fungal leaf diseases were present. They are now making their presence felt with a vengeance. These diseases infected trees and shrubs earlier, and they have continued to develop rapidly. Adding insult to injury, we had the extremely high winds affecting the tender leaf tissue, especially on maple trees. Some trees are now to the point of being, well, leafless.
Anthracnose is the number one fungal disease of good quality shade trees, and apple scab is starting to hit apples and crabapples. To give a brief overview, these diseases are preventable but not curable. They are seldom life threatening to the tree or shrub, but they can make things look rather unsightly. Many shade trees losing a large percentage of their leaves will often set another set of leaves within four to six weeks. Apples and crabapples are less likely to set another set of leaves, but it sometimes happens.
Anthracnose has different stages depending on the time of infection. There is a bud stage, where buds are killed as they begin to open. Next is a leaf stage, which affects only leaves. This stage is the one we are commonly seeing, and it infects leaves and gradually consumes the leaf. And the other stage is the twig stage which affects smaller twigs on trees and shrubs. This is one reason why sycamore trees tend to have so many small branches break. The infection leaves a brittle scar on the branch which makes it susceptible to breakage. There is actually a specific anthracnose disease for each shade tree. This means sycamore anthracnose, maple anthracnose, and so on.As I mentioned, once infection has occurred it can't be cured. The prevention part needs to begin with a regular spray program similar to production apples. This means starting when the leaves are just out of the bud in the early spring. The same kind of timing applies to ornamental trees. The main harm caused is the loss of food produced by the lost leaves, and the loss of energy to set another set of leaves. Fertilizer application at the lawn rate, to supply a pound of nitrogen per 1,000 square foot broadcast, will help the tree as much as anything.
May 19, 2010
If you have been following a foundation spray program all year, keep it up. If you haven't been, it is probably time to start. The foundation spray program is your first line of defense against nuisance pests in the house. It cuts down on crickets, millipedes, spiders, ants, and many others that find their way inside. And, with the crickets singing, it's only a matter of time before they find their way into your abode.
To accomplish a foundation spray, you would select a material such as permethrin or bifenthrin to begin with. Then spray the foundation and the adjacent foot or two of soil or plant material with the spray mixture. Both these products are cleared on most types of plants. Foundation treatments should be applied every 7-15 days depending on the temperatures. The materials break down quicker in hot weather.
Foundation treatments won't prevent everything from getting in the house, and they certainly won't kill things already in the house. For insects already in the house, you have a few options. The first is mechanical control. This is fancy language for something like a flyswatter, shoe, vacuum cleaner, flypaper, or glue boards. The next is chemical control. This basically means aerosol cans inside the house. The most common ones are for flying insects or ants, although many of the flying insect killers now have permethrin in them and can last quite a while.
May 17, 2010
May 17, 2010
We have had a relatively dry spring thus far in our area. This would indicate we should have less anthracnose in our good quality shade trees, but the damp period only needs to last a matter of hours. Currently most trees and shrubs have leaf problems. These can be from diseases such as anthracnose, injury from high winds and blowing debris, herbicide drift, or a combination of all the above.
In the case of anthracnose on shade trees, or apple scab on production and ornamental apples, one of the big things is the weather. This disease will continue to infect with night time temperatures below about 65 degrees and some wet weather. Granted, we have had nothing like the last two years, but we have had some wet weather. Symptoms include browning along the leaf margins and between the veins. The diseases often occur where there is less air movement such as the lower portions of the tree and toward the main trunk.
High winds have also dried things out and physically damaged tissue on tender leaves. Drying tissue also occurs along the leaf edges and between veins which carry water to the leaves. A good indicator of damage of this sort is having worse symptoms on one side of the tree, where the wind was directly hitting the leaves. Another way to check would be if you had a similar tree planted in a very protected location, then you could compare the two trees.
Herbicide drift is abundant again this year. Drift frequently occurs when we have hot, sunny conditions and experience vapors coming up off of treated areas. Not all the drift problems are initiated in a field across the road. Growth regulator herbicides can vapor drift for up to a mile and a half. These herbicides include 2,4-D, MCPP, and dicamba. These are used on corn fields, but also on lawns, ditches, pastures, and many other places. Injury can also come from your own lawn if you treated for broadleaf weeds, even using a weed and feed product. Sometimes the damage isn't from vapors, but can be from a heavy rain actually taking the product into the soil where it is taken in by the roots of trees and shrubs. Most herbicide injury would appear as distorted growth, including cupping, curling, or elongation of leaves.
