Question
QUESTION: I live in Iowa on boarder of area 4,5.  2 years ago I planted boxwood from Chicago land. 5 did not grow at all but did not die.5 grew some . Replaced the 5 that didn't grow  last year. Then the "good" 5 began to grow then developed brown leaves on one stem then more. Was told it was a bad winter and that could cause. About 3 still grew.   Replanted all in June with Plants from Canada Used the 3 live ones to try in other places.( more sun, slightly different soil.) Now about three weeks ago the " good ones" started to die back. Brown leaves on a small stem then a little more. Now one of the new plants shows the same leaf die back.  We have had the coolest summer in many years only a 2,3 days in low 90's. Frequent rains.
Most of plants on West side of house, Bilevel. Mostly shade but westerly winds provide air movement. Cause? Treatment

ANSWER: Richard:

Boxwood can develop a few root diseases, including a Phytophthora root rot that is assoc./ w too much water in the soil (e.g. poor drainage).  The lower stem gets black when you remove the bark near the soil line. Check for that. If the plant was transplanted from a pot, be sure to check the root ball for compactness- that is becoming pot bound, too many roots that are compact.  Plants sometimes just sit in limbo when put out in the landscape.  You might need to "fluff" up the root ball just prior to putting them in the ground. This will help their chances of survival when set out.  I suspect they may have got a bit of shock when they got set out.  A little care on the front end can go a long way.

Steve

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

QUESTION: Thanks for the great response. I checked and the stems were black at root line. Checked roots when I planted. most Ok, still I cut and loosened a few where seem needed.
1. Is there any treatment I can use?
2. Since I planted new plants where old were, will the new plants get the same disease?
3. Would it help if I dug the plants up added some sand/ peat/manure???and Replant?
4. Other suggestions. For plants ever green, foundation, shade, deer resistant, soil usually dry out but times of moisture climate zone 4/5
Again, Thanks for the timely info.

 stanafd

Answer
Richard:
Replacement following removal of the diseased plant is the best. Try to get out the entire plant and roots if feasible. Start with healthy replacements. The water drainage issue must be addressed or the same problem can come up again, since if the fungus is Phytophthora, it can stay in the soil for extended periods and it can attack a lot of different plants too- waiting for an opportunity to hop on a stressed plant- so the key is to avoid that stress factor- to keep the fungus for attacking. The new plants CAN get the disease IF they are allowed to sit in a wet soil environment for extended periods in which the water cannot drain away from the root profile.  Making sure of good drainage is very important.  There are some expensive chemicals (e.g. Subdue Maxx or Banrot) than can be applied to the soil as a drench, but if the plant is too far along, then it may not cure the plant. Both materials are probably not readily available in small amounts for the homeowner- just the professional growers.

Do not add peat to the soil to correct a drainage problem- this stuff holds water like a sponge. Sand serves a better purpose or even perlite.

Regards
Steve