Expert: Long Island Gardener - 6/11/2008

Question
Hello!

I live in Benton, Arkansas. Ok, let me see if I can explain this problem we are having with our plants. We have a big rock garden (use to be a fountain) that we decided to plant flowers in. We used regular dirt to fill in the garden and laid landscaping black paper down to keep the grass and weeds from coming through. Then, we added topsoil on top of that and planted our flowers. I have petunias,delphiniums, snapdragons, hosta, zinnia's, blazing stars, iris and impatiens. The problem is that these plants are blooming like crazy, but they are not getting taller or bushing out. (with the exception of the zinnia's and iris's, they are doing fine) I planted them in early April from flats, but they are still about the same size they were back then and this is now June. I planted zinnia seeds the same time I planted the actual plants and the ones I planted from seed are gorgeous and about knee high now, but everything else looks like it hasn't grown at all other than bloom like crazy.
I would have figured they would have taken off by now. The garden is in a spot where it receives full sun till around 3 and then it's in the shade. I have been spraying on plant food every two weeks and watering every other day. The heat here hasn't been bad so far this year mainly lingering between the mid 80's to mid 90's. Why do you think these plants are not growing to their full potential? Do you think I am watering them to much or could it be that it's still to early? I thought about adding cow manure, but not sure if that is what I need to use or not. What would you suggest at this point?

Thanks!
Kimberly

Answer
Thanks for your detailed question, Kimberly. Unfortunately I have to ask you a few more questions - and it may seem obvious to you, but I still have to be sure I understand exactly what you are asking.

So not to belabor this further here's what I need to know:

1. What are the dimensions of this bed you have planted -- how deep is it, and how wide and high?  (Do the plant roots have the room they need?)

2. You are giving the same care to Delphiniums and Irises as Snapdragons, Petunias and Zinnias?  Same fertilizer (which is what? I would like an N-P-K and frequency apx of application -- you mentioned spray, is that in addition to a root/soil dose, or do you only spray)?

3. The Zinnias and Irises are blooming satisfactorily, correct? They are 'bushing out' -- growing stems from their sides and blooming?  (Have you 'pinched' them -- snipped off the tip of the main stem, which triggers growth at nodes below it?  Can I assume the Zinnias and Irises are not expected to 'bush out' which is why you are satisfied with their performance -- or are these in fact 'bushing'?

4. How much do you water?

5. Are you unhappy with the height these plants are blooming at?  Are you unhappy with the height of ALL of them?  Which ones are you satisfied with and how tall exactly are they?

rsvp,

L.I.G.