Only mums and pansies ...pansies bloom in the cooler weather but the white ones do have a colored center.

Pink and white snapdragons.

as in the pic, snap dragons, baby's breath, gladioli (plant later than usual) dahlias.....any flower can be grown inside

I would like to suggest white dahlia's. They are a very sturdy stemmed flower for arranging.

Asters

There are a number of white chrysanthemums that come in a variety of different shapes and sizes. Look at the website kingsmums.com. My family have been members of the National Chrysanthemum society for over 40 years and they have the best selection and prices. Mums are super easy to grow. Another suggestion would be white roses. Oct 21 in Pickens Co. will be pretty close to the first frost, but it's also a time when roses have a second flush of blooms because of the cooler weather. Good luck!

Snap dragons

If you order good bulbs (obviously white flowering) and get them WAY ahead of time they need at LEAST 40 days in dormancy (which means in about a 45 dergree temp in your fridge crisper) (or basement or cooled pantry) You can get bulbs to grow at anytime, if you trick them into a 2 month dormancy which is nec. for them to bloom just plan ahead.

Oh, just thought of something else. How about a white buddleia bush? They grow fast and I'll bet if they get one thats about a 5 gallon size, it'll still have blossoms in Oct.

Mums, Delta pure white pansies, white snapdragons, diamond frost euphorbia, white roses (JohnKennedy for one) White butterfly bushes to name a few.

Stock White Flower is refined and graceful with ruffled blooms that adorn tall leafy stalks. A true white flower that releases a captivating scent, Stock will add an exquisite touch to a classic romantic wedding

White Camillias, lilies and white roses should still be in bloom for you

LOL, you know what else they could do? The could get a bunch of tulip, crocus, amaryllis and white daffodil bulbs, count back however many weeks it takes for them to bloom, and force them inside the house (once they chill them for a few weeks in the fridge)!

She might also put out a call to her local master gardeners for help. I'm sure some would be willing to help her help her son. That would provide pretty much guaranteed blooms.

Mums, forced Tulips, forced PaperWhites,Roses, Lily,Gypsophilia,Gardenias,Camillias. Mums are great though for a fall event. You can get them in large bushel baskets.

Lily-of-the-Valley, snap-dragons, gardenias, roses, mums, grape hyacynths, stock, cosmos, white marigolds, white zinnias

There are white Cosmos, mums, even a fall blooming clematis, several types of wild flowers and you can always buy a couple of orchids (moth) and use them as well. It really depends on the climate you are in. Best wishes on the wedding.

@dianaN I really like the bulb forcing idea! It should work!

Walter, just in case she needs some more great ideas, here are 37 more on facebook :) http://www.facebook.com/Hometalk/posts/12194...

Mums would definitely be the most affordable and long-lasting flower, altho stocks make a lovely addition as an old-fashioned, sweet-smelling flower. Flowers don't have to be white for a wedding - I might consider other color schemes.

you might check out www.fiftyflowers.com .....they sell flowers by the bulk delivered fresh and under the "bulk" flowers section have a category specifically for wedding ideas where you can choose the color...just a thought

An anemone like Honorine Jobert

White Iceberg or Carpet roses. Pansies, Begonia, Angelonia, Mexican Zinnias, Mini petunias, the Wave petunia, mums. Nurseries tweak bloom times often. Many annuals are still in bloom here. Echinecea 'white swan'. And native ox-eye dasies should be in the middle of a new flush of blooms.. Hit them all with a bloom booster every two weeks. Amend beds well. If already amended, plant with a handful of Mushroom compost in each hole and some Osmecote or Dynamite slow release fert. If ...»

white sasanqua camellias, like 'white doves' variety may be blooming in october, depending on the weather, and pansy flowers are sweet and edible, would be great on the wedding cake...you might also think about forcing some bulbs to bloom at the right time, like white daffodils and hyacinths, or even paperwhites (easy process)...even petunias will take a good bit of cool weather, or begonias as long as they are under a porch... you really have lots of options since you have time to make it happen