Thursday, October 11, 2007
Be sure to get all of the roots when moving oak trees
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
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Q: I live in west central Florida and I have two oaks trees that I would like to move to a different location. They stand about 10-to-15 feet tall with a two-to-three inch base. When is the best time of the year to do this? How much of the root system must I get out? I'll be using just a shovel; no heavy equipment.
A: Select the time suited for your locality that fulfills the same twonvironmental conditions that we look for in selecting the optimum transplanting time here in western Virginia -- plant dormancy or slow growth time and soil conditions that are conducive for quick initiation of new root growth.
I am not familiar with plant signals of dormancy there in west central Florida. Evergreen and non-evergreen plant dormancy is easy for us to see here in this region when deciduous plants enter dormancy and become leafless. In your area, I would guess that plants like your oaks would become dormant in December.
Natural soil status best suited for transplanting occurs when the soil temperature is no longer stressfully hot as it becomes in mid summer but there is still warmth in the soil that is needed for immediate root growth following transplanting.
I’m guessing that these two environmental conditions needed for the optimum transplanting time for moving your Florida oaks will merge when your calendar says late fall or early winter.
You must get most if not all of the root system in order to expect success in moving your two oaks. A good rule of thumb to follow requires a root mass at least two feet in diameter for each inch of trunk thickness (diameter) measured at adult breast height. Your oaks probably have only a slightly smaller trunk diameter at that height than they do at the base.
The depth of the root mass transplanted is important too. Oaks have a deep-growing root system, although the exact depth depends on the soil where they are planted and how easy it is for roots to go way down. So, your ten to fifteen feet tall oaks could have three feet deep roots that must be dug. I hope that your west central Florida soil is easier to dig by hand than our clay-based soils are here in Roanoke.
Q: I have a question about what you said in late summer about moving hostas. You recommended that hostas growing here in Roanoke should be moved in September. I need to move six or eight variegated hostas from the spot to which I temporarily moved them a couple of years ago. But, the hot, dry weather we’ve had so far this fall has made me too scared to move the hostas. Did I wait too long? When can I move them, and how often do I need to water them?
A: If the weather is dry, water the hostas in their current location every five days if it stays fairly hot, and every seven to 10 days if the weather is cool.
Dig and transplant your hostas as soon as possible so that will have time to develop roots in their new locations before the ground becomes cold. No, you didn’t wait too long, but do this job soon.
Following transplanting, water your hostas once every seven to ten days until the leaves turn brown if the weather is dry.
Q: What can we Roanoke people do about all the brown stink bugs? The article that I read in the newspaper in September didn’t offer much hope. I’ve even smelled and seen these nasty stink bugs in my car. Help.
A: I don’t know of any effective insecticide that will kill these Brown Marmorated Stink Bugs either inside our homes and windows now in mid fall or should have been used outside homes in late summer or early fall before the stink bugs entered buildings (and cars) to find winter hiding places. Vacuuming these nuisance insects is our only option. Remove and dispose of the vacuum cleaner bag in an outside trashcan so that the cleaner and the place where it is stored don’t stink.
It’s also too late now in mid fall to seal cracks, around vents, and corners of your house because some stink bugs are probably already inside your walls, windows, and ceilings by now. Physically blocking all possible Brown Marmorated Stink Bug entry points could have been helpful while these bugs will still enjoying warmth and heat outside. Blocking those places now might save on winter heating bills but will hold the smelly nuisances inside your home.
Vacuuming any Brown Marmorated Stink Bugs found in your car and prompt disposal of the vacuum cleaner bag is the only remedy that I know of for these nuisances in cars.
Going after these bugs with a fly swatter, paper towel, or your bare hands is not a good idea. Bugs might die, but the strong smell will linger. Brown Marmorated Stink Bugs can emit their obnoxious odor whenever they feel threatened.
