Selecting, cutting, and storing dormant apple scionwood

Late January into mid-February is what I consider the best time to collect dormant apple scionwood in the Boulder area. Later, and a warm winter could mean buds already swelling — i.e. they are no longer dormant, but starting to grow. We want the wood to be dormant because when we graft it to a rootstock, the junction will need to heal before the rootstock can supply the scion with water and nutrients. If the scion starts to grow before the graft union heals, it is likely to die from lack of water for the emerging leaves.

Once the time has arrived for collecting wood, get a sharp pair of hand pruners and head out to the trees. Look for last year’s wood. Follow a relatively upright branch downward past each bud until you get to a spot where there’s a bit of a ringlike ridge around the branch. Small branches often grow out from a location just below here, and there are also usually a few buds crowded right above this spot. Higher up, the buds are farther apart.

Identify the bottom of last year's growth, where the ringlike structure and crowded buds are.  Cut scionwood from the portion of the branch above this area.

Identify the bottom of last year’s growth, where the ringlike structure and crowded buds are. Cut scionwood from the portion of the branch above this area. The diameter of the scionwood that’ll be cut from this branch is nearly ideal.

(As an aside for those who read Selecting budwood for summer bud grafting, the wood we’re looking for now is the same that one would have selected last summer for bud grafting, only now it has matured and the leaves are long gone.)

Ideally I’d cut scionwood that’s about 6-7mm (1/4″) in diameter, which is easy to work with and is close to the diameter of typical rootstock. However, sometimes there is no scionwood as thick as that. No problem. Get what you can, because you’ll probably be able to graft it.

Sometimes ideal scionwood is unavailable.  In that case, get the best scionwood you can.

Sometimes ideal scionwood is unavailable. In that case, get the best scionwood you can. Note the ballpoint pen for scale. The scionwood here is smaller than ideal.

Once you’ve cut your scions, they might look like this:

Here is the cut scionwood.

Here’s the cut scionwood. The piece on the left is nearly ideal. The thin wood on the right has just been cut from the branched wood below (the branched wood will be discarded).

Cut the wood to lengths that will fit in a gallon ziploc or similar plastic bag. Trim off the top inch or so, unless your scionwood is very short. Seal all cuts with a quick dip into a candle, to coat cut surfaces with wax. Of course, don’t leave the wood near the burning candle for more than a the fraction of a second it takes to coat the end with wax.

It’s hard to see the wax on the ends, but here is trimmed and sealed scionwood:

This scionwood has been cut to length for storage in a ziploc bag, and cut surfaces have been sealed with wax from a burning candle.

This scionwood has been cut to length for storage in a ziploc bag, and cut surfaces have been sealed with wax from a burning candle.

Lastly, mark your scions as to identity with some cloth medical tape or something similar. Store them in a refrigerator if possible, but do not put them into the fridge where you keep your food — gases given off by some foods may encourage the scions to break dormancy. I have a small ‘dorm fridge’ that I start up each year just for grafting season. If you don’t have a refrigerator, consider putting the scions on the shady side of a building (north side in our hemisphere), covering with enough leaves or other insulation to prevent freezing.

Finished scions, ready for storage until grafting begins in late March:

This scionwood has been labeled and is ready for storage.

This scionwood has been labeled and is ready for storage. These scions are from a USDA-collected wild apple I’ve grown out, and have a code number rather than a name like Honeycrisp or Fuji.

Selecting budwood for summer bud grafting

If you’re attempting T-budding, or cutting budwood for others to graft, now’s the time. I usually think of July 15 – Aug 1 as the best time. Earlier, and the buds may not be mature. Later, and the bark on the rootstock may not be slipping. Here’s a brief guide to selecting and preparing budwood.

First, find this year’s growth on a relatively upright, vigorous branch. You’re looking for the portion of the branch that has individual leaves attached directly to the branch … that’ll be the topmost section of the branch, right out to the tip. If you start at a branch tip and work your way down, make note of the spacing between the leaves. At the very tip they may be close together, but just a little ways down the branch they’ll be further apart. All of this is the current year’s growth.

The tree grows buds this summer at the junction between leaf and branch (the axil). They’re dormant for now, but each of these axillary buds has the potential to turn into a new branch next summer. The goal of T-budding is to remove these buds, get them onto the host rootstocks, and let the two parts knit together while the tree is still actively growing for the summer. If successful, next summer the bud will start growing and become the trunk of the new tree.

This is good budwood in the middle of the current year’s growth. Note that individual leaves attach directly to the apple branch. Axillary buds appropriate for grafting may be found where each leaf attaches to the branch.