What we are dealing with in many cases is the three-part whammy. There are disease symptoms, evidence of wind (environmental) damage, and evidence of herbicide injury as well. In all cases, there really isn't much you can do but wait it out. Water during dry periods to make sure there is adequate moisture. I wouldn't even fertilize, since that can make some herbicide drift situations worse with the growth regulators being encouraged. In most cases, there will be leaf drop. As long as there are good buds remaining, a new set of leaves should appear in four to six weeks. Some trees have shown dead tips this year. Those won't come back, but there will be additional growth from just below the dead areas.
May 5, 2010
Right now, people are noticing feeding damage on rose bushes of all types. On close inspection, many have found small, green, caterpillar-like insects. These are actually the larvae of small wasps, and they do feed on roses. It doesn't matter if the rose is a knock-out, a hybrid tea, or a standard.
Since these are not "caterpillars," Bt products for larvae of moths and butterflies won't work. Try Sevin, bifenthrin, or permethrin as chemical controls. Insecticidal soap properly applied should also give good control.
May 5, 2010
We are approaching the planting time for warm-loving vegetables, which is May 10 through June 1. These would include Lima beans, cucumber, eggplant, melons, pepper plants, sweet potato slips, pumpkins, and squash. You can also put out successive plantings of snap beans, beets, carrots, and sweet corn to extend the season.
May 5, 2010
Here is a listing of common borers and their control times: Ash borers (early June and early July), Bronze birch borer (mid May and repeat two times at two week intervals), Dogwood borer (mid May and mid June), Flatheaded apple borer (late May and repeat in three weeks), Lilac borer (early June and early July), Locust borer (late August and mid September), Mountain ash borer (early June and mid July), Peach tree borer (mid June and mid July), Viburnum borer (early June and early July), and Zimmerman pine moth (April or August). The Emerald ash borer, although not confirmed in our area at this time, control time in Michigan begins mid May and runs through mid July.
The product of choice for many borers is now permethrin, since Dursban is off the market. Imidacloprid is fairly new on the market. One trade name is Merit (sold for homeowners as Bayer Advanced Garden Tree and Shrub Insect Care). This product use rate is an ounce per inch of circumference of the tree trunk. You then mix it with three gallons of water and pour around the base of the tree. It may take a few months for it to translocate though the tree. A good time to apply it is in early spring when the sap rises. These treatments need to be completed by late May to have a chance of getting the current season borers. Each treatment lasts about a year. Fruit trees generally are treated differently with Sevin, or just using the regular spray program due to the possibility of residue in fruit.
Zimmerman pine moth is one of those "kind of borers." It generally affects only severely weakened trees, and goes just under the bark to girdle the cambium layer. It seems like older Scotch, red, and Austrian pines are favorites when they begin to decline. Bird damage from yellow bellied sapsuckers on trunks and main limbs also looks like borer damage to many. This bird damage is easily recognized by the evenly spaced holes in a straight line.
May 3, 2010
Call them buffalo gnats, black flies, and other unmentionable names, but they are back. The small flies, or gnats, are hatched in clean, running water. This is one indicator our water protection plans are succeeding. They will continue to hatch until water temperatures hit about 75 degrees. They will also travel up to 10 miles in search of a food source, meaning blood.
These insects can produce serious welts when they decide to bite. They tend to be worse during the day, and are seldom a problem inside buildings. In addition to people, they tend to attack birds. Young poultry and wild birds are especially vulnerable.
Control is difficult. Sprays of malathion, permethrin, or bifenthrin will help with controlling the buffalo gnats when outdoor activities must be held in infested areas. Dusts of permethrin will also help with outside poultry operations. Repellents of DEET, citronella, and vanilla may also provide some relief. Remember, only the females bite. When the bite occurs, a chemical is injected to help with blood flow. This is often the reason for the painful welts, usually on the face. Children also seem to be bitten, and affected, more than adults. The gnats seem to be attracted to white clothing. Navy blue seems to be their least favorite color.