Question
QUESTION: I rent.  About five years ago, my landlord planted a sour cherry tree.  I do not
know what variety it is, exactly.  It had been doing well, although the fruit
seemed to start to rot on the tree even before it was fully ripe.  The next door
neighbors recently reclaimed a yard that had gone very wild, and I think they
sprayed A LOT of weed killer around, and I suspect that the cherry tree took a
very large hit.  The leaves by the fence suddenly turned brown and shriveled
up, and gradually the whole tree has lost most of its leaves over the last
month.  it has been wet in Queens, so I know it is not drought damage.  Also,
the trunk is oozing sap in many places, but the leaves and the areas that are
"bleeding" do not seem like canker, from what I can tell (which is limited.  no
holes in the leave, no spots, they just turn brown and die), and I don't seem
to have an insect problem.

I have three questions.  Does a diagnosis of massive weed killer dose seem
logical, given the defoliation and the "bleeding".  If so, is there anything I can
do to give the tree a better chance of survival until the spring?  If not, and it
does die, are there implications for the soil surrounding the tree following
removal?

Thanks
Elizabeth

ANSWER: Since the problem started on one side toward where the herbicide was applied it does sound like this is what is killing the tree. With as much damage you described there is only a small chance that the tree will survive. I would try fertilizing the tree with  10-10-10 fertilizer at the rate of 1 cup per inch of trunk diameter scattered around the tree and watered in good. This will help the tree produce more roots. Then about all you can do is wait until spring and see if the tree leafs out. If it does I would fertilize again and water if it does not rain with 1 inch of water per week-place a pan under the tree and turn the sprinkler on and when the pan has 1 inch of water in it stop. This is called deep watering and will help the root system. IF it leafs out you can also add not more than 3 inches deep of organic mulch  around the tree out to about 2-3 feet not piled up on the trunk . This will hold moisture around the roots.

IF there is grass regrowing in the area that was sprayed the soil is fine if another tree is to be planted. There are many types of herbicides that can be sprayed for weed control on grass. Some are used to kill all the green and start over with sod etc, (Roundup is one of these). Others are for grass but some like Weed and Feed products will contain a herbicide that will not harm the grass BUT will kill other plants, More than likely this was what was used. As long as the weed treatment is not repeated the soil is OK.

---------- FOLLOW-UP ----------

QUESTION: Thanks.  Two more questions.  First, Could you elaborate on 10-10-10-
fertilizer, and are there organic options there?  Second, the yard next door
looks like scorched earth, and I think they used roundup. The weeds I had
been combating around the trees seem to have died, and there is no grass
there.  How can I tell if the soil is in fact, fine, and if it isn't, what can I do to
fix it by spring?

Elizabeth

Answer
A plant needs nutrients to survive. Most of these are provided by the soil, but soil varies tremendously in nutrient amounts, soil type, pH, and nutrient availability.

The three main nutrients that have been identified as absolutely necessary for plants are nitrogen (N), phosphorus (P) and potassium (K). These three are also known as macronutrients, and are the source of the three numbers commonly found on organic fertilizer labels. The numbers found on our Organic All-Purpose Fertilizer, for example, are 8-5-5. This is the percentage by weight of the N, P, and K found in the fertilizer.

Nitrogen (N) is probably the most widely recognized nutrient, known primarily for its ability to "green up" lawns. Nitrogen mainly affects vegetative growth and general health. Chlorophyll, the green substance in plants responsible for photosynthesis, is largely composed of nitrogen. It is also used heavily in new shoots, buds, and leaves. Air contains about 78% nitrogen, but atmospheric nitrogen is not readily available to plants. They must absorb it through the soil. Ammonium and nitrate are both readily available forms of nitrogen, but they are common in chemical fertilizers and leach heavily and quickly out of the soil. Nitrogen can be applied organically in many ways, including composted manure, blood meal, canola meal, fish powder and various liquid organic fertilizers. Keep in mind that many organic dry fertilizers are slow-release, helping the long-term nitrogen content and building up organic matter in the soil.

Phosphorus (P) is important for healthy roots and is used more heavily during blooming and seed set. Phosphorus is easily rendered unavailable to plants when the pH is slightly unbalanced. It is released in soil through decomposing organic matter.

Potassium (K), sometimes known as potash, is important for general health of plants. It is key in the formation of cholorphyll and other plant compounds. Potassium is also known to help with disease resistance.

10-10-10 is a general fertilizer that will give the tree the elements it needs. Organic fertilizers are ok but there is not a good way to know the amounts of the N-P-K in the substance used. Also if they are used it is best to not use fresh organic fertilizer these may burn the plant since they may contain too much N.

Sounds like the herbicide used was 2-4D or dicamba both can be picked up by the tree roots and taken into the trees system. Roundup usually will kill any green plant it is sprayed on but will not be picked up by roots. Both of these herbicides have a short life in soil so there should not be any carry over for future plantings. About the only thing you can do for the tree is water and hope for the best. If it were me I would ask the neighbor to replace the tree since it sounds like they caused the problem with the use of too much herbicide.