As you continue down the branch, eventually you’ll reach a point where the leaves, or the scars where leaves could have been, get quite close together, and there is often a ringlike structure around the branch here. This is the bottom of the current year’s growth. Below, leaves don’t attach individually and directly to the branch, but rather to side branches of the branch you’re examining.

Note the close spacing of leaves on the branch in the top half of the image. That area is the bottom of this year’s growth. Below is older wood.

In the next several photos, you can see how I prepared budwood from an apple branch.

1. Here’s the branch as cut from the tree

Here is a branch from an apple tree in my yard. The bottom half-centimeter is last year’s wood, and everything above is this year’s growth.

2. With hand pruners or scissors, remove each leaf blade, but leave the petiole (‘leaf stem’) to use as a bud handle later.

Leaf blades have been removed. Petioles (‘leaf stems’) are left on the branch.

3. Close up of prepared branch.

The petiole attaches the leaf blade (now removed) to the branch, and makes a fine bud handle.

4. Finished budwood. The middle section provides the best budwood.

Finished budwood. Select only the middle section if your branch is long enough, as these are the best-quality buds. Upper and lower portions will be discarded.

Budwood is perishable and should be used as soon as possible. That said, it is frequently shipped through the mail successfully. Put the budwood in a plastic bag with a zip seal, and mail it in a padded envelope.

(I hope eventually to post how-tos for T-budding … but for now just wanted to get budwood selection information out to some people with heirloom apple trees that they want to propagate)

Did you learn about us in Colorado Gardener?

The June 2017 edition of Colorado Gardener has an article we contributed on the topic of popularizing grafting skills as a way to build appreciation for Colorado’s historic apples. In addition to the better-known West Slope fruit-growing districts, Canon City, Wheatridge/Arvada, Boulder, Longmont and other areas on the Front Range once had vibrant orchard industries. There are surely hundreds, possibly thousands, of trees still alive from that golden era of apple growing before the advent of supermarket chains. These trees have both historical and horticultural value.

This tree in Boulder's Whittier neigborhood was described to us as being a big tree when the previous owner of the property was young.  It's trunk, though decaying, is very large.  We have grafted several new copies of this tree. (c) 2017 by Eric Johnson

Among these elder trees are surely some lost varieties — cultivars known to have originated here but which are otherwise forgotten. Because they grow well in our conditions, they represent an opportunity for small growers whose focus is local markets, as well as backyard orchardists.

With inspiration from Montezuma Orchard Restoration Project (they’ve already rediscovered the Colorado Orange and other lost apples, and done terrific work to bring back the orchard industry in the Cortez area) and others, we’re beginning an effort to locate old historic apple trees along Colorado’s Front Range and graft new copies of them. We’d welcome your help, if you’re interested in moving this project forward — a little, a lot, or anywhere in between.

As a starting point, we need to know where old trees are and develop criteria for prioritizing which ones to save. If you know of trees we ought to consider, can you provide an address or (better) GPS coordinates, plus a couple of photos? (Please be respectful of private property and appreciative of owners who have kept these special trees alive)

We anticipate that during the busy summer months we won’t be able to visit many trees, but can probably put more energy into that in September/October. We’d love to be in touch now, though, with folks who’d like to work on Front Range apples and orchard history. Please send us a message!

Meanwhile, what else could we all work on? How about bud grafting? After a successful dormant grafting workshop in April, we’d like to tackle a workshop or two of bud grafting this summer. If you have a tree that needs preserving, there’s a window of opportunity in July when apples can be easily ‘budded’. We have a small supply of rootstocks onto which buds can be grafted. Interested in bud grafting this summer?

This is going to be a lot of fun.

Grafting workshop, Saturday 3/18

Want to learn how to graft apples? We’re planning a workshop for Saturday, March 18, mid-morning to about noon. Rootstock and choice of apple varieties will be available. The cost will be a few dollars. Come and graft your own tree to take home! If interested, please let us know: http://bit.ly/contact_wm

Grafting classes and rootstock planting, 2017

We’re planning to distribute low-cost rootstocks ($1-$3 per tree) and hold a couple of grafting workshops in early Spring, 2017. Are you interested in planting a rootstock for later grafting to an apple cultivar of your choosing? Please contact us if so, and we’ll put you on the email notification list. You may also want to follow us on twitter (@widespreadmalus) or on facebook (http://www.facebook.com/widespreadmalus).

Who’s doing what with apple biodiversity?

