Friday, August 29, 2008

Fall is for planting

Everyone thinks of Spring planting but what about Fall? Just about everything you plant in the spring can also be fall planted. And many of our favorite plants must be established in the fall. Think bulbs… and not just the pretty ones, garlic, too.
The reason that fall is such a great planting season is that the soil is warm and we have a very long growing season from September until about Thanksgiving. Think about that… 90 days of growing weather. True, many plants aren’t pproducing much shoot growth. But the roots of many plants continue to function long after shoots appear dormant. Sure, we’ll have a frost in mid-October but most years this is followed by many days of frost free temperatures.
So, thinking about a tree or shrub for the backyard? Now is a great time to get to the garden center and look over the inventory. Many places offer good deal at the end of the season. Pick plants carefully and be sure they have been well cared for during the summer season. Plant as soon as possible, water well and mulch to get them off to a good start. Certain species are known to be difficult to transplant and probable should not be fall planted. Some oaks, magnolias, Stewartia, sweetgum, crape myrtle, hawthorn and hornbeams are best planted in the spring.
When it comes to lawns, fall is the best season for renovation and establishment. Warm soil, cool nights and reduced weed pressure all add up to success. Even lawn maintenance practices such as liming, fertilization and weed control have more bang for the buck when done in the fall.
How about those bulbs? An afternoon spent in October planting bulbs pays big dividends in the spring. Want to see those impressive displays of color like you see in formal gardens and landscapes? Buy bulbs by the hundreds rather than the dozen and your landscape will shine. On-line or catalog prices on these quantities are really attractive. Get together with the neighbors and make a big purchase.
Finally, my favorite…. Garlic. Maybe it’s not the prettiest plant in the garden but this vegetable is easy to grow, stores well and has better quality when home grown than you can buy at the supermarket. Find a garlic supplier in the Northeast U.S and plan to have the bulbs delivered in October. Plant about Columbus Day or even a little later in rich garden soil. You’ll be rewarded about the 4th of July next year.
Fall is for planting. Get to work!

Thursday, August 28, 2008

Japanese Stiltgrass

If you drive along the shady, back-roads of Bucks County you’ve seen Japanese stiltgrass. It is the green grass growing on the road sides. While it provides a pretty fringe to the roadway, this is a nasty invasive plant. One of my early encounters with it was when a naturalist at Bowman’s Hill Wildflower Preserve called about 20 years ago to ask me what could be done to control it. It was crowding out the dainty wild flowers.
Japanese Stilitgrass, Microstegium vimineum, is a summer annual grass that is native to Asia and was probably introduced to the U.S in the early 1900’s. It germinates in early spring and dies each fall when we have a killing frost, surviving only as seed.
Stiltgrass has a lot in common with crabgrass. Same life cycle. In fact, most of the controls used for crabgrass, chemical and non-chemical, work for stiltgrass. Stilt grass appears to be much more shade tolerant than crabgrass which is why it creeps in corm those shady areas and into garden beds and lawns.
Establishing dense, competitive turf is the answer where stiltgrass threatens lawns. . Use a shade tolerant grass species such as fine fescue in shady areas and fertilize to keep it dense. Apply a pre-emerge crabgrass control product in early April to prevent stilt grass germination. In landscape beds, preemerge herbicides will do the trick or you can simply pull and mow it all season.
Unfortunately, in unmanaged areas it will continue to dominate those fringe spaces, crowding out other plants.

Monday, August 18, 2008

Bagworms "Appear"

Yes, it may seem that this bug just appeared but bagworms have been feeding since early June. Most folks don’t notice bagworms until they have devoured most of the foliage of their favorite host plants such as arborvitae and juniper. Bagworms seem to prefer conifers but they are known to feed on more than 125 different plant species including sycamore, honeylocust and elm. Bagworms can be deadly to some plants. Evergreens that are defoliated do not recover. Deciduous plants can tolerate the feeding much better.
It is important to realize that the treatment time for this insect has passed. You may have the urge for revenge… but hold off. You can get ‘em next year when they are vulnerable.

