Question
In an outdoor shade sturture garden center, (Plastic), when impatients arrive in beautiful condition, but a week later are showing signs of stress, ie. brown leaves, is this too much watering, moisture or is the green house too hot?  What can be done in this setting to prevent this?
Also if some one planted green velvet boxwood in a clay slightly ammended soil and fertilized with a high acid fertilizer and now the plants are dying, can anything be done to revive them, and when replacing them, besides amending the soil with peat,sheep compost, black earth and other organic matter, what fertilizer would you recommend, as in balance of nit, phos, potas numbers?  
Thanks for any help or references you can provide.

Sincerely
dale

Answer
Dale,
Browning leaves is usually a sign of either drying up or fertilizer burn (too much fertilizer or fertilizing thirsty plants)  Usually, if there is too much moisture, the plants will either rot at soil level or turn yellow and limp all over.  Too much heat will cause the plants to go limp.  Impatiens usually take quite a bit of heat in the greenhouse or outdoors, so I'm not sure that this would be your problem.  Clip browning plants down by 1/3 to 1/2 and water when dry but not before, and don't let them get so dry as to wilt.

Boxwood want soil that is well amended.  Usually you don't need to fertilize a newly planted shrub - waiting until the second year is best.  Keep in mind that most plants come from the grower well fed, and fertilizer pushes growth that a newly planted plant doesn't have the root system to support.

I think that when it comes to fertilizing perennials, shrubs and trees, it's best to remember how these plants are "fed" in the wild...there is no little fertilizer fairy flying around the woods and fields sprinkling fertilizer!  Plants are fed slowly by the organic matter that falls on the soil and breaks down.  As gardeners we need to remember that this is how the system works.  Amending your soil as you describe, digging the amendements in deep and wide, will be fine for the first year.  Water the plants deeply once a week if it doesn't rain.  Next year, fertilize with any organic fertilizer (always my first choice because the nutrients are slow-release) with fairly even numbers across the board.

I hope this helps!
C.L.
www.gardenlady.com