Encouraging Rosa Rugosa to grow quickly?
 

I have a very young hedge of rosa rugosa, some planted over the winter and
some last spring, none of it more than about 15" high. As it forms a hedge
that provides an essential boundary (previous occupant chopped down a mature
hedge for no apparent reason) I'd really like it to grow as much as possible
this year. I can keep it watered even with watering cans if necessary but I'm
wondering what else I can do. I've given it all a sprinkling of Toprose,
which come to think about it may not even be appropriate for this species
since it grows in the wild in relatively poor soil. I'll give it a mulch too.
Is there anything else I can do to get it to grow quickly? I need it to get
to about three or four feet high ASAP. TIA for any ideas.

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