What can i buy now that will look good in 4 weeks

My garden is starting to look less than colourful in the semi shaded bit. We have a big party coming up on 2 September. What can I buy now which will add some colour quickly (and in years to come hopefully)

Anyone with any ideas please

B

 

Today I bought a few Phlox plants still in tight bud,and I hope they will be with me into next year too.

 

Penstemon ought to do the trick. If it's fading at the moment, cut it well back, and it'll be looking great in about 3 weeks. Advice given to me last year to get things ready for a client's daughter's wedding. It worked :D

 

How about Fuchsias - but leave them in their pot, when you plant them, then they won't check - they are in flower now and will flower until the first frosts.

Then there's dahlias - they still have these in the garden centres.

 

Ive got two rose of sharon (hibisus) witch will be in flower in a week or so, both standards, got them from B&Q last year.

 

Asters - they are easy and if you keep them dead headed they will keep flowering until frost, such vibrant colours too, my garden is very colourful with them all and so early this year too.