Hot callus pipe grafting
I'd like to start a thread on this too. I know we're all going crazy with plants crying for attention right now, when does that stop again...December?
I'll try to copy a favorite link
These folks don't mention cedrus, either. I just happen to have maybe 50 seedlings right now in 1 gal. which could be grafted in another year or so. Can you tell me what makes them poor candidates for callus tubes?
The beech apparently works great, but I'd have to buy rootstocks for that. Also have a few jap. maple seedlings from this spring, could graft them tho people up here just tend to bud them in the field in summer...no greenhouse or anything needed.
I read a discussion by a propagator from Schmidt, in Boring, OR, on grafting conifers. He mentioned that each species needed different conditions, so a callus pipe might work for one type but probably not all. Definitely remember he said spruce were the most finicky.
I'm mostly trying to stay away from investing in a big "overhead", hoping to do stuff inexpensively as long as it works. This seems to be the great thing about the callus tubes, work just as well as a greenhouse for many items, but at a fraction of the cost to setup and run.
In our mild climates, I'm pretty sure a low PVC tunnel would be all that's needed to house the pipe all winter--I can build that for about $1 a square foot.
As Ann would say, Having FUN!
Glen in BC
I made the mistake of checking this thread when my DH is outside the window, gunning the tractor engine and waiting for me to come out and help auger the holes for the posts on the endwalls of the new greenhouse. So I will write a L-O_O_O_O_N_G one about callus devices as soon as I can get a chance. For now, conifers knit very easily with a humid, 55-65 degree f. environment because conifers are never truly dormant. It's easy to get the juices flowing and cause callus formation. Deciduous trees respond to the hot tube because the heat wakes up the cells around the graft, but leaves the tops and roots dormant. I really prefer not to reveal where I work, but suffice it to say that I am in a position to rub elbows with many, many wholesale nurseries in Oregon, Schmidt included, and I have seen 3 different approaches to hot callusing that are very interesting. Will get on with descriptions and comparisons after dinner and chores, maybe! Now, out in the 95 degree sun to build the gh! Susan
I'm back, Glen!
Well, we worked on the greenhouse till midnight on Friday, got up and went at it again all day Saturday (it hit 100 degrees f by 1 in the afternoon, and I've got the tan/burn to prove it!), finished the crosspieces on the endwalls by the lights of my pickup truck at 11:00pm. Attached the poly lock channel Sunday, then took a break to go fix fence in the pasture where the cows will be going this week. Returned hoping to install the poly, but a front was coming in, and we suddenly had 20 mile an hour wind. So actually had time to build a new automatic waterer for the horses, and bar-b-q steaks!
So, as for the hot callus tubes: It's a good thing I checked out your link before I started writing, because it does a better job than I could, of describing a tube made with an electric wire. The other tube device I've seen was at Richard Bush's nursery, and he used a much larger outer tube in order to run 1/2" pvc with hot water from his boiler for the heat inside. He also used pumice instead of sawdust, and had the whole thing rigged up on a table with an expanded steel top. Seemed like a whole lot of hoo-ha to me, more work and expense than it was worth. He spent quite a bit of time developing a jig so the notches could be made in the pvc with a router.
But the best I've seen by far is the cheapest, easiest, breaks down to store in no room at all, and requires almost no tools to put together. It calls for the electric heating wire and thermostat used in the first tube, but instead of notching a pipe to receive the grafts, the wire is strapped with electric tape to a length of 2x4 lumber. The wire is covered with a very thin strip of foam rubber that can be moistened to keep the wire from burning or drying out the callusing tissue. The 2x4 is laid on the ground in a dark, cool corner of a cold frame with electric wire facing up, and the grafts are laid over the foam-covered wire. Another piece of foam over the top, and another 2x4 to hold them down and in place. A rock on either end of the top 2x4 keeps the whole thing together! This nursery grafts onto bare root stock, so once the grafts are placed on the hotwire, the roots are covered with damp sawdust. Because there is no notched tube, the rootstock can be placed side by side, and several hundred fit on one length of lumber. If rootstock is potted, there is no space wasted if notches aren't spaced for the specific pot size.