Here’s a quick review of the bagworm life cycle. Right now they are mature larvae (caterpillar form) encased in a cocoon-like “bag” made up of parts of the plant they are feeding on. Soon, they will stop feeding and pass into a resting stage (pupae). Later this summer the moth-like adults emerge. Actually, only the males leave the bag. Females lure in the males, mate and then die, leaving 500-1000 eggs to overwinter. So, some bags that you see from September through Spring are empty. These are remnants of male bagworms. Some contain eggs… remains of the female insects.

About Memorial Day, 2009, we can expect the little buggers to hatch. They begin feeding in June but go un-noticed by most folks as they blend into the background of the plants they are feeding on. But this is the time to drop the hammer on them. By mid -June most of the eggs should have hatched and small larvae are feeding. The biological insecticide called Bt can be effective if your timing and spray coverage is good. Conventional insecticides such as carbaryl (Sevin) and synthetic pyrethrins are also effective. So, if you have signs of bagworm feeding, mark your 2009 calendar for Flag Day and plan to treat then.
What? You want to pick off all of the bags. OK. Have fun. But don’t call me if you off the ladder. Seriously, hand picking is OK but your chances of getting them all are slim. There is some gratification in hand picking but it ain’t worth breaking a leg.

PS Photo by Sarah Pickel, PA Department of Agriculture. Look closely and you can see the pupal case protruding from the open end of the bag.

Friday, August 8, 2008

Your lawn has never looked worse

Your lawn has never looked worse… and you can consider that a complement. What I mean is that your lawn may look a bit ragged about now, but that is normal. Most of the grass species we use for lawns, such as Kentucky bluegrass, perennial ryegrass and the fescues are “cool season” grasses. They thrive under cool moist conditions and go dormant or are very stressed under hot temperatures and drought stress. So your expectations should be low in mid August. That lawn has been struggling for months. OK, those of you with irrigation systems can expect more green but most of us aren't in that boat.

But as day length shortens, temperatures moderate and rains replenish soil moisture… lawns ought to perk up. September is a great time to re-seed patches of turf that just couldn't take the stresses of summer. Plan now for reseeding. If you have large areas that have petered out, consider hiring help or renting a slit-seeder to re-seed. Soil-seed contact is essential. If you simply toss seed onto the bare areas you are just feeding the birds. If you have very small areas to re-seed, scratch them up with a stiff rake before seeding. Firm the seed bed after seeding.

Whether you are re-seeding or not, September is an important month to fertilize. An application of 10 pounds of 10-6-4 fertilizer per 1000 square feet, or its equivalent from other nitrogen sources, is a very good way to encourage growth that will repair summer’s damages.

Other fall lawn care includes liming and broadleaf weed control. Stay tuned for more on that subject. For tips on renovating a really lousy lawn, check out this Penn State resource.

Tuesday, August 5, 2008

Zukes Croak... Squash Vine Borer

Help! My zucchini are dead!

Many people will tell you that zucchini are a fool proof crop but not so for me. Each year, squash vine borers kill my zukes in early August. This insect bores through the stems and wrecks the plants plumbing, resulting in wilted and then dead plants. Squash vine borer problems are easy to diagnose. The stems, at ground level, are an unsightly mess of chewed plant bits. Yellow frass (caterpillar crap) often oozes from wounds. Dig around in the stems and you’ll find a nice fat larvae, eating the stems from the inside out. Plants wilt because the water conducting tissue of the plant is destroyed.
Plants will limp along, partially damaged for a long time, but they eventually wilt and die. No more zukes. By this time maybe you’ve had enough squash or your perhaps neighbor’s crop is just coming on.
What can be done?. I haven’t tried the frequently describe method of slitting open the zuke stems and stabbing the squash vine borer larvae with a wire. Done early enough this might work. A sure-fire method is to apply an insecticide at the base of the plant stems where female squash vine borers lay their eggs. Most over the counter vegetable insecticides will do the job. Apply in late June and early July and you should kill the larvae that hatch from recently laid eggs. Note that the entire plant does not need to be treated, just the stem, where it enters the soil.
It’s too late for insecticide treatments this year. So, make a note in your garden journal and prepare for 2009. Check out Penn State’s football rival, Ohio State, for a very thorough description of this pest and all of the control options.