I am wondering the best way to attach the grapevine to the middle tier of the cake? I have to travel about 50 miles with it. I was thinking of using chocolate and then adding pearl striaght pins for extra security. Does anyone know if this will work or have any ideas? Thanks in advance!

Personally, as a baker and sewer, I would never insert a straight pin in food.  Pearl dragees are commonly used in pastry making; there's no guarantee pearl straight pins won't be mistaken for dragees or overlooked before serving.

My food philosophy is if it's not 100% edible, I will not use it on/in food.  Pins are so difficult to see; my brother ended up having multiple surgeries when a straight pin went into his leg while he was wrestling around with another brother.  The pin was dropped on the floor and no one saw it.  It broke into pieces after entering his leg, thus multiple surgeries to remove it all.

I'm not sure I would use a grapevine either.  I live in the heart of California wine country.  I actually live on a vineyard.  Vineyards are heavily sprayed with a lot of chemicals; over 25 million pounds of pesticides are sprayed on wine grapes in California, including more than 400,000 pounds of Roundup.  They know that at least 5 of the 9 most commonly used pesticides remain on the grapes (Tests show the presence in the finished wine) in doses that exceed the NOEL levels.  NOEL measure the highest dose of a chemical before it causes detectable adverse biological effects.  So much pesticide is used that tests found grape vines are systematically contaminated with pesticide residue.  

Those are good points. I know the chocolate would be ok if it will help the decoration to stay in place. Do you have any ideas what I  can use in place of the grapevine? The wedding  is in a couple of weeks and the bride definitely wants her cake to look like this. 

you can make some twigs & tendrils out of candy clay or fondant or a combination of the two -- dust them with cocoa powder -- the beauty here is anything skinny will work -- i mean they could even crack -- let them set up on something rounded so they will work for you -- and I would also mix another dust with cocoa and some yellow for a highlight -- you could even pipe real chocolate --

sounds like fun best to you

I wonder if the cocoa powder would transfer to the white fondant. Just a thought, I wonder if I  can seal the grapevine  with corn syrup or piping gel? I keep calling it a grapevine. It is a wreath that I  purchased and took apart. I am not sure that is what it is but it looks like the picture.

Thank you both for your helpful replies!

if you don't do it right it will transfer -- grapevines are real dry -- the cocoa gives that effect -- you brush it on --

this is a little ironic -- you're worried about cocoa powder on the fondant but not pesticide --

edited to say -- where you can control the cocoa which of course is edible but you can't control what is already grown into the grapevine and putting pesticides onto food is scary

but I do understand that's what the bride wants and you've already committed to that  and you need that look but i would make it

I made a cake very similiar to this one a few years ago....I used the Wilton Vine and Blossom silicone mold to make the vines, then added a few extra hand rolled pieces here and there to make it more full.  I agree with the rest....never put pins in a cake!  To easy for one to get overlooked and then it's a law suit waiting to happen!  I really don't like using real vines and all...the bark flakes off and, really, it's like the wires in cake issue...you never know what the vines have been exposed to...pesticides, fertilizers, etc.

I am concerned about the pesticides. I was trying to figure how to get the fondant with the cocoa on the cake and not smear it . I can totally see myself doing that :) I will have to look and see if  I can find the Wilton mold. I am from a small town so I will have to go somewhere else to find it. I will look into other options and see what I can figure out.  Thanks to all for your help!

K8memphis & Jeff are a couple of the most knowledgeable & experienced bakers and decorators on this site, so I wouldn't hesitate to take their advise.  One of the areas of business that I think is only developed through experience is management of client expectation.  Clients come to you expecting not just quality product and customer service, but knowledge of your craft. The client isn't expected to know food proceeding law, know what's edible, or what's safe.  They don't know the cost of ingredients and the labor involved in production.  They come with a vision, with high expectation, but no knowledge of the issue involved in food production.  I believe managing client expecation effectively means listening for the design details that are most important, then offering the client options that will bring the details to life, without posing health risks and breaking their budget.  

This lesson was taught to me when I spent hours designing a backyard deck and landscape plan.  The architect listened, looked at my plans and then explained my plan wasn't feasible because the cost of the deck alone would be around $95,000.  In his next breath he asked me to trust him as a professional, then asked if he could take my design and alter it to preserve my concept, but make necessary changes to bring it in on budget. I ended up with a beautiful deck that incorporated all my lines, but on a smaller scale, and I didn't even notice the few components he changed out for more cost effective materials. 

I really do appreciate all the advice . I plan on going out of town to see if I  can find an alternative. I saw so mamy cakes online with what looks like real grapevine. I never thought of the pesticides an l guess alot of others don't  either. So I  do appreciate  the help. Hopefully I can find something. I spoke with the bride and she really wants the grapevine. If I  cant  find organic or fake l guess we will change that tier. Thanks to everyone who helped!