In one further small step of brilliance, the bareroot stock at this nursey is removed from the hotwire after 2 to 3 weeks, the budding strips are removed so the callus can be checked, and then they are divided into groups of 100 and heeled into sawdust in 5-gallon plastic buckets that have drain holes drilled around the bottom. Set in a cool spot in the cold frame until time to field plant in spring. Each row is 100 trees long, and each bucket has 100 to plant out. It makes it very easy for the workers to get the job done.
One precaution -- moisture is needed to keep the plants from drying out and dying where they contact the hotwire. HOWEVER, if water penetrates to the cut edges of the graft inside the wrap of the budding strip, the graft can be ruined, so don't be flooding the system, just dampening! This system is great for deciduous trees and shrubs, the success rate is far better than dormant-grafting in a heated greenhouse, and the single electric wire costs far less than 4 months of natural gas or propane! I'm planning to run trials with Japanese Maples, Beech and Birch this year to compare to late summer budding and grafting. It would be nice to extend my deciduous grafting window through the year so I don't have 10,000 grafts demanding to be done in 2-1/2 short months!
Susan-it will take me a bit to digest that great description. Wow, thanks for all the trouble, like you've got nothing else to do, sounds like!
Myself, I've never grafted anything, but have to give it a try. So a real amateur question here...are you doing any grafting in late summer, I thought the normal time was late winter. I have seen late summer mentioned, but couldn't figure out how you would do it since stuff wouldn't be dormant at all.
The cedrus, for e.g., is mentioned as being grafted either late winter or late summer. The winter I can understand, normally done in a cool greenhouse. In summer, would this just work in a shady spot, the grafting rubbers protecting the graft itself enough to allow it to knit. Would it be better in a shaded intermittent mist area...tho you mention you don't want water getting right into the graft.
With the hot callus deal, the grafting would still be in the dormant season, so this helps you extend your grafting season for deciduous...?
Sourcing small quantities of rootstock will be a trick, since I can't seem to grow them that well myself. On the other hand, the one grafting greenhouse I visited bought in rootstocks rather than growing them, because of the uniformity they could get from purchased stock.
Hope that greenouse is up, and you can spend more time barbequing this summer
Glen in BC
I should stop writing epistles at midnight! Even my clearest thoughts appear garbled in print the next day.
As for summer grafting -- I have read that you can graft some conifers, and especially cedrus, in late summer when the buds have set and hardened. Have never tried it, there's enough other work to do then. We routinely do cedrus starting November 1, and we're into 5-needle pines by Nov. 10. Spruces like it a little colder, and I have heard they benefit from waiting till after a freeze. We never get to them till after Christmas anyway, but I think I'll try a few very early this year just to see what happens. I think most people who are doing just a few, do all their conifers in Jan/Feb, but when the workload demands 4 or 5 months to complete, you learn how far to push the boundaries!
Deciduous trees that are chip budded are done in late July, August, September, and in some extreme cases, October. The bud has hardened off at that time, and the apical dominance of the rootstock above it will keep it dormant until the rootstock is cut back the following spring. "June budding" is chip budding that is done on growing rootstock in the spring with budwood that was cut dormant and stored in the cooler. It's mostly used as a re-grafting method for the previous summer's chip buds that failed.
Japanese Maples grow 2 or 3 flushes per season, and you can summer graft anytime that the most recent flush has hardened off a bit. Last year it was late July before I saw anything ready, and I grafted on and off till October. This year, we had wierd weather, and the first flush was hardened and ready to go on many of the JM's here about 10 days ago. The leaves are cut off the scion before grafting, and I like to get it done early enough that the buds can flush once more before going dormant.
You have got to try your hand at grafting! Once you have your first success, you're hooked! Cedrus isn't the easiest one to start with, mostly because it takes 2 to 3 years to get a seedling rootstock big enough to do carpentry on. Scions often can't be cut from the most recent flush of growth, because they generally are too fine and small. You sometimes have to cut back to 2nd or 3rd year wood on a Cedrus scion to get the caliper, but then the doggone thing is 10" long! 5-needle pines and true firs (Abies) are very easy, and very forgiving of beginners' attempts. Ya just gotta do it!
Going to try to get the poly up tonight, but we have to move the cows down, and then one of my daughter's ewes mis-read the calendar and lambed this morning, so we'll see...