aluminum foil for shading grafted pine scions

I've decided to have another go at grafting P. parviflora onto P. thunbergii rootstock.
I don't have a way to shield my grafts from summer sun. I also have no greenhouse or mist system.
Several web articles and blogs have mentioned covering the newly tied scions with aluminum
foil in order to prevent needle scorching. Brent Walston mentioned other grafters sometimes doing
this. A 2008 BSSF article stated that Jim Gremel does this with shimpaku grafts.

Does anybody know how long to leave the foil on? Do the scions not need to photosynthesize?

Dredging old posts...

I've recently done several grafts on juniper and boxwood and used both duct tape and aluminum foil.  Biggest thing I can tell you is that it is used as a shield from direct sunlight, like an awning or an umbrella...it doesn't and shouldn't cover the graft totally so they can photosynthesize the entire time still.  

I leave them on until I see the scion growing.  IF the scion is inside a plastic wrap or bag, make sure you open those up slowly first then remove the plastic (after several days or weeks) BEFORE you remove the aluminum shield.  

I (shamefully) had toasted grafts because the plastic bag became too hot (though the temp was only low 80s) and literally cooked the scion inside.

I'll be honest: I only got 4 out of 23 to take. And my best one got gnawed off
by a deer. But I'm still super excited. Woo Hoo!

In his video, Ryan Neil said that the cocoons would "pooch out" when the buds
began extending. I think that I wrapped mine too tight as there was no pooching out.
Even worse, I couldn't see the buds extending because they were hidden by the
needles and the translucence of the parafilm.

I grafted on around March 22. I got tired of trying to figure out if the buds were
extending and began opening my cocoons on June 1st. To my surprise, some of the
buds had already extended about an inch.

One of many flaws in my technique is that many of the needles rotted before and
during bud extension. This might not be an issue, but it looks awfully nasty.

Also, one bud remained tight and unreleased - I assumed the graft was a failure
and just took the parafilm and foil off. I'll be damned if the thing didn't start
pushing and opening in early August. THE BUD PUSHED AND OPENED IN FULL SUN
WITH NO DESSICATION PROTECTION. I think that's very interesting. Maybe
moisture control is only necessary until the graft calluses?

Oh yeah - one other interesting tidbit. Two of the grafts that took were left outside
when the temperature dipped down to 23 degrees Fahrenheit. They were, however,
covered with a cotton blanket and 6" of straw.

Casey

4 out of 23 is not bad...learn from them (both success and failure) and your next batch should be much better. You will just get better.

It is a good skill to have.

Congrats!

Agreed, 4 out of 23 is about an 18% success rate - not bad at all for an amateur. Even professionals, doing hundreds of grafts a season are usually happy if they get over 70% success. So getting the few you got is a good start.

I have been trying the parafilm technique as outlined by Ryan Neil and Peter Tea and others. My success rate is about 10% over the last 2 years and about 20 grafts. I'm slowly learning. One thing is certain, the understock tree needs sun to stay healthy while the graft is healing. Also my successes did get sun right away. I did leaves small gaps at the end of my parafilm wrap on the scion, the ones that took were these. Now I must point out that we have had an unusually cool and wet summer, more like a mild winter in Texas than a normal Chicago summer. So if I were in a hotter climate making an aluminium tent or canopy over the scion might be a good idea in a hot summer or high elevation, intense sun area.

My successes so far are one JWP 'Glauca' onto JWP, and one JBP 'Hakuko' onto P. nigra. So far so good. But until the graft is 4 or 5 years old and the foliage of the understock has been completely removed I would not count these as total successes.

Grafting is an 'art' there is a touch to it. It takes practice, the only way to get good at it is to do many of them, observe and learn from each.