Thursday, October 14, 2004
Apples, lime, chickweed, yellow jackets and stumps
John Arbogast
Landscape consultant John Arbogast answers your questions every Thursday. Send questions about your lawn, garden, plants, or insects to:
Dear John
5102 Greenfield St. SW
Roanoke, Va. 24018
Or send an e-mail. Answers will be given only in this column. Please don't send pictures or samples.
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Q: (1.) Why did three of my apple trees make no fruit while four apple trees did? (2.) I fertilized my lawn this fall like you recommended and am wondering what do I put on it in the spring to keep it green and to kill weeds? (3.) When is to best time to put lime down? (4.) What is the best chickweed killer and why was there so much of this weed this past spring?
A: (1.) The age of apple trees can prevent production. Dwarf apple trees normally must be at least 4- to 5-years-old before they make apples. Semi-dwarf and standard apple trees must be older than that. Another possibility is that many apple varieties need pollen from at least two other varieties in order to produce apples. A few apple varieties need only one other variety, as does my favorite Golden Delicious Apple.
(2.) Apply most any lawn fertilizer only at half strength to a bluegrass or fescue lawn in May to improve the late spring color. Unless we have a very wet winter that washes nutrients down into the subsoil below the grass roots, the fertilizer applied in the fall should carry a bluegrass or fescue lawn through the following summer, meaning that spring fertilizing is optional rather than required.
(3.) Lime should be put down only where soil test results indicate the need. Frozen soil should be avoided because the lime will just sit there until the thaw. Also, lime and certain lawn fertilizers can be lost to the atmosphere if they are applied within 10 days of each other.
(4.) Chickweed is either a winter annual weed meaning that its seeds germinate in early to mid fall or else it can be a perennial weed that begins to grow out of dormancy in early to mid fall. Those times are important because they tell us that these weeds are in a tender stage then and thus easier to kill. Use any lawn weed killer containing the active ingredient Dicamba at that time rather than waiting until chickweed is blooming in the spring, when you'll have to use a weed 'n feed product
Q: Yellow jackets seem to be everywhere this year, the most worrisome has been INSIDE THE HOUSE near the French doors glass windows beside the fireplace. Every day we find several more but luckily they are usually dead or near dead. We have investigated everything we can think of and cannot determine how they get inside the house. Do you have any other ideas as to how they could get inside the house?
A: They're probably living inside the walls or between the first floor ceiling and second floor flooring, having found their way in there from the attic into which they could have entered either through a vent or maybe from narrow openings in vinyl covering of the eaves.
The specific location of living yellow jackets or dead bodies tells us that the nest is probably nearby to that spot. I watched hornets many years ago going into an attic by way of the small opening in the eave where the electrical and compressed gas service went from an outdoor heat pump unit into the attic to reach the heating and air conditioning attic unit.
Once a yellow jacket nest is built in an attic, it is possible for the yellow jackets to enter rooms by way of ceiling light fixtures, especially if their is even a small opening in the ceiling drywall around the ceiling light fixture.
Walk around your house slowly on a sunny day soon to see if you can spot yellow jackets flying into any small entrance or coming out of any hole near your French doors.
Also look near other dorrs if your house is rather new. I believe state building code requires that an electrical outlet must be installed in the outside wall close to all doors. It is possible that yellow jackets found a small crack in your brick or siding around that outlet, and are coming inside from the studs in that wall there. The nest could be either up or down from an opening around that outlet, or from any crack that yellow jackets use to gain entrance to the walls of your house, so spraying that small opening itself might not reach the actual nest spot.
Q: How do I remove a tree from the crevice of a window well without causing any possible damage to my outdoor water line? Is there anything I can use to kill the roots rather quickly?
A: Before plants go into fall dormancy go to a well-stocked garden center to read product labels of a brush killer to select one that is labeled for "stump application."
Then cut your tree as low as you can and apply that brush killer as directed on the label onto that stump. Your goal is to have that chemical safely absorbed by the stump and moved down to the roots to kill them so that a new tree won't emerge. The "stump application" is safe to adjacent plants.