I thought it would be nice to have a list of projects working to protect apple biodiversity in North America (or elsewhere, if any readers can add information in the comments). Here’s a start:

  • Widespread Malus … that’s us! Working to build a highly diverse collection of Malus sieversii, as well as distribute scions, grafted trees, and seedlings.
  • Apple Diversity Group … a collaboration between Dalhousie University and Agriculture Canada, this group’s Apple Biodiversity Collection in Nova Scotia has 1000+ different apples, including about a hundred Malus sieversii.
  • USDA Plant Genetic Resources Unit … located in Geneva, NY, USDA PGRU maintains one of the world’s most extensive apple collections, including diverse wild apples (M. sieversii, M. orientalis, and others). Interested members of the public may request open-pollinated M. sieversii seed from PGRU.
  • Temperate Orchard Conservancy … located in Oregon, TOC is replicating the Botner Collection (perhaps the largest private collection of apples in the world … 4,500 different apples).
  • Montezuma Orchard Restoration Project … promoting apples and orchards in Montezuma County, Colorado and around the state. Also locating and propagating rare Colorado Heritage apples.
  • North American Fruit Explorers … a group of folks interested in all kinds of fruit. There are quite a few members with their own diverse collections of apples and other fruit. Visit the web site or the facebook page.
  • Seed Savers Exchange … not just for seeds! Iowa-based SSE has quite a nice collection of apples (hundreds), and numerous members who share apple scions with other members.
  • Agrarian Sharing Network … is sharing diverse fruit and vegetable material in the Pacific Northwest. ASN has done extensive evaluations and cloning of the Botner collection and several other large bioregional collections, and is involved in a number of propagation fairs.

Can you help us add more projects to this list? Please send us an email!

312 apples grafted, and counting!

We’ve got 200+ trees grafted for 63rd Street Farm, to be planted out later this month. Also, a few for giveaways, and maybe 50 Malus sieversii grafted from scions received from USDA in Geneva, NY. There are about 15 Antonovka rootstocks left to graft … most of these will be grafted with Malus sieversii.

2016 grafted apples.

2016 grafted apples.

Are you interested in a Malus sieversii tree for Spring 2017? Let us know if so!

Grafting has begun …

We’ve started grafting some of the 200+ trees for the 63rd Street Farm orchard, to be located on the City of Boulder’s Andrus open space property just across the road from 63rd Street Farm. We planted out 50 Antonovka rootstocks at the farm last year in a nursery bed, and a few stray M-111s at home, and are starting to dig them up and bench graft them. First up: Golden Russet.

Heeled-in apple bench grafts in the shade of the north side of the house.

After grafting, our trees are ‘heeled in’ and covered with most sand or soil, in the shade of the north side of a building, to await healing over of the graft junction between scion and rootstock. It’s still early to be grafting, and we will probably need to protect these trees from freezes. Apple grafts heal well at 40-50 F, but severe cold would likely ruin them.


There are symptoms of an early spring out there (70°F today), and buds on some of the scion wood cut from around town are starting to swell. Not to say we won’t still have some tough winter conditions, but it’s better to graft, heel in, and protect the small trees than it is to try and graft with scionwood that is emerging from dormancy.

Malus sieversii from USDA … a Widespread Malus data compilation

FILE LINKS

This document in PDF format (100 kb)

Data compilation in Microsoft Excel format (962 kb)

Data compilation in Open Document Spreadsheet format (314 kb)

INTRODUCTION

Widespread Malus has compiled data on the USDA collection of Malus sieversii that might be useful in selecting accessions (scions or budwood) to request from USDA. We are collecting a ‘core diversity collection’ from the USDA collection that is especially diverse. Our goals are to make this diversity available to others, to grow out large number of open-pollinated seedlings, and make deliberate crosses with hand pollination in pursuit of useful new apple cultivars. However, there are a large number of other Malus sieversii in the USDA apple collection that will not be part of our diversity subset.

USDA’s Malus sieversii collection has enormous genetic diversity, and could serve as a useful reservoir of genes for use in breeding projects. There is already work being done in academia and by small numbers of nursery professionals and/or hobbyists.

We are hopeful that others can use this data compilation in their own work.

The data have been compiled into a Microsoft Excel format as well as Open Document Spreadsheet format (which may be opened by freely-available Open Office or its descendents). We may also make some data available in other formats. Inquiries regarding how to use the data are welcome.

We are responsible for any data-processing errors in this document, but we are not responsible for any requests you may make from USDA. We recommend that you cross-check your request with the GRIN database itself, and with the USDA Apple Catalog, to ensure you are requesting what you expect. Search the GRIN database at:

http://www.ars-grin.gov/npgs/searchgrin.html

Download USDA’s Apple Catalog from the link in the next section.

REQUESTING MATERIAL FROM USDA

Please consider carefully your ability to make use of any material you request from USDA. USDA personnel do an amazing job of maintaining this collection (and many others), often with limited resources. If you are not sure you can use what you are considering requesting, perhaps a request for this material isn’t the best use of your (or their) time.

USDA’s cutoff date for scion wood requests is January 10th (for shipment by March 20th). To request scion wood, you should download the USDA Apple Catalog, at:

http://www.ars.usda.gov/services/software/software.htm?modecode=80-60-05-00

There is a request form at the front of the catalog. The catalog is in Adobe Acrobat (PDF) format.

We had a bit of difficulty locating rootstock last month for March 2016 delivery, and suggest that you order ASAP if you have not yet done so. We ordered this year from Willamette Nursery and CopenHaven Farms (we received excellent rootstocks from Willamette in the past, and are ordering from CopenHaven for the first time this year, but are not recommending any particular nursery in this document).

In addition to, or instead of, requesting scions from USDA, you may wish to consider growing open-pollinated seedlings of Malus sieversii trees in the collection. If so, request "100 Open-Pollinated Malus sieversii seeds" on the order form. Requests for these seeds are typically filled with 25 seeds from each of four mother trees. If you are interested in cooperating with others to diversify the seeds you grow, please let us know. For example, we may be able to share seeds among several people so that instead of 25 seeds from each of four mother trees, each person ends up with 5 seeds from each of 20 mother trees. Pollen parents for these seeds are not known.

HOW THE DATA COMPILATION IS ORGANIZED

Not all USDA records for Malus sieversii are in the compilation. Both the USDA Apple Catalog and the GRIN page for each accession were examined. (see the BLUE-LETTERED columns in the image below. Y = available, N = not available, blank = no data) If the accession was in the GRIN database, but wasn’t indicated as AVAILABLE in the apple catalog or the accession’s GRIN page, it was not included. Some accessions were available as seeds and are available only for academic research; these were not included, either. Some accessions are listed in the GRIN page as "check regarding availability" — these are indicated with an M for maybe.

Note that the Apple Catalog and the GRIN page availability information may conflict. This is most likely due to GMAL accessions not being in the permanent catalog, and many/most of these GMAL accessions will be cut down during Winter 2015/2016 to make room for additional trees in the permanent collection. If you are interested in a GMAL accession that is not listed as being in the apple catalog, you should request it this year. We have inquired to make sure that trees have not yet been cut, but haven’t heard back by time of publication.

Apples that may be available from Widespread Malus are indicated in the RED-LETTERED column. However, quantities are extremely limited this year as we have barely begun our collection.

Screen shot from data compilation spreadsheet

The spreadsheet document has multiple "tabs" shown along the bottom. The first two, FULL SET BY PRIMARY ID and FULL SET BY BRIX contain all the records in the data set. Several other tabs (PARTIAL — FB RESISTANCE, PARTIAL — SCAB RESISTANCE, PARTIAL — ASTRIN. & BRIX>=11.5, and DIVERSITY CORE SETS) include only the relevant records. Two other tabs include descriptions of what data is in each column and references used in compiling this data set.

Negative 9 in a numeric column means NO DATA.

USING THE DATA COMPILATION TO FIND TREES OF INTEREST

  1. If you are interested in helping Widespread Malus build out diversity core set collections, you may want to request accessions from the DIVERSITY CORE SETS tab that we have not yet acquired. We may request scions of these accessions from you in the future, and of course you may request accessions from us. Would you like to coordinate requests for this material this year? Let us know … perhaps several requests can be coordinated to maximize the diversity of scions received.
  2. If you have other interests, we have provided several subsets of this data … for fireblight resistance, scab resistance, and astringent flavor with high BRIX. However, you can sort the data yourself if you are familiar with spreadsheet software.
  3. Are you willing to share scionwood or budwood with us or others? You are under no obligation to do so by using this compilation, but if you are willing, we’d love to know about it. Please let us know what you are requesting so that we know about it.
  4. If you need assistance sorting through the data, you’re welcome to contact us. We are not plant breeders, nursery professionals or biologists, but we’re happy to make suggestions if you’d like, based on the information in the data compilation.
  5. Note that a great number of the accessions that are available do not have any observations/attributes in the data set. Unless you are interested in rolling the dice to see what you get, these accessions will probably not be of use to you.

ONGOING COOPERATION/PARTNERSHIP WITH WIDESPREAD MALUS?

We welcome your interest in the genetic treasure that wild Malus sieversii represents. We all owe a great debt to USDA for making this material available, and to Central Asian nations who made it possible for USDA to acquire these trees.

We are promoting apple-growing more generally in the Boulder, Colorado area. We are also interested in cider making, providing educational opportunities regarding apples, and promoting native pollinator conservation through our orchard projects.

We hope you’ll keep up with our work at widespreadmalus.com or via Twitter (@widespreadmalus). Contact us by email at the addresses on the web site.